[gtk/kill-containers: 88/99] Replace most remaining uses of container api



commit c9e95509f28f8d0da5095e49ef8915d9c0f7c78f
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat May 9 08:26:52 2020 -0400

    Replace most remaining uses of container api
    
    These are all on GtkBox or enumerating children.

 demos/constraint-editor/constraint-editor-window.c |   8 +-
 demos/gtk-demo/assistant.c                         |   6 +-
 demos/gtk-demo/clipboard.c                         |  26 +-
 demos/gtk-demo/combobox.c                          |  18 +-
 demos/gtk-demo/constraints.c                       |   4 +-
 demos/gtk-demo/constraints2.c                      |   4 +-
 demos/gtk-demo/constraints3.c                      |   4 +-
 demos/gtk-demo/css_accordion.c                     |  20 +-
 demos/gtk-demo/css_basics.c                        |  10 +-
 demos/gtk-demo/css_multiplebgs.c                   |  10 +-
 demos/gtk-demo/css_pixbufs.c                       |   8 +-
 demos/gtk-demo/css_shadows.c                       |  14 +-
 demos/gtk-demo/demotaggedentry.c                   |  16 +-
 demos/gtk-demo/dialog.c                            |  20 +-
 demos/gtk-demo/dnd.c                               |  20 +-
 demos/gtk-demo/drawingarea.c                       |   8 +-
 demos/gtk-demo/editable_cells.c                    |  10 +-
 demos/gtk-demo/entry_completion.c                  |   4 +-
 demos/gtk-demo/entry_undo.c                        |   4 +-
 demos/gtk-demo/expander.c                          |   4 +-
 demos/gtk-demo/font_features.c                     |  12 +-
 demos/gtk-demo/gears.c                             |  12 +-
 demos/gtk-demo/glarea.c                            |  12 +-
 demos/gtk-demo/headerbar.c                         |   4 +-
 demos/gtk-demo/iconview.c                          |   8 +-
 demos/gtk-demo/images.c                            |  56 +-
 demos/gtk-demo/infobar.c                           |  32 +-
 demos/gtk-demo/list_store.c                        |   4 +-
 demos/gtk-demo/listbox.c                           |   4 +-
 demos/gtk-demo/overlay.c                           |   4 +-
 demos/gtk-demo/panes.c                             |   6 +-
 demos/gtk-demo/password_entry.c                    |   4 +-
 demos/gtk-demo/rotated_text.c                      |   4 +-
 demos/gtk-demo/search_entry.c                      |   8 +-
 demos/gtk-demo/search_entry2.c                     |  20 +-
 demos/gtk-demo/sidebar.c                           |   4 +-
 demos/gtk-demo/sizegroup.c                         |   6 +-
 demos/gtk-demo/sliding_puzzle.c                    |   2 +-
 demos/gtk-demo/spinner.c                           |  18 +-
 demos/gtk-demo/tagged_entry.c                      |   8 +-
 demos/gtk-demo/textscroll.c                        |   2 +-
 demos/gtk-demo/tree_store.c                        |   4 +-
 demos/node-editor/node-editor-window.c             |   4 +-
 demos/widget-factory/widget-factory.c              |  21 +-
 docs/tools/widgets.c                               | 186 +++---
 examples/application10/exampleappwin.c             |  10 +-
 examples/application8/exampleappwin.c              |  10 +-
 examples/application9/exampleappwin.c              |  10 +-
 examples/bp/bloatpad.c                             |  16 +-
 examples/hello-world.c                             |   2 +-
 examples/search-bar.c                              |   4 +-
 gtk/a11y/gtklabelaccessible.c                      |  23 -
 gtk/a11y/gtknotebookpageaccessible.c               |  33 +-
 gtk/a11y/gtkscrolledwindowaccessible.c             |  49 +-
 gtk/a11y/gtkwidgetaccessible.c                     |  23 +-
 gtk/gtkactionbar.c                                 |   6 +-
 gtk/gtkappchooserdialog.c                          |   6 +-
 gtk/gtkassistant.c                                 |  30 +-
 gtk/gtkcalendar.c                                  |  12 +-
 gtk/gtkcolorchooserwidget.c                        |  56 +-
 gtk/gtkcombobox.c                                  |   2 +-
 gtk/gtkcustompaperunixdialog.c                     |  24 +-
 gtk/gtkdialog.c                                    |  39 +-
 gtk/gtkemojichooser.c                              |  14 +-
 gtk/gtkemojicompletion.c                           |  12 +-
 gtk/gtkentrycompletion.c                           |   4 +-
 gtk/gtkexpander.c                                  |  30 +-
 gtk/gtkfilechooserbutton.c                         |   6 +-
 gtk/gtkfilechooserdialog.c                         |   4 +-
 gtk/gtkfilechooserwidget.c                         |  26 +-
 gtk/gtkfontbutton.c                                |   8 +-
 gtk/gtkfontchooserwidget.c                         |  20 +-
 gtk/gtkgrid.c                                      |  14 +-
 gtk/gtkheaderbar.c                                 |  12 +-
 gtk/gtkinfobar.c                                   |  73 +--
 gtk/gtkmenubutton.c                                |   4 +-
 gtk/gtkmenusectionbox.c                            |  55 +-
 gtk/gtkmessagedialog.c                             |   2 +-
 gtk/gtkmodelbutton.c                               |   6 +-
 gtk/gtkmountoperation.c                            |  36 +-
 gtk/gtknotebook.c                                  |  31 +-
 gtk/gtkpaned.c                                     |  10 +-
 gtk/gtkpathbar.c                                   |   4 +-
 gtk/gtkplacesview.c                                |  10 +-
 gtk/gtkprintbackend.c                              |  16 +-
 gtk/gtkprinteroptionwidget.c                       |  29 +-
 gtk/gtkprintoperation-win32.c                      |   2 +-
 gtk/gtkprintunixdialog.c                           |  30 +-
 gtk/gtkradiobutton.c                               |   6 +-
 gtk/gtkscrolledwindow.c                            |   6 +-
 gtk/gtkshortcutsgroup.c                            |  30 +-
 gtk/gtkshortcutssection.c                          |  69 +-
 gtk/gtkshortcutsshortcut.c                         |  10 +-
 gtk/gtkshortcutswindow.c                           |  38 +-
 gtk/gtktext.c                                      |   4 +-
 gtk/gtktextview.c                                  |   4 +-
 gtk/gtktogglebutton.c                              |   4 +-
 gtk/gtktooltipwindow.c                             |   4 +-
 gtk/gtktreepopover.c                               |   6 +-
 gtk/gtktreeviewcolumn.c                            |  10 +-
 gtk/gtkwidget.c                                    |   4 +-
 gtk/gtkwindow.c                                    |  20 +-
 gtk/inspector/action-editor.c                      |  18 +-
 gtk/inspector/actions.c                            |  10 +-
 gtk/inspector/controllers.c                        |   8 +-
 gtk/inspector/general.c                            |   8 +-
 gtk/inspector/misc-info.c                          |   4 +-
 gtk/inspector/object-tree.c                        |  14 +-
 gtk/inspector/prop-editor.c                        |  52 +-
 gtk/inspector/prop-list.c                          |  10 +-
 gtk/inspector/recorder.c                           |  18 +-
 gtk/inspector/shortcuts.c                          |   4 +-
 gtk/inspector/size-groups.c                        |  14 +-
 gtk/inspector/strv-editor.c                        |  14 +-
 gtk/tools/gtk-builder-tool-preview.c               |   2 +-
 tests/gdkgears.c                                   |  40 +-
 tests/motion-compression.c                         |   6 +-
 tests/overlayscroll.c                              |   6 +-
 tests/print-editor.c                               |  12 +-
 tests/scrolling-performance.c                      |   2 +-
 tests/showrendernode.c                             |   4 +-
 tests/syncscroll.c                                 |   8 +-
 tests/testaccel.c                                  |   4 +-
 tests/testadjustsize.c                             |  16 +-
 tests/testappchooser.c                             |   2 +-
 tests/testappchooserbutton.c                       |  12 +-
 tests/testassistant.c                              |  14 +-
 tests/testbaseline.c                               |  76 +--
 tests/testblur.c                                   |   4 +-
 tests/testborderdrawing.c                          |  22 +-
 tests/testbox.c                                    |  24 +-
 tests/testbuttons.c                                |  30 +-
 tests/testcalendar.c                               |  38 +-
 tests/testcellarea.c                               |  52 +-
 tests/testcellrenderertext.c                       |   8 +-
 tests/testclipboard2.c                             |  22 +-
 tests/testcombo.c                                  |  68 +-
 tests/testcombochange.c                            |  24 +-
 tests/testdialog.c                                 |  34 +-
 tests/testdnd.c                                    |   2 +-
 tests/testdnd2.c                                   |   6 +-
 tests/testdnd3.c                                   |  10 +-
 tests/testellipsise.c                              |   6 +-
 tests/testentrycompletion.c                        |  12 +-
 tests/testentryicons.c                             |  14 +-
 tests/testexpand.c                                 |  20 +-
 tests/testexpander.c                               |   9 +-
 tests/testfilechooser.c                            |  20 +-
 tests/testfilechooserbutton.c                      |  22 +-
 tests/testflowbox.c                                |  54 +-
 tests/testfontchooser.c                            |   2 +-
 tests/testframe.c                                  |   4 +-
 tests/testfullscreen.c                             |   6 +-
 tests/testgaction.c                                |   6 +-
 tests/testgiconpixbuf.c                            |  14 +-
 tests/testglarea.c                                 |  12 +-
 tests/testgmenu.c                                  |  12 +-
 tests/testgrid.c                                   |  36 +-
 tests/testgtk.c                                    | 695 ++++++++++-----------
 tests/testheaderbar.c                              |   8 +-
 tests/testheightforwidth.c                         |   2 +-
 tests/testhover.c                                  |  14 +-
 tests/testiconview-keynav.c                        |   8 +-
 tests/testiconview.c                               |  24 +-
 tests/testinfobar.c                                |  10 +-
 tests/testinhibitshortcuts.c                       |   4 +-
 tests/testlevelbar.c                               |   8 +-
 tests/testlist.c                                   |  47 +-
 tests/testlist2.c                                  |  13 +-
 tests/testlist3.c                                  |  14 +-
 tests/testlist4.c                                  |   2 +-
 tests/testlockbutton.c                             |  18 +-
 tests/testlogout.c                                 |   4 +-
 tests/testmodelbutton.c                            |   8 +-
 tests/testnotebookdnd.c                            |   8 +-
 tests/testorientable.c                             |   6 +-
 tests/testoutsetshadowdrawing.c                    |  22 +-
 tests/testoverlay.c                                |   6 +-
 tests/testoverlaystyleclass.c                      |   2 +-
 tests/testpixbuf-scale.c                           |  10 +-
 tests/testpopover.c                                |   6 +-
 tests/testrevealer2.c                              |   4 +-
 tests/testscale.c                                  |  28 +-
 tests/testscrolledge.c                             |   4 +-
 tests/testscrolledwindow.c                         |  62 +-
 tests/testselectionmode.c                          |   8 +-
 tests/testsensitive.c                              |   8 +-
 tests/testsounds.c                                 |   4 +-
 tests/testspinbutton.c                             |   6 +-
 tests/teststack.c                                  |  36 +-
 tests/testswitch.c                                 |  22 +-
 tests/testtextview2.c                              |  20 +-
 tests/testtoolbar2.c                               |  10 +-
 tests/testtooltips.c                               |  32 +-
 tests/testtreecolumns.c                            |  30 +-
 tests/testtreecolumnsizing.c                       |   6 +-
 tests/testtreednd.c                                |   4 +-
 tests/testtreeedit.c                               |  12 +-
 tests/testtreeflow.c                               |   8 +-
 tests/testtreefocus.c                              |   8 +-
 tests/testtreelistmodel.c                          |  24 +-
 tests/testtreesort.c                               |  16 +-
 tests/testtreeview.c                               |   6 +-
 tests/testvolumebutton.c                           |   8 +-
 tests/testwidgettransforms.c                       |   8 +-
 tests/testwindowsize.c                             |   2 +-
 tests/treestoretest.c                              |  30 +-
 testsuite/a11y/children.c                          |   4 +-
 testsuite/gtk/action.c                             |   4 +-
 testsuite/gtk/gestures.c                           |  56 +-
 testsuite/gtk/propertylookuplistmodel.c            |   4 +-
 testsuite/gtk/widgetorder.c                        |   6 +-
 212 files changed, 2016 insertions(+), 2065 deletions(-)
---
diff --git a/demos/constraint-editor/constraint-editor-window.c 
b/demos/constraint-editor/constraint-editor-window.c
index bf18b6acc1..001eab3ba2 100644
--- a/demos/constraint-editor/constraint-editor-window.c
+++ b/demos/constraint-editor/constraint-editor-window.c
@@ -608,7 +608,7 @@ create_widget_func (gpointer item,
   gtk_label_set_xalign (GTK_LABEL (label), 0.0);
   gtk_widget_set_hexpand (label, TRUE);
   gtk_list_box_row_set_child (GTK_LIST_BOX_ROW (row), box);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   if (GTK_IS_CONSTRAINT (item) || GTK_IS_CONSTRAINT_GUIDE (item))
     {
@@ -616,18 +616,18 @@ create_widget_func (gpointer item,
       gtk_button_set_has_frame (GTK_BUTTON (button), FALSE);
       g_signal_connect (button, "clicked", G_CALLBACK (row_edit), win);
       g_object_set_data (G_OBJECT (row), "edit", button);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
       button = gtk_button_new_from_icon_name ("edit-delete-symbolic");
       gtk_button_set_has_frame (GTK_BUTTON (button), FALSE);
       g_signal_connect (button, "clicked", G_CALLBACK (row_delete), win);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
     }
   else if (GTK_IS_WIDGET (item))
     {
       button = gtk_button_new_from_icon_name ("edit-delete-symbolic");
       gtk_button_set_has_frame (GTK_BUTTON (button), FALSE);
       g_signal_connect (button, "clicked", G_CALLBACK (row_delete), win);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
     }
 
   g_free (freeme);
diff --git a/demos/gtk-demo/assistant.c b/demos/gtk-demo/assistant.c
index c1da7b02e6..53bc8db5a4 100644
--- a/demos/gtk-demo/assistant.c
+++ b/demos/gtk-demo/assistant.c
@@ -95,12 +95,12 @@ create_page1 (GtkWidget *assistant)
   gtk_widget_set_margin_bottom (box, 12);
 
   label = gtk_label_new ("You must fill out this entry to continue:");
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   entry = gtk_entry_new ();
   gtk_entry_set_activates_default (GTK_ENTRY (entry), TRUE);
   gtk_widget_set_valign (entry, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (box), entry);
+  gtk_box_append (GTK_BOX (box), entry);
   g_signal_connect (G_OBJECT (entry), "changed",
                     G_CALLBACK (on_entry_changed), assistant);
 
@@ -123,7 +123,7 @@ create_page2 (GtkWidget *assistant)
   checkbutton = gtk_check_button_new_with_label ("This is optional data, you may continue "
                                                  "even if you do not check this");
   gtk_widget_set_valign (checkbutton, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (box), checkbutton);
+  gtk_box_append (GTK_BOX (box), checkbutton);
 
   gtk_assistant_append_page (GTK_ASSISTANT (assistant), box);
   gtk_assistant_set_page_complete (GTK_ASSISTANT (assistant), box, TRUE);
diff --git a/demos/gtk-demo/clipboard.c b/demos/gtk-demo/clipboard.c
index fbecef7506..45556a2ed6 100644
--- a/demos/gtk-demo/clipboard.c
+++ b/demos/gtk-demo/clipboard.c
@@ -120,66 +120,66 @@ do_clipboard (GtkWidget *do_widget)
 
       label = gtk_label_new ("\"Copy\" will copy the text\nin the entry to the clipboard");
 
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
       gtk_widget_set_margin_start (hbox, 8);
       gtk_widget_set_margin_end (hbox, 8);
       gtk_widget_set_margin_top (hbox, 8);
       gtk_widget_set_margin_bottom (hbox, 8);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       /* Create the first entry */
       entry = gtk_entry_new ();
-      gtk_container_add (GTK_CONTAINER (hbox), entry);
+      gtk_box_append (GTK_BOX (hbox), entry);
 
       /* Create the button */
       button = gtk_button_new_with_mnemonic (_("_Copy"));
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
       g_signal_connect (button, "clicked",
                         G_CALLBACK (copy_button_clicked), entry);
 
       label = gtk_label_new ("\"Paste\" will paste the text from the clipboard to the entry");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
       gtk_widget_set_margin_start (hbox, 8);
       gtk_widget_set_margin_end (hbox, 8);
       gtk_widget_set_margin_top (hbox, 8);
       gtk_widget_set_margin_bottom (hbox, 8);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       /* Create the second entry */
       entry = gtk_entry_new ();
-      gtk_container_add (GTK_CONTAINER (hbox), entry);
+      gtk_box_append (GTK_BOX (hbox), entry);
 
       /* Create the button */
       button = gtk_button_new_with_mnemonic (_("_Paste"));
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
       g_signal_connect (button, "clicked",
                         G_CALLBACK (paste_button_clicked), entry);
 
       label = gtk_label_new ("Images can be transferred via the clipboard, too");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
       gtk_widget_set_margin_start (hbox, 8);
       gtk_widget_set_margin_end (hbox, 8);
       gtk_widget_set_margin_top (hbox, 8);
       gtk_widget_set_margin_bottom (hbox, 8);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       /* Create the first image */
       image = demo_image_new ("dialog-warning");
-      gtk_container_add (GTK_CONTAINER (hbox), image);
+      gtk_box_append (GTK_BOX (hbox), image);
 
       /* Create the second image */
       image = demo_image_new ("process-stop");
-      gtk_container_add (GTK_CONTAINER (hbox), image);
+      gtk_box_append (GTK_BOX (hbox), image);
 
       /* Create the third image */
       image = demo_image_new ("weather-clear");
-      gtk_container_add (GTK_CONTAINER (hbox), image);
+      gtk_box_append (GTK_BOX (hbox), image);
     }
 
   if (!gtk_widget_get_visible (window))
diff --git a/demos/gtk-demo/combobox.c b/demos/gtk-demo/combobox.c
index 2be94b3c8c..3ed180a9b5 100644
--- a/demos/gtk-demo/combobox.c
+++ b/demos/gtk-demo/combobox.c
@@ -328,7 +328,7 @@ do_combobox (GtkWidget *do_widget)
      *  insensitive rows
      */
     frame = gtk_frame_new ("Items with icons");
-    gtk_container_add (GTK_CONTAINER (vbox), frame);
+    gtk_box_append (GTK_BOX (vbox), frame);
 
     box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
     gtk_widget_set_margin_start (box, 5);
@@ -340,7 +340,7 @@ do_combobox (GtkWidget *do_widget)
     model = create_icon_store ();
     combo = gtk_combo_box_new_with_model (model);
     g_object_unref (model);
-    gtk_container_add (GTK_CONTAINER (box), combo);
+    gtk_box_append (GTK_BOX (box), combo);
 
     renderer = gtk_cell_renderer_pixbuf_new ();
     gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combo), renderer, FALSE);
@@ -372,7 +372,7 @@ do_combobox (GtkWidget *do_widget)
     /* A combobox demonstrating trees.
      */
     frame = gtk_frame_new ("Where are we ?");
-    gtk_container_add (GTK_CONTAINER (vbox), frame);
+    gtk_box_append (GTK_BOX (vbox), frame);
 
     box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
     gtk_widget_set_margin_start (box, 5);
@@ -384,7 +384,7 @@ do_combobox (GtkWidget *do_widget)
     model = create_capital_store ();
     combo = gtk_combo_box_new_with_model (model);
     g_object_unref (model);
-    gtk_container_add (GTK_CONTAINER (box), combo);
+    gtk_box_append (GTK_BOX (box), combo);
 
     renderer = gtk_cell_renderer_text_new ();
     gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combo), renderer, TRUE);
@@ -403,7 +403,7 @@ do_combobox (GtkWidget *do_widget)
 
     /* A GtkComboBoxEntry with validation */
     frame = gtk_frame_new ("Editable");
-    gtk_container_add (GTK_CONTAINER (vbox), frame);
+    gtk_box_append (GTK_BOX (vbox), frame);
 
     box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
     gtk_widget_set_margin_start (box, 5);
@@ -414,7 +414,7 @@ do_combobox (GtkWidget *do_widget)
 
     combo = gtk_combo_box_text_new_with_entry ();
     fill_combo_entry (combo);
-    gtk_container_add (GTK_CONTAINER (box), combo);
+    gtk_box_append (GTK_BOX (box), combo);
 
     entry = g_object_new (TYPE_MASK_ENTRY, NULL);
     MASK_ENTRY (entry)->mask = "^([0-9]*|One|Two|2\302\275|Three)$";
@@ -423,7 +423,7 @@ do_combobox (GtkWidget *do_widget)
 
     /* A combobox with string IDs */
     frame = gtk_frame_new ("String IDs");
-    gtk_container_add (GTK_CONTAINER (vbox), frame);
+    gtk_box_append (GTK_BOX (vbox), frame);
 
     box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
     gtk_widget_set_margin_start (box, 5);
@@ -436,13 +436,13 @@ do_combobox (GtkWidget *do_widget)
     gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "never", "Not visible");
     gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "when-active", "Visible when active");
     gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), "always", "Always visible");
-    gtk_container_add (GTK_CONTAINER (box), combo);
+    gtk_box_append (GTK_BOX (box), combo);
 
     entry = gtk_entry_new ();
     g_object_bind_property (combo, "active-id",
                             entry, "text",
                             G_BINDING_BIDIRECTIONAL);
-    gtk_container_add (GTK_CONTAINER (box), entry);
+    gtk_box_append (GTK_BOX (box), entry);
   }
 
   if (!gtk_widget_get_visible (window))
diff --git a/demos/gtk-demo/constraints.c b/demos/gtk-demo/constraints.c
index b6c5df0bd3..fc6eb5d72b 100644
--- a/demos/gtk-demo/constraints.c
+++ b/demos/gtk-demo/constraints.c
@@ -271,10 +271,10 @@ do_constraints (GtkWidget *do_widget)
      grid = g_object_new (simple_grid_get_type (), NULL);
      gtk_widget_set_hexpand (grid, TRUE);
      gtk_widget_set_vexpand (grid, TRUE);
-     gtk_container_add (GTK_CONTAINER (box), grid);
+     gtk_box_append (GTK_BOX (box), grid);
 
      button = gtk_button_new_with_label ("Close");
-     gtk_container_add (GTK_CONTAINER (box), button);
+     gtk_box_append (GTK_BOX (box), button);
      gtk_widget_set_hexpand (grid, TRUE);
      g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy), window);
diff --git a/demos/gtk-demo/constraints2.c b/demos/gtk-demo/constraints2.c
index 2a9477e048..0e2502505a 100644
--- a/demos/gtk-demo/constraints2.c
+++ b/demos/gtk-demo/constraints2.c
@@ -227,10 +227,10 @@ do_constraints2 (GtkWidget *do_widget)
      grid = g_object_new (interactive_grid_get_type (), NULL);
      gtk_widget_set_hexpand (grid, TRUE);
      gtk_widget_set_vexpand (grid, TRUE);
-     gtk_container_add (GTK_CONTAINER (box), grid);
+     gtk_box_append (GTK_BOX (box), grid);
 
      button = gtk_button_new_with_label ("Close");
-     gtk_container_add (GTK_CONTAINER (box), button);
+     gtk_box_append (GTK_BOX (box), button);
      gtk_widget_set_hexpand (grid, TRUE);
      g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy), window);
diff --git a/demos/gtk-demo/constraints3.c b/demos/gtk-demo/constraints3.c
index 0edc5b8ebd..64d484abb6 100644
--- a/demos/gtk-demo/constraints3.c
+++ b/demos/gtk-demo/constraints3.c
@@ -147,10 +147,10 @@ do_constraints3 (GtkWidget *do_widget)
      grid = g_object_new (vfl_grid_get_type (), NULL);
      gtk_widget_set_hexpand (grid, TRUE);
      gtk_widget_set_vexpand (grid, TRUE);
-     gtk_container_add (GTK_CONTAINER (box), grid);
+     gtk_box_append (GTK_BOX (box), grid);
 
      button = gtk_button_new_with_label ("Close");
-     gtk_container_add (GTK_CONTAINER (box), button);
+     gtk_box_append (GTK_BOX (box), button);
      gtk_widget_set_hexpand (grid, TRUE);
      g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy), window);
diff --git a/demos/gtk-demo/css_accordion.c b/demos/gtk-demo/css_accordion.c
index c81047b3cc..45e3538803 100644
--- a/demos/gtk-demo/css_accordion.c
+++ b/demos/gtk-demo/css_accordion.c
@@ -9,9 +9,13 @@
 static void
 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
 {
+  GtkWidget *child;
+
   gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
-  if (GTK_IS_CONTAINER (widget))
-    gtk_container_forall (GTK_CONTAINER (widget), (GtkCallback) apply_css, provider);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    apply_css (child, provider);
 }
 
 GtkWidget *
@@ -36,22 +40,22 @@ do_css_accordion (GtkWidget *do_widget)
       gtk_window_set_child (GTK_WINDOW (window), container);
 
       child = gtk_button_new_with_label ("This");
-      gtk_container_add (GTK_CONTAINER (container), child);
+      gtk_box_append (GTK_BOX (container), child);
 
       child = gtk_button_new_with_label ("Is");
-      gtk_container_add (GTK_CONTAINER (container), child);
+      gtk_box_append (GTK_BOX (container), child);
 
       child = gtk_button_new_with_label ("A");
-      gtk_container_add (GTK_CONTAINER (container), child);
+      gtk_box_append (GTK_BOX (container), child);
 
       child = gtk_button_new_with_label ("CSS");
-      gtk_container_add (GTK_CONTAINER (container), child);
+      gtk_box_append (GTK_BOX (container), child);
 
       child = gtk_button_new_with_label ("Accordion");
-      gtk_container_add (GTK_CONTAINER (container), child);
+      gtk_box_append (GTK_BOX (container), child);
 
       child = gtk_button_new_with_label (":-)");
-      gtk_container_add (GTK_CONTAINER (container), child);
+      gtk_box_append (GTK_BOX (container), child);
 
       provider = GTK_STYLE_PROVIDER (gtk_css_provider_new ());
       gtk_css_provider_load_from_resource (GTK_CSS_PROVIDER (provider), "/css_accordion/css_accordion.css");
diff --git a/demos/gtk-demo/css_basics.c b/demos/gtk-demo/css_basics.c
index fed09bb1e5..cd51fc9d76 100644
--- a/demos/gtk-demo/css_basics.c
+++ b/demos/gtk-demo/css_basics.c
@@ -55,9 +55,13 @@ css_text_changed (GtkTextBuffer  *buffer,
 static void
 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
 {
+  GtkWidget *child;
+
   gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
-  if (GTK_IS_CONTAINER (widget))
-    gtk_container_forall (GTK_CONTAINER (widget), (GtkCallback) apply_css, provider);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    apply_css (child, provider);
 }
 
 GtkWidget *
@@ -93,7 +97,7 @@ do_css_basics (GtkWidget *do_widget)
       container = gtk_scrolled_window_new (NULL, NULL);
       gtk_window_set_child (GTK_WINDOW (window), container);
       child = gtk_text_view_new_with_buffer (text);
-      gtk_container_add (GTK_CONTAINER (container), child);
+      gtk_box_append (GTK_BOX (container), child);
       g_signal_connect (text, "changed",
                         G_CALLBACK (css_text_changed), provider);
 
diff --git a/demos/gtk-demo/css_multiplebgs.c b/demos/gtk-demo/css_multiplebgs.c
index f9a66a5b35..55af50c00c 100644
--- a/demos/gtk-demo/css_multiplebgs.c
+++ b/demos/gtk-demo/css_multiplebgs.c
@@ -69,9 +69,13 @@ drawing_area_draw (GtkDrawingArea *da,
 static void
 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
 {
+  GtkWidget *child;
+
   gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
-  if (GTK_IS_CONTAINER (widget))
-    gtk_container_forall (GTK_CONTAINER (widget), (GtkCallback) apply_css, provider);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    apply_css (child, provider);
 }
 
 GtkWidget *
@@ -100,7 +104,7 @@ do_css_multiplebgs (GtkWidget *do_widget)
       gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (child),
                                       drawing_area_draw,
                                       NULL, NULL);
-      gtk_container_add (GTK_CONTAINER (container), child);
+      gtk_box_append (GTK_BOX (container), child);
 
       child = gtk_button_new ();
       gtk_overlay_add_overlay (GTK_OVERLAY (container), child);
diff --git a/demos/gtk-demo/css_pixbufs.c b/demos/gtk-demo/css_pixbufs.c
index b05e208edc..88dd41e8fd 100644
--- a/demos/gtk-demo/css_pixbufs.c
+++ b/demos/gtk-demo/css_pixbufs.c
@@ -55,9 +55,13 @@ css_text_changed (GtkTextBuffer  *buffer,
 static void
 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
 {
+  GtkWidget *child;
+
   gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
-  if (GTK_IS_CONTAINER (widget))
-    gtk_container_forall (GTK_CONTAINER (widget), (GtkCallback) apply_css, provider);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    apply_css (child, provider);
 }
 
 GtkWidget *
diff --git a/demos/gtk-demo/css_shadows.c b/demos/gtk-demo/css_shadows.c
index ba94b888f2..54c6a3c4c8 100644
--- a/demos/gtk-demo/css_shadows.c
+++ b/demos/gtk-demo/css_shadows.c
@@ -53,9 +53,13 @@ css_text_changed (GtkTextBuffer  *buffer,
 static void
 apply_css (GtkWidget *widget, GtkStyleProvider *provider)
 {
+  GtkWidget *child;
+
   gtk_style_context_add_provider (gtk_widget_get_style_context (widget), provider, G_MAXUINT);
-  if (GTK_IS_CONTAINER (widget))
-    gtk_container_forall (GTK_CONTAINER (widget), (GtkCallback) apply_css, provider);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    apply_css (child, provider);
 }
 
 static GtkWidget *
@@ -68,13 +72,13 @@ create_toolbar (void)
   gtk_widget_set_valign (toolbar, GTK_ALIGN_CENTER);
 
   item = gtk_button_new_from_icon_name ("go-next");
-  gtk_container_add (GTK_CONTAINER (toolbar), item);
+  gtk_box_append (GTK_BOX (toolbar), item);
 
   item = gtk_button_new_from_icon_name ("go-previous");
-  gtk_container_add (GTK_CONTAINER (toolbar), item);
+  gtk_box_append (GTK_BOX (toolbar), item);
 
   item = gtk_button_new_with_label ("Hello World");
-  gtk_container_add (GTK_CONTAINER (toolbar), item);
+  gtk_box_append (GTK_BOX (toolbar), item);
 
   return toolbar;
 }
diff --git a/demos/gtk-demo/demotaggedentry.c b/demos/gtk-demo/demotaggedentry.c
index ba2b348839..ed92460e0c 100644
--- a/demos/gtk-demo/demotaggedentry.c
+++ b/demos/gtk-demo/demotaggedentry.c
@@ -49,7 +49,7 @@ demo_tagged_entry_init (DemoTaggedEntry *entry)
   gtk_widget_set_vexpand (priv->entry, TRUE);
   gtk_widget_set_hexpand (priv->box, FALSE);
   gtk_widget_set_vexpand (priv->box, FALSE);
-  gtk_container_add (GTK_CONTAINER (priv->box), priv->entry);
+  gtk_box_append (GTK_BOX (priv->box), priv->entry);
   gtk_editable_init_delegate (GTK_EDITABLE (entry));
 }
 
@@ -188,7 +188,7 @@ demo_tagged_entry_add_tag (DemoTaggedEntry *entry,
 
   g_return_if_fail (DEMO_IS_TAGGED_ENTRY (entry));
 
-  gtk_container_add (GTK_CONTAINER (priv->box), tag);
+  gtk_box_append (GTK_BOX (priv->box), tag);
 }
 
 void
@@ -201,7 +201,7 @@ demo_tagged_entry_insert_tag_after (DemoTaggedEntry *entry,
   g_return_if_fail (DEMO_IS_TAGGED_ENTRY (entry));
 
   if (sibling == NULL)
-    gtk_container_add (GTK_CONTAINER (priv->box), tag);
+    gtk_box_append (GTK_BOX (priv->box), tag);
   else
     gtk_box_insert_child_after (GTK_BOX (priv->box), tag, sibling); 
 }
@@ -214,7 +214,7 @@ demo_tagged_entry_remove_tag (DemoTaggedEntry *entry,
 
   g_return_if_fail (DEMO_IS_TAGGED_ENTRY (entry));
 
-  gtk_container_remove (GTK_CONTAINER (priv->box), tag);
+  gtk_box_remove (GTK_BOX (priv->box), tag);
 }
 
 struct _DemoTaggedEntryTag
@@ -268,7 +268,7 @@ demo_tagged_entry_tag_init (DemoTaggedEntryTag *tag)
   tag->box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_set_parent (tag->box, GTK_WIDGET (tag));
   tag->label = gtk_label_new ("");
-  gtk_container_add (GTK_CONTAINER (tag->box), tag->label);
+  gtk_box_append (GTK_BOX (tag->box), tag->label);
 
   gesture = gtk_gesture_click_new ();
   g_signal_connect (gesture, "released", G_CALLBACK (on_released), tag);
@@ -460,7 +460,7 @@ demo_tagged_entry_tag_set_has_close_button (DemoTaggedEntryTag *tag,
 
   if (!has_close_button && tag->button)
     {
-      gtk_container_remove (GTK_CONTAINER (tag->box), tag->button);
+      gtk_box_remove (GTK_BOX (tag->box), tag->button);
       tag->button = NULL;
     }
   else if (has_close_button && tag->button == NULL)
@@ -469,11 +469,11 @@ demo_tagged_entry_tag_set_has_close_button (DemoTaggedEntryTag *tag,
 
       image = gtk_image_new_from_icon_name ("window-close-symbolic");
       tag->button = gtk_button_new ();
-      gtk_container_add (GTK_CONTAINER (tag->button), image);
+      gtk_box_append (GTK_BOX (tag->button), image);
       gtk_widget_set_halign (tag->button, GTK_ALIGN_CENTER);
       gtk_widget_set_valign (tag->button, GTK_ALIGN_CENTER);
       gtk_button_set_has_frame (GTK_BUTTON (tag->button), FALSE);
-      gtk_container_add (GTK_CONTAINER (tag->box), tag->button);
+      gtk_box_append (GTK_BOX (tag->box), tag->button);
       g_signal_connect (tag->button, "clicked", G_CALLBACK (on_button_clicked), tag);
     }
 
diff --git a/demos/gtk-demo/dialog.c b/demos/gtk-demo/dialog.c
index 673a6e21f2..99953a5cb5 100644
--- a/demos/gtk-demo/dialog.c
+++ b/demos/gtk-demo/dialog.c
@@ -56,16 +56,16 @@ interactive_dialog_clicked (GtkButton *button,
   content_area = gtk_dialog_get_content_area (GTK_DIALOG (dialog));
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
-  gtk_container_add (GTK_CONTAINER (content_area), hbox);
+  gtk_box_append (GTK_BOX (content_area), hbox);
 
   image = gtk_image_new_from_icon_name ("dialog-question");
   gtk_image_set_icon_size (GTK_IMAGE (image), GTK_ICON_SIZE_LARGE);
-  gtk_container_add (GTK_CONTAINER (hbox), image);
+  gtk_box_append (GTK_BOX (hbox), image);
 
   table = gtk_grid_new ();
   gtk_grid_set_row_spacing (GTK_GRID (table), 4);
   gtk_grid_set_column_spacing (GTK_GRID (table), 4);
-  gtk_container_add (GTK_CONTAINER (hbox), table);
+  gtk_box_append (GTK_BOX (hbox), table);
   label = gtk_label_new_with_mnemonic ("_Entry 1");
   gtk_grid_attach (GTK_GRID (table), label, 0, 0, 1, 1);
   local_entry1 = gtk_entry_new ();
@@ -127,29 +127,29 @@ do_dialog (GtkWidget *do_widget)
 
       /* Standard message dialog */
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
       button = gtk_button_new_with_mnemonic ("_Message Dialog");
       g_signal_connect (button, "clicked",
                         G_CALLBACK (message_dialog_clicked), NULL);
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
-      gtk_container_add (GTK_CONTAINER (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+      gtk_box_append (GTK_BOX (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
 
       /* Interactive dialog*/
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
       vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 
       button = gtk_button_new_with_mnemonic ("_Interactive Dialog");
       g_signal_connect (button, "clicked",
                         G_CALLBACK (interactive_dialog_clicked), NULL);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox2);
-      gtk_container_add (GTK_CONTAINER (vbox2), button);
+      gtk_box_append (GTK_BOX (hbox), vbox2);
+      gtk_box_append (GTK_BOX (vbox2), button);
 
       table = gtk_grid_new ();
       gtk_grid_set_row_spacing (GTK_GRID (table), 4);
       gtk_grid_set_column_spacing (GTK_GRID (table), 4);
-      gtk_container_add (GTK_CONTAINER (hbox), table);
+      gtk_box_append (GTK_BOX (hbox), table);
 
       label = gtk_label_new_with_mnemonic ("_Entry 1");
       gtk_grid_attach (GTK_GRID (table), label, 0, 0, 1, 1);
diff --git a/demos/gtk-demo/dnd.c b/demos/gtk-demo/dnd.c
index 7cf44e2c62..171fe4a361 100644
--- a/demos/gtk-demo/dnd.c
+++ b/demos/gtk-demo/dnd.c
@@ -204,30 +204,30 @@ pressed_cb (GtkGesture *gesture,
       gtk_popover_set_has_arrow (GTK_POPOVER (menu), FALSE);
       gtk_popover_set_pointing_to (GTK_POPOVER (menu), &(GdkRectangle){ x, y, 1, 1});
       box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-      gtk_container_add (GTK_CONTAINER (menu), box);
+      gtk_box_append (GTK_BOX (menu), box);
 
       item = gtk_button_new_with_label ("New");
       gtk_button_set_has_frame (GTK_BUTTON (item), FALSE);
       g_signal_connect (item, "clicked", G_CALLBACK (new_item_cb), widget);
-      gtk_container_add (GTK_CONTAINER (box), item);
+      gtk_box_append (GTK_BOX (box), item);
 
       item = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box), item);
+      gtk_box_append (GTK_BOX (box), item);
 
       item = gtk_button_new_with_label ("Edit");
       gtk_button_set_has_frame (GTK_BUTTON (item), FALSE);
       gtk_widget_set_sensitive (item, child != NULL && child != widget);
       g_signal_connect (item, "clicked", G_CALLBACK (edit_cb), child);
-      gtk_container_add (GTK_CONTAINER (box), item);
+      gtk_box_append (GTK_BOX (box), item);
 
       item = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box), item);
+      gtk_box_append (GTK_BOX (box), item);
 
       item = gtk_button_new_with_label ("Delete");
       gtk_button_set_has_frame (GTK_BUTTON (item), FALSE);
       gtk_widget_set_sensitive (item, child != NULL && child != widget);
       g_signal_connect (item, "clicked", G_CALLBACK (delete_cb), child);
-      gtk_container_add (GTK_CONTAINER (box), item);
+      gtk_box_append (GTK_BOX (box), item);
 
       gtk_popover_popup (GTK_POPOVER (menu));
     }
@@ -444,10 +444,10 @@ do_dnd (GtkWidget *do_widget)
       gtk_window_set_child (GTK_WINDOW (window), box);
 
       box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (box), box2);
+      gtk_box_append (GTK_BOX (box), box2);
 
       canvas = canvas_new ();
-      gtk_container_add (GTK_CONTAINER (box2), canvas);
+      gtk_box_append (GTK_BOX (box2), canvas);
 
       n_items = 0;
 
@@ -468,7 +468,7 @@ do_dnd (GtkWidget *do_widget)
       gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                       GTK_POLICY_AUTOMATIC,
                                       GTK_POLICY_NEVER);
-      gtk_container_add (GTK_CONTAINER (box), sw);
+      gtk_box_append (GTK_BOX (box), sw);
 
       box3 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
       gtk_widget_add_css_class (box3, "linked");
@@ -485,7 +485,7 @@ do_dnd (GtkWidget *do_widget)
                                  "rgba", &rgba,
                                  "selectable", FALSE,
                                  NULL);
-          gtk_container_add (GTK_CONTAINER (box3), swatch);
+          gtk_box_append (GTK_BOX (box3), swatch);
         }
     }
 
diff --git a/demos/gtk-demo/drawingarea.c b/demos/gtk-demo/drawingarea.c
index 4309d99573..63e4bd6812 100644
--- a/demos/gtk-demo/drawingarea.c
+++ b/demos/gtk-demo/drawingarea.c
@@ -213,11 +213,11 @@ do_drawingarea (GtkWidget *do_widget)
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label),
                             "<u>Checkerboard pattern</u>");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       frame = gtk_frame_new (NULL);
       gtk_widget_set_vexpand (frame, TRUE);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       da = gtk_drawing_area_new ();
       gtk_drawing_area_set_content_width (GTK_DRAWING_AREA (da), 100);
@@ -232,11 +232,11 @@ do_drawingarea (GtkWidget *do_widget)
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label),
                             "<u>Scribble area</u>");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       frame = gtk_frame_new (NULL);
       gtk_widget_set_vexpand (frame, TRUE);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       da = gtk_drawing_area_new ();
       gtk_drawing_area_set_content_width (GTK_DRAWING_AREA (da), 100);
diff --git a/demos/gtk-demo/editable_cells.c b/demos/gtk-demo/editable_cells.c
index 05ed5fe7ba..ef6ead843f 100644
--- a/demos/gtk-demo/editable_cells.c
+++ b/demos/gtk-demo/editable_cells.c
@@ -361,7 +361,7 @@ do_editable_cells (GtkWidget *do_widget)
       gtk_widget_set_margin_bottom (vbox, 5);
       gtk_window_set_child (GTK_WINDOW (window), vbox);
 
-      gtk_container_add (GTK_CONTAINER (vbox),
+      gtk_box_append (GTK_BOX (vbox),
                           gtk_label_new ("Shopping list (you can edit the cells!)"));
 
       sw = gtk_scrolled_window_new (NULL, NULL);
@@ -369,7 +369,7 @@ do_editable_cells (GtkWidget *do_widget)
       gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                       GTK_POLICY_AUTOMATIC,
                                       GTK_POLICY_AUTOMATIC);
-      gtk_container_add (GTK_CONTAINER (vbox), sw);
+      gtk_box_append (GTK_BOX (vbox), sw);
 
       /* create models */
       items_model = create_items_model ();
@@ -391,17 +391,17 @@ do_editable_cells (GtkWidget *do_widget)
       /* some buttons */
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
       gtk_box_set_homogeneous (GTK_BOX (hbox), TRUE);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       button = gtk_button_new_with_label ("Add item");
       g_signal_connect (button, "clicked",
                         G_CALLBACK (add_item), treeview);
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
       button = gtk_button_new_with_label ("Remove item");
       g_signal_connect (button, "clicked",
                         G_CALLBACK (remove_item), treeview);
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
       gtk_window_set_default_size (GTK_WINDOW (window), 320, 200);
     }
diff --git a/demos/gtk-demo/entry_completion.c b/demos/gtk-demo/entry_completion.c
index 6a23b78d67..6e2d28400c 100644
--- a/demos/gtk-demo/entry_completion.c
+++ b/demos/gtk-demo/entry_completion.c
@@ -61,11 +61,11 @@ do_entry_completion (GtkWidget *do_widget)
 
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label), "Completion demo, try writing <b>total</b> or <b>gnome</b> 
for example.");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       /* Create our entry */
       entry = gtk_entry_new ();
-      gtk_container_add (GTK_CONTAINER (vbox), entry);
+      gtk_box_append (GTK_BOX (vbox), entry);
 
       /* Create the completion object */
       completion = gtk_entry_completion_new ();
diff --git a/demos/gtk-demo/entry_undo.c b/demos/gtk-demo/entry_undo.c
index 39bebb8d30..752d87849c 100644
--- a/demos/gtk-demo/entry_undo.c
+++ b/demos/gtk-demo/entry_undo.c
@@ -37,12 +37,12 @@ do_entry_undo (GtkWidget *do_widget)
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label),
                             "Use Primary+z or Primary+Shift+z to undo or redo changes");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       /* Create our entry */
       entry = gtk_entry_new ();
       gtk_editable_set_enable_undo (GTK_EDITABLE (entry), TRUE);
-      gtk_container_add (GTK_CONTAINER (vbox), entry);
+      gtk_box_append (GTK_BOX (vbox), entry);
     }
 
   if (!gtk_widget_get_visible (window))
diff --git a/demos/gtk-demo/expander.c b/demos/gtk-demo/expander.c
index 63ef27081d..46ccff1833 100644
--- a/demos/gtk-demo/expander.c
+++ b/demos/gtk-demo/expander.c
@@ -79,8 +79,8 @@ do_expander (GtkWidget *do_widget)
                                 "innuendo, just to make you scroll down or "
                                 "resize the window. Do it already !", -1);
       gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), tv);
-      gtk_container_add (GTK_CONTAINER (expander), sw);
-      gtk_container_add (GTK_CONTAINER (area), expander);
+      gtk_box_append (GTK_BOX (expander), sw);
+      gtk_box_append (GTK_BOX (area), expander);
       g_signal_connect (expander, "notify::expanded",
                         G_CALLBACK (expander_cb), window);
 
diff --git a/demos/gtk-demo/font_features.c b/demos/gtk-demo/font_features.c
index 818164d5f3..000d5d9f63 100644
--- a/demos/gtk-demo/font_features.c
+++ b/demos/gtk-demo/font_features.c
@@ -194,7 +194,7 @@ add_check_group (GtkWidget   *box,
   pango_attr_list_insert (attrs, pango_attr_weight_new (PANGO_WEIGHT_BOLD));
   gtk_label_set_attributes (GTK_LABEL (label), attrs);
   pango_attr_list_unref (attrs);
-  gtk_container_add (GTK_CONTAINER (group), label);
+  gtk_box_append (GTK_BOX (group), label);
 
   for (i = 0; tags[i]; i++)
     {
@@ -211,7 +211,7 @@ add_check_group (GtkWidget   *box,
       g_signal_connect (feat, "notify::inconsistent", G_CALLBACK (update_display), NULL);
       g_signal_connect (feat, "clicked", G_CALLBACK (feat_clicked), NULL);
 
-      gtk_container_add (GTK_CONTAINER (group), feat);
+      gtk_box_append (GTK_BOX (group), feat);
 
       item = g_new (FeatureItem, 1);
       item->name = tags[i];
@@ -223,7 +223,7 @@ add_check_group (GtkWidget   *box,
       feature_items = g_list_prepend (feature_items, item);
     }
 
-  gtk_container_add (GTK_CONTAINER (box), group);
+  gtk_box_append (GTK_BOX (box), group);
 }
 
 static void
@@ -248,7 +248,7 @@ add_radio_group (GtkWidget *box,
   pango_attr_list_insert (attrs, pango_attr_weight_new (PANGO_WEIGHT_BOLD));
   gtk_label_set_attributes (GTK_LABEL (label), attrs);
   pango_attr_list_unref (attrs);
-  gtk_container_add (GTK_CONTAINER (group), label);
+  gtk_box_append (GTK_BOX (group), label);
 
   for (i = 0; tags[i]; i++)
     {
@@ -268,7 +268,7 @@ add_radio_group (GtkWidget *box,
       g_signal_connect (feat, "notify::active", G_CALLBACK (update_display), NULL);
       g_object_set_data (G_OBJECT (feat), "default", group_button);
 
-      gtk_container_add (GTK_CONTAINER (group), feat);
+      gtk_box_append (GTK_BOX (group), feat);
 
       item = g_new (FeatureItem, 1);
       item->name = tags[i];
@@ -280,7 +280,7 @@ add_radio_group (GtkWidget *box,
       feature_items = g_list_prepend (feature_items, item);
     }
 
-  gtk_container_add (GTK_CONTAINER (box), group);
+  gtk_box_append (GTK_BOX (box), group);
 }
 
 static void
diff --git a/demos/gtk-demo/gears.c b/demos/gtk-demo/gears.c
index e7a198e55b..54dfa5f0f3 100644
--- a/demos/gtk-demo/gears.c
+++ b/demos/gtk-demo/gears.c
@@ -53,7 +53,7 @@ create_axis_slider (GtkGears *gears,
     }
 
   label = gtk_label_new (text);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
   gtk_widget_show (label);
 
   adj = gtk_adjustment_new (gtk_gears_get_axis (gears, axis), 0.0, 360.0, 1.0, 12.0, 0.0);
@@ -63,7 +63,7 @@ create_axis_slider (GtkGears *gears,
                     gears);
   slider = gtk_scale_new (GTK_ORIENTATION_VERTICAL, adj);
   gtk_scale_set_draw_value (GTK_SCALE (slider), FALSE);
-  gtk_container_add (GTK_CONTAINER (box), slider);
+  gtk_box_append (GTK_BOX (box), slider);
   gtk_widget_set_vexpand (slider, TRUE);
   gtk_widget_show (slider);
 
@@ -111,19 +111,19 @@ do_gears (GtkWidget *do_widget)
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, FALSE);
       gtk_box_set_spacing (GTK_BOX (box), 6);
-      gtk_container_add (GTK_CONTAINER (box), hbox);
+      gtk_box_append (GTK_BOX (box), hbox);
 
       gears = gtk_gears_new ();
       gtk_widget_set_hexpand (gears, TRUE);
       gtk_widget_set_vexpand (gears, TRUE);
-      gtk_container_add (GTK_CONTAINER (hbox), gears);
+      gtk_box_append (GTK_BOX (hbox), gears);
 
       for (i = 0; i < GTK_GEARS_N_AXIS; i++)
-        gtk_container_add (GTK_CONTAINER (hbox), create_axis_slider (GTK_GEARS (gears), i));
+        gtk_box_append (GTK_BOX (hbox), create_axis_slider (GTK_GEARS (gears), i));
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, FALSE);
       gtk_box_set_spacing (GTK_BOX (hbox), 6);
-      gtk_container_add (GTK_CONTAINER (box), hbox);
+      gtk_box_append (GTK_BOX (box), hbox);
 
       gtk_gears_set_fps_label (GTK_GEARS (gears), GTK_LABEL (fps_label));
     }
diff --git a/demos/gtk-demo/glarea.c b/demos/gtk-demo/glarea.c
index 8de86d1765..5c2fb898c3 100644
--- a/demos/gtk-demo/glarea.c
+++ b/demos/gtk-demo/glarea.c
@@ -354,7 +354,7 @@ create_axis_slider (int axis)
     }
 
   label = gtk_label_new (text);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
   gtk_widget_show (label);
 
   adj = gtk_adjustment_new (0.0, 0.0, 360.0, 1.0, 12.0, 0.0);
@@ -362,7 +362,7 @@ create_axis_slider (int axis)
                     G_CALLBACK (on_axis_value_change),
                     GINT_TO_POINTER (axis));
   slider = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL, adj);
-  gtk_container_add (GTK_CONTAINER (box), slider);
+  gtk_box_append (GTK_BOX (box), slider);
   gtk_widget_set_hexpand (slider, TRUE);
   gtk_widget_show (slider);
 
@@ -406,7 +406,7 @@ create_glarea_window (GtkWidget *do_widget)
   gl_area = gtk_gl_area_new ();
   gtk_widget_set_hexpand (gl_area, TRUE);
   gtk_widget_set_vexpand (gl_area, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), gl_area);
+  gtk_box_append (GTK_BOX (box), gl_area);
 
   /* We need to initialize and free GL resources, so we use
    * the realize and unrealize signals on the widget
@@ -418,15 +418,15 @@ create_glarea_window (GtkWidget *do_widget)
   g_signal_connect (gl_area, "render", G_CALLBACK (render), NULL);
 
   controls = gtk_box_new (GTK_ORIENTATION_VERTICAL, FALSE);
-  gtk_container_add (GTK_CONTAINER (box), controls);
+  gtk_box_append (GTK_BOX (box), controls);
   gtk_widget_set_hexpand (controls, TRUE);
 
   for (i = 0; i < N_AXIS; i++)
-    gtk_container_add (GTK_CONTAINER (controls), create_axis_slider (i));
+    gtk_box_append (GTK_BOX (controls), create_axis_slider (i));
 
   button = gtk_button_new_with_label ("Quit");
   gtk_widget_set_hexpand (button, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (gtk_window_destroy), window);
 
   return window;
diff --git a/demos/gtk-demo/headerbar.c b/demos/gtk-demo/headerbar.c
index 7f1acfa652..dcb15a51c7 100644
--- a/demos/gtk-demo/headerbar.c
+++ b/demos/gtk-demo/headerbar.c
@@ -43,10 +43,10 @@ do_headerbar (GtkWidget *do_widget)
       gtk_widget_add_css_class (box, "linked");
       button = gtk_button_new ();
       gtk_button_set_child (GTK_BUTTON (button), gtk_image_new_from_icon_name ("pan-start-symbolic"));
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
       button = gtk_button_new ();
       gtk_button_set_child (GTK_BUTTON (button), gtk_image_new_from_icon_name ("pan-end-symbolic"));
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
 
       gtk_header_bar_pack_start (GTK_HEADER_BAR (header), box);
 
diff --git a/demos/gtk-demo/iconview.c b/demos/gtk-demo/iconview.c
index 45dc455e41..f214013c78 100644
--- a/demos/gtk-demo/iconview.c
+++ b/demos/gtk-demo/iconview.c
@@ -266,14 +266,14 @@ do_iconview (GtkWidget *do_widget)
       gtk_window_set_child (GTK_WINDOW (window), vbox);
 
       tool_bar = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (vbox), tool_bar);
+      gtk_box_append (GTK_BOX (vbox), tool_bar);
 
       up_button = gtk_button_new_with_mnemonic ("_Up");
       gtk_widget_set_sensitive (GTK_WIDGET (up_button), FALSE);
-      gtk_container_add (GTK_CONTAINER (tool_bar), up_button);
+      gtk_box_append (GTK_BOX (tool_bar), up_button);
 
       home_button = gtk_button_new_with_mnemonic ("_Home");
-      gtk_container_add (GTK_CONTAINER (tool_bar), home_button);
+      gtk_box_append (GTK_BOX (tool_bar), home_button);
 
 
       sw = gtk_scrolled_window_new (NULL, NULL);
@@ -283,7 +283,7 @@ do_iconview (GtkWidget *do_widget)
                                       GTK_POLICY_AUTOMATIC);
       gtk_widget_set_vexpand (sw, TRUE);
 
-      gtk_container_add (GTK_CONTAINER (vbox), sw);
+      gtk_box_append (GTK_BOX (vbox), sw);
 
       /* Create the store and fill it with the contents of '/' */
       parent = g_strdup ("/");
diff --git a/demos/gtk-demo/images.c b/demos/gtk-demo/images.c
index 8dc68de316..90684bc0ed 100644
--- a/demos/gtk-demo/images.c
+++ b/demos/gtk-demo/images.c
@@ -293,24 +293,16 @@ static void
 toggle_sensitivity_callback (GtkWidget *togglebutton,
                              gpointer   user_data)
 {
-  GtkContainer *container = user_data;
-  GList *list;
-  GList *tmp;
+  GtkWidget *child;
 
-  list = gtk_container_get_children (container);
-
-  tmp = list;
-  while (tmp != NULL)
+  for (child = gtk_widget_get_first_child (GTK_WIDGET (user_data));
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
     {
       /* don't disable our toggle */
-      if (GTK_WIDGET (tmp->data) != togglebutton)
-        gtk_widget_set_sensitive (GTK_WIDGET (tmp->data),
-                                  !gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (togglebutton)));
-
-      tmp = tmp->next;
+      if (child != togglebutton)
+        gtk_widget_set_sensitive (child, !gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (togglebutton)));
     }
-
-  g_list_free (list);
 }
 
 
@@ -348,20 +340,20 @@ do_images (GtkWidget *do_widget)
       gtk_window_set_child (GTK_WINDOW (window), base_vbox);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 16);
-      gtk_container_add (GTK_CONTAINER (base_vbox), hbox);
+      gtk_box_append (GTK_BOX (base_vbox), hbox);
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox);
+      gtk_box_append (GTK_BOX (hbox), vbox);
 
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label),
                             "<u>Image loaded from a file</u>");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       frame = gtk_frame_new (NULL);
       gtk_widget_set_halign (frame, GTK_ALIGN_CENTER);
       gtk_widget_set_valign (frame, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       image = gtk_image_new_from_icon_name ("gtk3-demo");
       gtk_image_set_icon_size (GTK_IMAGE (image), GTK_ICON_SIZE_LARGE);
@@ -374,12 +366,12 @@ do_images (GtkWidget *do_widget)
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label),
                             "<u>Animation loaded from a file</u>");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       frame = gtk_frame_new (NULL);
       gtk_widget_set_halign (frame, GTK_ALIGN_CENTER);
       gtk_widget_set_valign (frame, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       picture = gtk_picture_new_for_resource ("/images/floppybuddy.gif");
 
@@ -390,12 +382,12 @@ do_images (GtkWidget *do_widget)
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label),
                             "<u>Symbolic themed icon</u>");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       frame = gtk_frame_new (NULL);
       gtk_widget_set_halign (frame, GTK_ALIGN_CENTER);
       gtk_widget_set_valign (frame, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       gicon = g_themed_icon_new_with_default_fallbacks ("battery-caution-charging-symbolic");
       image = gtk_image_new_from_gicon (gicon);
@@ -406,17 +398,17 @@ do_images (GtkWidget *do_widget)
 
       /* Progressive */
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox);
+      gtk_box_append (GTK_BOX (hbox), vbox);
 
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label),
                             "<u>Progressive image loading</u>");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       frame = gtk_frame_new (NULL);
       gtk_widget_set_halign (frame, GTK_ALIGN_CENTER);
       gtk_widget_set_valign (frame, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       /* Create an empty image for now; the progressive loader
        * will create the pixbuf and fill it in.
@@ -428,17 +420,17 @@ do_images (GtkWidget *do_widget)
 
       /* Video */
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox);
+      gtk_box_append (GTK_BOX (hbox), vbox);
 
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label),
                             "<u>Displaying video</u>");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       frame = gtk_frame_new (NULL);
       gtk_widget_set_halign (frame, GTK_ALIGN_CENTER);
       gtk_widget_set_valign (frame, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       video = gtk_video_new_for_resource ("/images/gtk-logo.webm");
       gtk_media_stream_set_loop (gtk_video_get_media_stream (GTK_VIDEO (video)), TRUE);
@@ -446,22 +438,22 @@ do_images (GtkWidget *do_widget)
 
       /* Widget paintables */
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox);
+      gtk_box_append (GTK_BOX (hbox), vbox);
 
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label),
                             "<u>GtkWidgetPaintable</u>");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       paintable = gtk_widget_paintable_new (do_widget);
       picture = gtk_picture_new_for_paintable (paintable);
       gtk_widget_set_size_request (picture, 100, 100);
       gtk_widget_set_valign (picture, GTK_ALIGN_START);
-      gtk_container_add (GTK_CONTAINER (vbox), picture);
+      gtk_box_append (GTK_BOX (vbox), picture);
 
       /* Sensitivity control */
       button = gtk_toggle_button_new_with_mnemonic ("_Insensitive");
-      gtk_container_add (GTK_CONTAINER (base_vbox), button);
+      gtk_box_append (GTK_BOX (base_vbox), button);
 
       g_signal_connect (button, "toggled",
                         G_CALLBACK (toggle_sensitivity_callback),
diff --git a/demos/gtk-demo/infobar.c b/demos/gtk-demo/infobar.c
index 12fbe71c5b..786babbec6 100644
--- a/demos/gtk-demo/infobar.c
+++ b/demos/gtk-demo/infobar.c
@@ -66,73 +66,73 @@ do_infobar (GtkWidget *do_widget)
       gtk_window_set_child (GTK_WINDOW (window), vbox);
 
       bar = gtk_info_bar_new ();
-      gtk_container_add (GTK_CONTAINER (vbox), bar);
+      gtk_box_append (GTK_BOX (vbox), bar);
       gtk_info_bar_set_message_type (GTK_INFO_BAR (bar), GTK_MESSAGE_INFO);
       label = gtk_label_new ("This is an info bar with message type GTK_MESSAGE_INFO");
       gtk_label_set_wrap (GTK_LABEL (label), TRUE);
       gtk_label_set_xalign (GTK_LABEL (label), 0);
-      gtk_container_add (GTK_CONTAINER (bar), label);
+      gtk_box_append (GTK_BOX (bar), label);
 
       button = gtk_toggle_button_new_with_label ("Message");
       g_object_bind_property (bar, "revealed", button, "active", G_BINDING_BIDIRECTIONAL | 
G_BINDING_SYNC_CREATE);
-      gtk_container_add (GTK_CONTAINER (actions), button);
+      gtk_box_append (GTK_BOX (actions), button);
 
       bar = gtk_info_bar_new ();
-      gtk_container_add (GTK_CONTAINER (vbox), bar);
+      gtk_box_append (GTK_BOX (vbox), bar);
       gtk_info_bar_set_message_type (GTK_INFO_BAR (bar), GTK_MESSAGE_WARNING);
       label = gtk_label_new ("This is an info bar with message type GTK_MESSAGE_WARNING");
       gtk_label_set_wrap (GTK_LABEL (label), TRUE);
       gtk_label_set_xalign (GTK_LABEL (label), 0);
-      gtk_container_add (GTK_CONTAINER (bar), label);
+      gtk_box_append (GTK_BOX (bar), label);
 
       button = gtk_toggle_button_new_with_label ("Warning");
       g_object_bind_property (bar, "revealed", button, "active", G_BINDING_BIDIRECTIONAL | 
G_BINDING_SYNC_CREATE);
-      gtk_container_add (GTK_CONTAINER (actions), button);
+      gtk_box_append (GTK_BOX (actions), button);
 
       bar = gtk_info_bar_new_with_buttons (_("_OK"), GTK_RESPONSE_OK, NULL);
       gtk_info_bar_set_show_close_button (GTK_INFO_BAR (bar), TRUE);
       g_signal_connect (bar, "response", G_CALLBACK (on_bar_response), window);
-      gtk_container_add (GTK_CONTAINER (vbox), bar);
+      gtk_box_append (GTK_BOX (vbox), bar);
       gtk_info_bar_set_message_type (GTK_INFO_BAR (bar), GTK_MESSAGE_QUESTION);
       label = gtk_label_new ("This is an info bar with message type GTK_MESSAGE_QUESTION");
       gtk_label_set_wrap (GTK_LABEL (label), TRUE);
       gtk_label_set_xalign (GTK_LABEL (label), 0);
-      gtk_container_add (GTK_CONTAINER (bar), label);
+      gtk_box_append (GTK_BOX (bar), label);
       gtk_info_bar_set_default_response (GTK_INFO_BAR (bar), GTK_RESPONSE_OK);
 
       button = gtk_toggle_button_new_with_label ("Question");
       g_object_bind_property (bar, "revealed", button, "active", G_BINDING_BIDIRECTIONAL | 
G_BINDING_SYNC_CREATE);
-      gtk_container_add (GTK_CONTAINER (actions), button);
+      gtk_box_append (GTK_BOX (actions), button);
 
       bar = gtk_info_bar_new ();
-      gtk_container_add (GTK_CONTAINER (vbox), bar);
+      gtk_box_append (GTK_BOX (vbox), bar);
       gtk_info_bar_set_message_type (GTK_INFO_BAR (bar), GTK_MESSAGE_ERROR);
       label = gtk_label_new ("This is an info bar with message type GTK_MESSAGE_ERROR");
       gtk_label_set_wrap (GTK_LABEL (label), TRUE);
       gtk_label_set_xalign (GTK_LABEL (label), 0);
-      gtk_container_add (GTK_CONTAINER (bar), label);
+      gtk_box_append (GTK_BOX (bar), label);
 
       button = gtk_toggle_button_new_with_label ("Error");
       g_object_bind_property (bar, "revealed", button, "active", G_BINDING_BIDIRECTIONAL | 
G_BINDING_SYNC_CREATE);
 
-      gtk_container_add (GTK_CONTAINER (actions), button);
+      gtk_box_append (GTK_BOX (actions), button);
 
       bar = gtk_info_bar_new ();
-      gtk_container_add (GTK_CONTAINER (vbox), bar);
+      gtk_box_append (GTK_BOX (vbox), bar);
       gtk_info_bar_set_message_type (GTK_INFO_BAR (bar), GTK_MESSAGE_OTHER);
       label = gtk_label_new ("This is an info bar with message type GTK_MESSAGE_OTHER");
       gtk_label_set_wrap (GTK_LABEL (label), TRUE);
       gtk_label_set_xalign (GTK_LABEL (label), 0);
-      gtk_container_add (GTK_CONTAINER (bar), label);
+      gtk_box_append (GTK_BOX (bar), label);
 
       button = gtk_toggle_button_new_with_label ("Other");
       g_object_bind_property (bar, "revealed", button, "active", G_BINDING_BIDIRECTIONAL | 
G_BINDING_SYNC_CREATE);
-      gtk_container_add (GTK_CONTAINER (actions), button);
+      gtk_box_append (GTK_BOX (actions), button);
 
       frame = gtk_frame_new ("An example of different info bars");
       gtk_widget_set_margin_top (frame, 8);
       gtk_widget_set_margin_bottom (frame, 8);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       gtk_widget_set_halign (actions, GTK_ALIGN_CENTER);
 
diff --git a/demos/gtk-demo/list_store.c b/demos/gtk-demo/list_store.c
index da9e9d18d8..9a196dcb09 100644
--- a/demos/gtk-demo/list_store.c
+++ b/demos/gtk-demo/list_store.c
@@ -267,14 +267,14 @@ do_list_store (GtkWidget *do_widget)
       gtk_window_set_child (GTK_WINDOW (window), vbox);
 
       label = gtk_label_new ("This is the bug list (note: not based on real data, it would be nice to have a 
nice ODBC interface to bugzilla or so, though).");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       sw = gtk_scrolled_window_new (NULL, NULL);
       gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (sw), TRUE);
       gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                       GTK_POLICY_NEVER,
                                       GTK_POLICY_AUTOMATIC);
-      gtk_container_add (GTK_CONTAINER (vbox), sw);
+      gtk_box_append (GTK_BOX (vbox), sw);
 
       /* create tree model */
       model = create_model ();
diff --git a/demos/gtk-demo/listbox.c b/demos/gtk-demo/listbox.c
index ae67cf91df..69cbb8b334 100644
--- a/demos/gtk-demo/listbox.c
+++ b/demos/gtk-demo/listbox.c
@@ -357,11 +357,11 @@ do_listbox (GtkWidget *do_widget)
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 12);
       gtk_window_set_child (GTK_WINDOW (window), vbox);
       label = gtk_label_new ("Messages from GTK and friends");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
       scrolled = gtk_scrolled_window_new (NULL, NULL);
       gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled), GTK_POLICY_NEVER, 
GTK_POLICY_AUTOMATIC);
       gtk_widget_set_vexpand (scrolled, TRUE);
-      gtk_container_add (GTK_CONTAINER (vbox), scrolled);
+      gtk_box_append (GTK_BOX (vbox), scrolled);
       listbox = gtk_list_box_new ();
       gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolled), listbox);
 
diff --git a/demos/gtk-demo/overlay.c b/demos/gtk-demo/overlay.c
index 61037b3401..425caf1469 100644
--- a/demos/gtk-demo/overlay.c
+++ b/demos/gtk-demo/overlay.c
@@ -66,7 +66,7 @@ do_overlay (GtkWidget *do_widget)
       gtk_widget_set_can_target (label, FALSE);
       gtk_widget_set_margin_top (label, 8);
       gtk_widget_set_margin_bottom (label, 8);
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
       gtk_overlay_add_overlay (GTK_OVERLAY (overlay), vbox);
@@ -76,7 +76,7 @@ do_overlay (GtkWidget *do_widget)
       gtk_entry_set_placeholder_text (GTK_ENTRY (entry), "Your Lucky Number");
       gtk_widget_set_margin_top (entry, 8);
       gtk_widget_set_margin_bottom (entry, 8);
-      gtk_container_add (GTK_CONTAINER (vbox), entry);
+      gtk_box_append (GTK_BOX (vbox), entry);
 
       gtk_window_set_child (GTK_WINDOW (window), overlay);
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
diff --git a/demos/gtk-demo/panes.c b/demos/gtk-demo/panes.c
index f47cc32b60..e756a181e3 100644
--- a/demos/gtk-demo/panes.c
+++ b/demos/gtk-demo/panes.c
@@ -128,7 +128,7 @@ do_panes (GtkWidget *do_widget)
       gtk_widget_set_margin_end (vpaned, 5);
       gtk_widget_set_margin_top (vpaned, 5);
       gtk_widget_set_margin_bottom (vpaned, 5);
-      gtk_container_add (GTK_CONTAINER (vbox), vpaned);
+      gtk_box_append (GTK_BOX (vbox), vpaned);
 
       hpaned = gtk_paned_new (GTK_ORIENTATION_HORIZONTAL);
       gtk_paned_set_start_child (GTK_PANED (vpaned), hpaned);
@@ -150,13 +150,13 @@ do_panes (GtkWidget *do_widget)
 
       /* Now create toggle buttons to control sizing */
 
-      gtk_container_add (GTK_CONTAINER (vbox),
+      gtk_box_append (GTK_BOX (vbox),
                           create_pane_options (GTK_PANED (hpaned),
                                                "Horizontal",
                                                "Left",
                                                "Right"));
 
-      gtk_container_add (GTK_CONTAINER (vbox),
+      gtk_box_append (GTK_BOX (vbox),
                           create_pane_options (GTK_PANED (vpaned),
                                                "Vertical",
                                                "Top",
diff --git a/demos/gtk-demo/password_entry.c b/demos/gtk-demo/password_entry.c
index 478bcf2c08..fd72e148a8 100644
--- a/demos/gtk-demo/password_entry.c
+++ b/demos/gtk-demo/password_entry.c
@@ -61,7 +61,7 @@ do_password_entry (GtkWidget *do_widget)
                     "activates-default", TRUE,
                     NULL);
       g_signal_connect (entry, "notify::text", G_CALLBACK (update_button), NULL);
-      gtk_container_add (GTK_CONTAINER (box), entry);
+      gtk_box_append (GTK_BOX (box), entry);
 
       entry2 = gtk_password_entry_new ();
       gtk_password_entry_set_show_peek_icon (GTK_PASSWORD_ENTRY (entry2), TRUE);
@@ -70,7 +70,7 @@ do_password_entry (GtkWidget *do_widget)
                     "activates-default", TRUE,
                     NULL);
       g_signal_connect (entry2, "notify::text", G_CALLBACK (update_button), NULL);
-      gtk_container_add (GTK_CONTAINER (box), entry2);
+      gtk_box_append (GTK_BOX (box), entry2);
 
       button = gtk_button_new_with_mnemonic ("_Done");
       gtk_widget_add_css_class (button, "suggested-action");
diff --git a/demos/gtk-demo/rotated_text.c b/demos/gtk-demo/rotated_text.c
index a387a6cf7f..0af45dc017 100644
--- a/demos/gtk-demo/rotated_text.c
+++ b/demos/gtk-demo/rotated_text.c
@@ -188,7 +188,7 @@ do_rotated_text (GtkWidget *do_widget)
 
       /* Add a drawing area */
       drawing_area = gtk_drawing_area_new ();
-      gtk_container_add (GTK_CONTAINER (box), drawing_area);
+      gtk_box_append (GTK_BOX (box), drawing_area);
       gtk_widget_add_css_class (drawing_area, GTK_STYLE_CLASS_VIEW);
 
       gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (drawing_area),
@@ -197,7 +197,7 @@ do_rotated_text (GtkWidget *do_widget)
 
       /* And a label */
       label = gtk_label_new (text);
-      gtk_container_add (GTK_CONTAINER (box), label);
+      gtk_box_append (GTK_BOX (box), label);
 
       /* Set up fancy stuff on the label */
       layout = gtk_label_get_layout (GTK_LABEL (label));
diff --git a/demos/gtk-demo/search_entry.c b/demos/gtk-demo/search_entry.c
index c48e88b3b3..aa3872b858 100644
--- a/demos/gtk-demo/search_entry.c
+++ b/demos/gtk-demo/search_entry.c
@@ -273,23 +273,23 @@ do_search_entry (GtkWidget *do_widget)
 
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label), "Search entry demo");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       /* Create our entry */
       entry = gtk_entry_new ();
       gtk_entry_set_icon_from_icon_name (GTK_ENTRY (entry),
                                          GTK_ENTRY_ICON_PRIMARY,
                                          "edit-find-symbolic");
-      gtk_container_add (GTK_CONTAINER (hbox), entry);
+      gtk_box_append (GTK_BOX (hbox), entry);
 
       /* Create the find and cancel buttons */
       notebook = gtk_notebook_new ();
       gtk_notebook_set_show_tabs (GTK_NOTEBOOK (notebook), FALSE);
       gtk_notebook_set_show_border (GTK_NOTEBOOK (notebook), FALSE);
-      gtk_container_add (GTK_CONTAINER (hbox), notebook);
+      gtk_box_append (GTK_BOX (hbox), notebook);
 
       find_button = gtk_button_new_with_label ("Find");
       g_signal_connect (find_button, "clicked",
diff --git a/demos/gtk-demo/search_entry2.c b/demos/gtk-demo/search_entry2.c
index a2033d1e8b..29d417adf1 100644
--- a/demos/gtk-demo/search_entry2.c
+++ b/demos/gtk-demo/search_entry2.c
@@ -81,38 +81,38 @@ do_search_entry2 (GtkWidget *do_widget)
       entry = gtk_search_entry_new ();
       container = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
       gtk_widget_set_halign (container, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (container), entry);
+      gtk_box_append (GTK_BOX (container), entry);
       searchbar = gtk_search_bar_new ();
       gtk_search_bar_connect_entry (GTK_SEARCH_BAR (searchbar), GTK_EDITABLE (entry));
       gtk_search_bar_set_show_close_button (GTK_SEARCH_BAR (searchbar), FALSE);
       gtk_search_bar_set_child (GTK_SEARCH_BAR (searchbar), container);
-      gtk_container_add (GTK_CONTAINER (vbox), searchbar);
+      gtk_box_append (GTK_BOX (vbox), searchbar);
 
       /* Hook the search bar to key presses */
       gtk_search_bar_set_key_capture_widget (GTK_SEARCH_BAR (searchbar), window);
 
       /* Help */
       label = gtk_label_new ("Start Typing to search");
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
 
       /* Toggle button */
       button = gtk_toggle_button_new_with_label ("Search");
       g_object_bind_property (button, "active",
                               searchbar, "search-mode-enabled",
                               G_BINDING_BIDIRECTIONAL);
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
 
       /* Result */
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       label = gtk_label_new ("Result:");
       gtk_label_set_xalign (GTK_LABEL (label), 0.0);
       gtk_widget_set_margin_start (label, 6);
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       label = gtk_label_new ("");
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       g_signal_connect (entry, "search-changed",
                         G_CALLBACK (search_changed_cb), label);
@@ -120,15 +120,15 @@ do_search_entry2 (GtkWidget *do_widget)
                         G_CALLBACK (changed_cb), label);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       label = gtk_label_new ("Signal:");
       gtk_label_set_xalign (GTK_LABEL (label), 0.0);
       gtk_widget_set_margin_start (label, 6);
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       label = gtk_label_new ("");
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       g_signal_connect (entry, "search-changed",
                         G_CALLBACK (search_changed), label);
diff --git a/demos/gtk-demo/sidebar.c b/demos/gtk-demo/sidebar.c
index 965c6d7598..4ff4aa17b9 100644
--- a/demos/gtk-demo/sidebar.c
+++ b/demos/gtk-demo/sidebar.c
@@ -47,14 +47,14 @@ do_sidebar (GtkWidget *do_widget)
 
       box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
       sidebar = gtk_stack_sidebar_new ();
-      gtk_container_add (GTK_CONTAINER (box), sidebar);
+      gtk_box_append (GTK_BOX (box), sidebar);
 
       stack = gtk_stack_new ();
       gtk_stack_set_transition_type (GTK_STACK (stack), GTK_STACK_TRANSITION_TYPE_SLIDE_UP_DOWN);
       gtk_stack_sidebar_set_stack (GTK_STACK_SIDEBAR (sidebar), GTK_STACK (stack));
       gtk_widget_set_hexpand (stack, TRUE);
 
-      gtk_container_add (GTK_CONTAINER (box), stack);
+      gtk_box_append (GTK_BOX (box), stack);
 
       for (i=0; (c = *(pages+i)) != NULL; i++ )
         {
diff --git a/demos/gtk-demo/sizegroup.c b/demos/gtk-demo/sizegroup.c
index e61d5ac758..a3e3547b8b 100644
--- a/demos/gtk-demo/sizegroup.c
+++ b/demos/gtk-demo/sizegroup.c
@@ -118,7 +118,7 @@ do_sizegroup (GtkWidget *do_widget)
 
       /* Create one frame holding color options */
       frame = gtk_frame_new ("Color Options");
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       table = gtk_grid_new ();
       gtk_widget_set_margin_start (table, 5);
@@ -134,7 +134,7 @@ do_sizegroup (GtkWidget *do_widget)
 
       /* And another frame holding line style options */
       frame = gtk_frame_new ("Line Options");
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       table = gtk_grid_new ();
       gtk_widget_set_margin_start (table, 5);
@@ -150,7 +150,7 @@ do_sizegroup (GtkWidget *do_widget)
 
       /* And a check button to turn grouping on and off */
       check_button = gtk_check_button_new_with_mnemonic ("_Enable grouping");
-      gtk_container_add (GTK_CONTAINER (vbox), check_button);
+      gtk_box_append (GTK_BOX (vbox), check_button);
 
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check_button), TRUE);
       g_signal_connect (check_button, "toggled",
diff --git a/demos/gtk-demo/sliding_puzzle.c b/demos/gtk-demo/sliding_puzzle.c
index 09e8c4bdbd..dbe8129e60 100644
--- a/demos/gtk-demo/sliding_puzzle.c
+++ b/demos/gtk-demo/sliding_puzzle.c
@@ -387,7 +387,7 @@ add_choice (GtkWidget    *container,
   icon = gtk_image_new_from_paintable (paintable);
   gtk_image_set_icon_size (GTK_IMAGE (icon), GTK_ICON_SIZE_LARGE);
 
-  gtk_container_add (GTK_CONTAINER (container), icon);
+  gtk_box_append (GTK_BOX (container), icon);
 }
 
 GtkWidget *
diff --git a/demos/gtk-demo/spinner.c b/demos/gtk-demo/spinner.c
index 4582728646..21c33441e9 100644
--- a/demos/gtk-demo/spinner.c
+++ b/demos/gtk-demo/spinner.c
@@ -55,34 +55,34 @@ do_spinner (GtkWidget *do_widget)
     gtk_widget_set_margin_end (vbox, 5);
     gtk_widget_set_margin_top (vbox, 5);
     gtk_widget_set_margin_bottom (vbox, 5);
-    gtk_container_add (GTK_CONTAINER (content_area), vbox);
+    gtk_box_append (GTK_BOX (content_area), vbox);
 
     /* Sensitive */
     hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
     spinner = gtk_spinner_new ();
-    gtk_container_add (GTK_CONTAINER (hbox), spinner);
-    gtk_container_add (GTK_CONTAINER (hbox), gtk_entry_new ());
-    gtk_container_add (GTK_CONTAINER (vbox), hbox);
+    gtk_box_append (GTK_BOX (hbox), spinner);
+    gtk_box_append (GTK_BOX (hbox), gtk_entry_new ());
+    gtk_box_append (GTK_BOX (vbox), hbox);
     spinner_sensitive = spinner;
 
     /* Disabled */
     hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
     spinner = gtk_spinner_new ();
-    gtk_container_add (GTK_CONTAINER (hbox), spinner);
-    gtk_container_add (GTK_CONTAINER (hbox), gtk_entry_new ());
-    gtk_container_add (GTK_CONTAINER (vbox), hbox);
+    gtk_box_append (GTK_BOX (hbox), spinner);
+    gtk_box_append (GTK_BOX (hbox), gtk_entry_new ());
+    gtk_box_append (GTK_BOX (vbox), hbox);
     spinner_unsensitive = spinner;
     gtk_widget_set_sensitive (hbox, FALSE);
 
     button = gtk_button_new_with_label (_("Play"));
     g_signal_connect (G_OBJECT (button), "clicked",
                       G_CALLBACK (on_play_clicked), spinner);
-    gtk_container_add (GTK_CONTAINER (vbox), button);
+    gtk_box_append (GTK_BOX (vbox), button);
 
     button = gtk_button_new_with_label (_("Stop"));
     g_signal_connect (G_OBJECT (button), "clicked",
                       G_CALLBACK (on_stop_clicked), spinner);
-    gtk_container_add (GTK_CONTAINER (vbox), button);
+    gtk_box_append (GTK_BOX (vbox), button);
 
     /* Start by default to test for:
      * https://bugzilla.gnome.org/show_bug.cgi?id=598496 */
diff --git a/demos/gtk-demo/tagged_entry.c b/demos/gtk-demo/tagged_entry.c
index a17e2d1188..50020c19cf 100644
--- a/demos/gtk-demo/tagged_entry.c
+++ b/demos/gtk-demo/tagged_entry.c
@@ -82,19 +82,19 @@ do_tagged_entry (GtkWidget *do_widget)
       gtk_window_set_child (GTK_WINDOW (window), box);
 
       entry = demo_tagged_entry_new ();
-      gtk_container_add (GTK_CONTAINER (box), entry);
+      gtk_box_append (GTK_BOX (box), entry);
 
       box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
       gtk_widget_set_halign (box2, GTK_ALIGN_END);
-      gtk_container_add (GTK_CONTAINER (box), box2);
+      gtk_box_append (GTK_BOX (box), box2);
 
       button = gtk_button_new_with_mnemonic ("Add _Tag");
       g_signal_connect (button, "clicked", G_CALLBACK (add_tag), entry);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_check_button_new_with_mnemonic ("_Spinner");
       g_signal_connect (button, "toggled", G_CALLBACK (toggle_spinner), entry);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       
       button = gtk_button_new_with_mnemonic ("_Done");
       gtk_widget_add_css_class (button, "suggested-action");
diff --git a/demos/gtk-demo/textscroll.c b/demos/gtk-demo/textscroll.c
index 6e2b4045fc..8d79d084f4 100644
--- a/demos/gtk-demo/textscroll.c
+++ b/demos/gtk-demo/textscroll.c
@@ -157,7 +157,7 @@ create_text_view (GtkWidget *hbox,
   guint timeout;
 
   swindow = gtk_scrolled_window_new (NULL, NULL);
-  gtk_container_add (GTK_CONTAINER (hbox), swindow);
+  gtk_box_append (GTK_BOX (hbox), swindow);
   textview = gtk_text_view_new ();
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (swindow), textview);
 
diff --git a/demos/gtk-demo/tree_store.c b/demos/gtk-demo/tree_store.c
index d37d7d2b7d..d2d1f50304 100644
--- a/demos/gtk-demo/tree_store.c
+++ b/demos/gtk-demo/tree_store.c
@@ -403,7 +403,7 @@ do_tree_store (GtkWidget *do_widget)
       gtk_widget_set_margin_bottom (vbox, 8);
       gtk_window_set_child (GTK_WINDOW (window), vbox);
 
-      gtk_container_add (GTK_CONTAINER (vbox),
+      gtk_box_append (GTK_BOX (vbox),
                           gtk_label_new ("Jonathan's Holiday Card Planning Sheet"));
 
       sw = gtk_scrolled_window_new (NULL, NULL);
@@ -411,7 +411,7 @@ do_tree_store (GtkWidget *do_widget)
       gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                       GTK_POLICY_AUTOMATIC,
                                       GTK_POLICY_AUTOMATIC);
-      gtk_container_add (GTK_CONTAINER (vbox), sw);
+      gtk_box_append (GTK_BOX (vbox), sw);
 
       /* create model */
       model = create_model ();
diff --git a/demos/node-editor/node-editor-window.c b/demos/node-editor/node-editor-window.c
index 0c036a4965..9859a9551b 100644
--- a/demos/node-editor/node-editor-window.c
+++ b/demos/node-editor/node-editor-window.c
@@ -787,13 +787,13 @@ node_editor_window_create_renderer_widget (gpointer item,
   gtk_widget_set_size_request (box, 120, 90);
 
   label = gtk_label_new (g_object_get_data (G_OBJECT (paintable), "description"));
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   picture = gtk_picture_new_for_paintable (paintable);
   /* don't ever scale up, we want to be as accurate as possible */
   gtk_widget_set_halign (picture, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (picture, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (box), picture);
+  gtk_box_append (GTK_BOX (box), picture);
 
   row = gtk_list_box_row_new ();
   gtk_list_box_row_set_child (GTK_LIST_BOX_ROW (row), box);
diff --git a/demos/widget-factory/widget-factory.c b/demos/widget-factory/widget-factory.c
index c394886b9a..46cac4a989 100644
--- a/demos/widget-factory/widget-factory.c
+++ b/demos/widget-factory/widget-factory.c
@@ -891,12 +891,12 @@ overshot (GtkScrolledWindow *sw, GtkPositionType pos, GtkWidget *widget)
     {
       if (silver)
         {
-          gtk_container_remove (GTK_CONTAINER (widget), silver);
+          gtk_list_box_remove (GTK_LIST_BOX (widget), silver);
           g_object_set_data (G_OBJECT (widget), "Silver", NULL);
         }
       if (gold)
         {
-          gtk_container_remove (GTK_CONTAINER (widget), gold);
+          gtk_list_box_remove (GTK_LIST_BOX (widget), gold);
           g_object_set_data (G_OBJECT (widget), "Gold", NULL);
         }
 
@@ -926,7 +926,7 @@ overshot (GtkScrolledWindow *sw, GtkPositionType pos, GtkWidget *widget)
                 "margin-bottom", 6,
                 "xalign", 0.0,
                 NULL);
-  gtk_container_add (GTK_CONTAINER (row), label);
+  gtk_box_append (GTK_BOX (row), label);
   gdk_rgba_parse (&rgba, color);
   swatch = g_object_new (g_type_from_name ("GtkColorSwatch"),
                          "rgba", &rgba,
@@ -941,8 +941,8 @@ overshot (GtkScrolledWindow *sw, GtkPositionType pos, GtkWidget *widget)
                          "height-request", 24,
                          NULL);
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (box), swatch);
-  gtk_container_add (GTK_CONTAINER (row), box);
+  gtk_box_append (GTK_BOX (box), swatch);
+  gtk_box_append (GTK_BOX (row), box);
   gtk_list_box_insert (GTK_LIST_BOX (widget), row, -1);
   row = gtk_widget_get_parent (row);
   gtk_list_box_row_set_activatable (GTK_LIST_BOX_ROW (row), FALSE);
@@ -1044,7 +1044,7 @@ populate_colors (GtkWidget *widget, GtkWidget *chooser)
                     "hexpand", TRUE,
                     "xalign", 0.0,
                     NULL);
-      gtk_container_add (GTK_CONTAINER (row), label);
+      gtk_box_append (GTK_BOX (row), label);
       gdk_rgba_parse (&rgba, colors[i].color);
       swatch = g_object_new (g_type_from_name ("GtkColorSwatch"),
                              "rgba", &rgba,
@@ -1059,8 +1059,8 @@ populate_colors (GtkWidget *widget, GtkWidget *chooser)
                              "height-request", 24,
                              NULL);
       box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (box), swatch);
-      gtk_container_add (GTK_CONTAINER (row), box);
+      gtk_box_append (GTK_BOX (box), swatch);
+      gtk_box_append (GTK_BOX (row), box);
       gtk_list_box_insert (GTK_LIST_BOX (widget), row, -1);
       row = gtk_widget_get_parent (row);
       gtk_list_box_row_set_activatable (GTK_LIST_BOX_ROW (row), FALSE);
@@ -1288,10 +1288,7 @@ close_selection_dialog (GtkWidget *dialog, gint response, GtkWidget *tv)
   if (response == GTK_RESPONSE_CANCEL)
     return;
 
-  box = gtk_dialog_get_content_area (GTK_DIALOG (dialog));
-  children = gtk_container_get_children (GTK_CONTAINER (box));
-  box = children->data;
-  g_list_free (children);
+  box = gtk_widget_get_first_child (gtk_dialog_get_content_area (GTK_DIALOG (dialog)));
   g_assert (GTK_IS_FLOW_BOX (box));
   children = gtk_flow_box_get_selected_children (GTK_FLOW_BOX (box));
 
diff --git a/docs/tools/widgets.c b/docs/tools/widgets.c
index 2a1858e978..93eca8f0e7 100644
--- a/docs/tools/widgets.c
+++ b/docs/tools/widgets.c
@@ -44,7 +44,7 @@ new_widget_info (const char *name,
       info->window = gtk_window_new ();
       info->include_decorations = FALSE;
       gtk_widget_show (widget);
-      gtk_container_add (GTK_CONTAINER (info->window), widget);
+      gtk_box_append (GTK_BOX (info->window), widget);
     }
   info->no_focus = TRUE;
 
@@ -92,9 +92,9 @@ create_switch (void)
   widget = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
   sw = gtk_switch_new ();
   gtk_switch_set_active (GTK_SWITCH (sw), TRUE);
-  gtk_container_add (GTK_CONTAINER (widget), sw);
+  gtk_box_append (GTK_BOX (widget), sw);
   sw = gtk_switch_new ();
-  gtk_container_add (GTK_CONTAINER (widget), sw);
+  gtk_box_append (GTK_BOX (widget), sw);
 
   gtk_widget_set_halign (widget, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (widget, GTK_ALIGN_CENTER);
@@ -151,16 +151,16 @@ create_menu_button (void)
   widget = gtk_menu_button_new ();
   image = gtk_image_new ();
   gtk_image_set_from_icon_name (GTK_IMAGE (image), "emblem-system-symbolic");
-  gtk_container_add (GTK_CONTAINER (widget), image);
+  gtk_box_append (GTK_BOX (widget), image);
   menu = gtk_popover_new ();
   gtk_menu_button_set_popover (GTK_MENU_BUTTON (widget), menu);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
   gtk_widget_set_halign (widget, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (widget, GTK_ALIGN_CENTER);
 
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new ("Menu Button"));
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new ("Menu Button"));
 
   return new_widget_info ("menu-button", vbox, SMALL);
 }
@@ -209,8 +209,8 @@ create_lockbutton (void)
   widget = gtk_lock_button_new (g_object_new (G_TYPE_TEST_PERMISSION, NULL));
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Lock Button"));
   gtk_widget_set_halign (vbox, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (vbox, GTK_ALIGN_CENTER);
@@ -253,11 +253,11 @@ create_radio (void)
 
   widget = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
   radio = gtk_radio_button_new_with_mnemonic (NULL, "Radio Button _One");
-  gtk_container_add (GTK_CONTAINER (widget), radio);
+  gtk_box_append (GTK_BOX (widget), radio);
   radio = gtk_radio_button_new_with_mnemonic_from_widget (GTK_RADIO_BUTTON (radio), "Radio Button _Two");
-  gtk_container_add (GTK_CONTAINER (widget), radio);
+  gtk_box_append (GTK_BOX (widget), radio);
   radio = gtk_radio_button_new_with_mnemonic_from_widget (GTK_RADIO_BUTTON (radio), "Radio Button T_hree");
-  gtk_container_add (GTK_CONTAINER (widget), radio);
+  gtk_box_append (GTK_BOX (widget), radio);
   gtk_widget_set_halign (widget, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (widget, GTK_ALIGN_CENTER);
 
@@ -288,8 +288,8 @@ create_accel_label (void)
   gtk_widget_hide (button);
 
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (box), widget);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), widget);
+  gtk_box_append (GTK_BOX (box), button);
 
   gtk_accel_label_set_accel (GTK_ACCEL_LABEL (widget), GDK_KEY_Q, GDK_CONTROL_MASK);
 
@@ -369,7 +369,7 @@ create_info_bar (void)
   widget = gtk_info_bar_new ();
   gtk_info_bar_set_show_close_button (GTK_INFO_BAR (widget), TRUE);
   gtk_info_bar_set_message_type (GTK_INFO_BAR (widget), GTK_MESSAGE_INFO);
-  gtk_container_add (GTK_CONTAINER (widget),
+  gtk_box_append (GTK_BOX (widget),
                      gtk_label_new ("Info Bar"));
 
   gtk_widget_set_halign (widget, GTK_ALIGN_FILL);
@@ -394,16 +394,16 @@ create_search_bar (void)
 
   entry = gtk_search_entry_new ();
   gtk_editable_set_text (GTK_EDITABLE (entry), "Search Bar");
-  gtk_container_add (GTK_CONTAINER (widget), entry);
+  gtk_box_append (GTK_BOX (widget), entry);
   gtk_widget_show (entry);
 
   gtk_search_bar_set_show_close_button (GTK_SEARCH_BAR (widget), TRUE);
   gtk_search_bar_set_search_mode (GTK_SEARCH_BAR (widget), TRUE);
 
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
 
   view = gtk_text_view_new ();
-  gtk_container_add (GTK_CONTAINER (box), view);
+  gtk_box_append (GTK_BOX (box), view);
 
   info = new_widget_info ("search-bar", box, SMALL);
 
@@ -421,16 +421,16 @@ create_action_bar (void)
 
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   view = gtk_text_view_new ();
-  gtk_container_add (GTK_CONTAINER (box), view);
+  gtk_box_append (GTK_BOX (box), view);
 
   widget = gtk_action_bar_new ();
 
   button = gtk_button_new_from_icon_name ("object-select-symbolic");
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (widget), button);
+  gtk_box_append (GTK_BOX (widget), button);
   button = gtk_button_new_from_icon_name ("call-start-symbolic");
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (widget), button);
+  gtk_box_append (GTK_BOX (widget), button);
   g_object_set (gtk_widget_get_parent (button),
                 "margin-start", 6,
                 "margin-end", 6,
@@ -441,7 +441,7 @@ create_action_bar (void)
 
   gtk_widget_show (widget);
 
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
 
   info = new_widget_info ("action-bar", box, SMALL);
 
@@ -456,7 +456,7 @@ create_text_view (void)
 
   widget = gtk_frame_new (NULL);
   text_view = gtk_text_view_new ();
-  gtk_container_add (GTK_CONTAINER (widget), text_view);
+  gtk_box_append (GTK_BOX (widget), text_view);
   /* Bad hack to add some size to the widget */
   gtk_text_buffer_set_text (gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view)),
                            "Multiline\nText\n\n", -1);
@@ -498,7 +498,7 @@ create_tree_view (void)
                                               g_object_new (GTK_TYPE_CELL_RENDERER_TEXT, "xalign", 0.5, 
NULL),
                                               "text", 2, NULL);
   gtk_tree_view_expand_all (GTK_TREE_VIEW (tree_view));
-  gtk_container_add (GTK_CONTAINER (widget), tree_view);
+  gtk_box_append (GTK_BOX (widget), tree_view);
 
   info = new_widget_info ("list-and-tree", widget, MEDIUM);
   info->no_focus = FALSE;
@@ -532,11 +532,11 @@ create_icon_view (void)
   gtk_icon_view_set_text_column (GTK_ICON_VIEW (icon_view), 0);
   gtk_icon_view_set_pixbuf_column (GTK_ICON_VIEW (icon_view), 1);
 
-  gtk_container_add (GTK_CONTAINER (widget), icon_view);
+  gtk_box_append (GTK_BOX (widget), icon_view);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Icon View"));
 
   info = new_widget_info ("icon-view", vbox, MEDIUM);
@@ -559,8 +559,8 @@ create_color_button (void)
   picker = gtk_color_button_new_with_rgba (&color);
   gtk_widget_set_halign (picker, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (picker, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), picker);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), picker);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Color Button"));
 
   return new_widget_info ("color-button", vbox, SMALL);
@@ -576,8 +576,8 @@ create_font_button (void)
   picker = gtk_font_button_new_with_font ("Sans Serif 10");
   gtk_widget_set_halign (picker, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (picker, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), picker);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), picker);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Font Button"));
 
   return new_widget_info ("font-button", vbox, SMALL);
@@ -599,13 +599,13 @@ create_file_button (void)
   gtk_widget_set_size_request (picker, 150, -1);
   gtk_widget_set_halign (picker, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (picker, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox2), picker);
-  gtk_container_add (GTK_CONTAINER (vbox2),
+  gtk_box_append (GTK_BOX (vbox2), picker);
+  gtk_box_append (GTK_BOX (vbox2),
                      gtk_label_new ("File Button (Files)"));
 
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox),
                      vbox2);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
 
   vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
@@ -619,10 +619,10 @@ create_file_button (void)
   g_object_unref (file);
   gtk_widget_set_halign (picker, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (picker, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox2), picker);
-  gtk_container_add (GTK_CONTAINER (vbox2),
+  gtk_box_append (GTK_BOX (vbox2), picker);
+  gtk_box_append (GTK_BOX (vbox2),
                      gtk_label_new ("File Button (Select Folder)"));
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox),
                      vbox2);
 
   return new_widget_info ("file-button", vbox, MEDIUM);
@@ -637,12 +637,12 @@ create_separator (void)
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_box_set_homogeneous (GTK_BOX (hbox), TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox),
+  gtk_box_append (GTK_BOX (hbox),
                      gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
-  gtk_container_add (GTK_CONTAINER (hbox),
+  gtk_box_append (GTK_BOX (hbox),
                      gtk_separator_new (GTK_ORIENTATION_VERTICAL));
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox),
                      g_object_new (GTK_TYPE_LABEL,
                                    "label", "Horizontal and Vertical\nSeparators",
                                    "justify", GTK_JUSTIFY_CENTER,
@@ -673,7 +673,7 @@ create_panes (void)
   gtk_paned_set_resize_end_child (GTK_PANED (pane), FALSE);
   gtk_paned_set_shrink_end_child (GTK_PANED (pane), FALSE);
 
-  gtk_container_add (GTK_CONTAINER (hbox), pane);
+  gtk_box_append (GTK_BOX (hbox), pane);
   pane = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
 
   frame = gtk_frame_new ("");
@@ -686,10 +686,10 @@ create_panes (void)
   gtk_paned_set_resize_end_child (GTK_PANED (pane), FALSE);
   gtk_paned_set_shrink_end_child (GTK_PANED (pane), FALSE);
 
-  gtk_container_add (GTK_CONTAINER (hbox), pane);
+  gtk_box_append (GTK_BOX (hbox), pane);
 
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox),
                      g_object_new (GTK_TYPE_LABEL,
                                    "label", "Horizontal and Vertical\nPanes",
                                    "justify", GTK_JUSTIFY_CENTER,
@@ -852,8 +852,8 @@ create_progressbar (void)
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
   gtk_widget_set_halign (widget, GTK_ALIGN_FILL);
   gtk_widget_set_valign (widget, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Progress Bar"));
 
   return new_widget_info ("progressbar", vbox, SMALL);
@@ -869,8 +869,8 @@ create_level_bar (void)
   gtk_level_bar_set_value (GTK_LEVEL_BAR (widget), 0.333);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Level Bar"));
 
   return new_widget_info ("levelbar", vbox, SMALL);
@@ -903,8 +903,8 @@ create_scrollbar (void)
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
   gtk_widget_set_halign (widget, GTK_ALIGN_FILL);
   gtk_widget_set_valign (widget, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Scrollbar"));
 
   return new_widget_info ("scrollbar", vbox, SMALL);
@@ -921,8 +921,8 @@ create_spinbutton (void)
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
   gtk_widget_set_halign (widget, GTK_ALIGN_FILL);
   gtk_widget_set_valign (widget, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Spin Button"));
 
   return new_widget_info ("spinbutton", vbox, SMALL);
@@ -936,13 +936,13 @@ create_statusbar (void)
   GtkWidget *vbox;
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox),
                       gtk_label_new ("Status Bar"));
   widget = gtk_statusbar_new ();
   gtk_widget_set_halign (widget, GTK_ALIGN_FILL);
   gtk_statusbar_push (GTK_STATUSBAR (widget), 0, "Hold on...");
 
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   info = new_widget_info ("statusbar", vbox, SMALL);
 
@@ -958,14 +958,14 @@ create_scales (void)
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_box_set_homogeneous (GTK_BOX (hbox), TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox),
+  gtk_box_append (GTK_BOX (hbox),
                      gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL,
                                                 0.0, 100.0, 1.0));
-  gtk_container_add (GTK_CONTAINER (hbox),
+  gtk_box_append (GTK_BOX (hbox),
                      gtk_scale_new_with_range (GTK_ORIENTATION_VERTICAL,
                                                 0.0, 100.0, 1.0));
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox),
                      g_object_new (GTK_TYPE_LABEL,
                                    "label", "Horizontal and Vertical\nScales",
                                    "justify", GTK_JUSTIFY_CENTER,
@@ -984,8 +984,8 @@ create_image (void)
   gtk_widget_set_valign (widget, GTK_ALIGN_CENTER);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Image"));
 
   return new_widget_info ("image", vbox, SMALL);
@@ -1004,8 +1004,8 @@ create_spinner (void)
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 3);
   gtk_widget_set_halign (widget, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (widget, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox),
                      gtk_label_new ("Spinner"));
 
   return new_widget_info ("spinner", vbox, SMALL);
@@ -1022,10 +1022,10 @@ create_volume_button (void)
   gtk_widget_set_size_request (widget, 100, 250);
 
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (widget), box);
+  gtk_box_append (GTK_BOX (widget), box);
 
   button = gtk_volume_button_new ();
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   gtk_scale_button_set_value (GTK_SCALE_BUTTON (button), 33);
   popup = gtk_scale_button_get_popup (GTK_SCALE_BUTTON (button));
@@ -1074,8 +1074,8 @@ create_appchooserbutton (void)
   picker = gtk_app_chooser_button_new ("text/plain");
   gtk_widget_set_halign (picker, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (picker, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), picker);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), picker);
+  gtk_box_append (GTK_BOX (vbox),
                       gtk_label_new ("Application Button"));
 
   return new_widget_info ("appchooserbutton", vbox, SMALL);
@@ -1171,9 +1171,9 @@ create_stack (void)
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 
-  gtk_container_add (GTK_CONTAINER (vbox), switcher);
-  gtk_container_add (GTK_CONTAINER (vbox), stack);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), switcher);
+  gtk_box_append (GTK_BOX (vbox), stack);
+  gtk_box_append (GTK_BOX (vbox),
                       gtk_label_new ("Stack"));
 
   return new_widget_info ("stack", vbox, ASIS);
@@ -1204,9 +1204,9 @@ create_stack_switcher (void)
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 
-  gtk_container_add (GTK_CONTAINER (vbox), switcher);
-  gtk_container_add (GTK_CONTAINER (vbox), stack);
-  gtk_container_add (GTK_CONTAINER (vbox),
+  gtk_box_append (GTK_BOX (vbox), switcher);
+  gtk_box_append (GTK_BOX (vbox), stack);
+  gtk_box_append (GTK_BOX (vbox),
                       gtk_label_new ("Stack Switcher"));
 
   return new_widget_info ("stackswitcher", vbox, ASIS);
@@ -1239,9 +1239,9 @@ create_sidebar (void)
   frame = gtk_frame_new (NULL);
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
 
-  gtk_container_add (GTK_CONTAINER (hbox), sidebar);
-  gtk_container_add (GTK_CONTAINER (hbox), gtk_separator_new (GTK_ORIENTATION_VERTICAL));
-  gtk_container_add (GTK_CONTAINER (hbox), stack);
+  gtk_box_append (GTK_BOX (hbox), sidebar);
+  gtk_box_append (GTK_BOX (hbox), gtk_separator_new (GTK_ORIENTATION_VERTICAL));
+  gtk_box_append (GTK_BOX (hbox), stack);
   gtk_frame_set_child (GTK_FRAME (frame), hbox);
 
   return new_widget_info ("sidebar", frame, ASIS);
@@ -1264,33 +1264,33 @@ create_list_box (void)
   button = gtk_label_new ("List Box");
   gtk_widget_set_hexpand (button, TRUE);
   gtk_widget_set_halign (button, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (row), button);
+  gtk_box_append (GTK_BOX (row), button);
   gtk_list_box_insert (GTK_LIST_BOX (list), row, -1);
   row = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (row), gtk_label_new ("Line One"));
+  gtk_box_append (GTK_BOX (row), gtk_label_new ("Line One"));
   button = gtk_check_button_new ();
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
   gtk_widget_set_hexpand (button, TRUE);
   gtk_widget_set_halign (button, GTK_ALIGN_END);
-  gtk_container_add (GTK_CONTAINER (row), button);
+  gtk_box_append (GTK_BOX (row), button);
   gtk_list_box_insert (GTK_LIST_BOX (list), row, -1);
   gtk_list_box_select_row (GTK_LIST_BOX (list), GTK_LIST_BOX_ROW (gtk_widget_get_parent (row)));
   row = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (row), gtk_label_new ("Line Two"));
+  gtk_box_append (GTK_BOX (row), gtk_label_new ("Line Two"));
   button = gtk_button_new_with_label ("2");
   gtk_widget_set_hexpand (button, TRUE);
   gtk_widget_set_halign (button, GTK_ALIGN_END);
-  gtk_container_add (GTK_CONTAINER (row), button);
+  gtk_box_append (GTK_BOX (row), button);
   gtk_list_box_insert (GTK_LIST_BOX (list), row, -1);
   row = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (row), gtk_label_new ("Line Three"));
+  gtk_box_append (GTK_BOX (row), gtk_label_new ("Line Three"));
   button = gtk_entry_new ();
   gtk_widget_set_hexpand (button, TRUE);
   gtk_widget_set_halign (button, GTK_ALIGN_END);
-  gtk_container_add (GTK_CONTAINER (row), button);
+  gtk_box_append (GTK_BOX (row), button);
   gtk_list_box_insert (GTK_LIST_BOX (list), row, -1);
 
-  gtk_container_add (GTK_CONTAINER (widget), list);
+  gtk_box_append (GTK_BOX (widget), list);
 
   info = new_widget_info ("list-box", widget, MEDIUM);
   info->no_focus = FALSE;
@@ -1315,24 +1315,24 @@ create_flow_box (void)
   gtk_flow_box_set_max_children_per_line (GTK_FLOW_BOX (box), 2);
   gtk_flow_box_set_selection_mode (GTK_FLOW_BOX (box), GTK_SELECTION_BROWSE);
   button = gtk_label_new ("Child One");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
   button = gtk_button_new_with_label ("Child Two");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
   child = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
-  gtk_container_add (GTK_CONTAINER (child), gtk_label_new ("Child Three"));
+  gtk_box_append (GTK_BOX (child), gtk_label_new ("Child Three"));
   button = gtk_check_button_new ();
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
-  gtk_container_add (GTK_CONTAINER (child), button);
-  gtk_container_add (GTK_CONTAINER (box), child);
+  gtk_box_append (GTK_BOX (child), button);
+  gtk_box_append (GTK_BOX (box), child);
   gtk_flow_box_select_child (GTK_FLOW_BOX (box),
                              GTK_FLOW_BOX_CHILD (gtk_widget_get_parent (child)));
 
-  gtk_container_add (GTK_CONTAINER (widget), box);
+  gtk_box_append (GTK_BOX (widget), box);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new ("Flow Box"));
+  gtk_box_append (GTK_BOX (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new ("Flow Box"));
   info = new_widget_info ("flow-box", vbox, ASIS);
   info->no_focus = FALSE;
 
@@ -1349,7 +1349,7 @@ create_gl_area (void)
   widget = gtk_frame_new (NULL);
 
   gears = gtk_gears_new ();
-  gtk_container_add (GTK_CONTAINER (widget), gears);
+  gtk_box_append (GTK_BOX (widget), gears);
  
   info = new_widget_info ("glarea", widget, MEDIUM);
 
diff --git a/examples/application10/exampleappwin.c b/examples/application10/exampleappwin.c
index 16a8658f36..ba0ffd94b6 100644
--- a/examples/application10/exampleappwin.c
+++ b/examples/application10/exampleappwin.c
@@ -69,8 +69,8 @@ update_words (ExampleAppWindow *win)
   GtkWidget *tab, *view, *row;
   GtkTextBuffer *buffer;
   GtkTextIter start, end;
-  GList *children, *l;
   gchar *word, *key;
+  GtkWidget *child;
 
   tab = gtk_stack_get_visible_child (GTK_STACK (win->stack));
 
@@ -100,10 +100,8 @@ update_words (ExampleAppWindow *win)
     }
 
 done:
-  children = gtk_container_get_children (GTK_CONTAINER (win->words));
-  for (l = children; l; l = l->next)
-    gtk_container_remove (GTK_CONTAINER (win->words), GTK_WIDGET (l->data));
-  g_list_free (children);
+  while ((child = gtk_widget_get_first_child (win->words)))
+    gtk_list_box_remove (GTK_LIST_BOX (win->words), child);
 
   g_hash_table_iter_init (&iter, strings);
   while (g_hash_table_iter_next (&iter, (gpointer *)&key, NULL))
@@ -111,7 +109,7 @@ done:
       row = gtk_button_new_with_label (key);
       g_signal_connect (row, "clicked",
                         G_CALLBACK (find_word), win);
-      gtk_container_add (GTK_CONTAINER (win->words), row);
+      gtk_box_append (GTK_BOX (win->words), row);
     }
 
   g_hash_table_unref (strings);
diff --git a/examples/application8/exampleappwin.c b/examples/application8/exampleappwin.c
index f21eeec5cc..79d885c427 100644
--- a/examples/application8/exampleappwin.c
+++ b/examples/application8/exampleappwin.c
@@ -67,8 +67,8 @@ update_words (ExampleAppWindow *win)
   GtkWidget *tab, *view, *row;
   GtkTextBuffer *buffer;
   GtkTextIter start, end;
-  GList *children, *l;
   gchar *word, *key;
+  GtkWidget *child;
 
   tab = gtk_stack_get_visible_child (GTK_STACK (win->stack));
 
@@ -98,10 +98,8 @@ update_words (ExampleAppWindow *win)
     }
 
 done:
-  children = gtk_container_get_children (GTK_CONTAINER (win->words));
-  for (l = children; l; l = l->next)
-    gtk_container_remove (GTK_CONTAINER (win->words), GTK_WIDGET (l->data));
-  g_list_free (children);
+  while ((child = gtk_widget_get_first_child (win->words)))
+    gtk_list_box_remove (GTK_LIST_BOX (win->words), child);
 
   g_hash_table_iter_init (&iter, strings);
   while (g_hash_table_iter_next (&iter, (gpointer *)&key, NULL))
@@ -109,7 +107,7 @@ done:
       row = gtk_button_new_with_label (key);
       g_signal_connect (row, "clicked",
                         G_CALLBACK (find_word), win);
-      gtk_container_add (GTK_CONTAINER (win->words), row);
+      gtk_box_append (GTK_BOX (win->words), row);
     }
 
   g_hash_table_unref (strings);
diff --git a/examples/application9/exampleappwin.c b/examples/application9/exampleappwin.c
index 725ee67df1..8ef660dd2e 100644
--- a/examples/application9/exampleappwin.c
+++ b/examples/application9/exampleappwin.c
@@ -69,8 +69,8 @@ update_words (ExampleAppWindow *win)
   GtkWidget *tab, *view, *row;
   GtkTextBuffer *buffer;
   GtkTextIter start, end;
-  GList *children, *l;
   gchar *word, *key;
+  GtkWidget *child;
 
   tab = gtk_stack_get_visible_child (GTK_STACK (win->stack));
 
@@ -100,10 +100,8 @@ update_words (ExampleAppWindow *win)
     }
 
 done:
-  children = gtk_container_get_children (GTK_CONTAINER (win->words));
-  for (l = children; l; l = l->next)
-    gtk_container_remove (GTK_CONTAINER (win->words), GTK_WIDGET (l->data));
-  g_list_free (children);
+  while ((child = gtk_widget_get_first_child (win->words)))
+    gtk_list_box_remove (GTK_LIST_BOX (win->words), child);
 
   g_hash_table_iter_init (&iter, strings);
   while (g_hash_table_iter_next (&iter, (gpointer *)&key, NULL))
@@ -111,7 +109,7 @@ done:
       row = gtk_button_new_with_label (key);
       g_signal_connect (row, "clicked",
                         G_CALLBACK (find_word), win);
-      gtk_container_add (GTK_CONTAINER (win->words), row);
+      gtk_box_append (GTK_BOX (win->words), row);
     }
 
   g_hash_table_unref (strings);
diff --git a/examples/bp/bloatpad.c b/examples/bp/bloatpad.c
index 0da7402374..c2ea00b07f 100644
--- a/examples/bp/bloatpad.c
+++ b/examples/bp/bloatpad.c
@@ -228,27 +228,27 @@ new_window (GApplication *app,
   button = gtk_toggle_button_new ();
   gtk_button_set_icon_name (GTK_BUTTON (button), "format-justify-left");
   gtk_actionable_set_detailed_action_name (GTK_ACTIONABLE (button), "win.justify::left");
-  gtk_container_add (GTK_CONTAINER (toolbar), button);
+  gtk_box_append (GTK_BOX (toolbar), button);
 
   button = gtk_toggle_button_new ();
   gtk_button_set_icon_name (GTK_BUTTON (button), "format-justify-center");
   gtk_actionable_set_detailed_action_name (GTK_ACTIONABLE (button), "win.justify::center");
-  gtk_container_add (GTK_CONTAINER (toolbar), button);
+  gtk_box_append (GTK_BOX (toolbar), button);
 
   button = gtk_toggle_button_new ();
   gtk_button_set_icon_name (GTK_BUTTON (button), "format-justify-right");
   gtk_actionable_set_detailed_action_name (GTK_ACTIONABLE (button), "win.justify::right");
-  gtk_container_add (GTK_CONTAINER (toolbar), button);
+  gtk_box_append (GTK_BOX (toolbar), button);
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
   gtk_widget_set_halign (box, GTK_ALIGN_END);
   label = gtk_label_new ("Fullscreen:");
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
   sw = gtk_switch_new ();
   gtk_widget_set_valign (sw, GTK_ALIGN_CENTER);
   gtk_actionable_set_action_name (GTK_ACTIONABLE (sw), "win.fullscreen");
-  gtk_container_add (GTK_CONTAINER (box), sw);
-  gtk_container_add (GTK_CONTAINER (toolbar), box);
+  gtk_box_append (GTK_BOX (box), sw);
+  gtk_box_append (GTK_BOX (toolbar), box);
 
   gtk_grid_attach (GTK_GRID (grid), toolbar, 0, 0, 1, 1);
 
@@ -406,12 +406,12 @@ edit_accels (GSimpleAction *action,
   gtk_window_set_application (GTK_WINDOW (dialog), app);
   actions = gtk_application_list_action_descriptions (app);
   combo = gtk_combo_box_text_new ();
-  gtk_container_add (GTK_CONTAINER (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), combo);
+  gtk_box_append (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), combo);
   for (i = 0; actions[i]; i++)
     gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo), actions[i], actions[i]);
   g_signal_connect (combo, "changed", G_CALLBACK (combo_changed), dialog);
   entry = gtk_entry_new ();
-  gtk_container_add (GTK_CONTAINER (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), entry);
+  gtk_box_append (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), entry);
   gtk_dialog_add_button (GTK_DIALOG (dialog), "Close", GTK_RESPONSE_CLOSE);
   gtk_dialog_add_button (GTK_DIALOG (dialog), "Set", GTK_RESPONSE_APPLY);
   g_signal_connect (dialog, "response", G_CALLBACK (response), dialog);
diff --git a/examples/hello-world.c b/examples/hello-world.c
index 5ee7062788..f4c058e978 100644
--- a/examples/hello-world.c
+++ b/examples/hello-world.c
@@ -25,7 +25,7 @@ activate (GtkApplication *app,
   button = gtk_button_new_with_label ("Hello World");
   g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (gtk_window_destroy), window);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   gtk_widget_show (window);
 }
diff --git a/examples/search-bar.c b/examples/search-bar.c
index c39dc8c140..5790852957 100644
--- a/examples/search-bar.c
+++ b/examples/search-bar.c
@@ -23,10 +23,10 @@ activate_cb (GtkApplication *app,
 
   entry = gtk_search_entry_new ();
   gtk_widget_set_hexpand (entry, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), entry);
+  gtk_box_append (GTK_BOX (box), entry);
 
   menu_button = gtk_menu_button_new ();
-  gtk_container_add (GTK_CONTAINER (box), menu_button);
+  gtk_box_append (GTK_BOX (box), menu_button);
 
   gtk_search_bar_connect_entry (GTK_SEARCH_BAR (search_bar), GTK_EDITABLE (entry));
   gtk_search_bar_set_key_capture_widget (GTK_SEARCH_BAR (search_bar), window);
diff --git a/gtk/a11y/gtklabelaccessible.c b/gtk/a11y/gtklabelaccessible.c
index 9ac1cd5a13..2048a7c0b3 100644
--- a/gtk/a11y/gtklabelaccessible.c
+++ b/gtk/a11y/gtklabelaccessible.c
@@ -445,29 +445,6 @@ gtk_label_accessible_ref_relation_set (AtkObject *obj)
           AtkObject *accessible_array[1];
           AtkRelation* relation;
 
-          if (!gtk_widget_get_can_focus (mnemonic_widget))
-            {
-            /*
-             * Handle the case where a GtkFileChooserButton is specified
-             * as the mnemonic widget. use the combobox which is a child of the
-             * GtkFileChooserButton as the mnemonic widget. See bug #359843.
-             */
-             if (GTK_IS_BOX (mnemonic_widget))
-               {
-                  GList *list, *tmpl;
-
-                  list = gtk_container_get_children (GTK_CONTAINER (mnemonic_widget));
-                  if (g_list_length (list) == 2)
-                    {
-                      tmpl = g_list_last (list);
-                      if (GTK_IS_COMBO_BOX(tmpl->data))
-                        {
-                          mnemonic_widget = GTK_WIDGET(tmpl->data);
-                        }
-                    }
-                  g_list_free (list);
-                }
-            }
           accessible_array[0] = gtk_widget_get_accessible (mnemonic_widget);
           relation = atk_relation_new (accessible_array, 1,
                                        ATK_RELATION_LABEL_FOR);
diff --git a/gtk/a11y/gtknotebookpageaccessible.c b/gtk/a11y/gtknotebookpageaccessible.c
index dcdfe16f03..09d089ebe3 100644
--- a/gtk/a11y/gtknotebookpageaccessible.c
+++ b/gtk/a11y/gtknotebookpageaccessible.c
@@ -36,31 +36,25 @@ G_DEFINE_TYPE_WITH_CODE (GtkNotebookPageAccessible, gtk_notebook_page_accessible
 
 
 static GtkWidget *
-find_label_child (GtkContainer *container)
+find_label_child (GtkWidget *widget)
 {
-  GList *children, *tmp_list;
   GtkWidget *child;
 
-  children = gtk_container_get_children (container);
-
-  child = NULL;
-  for (tmp_list = children; tmp_list != NULL; tmp_list = tmp_list->next)
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
     {
-      if (GTK_IS_LABEL (tmp_list->data))
-        {
-          child = GTK_WIDGET (tmp_list->data);
-          break;
-        }
-      else if (GTK_IS_CONTAINER (tmp_list->data))
+      if (GTK_IS_LABEL (child))
+        return child;
+      else
         {
-          child = find_label_child (GTK_CONTAINER (tmp_list->data));
-          if (child)
-            break;
+          GtkWidget *w = find_label_child (child);
+          if (w)
+            return w;
         }
     }
-  g_list_free (children);
 
-  return child;
+  return NULL;
 }
 
 static GtkWidget *
@@ -81,10 +75,7 @@ get_label_from_notebook_page (GtkNotebookPageAccessible *page)
   if (GTK_IS_LABEL (child))
     return child;
 
-  if (GTK_IS_CONTAINER (child))
-    child = find_label_child (GTK_CONTAINER (child));
-
-  return child;
+  return find_label_child (child);
 }
 
 static const gchar *
diff --git a/gtk/a11y/gtkscrolledwindowaccessible.c b/gtk/a11y/gtkscrolledwindowaccessible.c
index e18a5980ae..fc2822686e 100644
--- a/gtk/a11y/gtkscrolledwindowaccessible.c
+++ b/gtk/a11y/gtkscrolledwindowaccessible.c
@@ -99,12 +99,11 @@ gtk_scrolled_window_accessible_initialize (AtkObject *obj,
   obj->role = ATK_ROLE_SCROLL_PANE;
 }
 
-static gint
+static int
 gtk_scrolled_window_accessible_get_n_children (AtkObject *object)
 {
   GtkWidget *widget;
   GtkScrolledWindow *scrolled_window;
-  GList *children;
   gint n_children;
 
   widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (object));
@@ -113,10 +112,9 @@ gtk_scrolled_window_accessible_get_n_children (AtkObject *object)
 
   scrolled_window = GTK_SCROLLED_WINDOW (widget);
 
-  children = gtk_container_get_children (GTK_CONTAINER (widget));
-  n_children = g_list_length (children);
-  g_list_free (children);
-
+  n_children = 0;
+  if (gtk_scrolled_window_get_child (scrolled_window))
+    n_children++;
   if (gtk_scrolled_window_get_hscrollbar (scrolled_window))
     n_children++;
   if (gtk_scrolled_window_get_vscrollbar (scrolled_window))
@@ -132,9 +130,8 @@ gtk_scrolled_window_accessible_ref_child (AtkObject *obj,
   GtkWidget *widget;
   GtkScrolledWindow *scrolled_window;
   GtkWidget *hscrollbar, *vscrollbar;
-  GList *children, *tmp_list;
-  gint n_children;
-  AtkObject  *accessible = NULL;
+  GtkWidget *c;
+  GtkWidget *chosen = NULL;
 
   g_return_val_if_fail (child >= 0, NULL);
 
@@ -143,35 +140,21 @@ gtk_scrolled_window_accessible_ref_child (AtkObject *obj,
     return NULL;
 
   scrolled_window = GTK_SCROLLED_WINDOW (widget);
+  c = gtk_scrolled_window_get_child (scrolled_window);
   hscrollbar = gtk_scrolled_window_get_hscrollbar (scrolled_window);
   vscrollbar = gtk_scrolled_window_get_vscrollbar (scrolled_window);
 
-  children = gtk_container_get_children (GTK_CONTAINER (widget));
-  n_children = g_list_length (children);
-
-  if (child == n_children)
-    {
-      if (gtk_scrolled_window_get_hscrollbar (scrolled_window))
-        accessible = gtk_widget_get_accessible (hscrollbar);
-      else if (gtk_scrolled_window_get_vscrollbar (scrolled_window))
-        accessible = gtk_widget_get_accessible (vscrollbar);
-    }
-  else if (child == n_children + 1 &&
-           gtk_scrolled_window_get_hscrollbar (scrolled_window) &&
-           gtk_scrolled_window_get_vscrollbar (scrolled_window))
-    accessible = gtk_widget_get_accessible (vscrollbar);
-  else if (child < n_children)
-    {
-      tmp_list = g_list_nth (children, child);
-      if (tmp_list)
-        accessible = gtk_widget_get_accessible (GTK_WIDGET (tmp_list->data));
-    }
+  if (child == 2)
+    chosen = vscrollbar;
+  else if (child == 1)
+    chosen = c ? hscrollbar : vscrollbar;
+  else if (child == 0)
+    chosen = c ? c : (hscrollbar ? hscrollbar : vscrollbar);
 
-  g_list_free (children);
-  if (accessible)
-    g_object_ref (accessible);
+  if (chosen)
+    return g_object_ref (gtk_widget_get_accessible (chosen));
 
-  return accessible;
+  return NULL;
 }
 
 static void
diff --git a/gtk/a11y/gtkwidgetaccessible.c b/gtk/a11y/gtkwidgetaccessible.c
index 43b9c8cb9a..0587a33973 100644
--- a/gtk/a11y/gtkwidgetaccessible.c
+++ b/gtk/a11y/gtkwidgetaccessible.c
@@ -399,7 +399,7 @@ gtk_widget_accessible_get_index_in_parent (AtkObject *accessible)
   GtkWidget *widget;
   GtkWidget *parent_widget;
   gint index;
-  GList *children;
+  GtkWidget *ch;
 
   widget = gtk_accessible_get_widget (GTK_ACCESSIBLE (accessible));
 
@@ -436,24 +436,13 @@ gtk_widget_accessible_get_index_in_parent (AtkObject *accessible)
     }
 
   parent_widget = gtk_widget_get_parent (widget);
-  if (GTK_IS_CONTAINER (parent_widget))
+  for (ch = gtk_widget_get_first_child (parent_widget), index = 0;
+       ch != NULL;
+       ch = gtk_widget_get_next_sibling (ch), index++)
     {
-      children = gtk_container_get_children (GTK_CONTAINER (parent_widget));
-      index = g_list_index (children, widget);
-      g_list_free (children);
+      if (ch == widget)
+        break;
     }
-  else if (GTK_IS_WIDGET (parent_widget))
-    {
-      GtkWidget *child;
-
-      for (child = gtk_widget_get_first_child (parent_widget), index = 0; child; child = 
gtk_widget_get_next_sibling (child), index++)
-        {
-          if (child == widget)
-            break;
-        }
-    }
-  else
-    index = -1;
 
   return index;
 }
diff --git a/gtk/gtkactionbar.c b/gtk/gtkactionbar.c
index 523b66860d..12e541fae2 100644
--- a/gtk/gtkactionbar.c
+++ b/gtk/gtkactionbar.c
@@ -226,7 +226,7 @@ void
 gtk_action_bar_pack_start (GtkActionBar *action_bar,
                            GtkWidget    *child)
 {
-  gtk_container_add (GTK_CONTAINER (action_bar->start_box), child);
+  gtk_box_append (GTK_BOX (action_bar->start_box), child);
 }
 
 /**
@@ -256,9 +256,9 @@ gtk_action_bar_remove (GtkActionBar *action_bar,
                        GtkWidget    *child)
 {
   if (gtk_widget_get_parent (child) == action_bar->start_box)
-    gtk_container_remove (GTK_CONTAINER (action_bar->start_box), child);
+    gtk_box_remove (GTK_BOX (action_bar->start_box), child);
   else if (gtk_widget_get_parent (child) == action_bar->end_box)
-    gtk_container_remove (GTK_CONTAINER (action_bar->end_box), child);
+    gtk_box_remove (GTK_BOX (action_bar->end_box), child);
   else if (child == gtk_center_box_get_center_widget (GTK_CENTER_BOX (action_bar->center_box)))
     gtk_center_box_set_center_widget (GTK_CENTER_BOX (action_bar->center_box), NULL);
   else
diff --git a/gtk/gtkappchooserdialog.c b/gtk/gtkappchooserdialog.c
index be0e9c6c4d..3a6d5a97e3 100644
--- a/gtk/gtkappchooserdialog.c
+++ b/gtk/gtkappchooserdialog.c
@@ -317,7 +317,7 @@ construct_appchooser_widget (GtkAppChooserDialog *self)
   /* Need to build the appchooser widget after, because of the content-type construct-only property */
   self->app_chooser_widget = gtk_app_chooser_widget_new (self->content_type);
   gtk_widget_set_vexpand (self->app_chooser_widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (self->inner_box), self->app_chooser_widget);
+  gtk_box_append (GTK_BOX (self->inner_box), self->app_chooser_widget);
 
   g_signal_connect (self->app_chooser_widget, "application-selected",
                     G_CALLBACK (widget_application_selected_cb), self);
@@ -327,10 +327,10 @@ construct_appchooser_widget (GtkAppChooserDialog *self)
                     G_CALLBACK (widget_notify_for_button_cb), self);
 
   /* Add the custom button to the new appchooser */
-  gtk_container_add (GTK_CONTAINER (self->inner_box),
+  gtk_box_append (GTK_BOX (self->inner_box),
                      self->show_more_button);
 
-  gtk_container_add (GTK_CONTAINER (self->inner_box),
+  gtk_box_append (GTK_BOX (self->inner_box),
                      self->software_button);
 
   info = gtk_app_chooser_get_app_info (GTK_APP_CHOOSER (self->app_chooser_widget));
diff --git a/gtk/gtkassistant.c b/gtk/gtkassistant.c
index 55ccdce579..3f890c9552 100644
--- a/gtk/gtkassistant.c
+++ b/gtk/gtkassistant.c
@@ -408,21 +408,25 @@ add_to_header_bar (GtkAssistant *assistant,
 static void
 add_action_widgets (GtkAssistant *assistant)
 {
-  GList *children;
-  GList *l;
+  GList *children, *l;
+  GtkWidget *child;
 
   if (assistant->use_header_bar)
     {
-      children = gtk_container_get_children (GTK_CONTAINER (assistant->action_area));
+      children = NULL;
+      for (child = gtk_widget_get_last_child (assistant->action_area);
+           child != NULL;
+           child = gtk_widget_get_prev_sibling (child))
+        children = g_list_prepend (children, child);
       for (l = children; l != NULL; l = l->next)
         {
-          GtkWidget *child = l->data;
           gboolean has_default;
 
+          child = l->data;
           has_default = gtk_widget_has_default (child);
 
           g_object_ref (child);
-          gtk_container_remove (GTK_CONTAINER (assistant->action_area), child);
+          gtk_box_remove (GTK_BOX (assistant->action_area), child);
           add_to_header_bar (assistant, child);
           g_object_unref (child);
 
@@ -1129,8 +1133,8 @@ assistant_remove_page (GtkAssistant *assistant,
   gtk_size_group_remove_widget (assistant->title_size_group, page_info->regular_title);
   gtk_size_group_remove_widget (assistant->title_size_group, page_info->current_title);
 
-  gtk_container_remove (GTK_CONTAINER (assistant->sidebar), page_info->regular_title);
-  gtk_container_remove (GTK_CONTAINER (assistant->sidebar), page_info->current_title);
+  gtk_box_remove (GTK_BOX (assistant->sidebar), page_info->regular_title);
+  gtk_box_remove (GTK_BOX (assistant->sidebar), page_info->current_title);
 
   assistant->pages = g_list_remove_link (assistant->pages, element);
   assistant->visited_pages = g_slist_remove_all (assistant->visited_pages, page_info);
@@ -1166,9 +1170,13 @@ gtk_assistant_init (GtkAssistant *assistant)
   if (alternative_button_order (assistant))
     {
       GList *buttons, *l;
+      GtkWidget *child;
 
-      /* Reverse the action area children for the alternative button order setting */
-      buttons = gtk_container_get_children (GTK_CONTAINER (assistant->action_area));
+      buttons = NULL;
+      for (child = gtk_widget_get_last_child (assistant->action_area);
+           child != NULL;
+           child = gtk_widget_get_prev_sibling (child))
+        buttons = g_list_prepend (buttons, child);
 
       for (l = buttons; l; l = l->next)
         gtk_box_reorder_child_after (GTK_BOX (assistant->action_area), GTK_WIDGET (l->data), NULL);
@@ -1815,7 +1823,7 @@ add_to_action_area (GtkAssistant *assistant,
 {
   gtk_widget_set_valign (child, GTK_ALIGN_BASELINE);
 
-  gtk_container_add (GTK_CONTAINER (assistant->action_area), child);
+  gtk_box_append (GTK_BOX (assistant->action_area), child);
 }
 
 /**
@@ -1868,7 +1876,7 @@ gtk_assistant_remove_action_widget (GtkAssistant *assistant,
         update_actions_size (assistant);
     }
 
-  gtk_container_remove (GTK_CONTAINER (assistant->action_area), child);
+  gtk_box_remove (GTK_BOX (assistant->action_area), child);
 }
 
 /**
diff --git a/gtk/gtkcalendar.c b/gtk/gtkcalendar.c
index ff6b0569ae..0d0cb83b3f 100644
--- a/gtk/gtkcalendar.c
+++ b/gtk/gtkcalendar.c
@@ -596,12 +596,12 @@ gtk_calendar_init (GtkCalendar *calendar)
   calendar->arrow_widgets[3] = gtk_button_new_from_icon_name ("pan-end-symbolic");
   g_signal_connect_swapped (calendar->arrow_widgets[3], "clicked", G_CALLBACK (calendar_set_year_next), 
calendar);
 
-  gtk_container_add (GTK_CONTAINER (calendar->header_box), calendar->arrow_widgets[0]);
-  gtk_container_add (GTK_CONTAINER (calendar->header_box), calendar->month_name_stack);
-  gtk_container_add (GTK_CONTAINER (calendar->header_box), calendar->arrow_widgets[1]);
-  gtk_container_add (GTK_CONTAINER (calendar->header_box), calendar->arrow_widgets[2]);
-  gtk_container_add (GTK_CONTAINER (calendar->header_box), calendar->year_label);
-  gtk_container_add (GTK_CONTAINER (calendar->header_box), calendar->arrow_widgets[3]);
+  gtk_box_append (GTK_BOX (calendar->header_box), calendar->arrow_widgets[0]);
+  gtk_box_append (GTK_BOX (calendar->header_box), calendar->month_name_stack);
+  gtk_box_append (GTK_BOX (calendar->header_box), calendar->arrow_widgets[1]);
+  gtk_box_append (GTK_BOX (calendar->header_box), calendar->arrow_widgets[2]);
+  gtk_box_append (GTK_BOX (calendar->header_box), calendar->year_label);
+  gtk_box_append (GTK_BOX (calendar->header_box), calendar->arrow_widgets[3]);
 
   gtk_widget_set_parent (calendar->header_box, GTK_WIDGET (calendar));
 
diff --git a/gtk/gtkcolorchooserwidget.c b/gtk/gtkcolorchooserwidget.c
index ebfe4d8dc9..938af7632e 100644
--- a/gtk/gtkcolorchooserwidget.c
+++ b/gtk/gtkcolorchooserwidget.c
@@ -170,15 +170,18 @@ save_custom_colors (GtkColorChooserWidget *cc)
   GVariantBuilder builder;
   GVariant *variant;
   GdkRGBA color;
-  GList *children, *l;
   GtkWidget *child;
+  gboolean first;
 
   g_variant_builder_init (&builder, G_VARIANT_TYPE ("a(dddd)"));
 
-  children = gtk_container_get_children (GTK_CONTAINER (cc->custom));
-  for (l = g_list_nth (children, 1); l != NULL; l = l->next)
+  for (child = gtk_widget_get_first_child (cc->custom), first = TRUE;
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child), first = FALSE)
     {
-      child = l->data;
+      if (first)
+        continue;
+
       if (gtk_color_swatch_get_rgba (GTK_COLOR_SWATCH (child), &color))
         {
           double red, green, blue, alpha;
@@ -193,8 +196,6 @@ save_custom_colors (GtkColorChooserWidget *cc)
 
   variant = g_variant_builder_end (&builder);
   g_settings_set_value (cc->settings, "custom-colors", variant);
-
-  g_list_free (children);
 }
 
 static void
@@ -210,7 +211,6 @@ static void
 gtk_color_chooser_widget_set_use_alpha (GtkColorChooserWidget *cc,
                                         gboolean               use_alpha)
 {
-  GList *palettes, *p;
   GtkWidget *child;
   GtkWidget *grid;
 
@@ -220,11 +220,10 @@ gtk_color_chooser_widget_set_use_alpha (GtkColorChooserWidget *cc,
   cc->use_alpha = use_alpha;
   gtk_color_chooser_set_use_alpha (GTK_COLOR_CHOOSER (cc->editor), use_alpha);
 
-  palettes = gtk_container_get_children (GTK_CONTAINER (cc->palette));
-  for (p = palettes; p; p = p->next)
+  for (grid = gtk_widget_get_first_child (cc->palette);
+       grid != NULL;
+       grid = gtk_widget_get_next_sibling (grid))
     {
-      grid = p->data;
-
       for (child = gtk_widget_get_first_child (grid);
            child != NULL;
            child = gtk_widget_get_next_sibling (child))
@@ -233,7 +232,6 @@ gtk_color_chooser_widget_set_use_alpha (GtkColorChooserWidget *cc,
             gtk_color_swatch_set_use_alpha (GTK_COLOR_SWATCH (child), use_alpha);
         }
     }
-  g_list_free (palettes);
 
   gtk_widget_queue_draw (GTK_WIDGET (cc));
   g_object_notify (G_OBJECT (cc), "use-alpha");
@@ -313,7 +311,7 @@ remove_palette (GtkColorChooserWidget *cc)
       widget = l->data;
       if (widget == cc->custom_label || widget == cc->custom)
         continue;
-      gtk_container_remove (GTK_CONTAINER (cc->palette), widget);
+      gtk_box_remove (GTK_BOX (cc->palette), widget);
     }
   g_list_free (children);
 }
@@ -343,7 +341,7 @@ add_palette (GtkColorChooserWidget  *cc,
   gtk_widget_set_margin_bottom (grid, 12);
   gtk_grid_set_row_spacing (GTK_GRID (grid), 2);
   gtk_grid_set_column_spacing (GTK_GRID (grid), 4);
-  gtk_container_add (GTK_CONTAINER (cc->palette), grid);
+  gtk_box_append (GTK_BOX (cc->palette), grid);
 
   left = 0;
   right = colors_per_line - 1;
@@ -558,11 +556,11 @@ gtk_color_chooser_widget_init (GtkColorChooserWidget *cc)
   /* translators: label for the custom section in the color chooser */
   cc->custom_label = label = gtk_label_new (_("Custom"));
   gtk_widget_set_halign (label, GTK_ALIGN_START);
-  gtk_container_add (GTK_CONTAINER (cc->palette), label);
+  gtk_box_append (GTK_BOX (cc->palette), label);
 
   cc->custom = box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
   g_object_set (box, "margin-top", 12, NULL);
-  gtk_container_add (GTK_CONTAINER (cc->palette), box);
+  gtk_box_append (GTK_BOX (cc->palette), box);
 
   cc->button = button = gtk_color_swatch_new ();
   gtk_widget_set_name (button, "add-color-button");
@@ -572,7 +570,7 @@ gtk_color_chooser_widget_init (GtkColorChooserWidget *cc)
   connect_button_signals (button, cc);
   gtk_color_swatch_set_icon (GTK_COLOR_SWATCH (button), "list-add-symbolic");
   gtk_color_swatch_set_selectable (GTK_COLOR_SWATCH (button), FALSE);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   cc->settings = g_settings_new ("org.gtk.gtk4.Settings.ColorChooser");
   variant = g_settings_get_value (cc->settings, I_("custom-colors"));
@@ -598,7 +596,7 @@ gtk_color_chooser_widget_init (GtkColorChooserWidget *cc)
       g_free (text);
       g_free (name);
       connect_custom_signals (p, cc);
-      gtk_container_add (GTK_CONTAINER (box), p);
+      gtk_box_append (GTK_BOX (box), p);
 
       if (i == 8)
         break;
@@ -787,10 +785,16 @@ static void
 add_custom_color (GtkColorChooserWidget *cc,
                   const GdkRGBA         *color)
 {
-  GtkWidget *p;
+  GtkWidget *widget;
   GList *children;
+  GtkWidget *p;
+
+  children = NULL;
+  for (widget = gtk_widget_get_first_child (cc->custom);
+       widget != NULL;
+       widget = gtk_widget_get_next_sibling (widget))
+    children = g_list_prepend (children, widget);
 
-  children = gtk_container_get_children (GTK_CONTAINER (cc->custom));
   if (g_list_length (children) >= 9)
     {
       GtkWidget *last = gtk_widget_get_last_child (cc->custom);
@@ -798,7 +802,7 @@ add_custom_color (GtkColorChooserWidget *cc,
       if (last == (GtkWidget *)cc->current)
         cc->current = NULL;
 
-      gtk_container_remove (GTK_CONTAINER (cc->custom), last);
+      gtk_box_remove (GTK_BOX (cc->custom), last);
     }
   g_list_free (children);
 
@@ -819,15 +823,15 @@ gtk_color_chooser_widget_set_rgba (GtkColorChooser *chooser,
                                    const GdkRGBA   *color)
 {
   GtkColorChooserWidget *cc = GTK_COLOR_CHOOSER_WIDGET (chooser);
-  GList *palettes, *p;
   GtkWidget *swatch;
   GtkWidget *w;
+
   GdkRGBA c;
 
-  palettes = gtk_container_get_children (GTK_CONTAINER (cc->palette));
-  for (p = palettes; p; p = p->next)
+  for (w = gtk_widget_get_first_child (cc->palette);
+       w != NULL;
+       w = gtk_widget_get_next_sibling (w))
     {
-      w = p->data;
       if (!GTK_IS_GRID (w) && !GTK_IS_BOX (w))
         continue;
 
@@ -841,12 +845,10 @@ gtk_color_chooser_widget_set_rgba (GtkColorChooser *chooser,
           if (gdk_rgba_equal (color, &c))
             {
               select_swatch (cc, GTK_COLOR_SWATCH (swatch));
-              g_list_free (palettes);
               return;
             }
         }
     }
-  g_list_free (palettes);
 
   add_custom_color (cc, color);
 }
diff --git a/gtk/gtkcombobox.c b/gtk/gtkcombobox.c
index 266e1d1afe..5ab02aa0a3 100644
--- a/gtk/gtkcombobox.c
+++ b/gtk/gtkcombobox.c
@@ -1138,7 +1138,7 @@ gtk_combo_box_remove (GtkComboBox *combo_box,
                                               combo_box);
     }
 
-  gtk_container_remove (GTK_CONTAINER (priv->box), widget);
+  gtk_box_remove (GTK_BOX (priv->box), widget);
 
   priv->child = NULL;
 
diff --git a/gtk/gtkcustompaperunixdialog.c b/gtk/gtkcustompaperunixdialog.c
index e664c595cd..5948cdeb27 100644
--- a/gtk/gtkcustompaperunixdialog.c
+++ b/gtk/gtkcustompaperunixdialog.c
@@ -553,7 +553,7 @@ new_unit_widget (GtkCustomPaperUnixDialog *dialog,
   else
     gtk_spin_button_set_digits (GTK_SPIN_BUTTON (button), 1);
 
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   gtk_widget_show (button);
 
   data->spin_button = button;
@@ -567,7 +567,7 @@ new_unit_widget (GtkCustomPaperUnixDialog *dialog,
     label = gtk_label_new (_("mm"));
   gtk_widget_set_valign (label, GTK_ALIGN_BASELINE);
 
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
   gtk_widget_show (label);
   gtk_label_set_mnemonic_widget (GTK_LABEL (mnemonic_label), button);
 
@@ -1012,18 +1012,18 @@ populate_dialog (GtkCustomPaperUnixDialog *dialog)
   gtk_widget_set_margin_end (hbox, 20);
   gtk_widget_set_margin_top (hbox, 20);
   gtk_widget_set_margin_bottom (hbox, 20);
-  gtk_container_add (GTK_CONTAINER (content_area), hbox);
+  gtk_box_append (GTK_BOX (content_area), hbox);
   gtk_widget_show (hbox);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
   gtk_widget_show (vbox);
 
   scrolled = gtk_scrolled_window_new (NULL, NULL);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled),
                                   GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
   gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (scrolled), TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), scrolled);
+  gtk_box_append (GTK_BOX (vbox), scrolled);
   gtk_widget_show (scrolled);
 
   treeview = gtk_tree_view_new_with_model (GTK_TREE_MODEL (priv->custom_paper_list));
@@ -1052,23 +1052,23 @@ populate_dialog (GtkCustomPaperUnixDialog *dialog)
 
   gtk_widget_add_css_class (toolbar, "linked");
 
-  gtk_container_add (GTK_CONTAINER (vbox), toolbar);
+  gtk_box_append (GTK_BOX (vbox), toolbar);
 
   button = gtk_button_new_from_icon_name ("list-add-symbolic");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (add_custom_paper), dialog);
 
-  gtk_container_add (GTK_CONTAINER (toolbar), button);
+  gtk_box_append (GTK_BOX (toolbar), button);
 
   button = gtk_button_new_from_icon_name ("list-remove-symbolic");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (remove_custom_paper), dialog);
 
-  gtk_container_add (GTK_CONTAINER (toolbar), button);
+  gtk_box_append (GTK_BOX (toolbar), button);
 
   user_units = _gtk_print_get_default_user_units ();
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 18);
   priv->values_box = vbox;
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
   gtk_widget_show (vbox);
 
   grid = gtk_grid_new ();
@@ -1100,7 +1100,7 @@ populate_dialog (GtkCustomPaperUnixDialog *dialog)
 
   frame = wrap_in_frame (_("Paper Size"), grid);
   gtk_widget_show (grid);
-  gtk_container_add (GTK_CONTAINER (vbox), frame);
+  gtk_box_append (GTK_BOX (vbox), frame);
   gtk_widget_show (frame);
 
   grid = gtk_grid_new ();
@@ -1173,7 +1173,7 @@ populate_dialog (GtkCustomPaperUnixDialog *dialog)
                                      NULL, NULL);
 
   gtk_combo_box_set_active (GTK_COMBO_BOX (combo), 0);
-  gtk_container_add (GTK_CONTAINER (hbox), combo);
+  gtk_box_append (GTK_BOX (hbox), combo);
   gtk_widget_show (combo);
 
   g_signal_connect_swapped (combo, "changed",
@@ -1181,7 +1181,7 @@ populate_dialog (GtkCustomPaperUnixDialog *dialog)
 
   frame = wrap_in_frame (_("Paper Margins"), grid);
   gtk_widget_show (grid);
-  gtk_container_add (GTK_CONTAINER (vbox), frame);
+  gtk_box_append (GTK_BOX (vbox), frame);
   gtk_widget_show (frame);
 
   update_custom_widgets_from_list (dialog);
diff --git a/gtk/gtkdialog.c b/gtk/gtkdialog.c
index 64cd525586..ca0e67ed21 100644
--- a/gtk/gtkdialog.c
+++ b/gtk/gtkdialog.c
@@ -123,7 +123,7 @@
  *
  *  // Add the label, and show everything we’ve added
  *
- *  gtk_container_add (GTK_CONTAINER (content_area), label);
+ *  gtk_box_append (GTK_BOX (content_area), label);
  *  gtk_widget_show (dialog);
  * }
  * ]|
@@ -379,7 +379,7 @@ add_to_action_area (GtkDialog *dialog,
   GtkDialogPrivate *priv = gtk_dialog_get_instance_private (dialog);
 
   gtk_widget_set_valign (child, GTK_ALIGN_BASELINE);
-  gtk_container_add (GTK_CONTAINER (priv->action_area), child);
+  gtk_box_append (GTK_BOX (priv->action_area), child);
   apply_response_for_action_area (dialog, child, response_id);
 }
 
@@ -432,21 +432,28 @@ gtk_dialog_constructed (GObject *object)
   if (priv->use_header_bar)
     {
       GList *children, *l;
+      GtkWidget *child;
+
+      children = NULL;
+      for (child = gtk_widget_get_first_child (priv->action_area);
+           child != NULL;
+           child = gtk_widget_get_next_sibling (child))
+        children = g_list_append (children, child);
 
-      children = gtk_container_get_children (GTK_CONTAINER (priv->action_area));
       for (l = children; l != NULL; l = l->next)
         {
-          GtkWidget *child = l->data;
           gboolean has_default;
           ResponseData *rd;
           gint response_id;
 
+          child = l->data;
+
           has_default = gtk_widget_has_default (child);
           rd = get_response_data (child, FALSE);
           response_id = rd ? rd->response_id : GTK_RESPONSE_NONE;
 
           g_object_ref (child);
-          gtk_container_remove (GTK_CONTAINER (priv->action_area), child);
+          gtk_box_remove (GTK_BOX (priv->action_area), child);
           add_to_header_bar (dialog, child, response_id);
           g_object_unref (child);
 
@@ -610,22 +617,22 @@ static GList *
 get_action_children (GtkDialog *dialog)
 {
   GtkDialogPrivate *priv = gtk_dialog_get_instance_private (dialog);
+  GtkWidget *parent;
+  GtkWidget *child;
   GList *children;
 
   if (priv->constructed && priv->use_header_bar)
-    {
-      GtkWidget *child;
-
-      children = NULL;
-      for (child = gtk_widget_get_first_child (priv->headerbar);
-           child != NULL;
-           child = gtk_widget_get_next_sibling (child))
-        children = g_list_append (children, child);
-    }
+    parent = priv->headerbar;
   else
-    children = gtk_container_get_children (GTK_CONTAINER (priv->action_area));
+    parent = priv->action_area;
+
+  children = NULL;
+  for (child = gtk_widget_get_first_child (parent);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    children = g_list_prepend (children, child);
 
-  return children;
+  return g_list_reverse (children);
 }
 
 /* A far too tricky heuristic for getting the right initial
diff --git a/gtk/gtkemojichooser.c b/gtk/gtkemojichooser.c
index 89479f5ca5..98fd6e99f0 100644
--- a/gtk/gtkemojichooser.c
+++ b/gtk/gtkemojichooser.c
@@ -320,13 +320,19 @@ add_recent_item (GtkEmojiChooser *chooser,
   GList *children, *l;
   int i;
   GVariantBuilder builder;
+  GtkWidget *child;
 
   g_variant_ref (item);
 
   g_variant_builder_init (&builder, G_VARIANT_TYPE ("a((auss)u)"));
   g_variant_builder_add (&builder, "(@(auss)u)", item, modifier);
 
-  children = gtk_container_get_children (GTK_CONTAINER (chooser->recent.box));
+  children = NULL;
+  for (child = gtk_widget_get_last_child (chooser->recent.box);
+       child != NULL;
+       child = gtk_widget_get_prev_sibling (child))
+    children = g_list_prepend (children, child);
+
   for (l = children, i = 1; l; l = l->next, i++)
     {
       GVariant *item2 = g_object_get_data (G_OBJECT (l->data), "emoji-data");
@@ -334,13 +340,13 @@ add_recent_item (GtkEmojiChooser *chooser,
 
       if (modifier == modifier2 && g_variant_equal (item, item2))
         {
-          gtk_container_remove (GTK_CONTAINER (chooser->recent.box), l->data);
+          gtk_flow_box_remove (GTK_FLOW_BOX (chooser->recent.box), l->data);
           i--;
           continue;
         }
       if (i >= MAX_RECENT)
         {
-          gtk_container_remove (GTK_CONTAINER (chooser->recent.box), l->data);
+          gtk_flow_box_remove (GTK_FLOW_BOX (chooser->recent.box), l->data);
           continue;
         }
 
@@ -443,7 +449,7 @@ show_variations (GtkEmojiChooser *chooser,
   gtk_flow_box_set_selection_mode (GTK_FLOW_BOX (box), GTK_SELECTION_NONE);
   g_object_set (box, "accept-unpaired-release", TRUE, NULL);
   gtk_popover_set_child (GTK_POPOVER (popover), view);
-  gtk_container_add (GTK_CONTAINER (view), box);
+  gtk_box_append (GTK_BOX (view), box);
 
   g_signal_connect (box, "child-activated", G_CALLBACK (emoji_activated), parent_popover);
 
diff --git a/gtk/gtkemojicompletion.c b/gtk/gtkemojicompletion.c
index 9f5fe235c6..2a84ce853e 100644
--- a/gtk/gtkemojicompletion.c
+++ b/gtk/gtkemojicompletion.c
@@ -474,7 +474,7 @@ add_emoji_variation (GtkWidget *box,
   if (modifier != 0)
     g_object_set_data (G_OBJECT (child), "modifier", GUINT_TO_POINTER (modifier));
 
-  gtk_container_add (GTK_CONTAINER (child), label);
+  gtk_box_append (GTK_BOX (child), label);
   gtk_flow_box_insert (GTK_FLOW_BOX (box), child, -1);
 }
 
@@ -504,15 +504,15 @@ add_emoji (GtkWidget          *list,
   child = g_object_new (GTK_TYPE_LIST_BOX_ROW, "css-name", "emoji-completion-row", NULL);
   gtk_widget_set_focus_on_click (child, FALSE);
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (child), box);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (child), box);
+  gtk_box_append (GTK_BOX (box), label);
   g_object_set_data (G_OBJECT (child), "base", label);
 
   stack = gtk_stack_new ();
   gtk_stack_set_hhomogeneous (GTK_STACK (stack), TRUE);
   gtk_stack_set_vhomogeneous (GTK_STACK (stack), TRUE);
   gtk_stack_set_transition_type (GTK_STACK (stack), GTK_STACK_TRANSITION_TYPE_OVER_RIGHT_LEFT);
-  gtk_container_add (GTK_CONTAINER (box), stack);
+  gtk_box_append (GTK_BOX (box), stack);
   g_object_set_data (G_OBJECT (child), "stack", stack);
 
   g_variant_get_child (emoji_data, 2, "&s", &shortname);
@@ -548,11 +548,11 @@ populate_completion (GtkEmojiCompletion *completion,
                      const char         *text,
                      guint               offset)
 {
-  GtkWidget *child;
   guint n_matches;
   guint n_added;
   GVariantIter iter;
   GVariant *item;
+  GtkWidget *child;
 
   if (completion->text != text)
     {
@@ -563,7 +563,7 @@ populate_completion (GtkEmojiCompletion *completion,
   completion->offset = offset;
 
   while ((child = gtk_widget_get_first_child (completion->list)))
-    gtk_container_remove (GTK_CONTAINER (completion->list), child);
+    gtk_list_box_remove (GTK_LIST_BOX (completion->list), child);
 
   completion->active = NULL;
 
diff --git a/gtk/gtkentrycompletion.c b/gtk/gtkentrycompletion.c
index 2aa691fe65..e2128842db 100644
--- a/gtk/gtkentrycompletion.c
+++ b/gtk/gtkentrycompletion.c
@@ -609,7 +609,7 @@ gtk_entry_completion_constructed (GObject *object)
                                  priv->tree_view);
   gtk_widget_set_hexpand (priv->scrolled_window, TRUE);
   gtk_widget_set_vexpand (priv->scrolled_window, TRUE);
-  gtk_container_add (GTK_CONTAINER (priv->vbox), priv->scrolled_window);
+  gtk_box_append (GTK_BOX (priv->vbox), priv->scrolled_window);
 
   /* we don't want to see the action treeview when no actions have
    * been inserted, so we pack the action treeview after the first
@@ -1197,7 +1197,7 @@ gtk_entry_completion_insert_action (GtkEntryCompletion *completion,
                                 path, NULL, FALSE);
       gtk_tree_path_free (path);
 
-      gtk_container_add (GTK_CONTAINER (completion->priv->vbox),
+      gtk_box_append (GTK_BOX (completion->priv->vbox),
                           completion->priv->action_view);
       gtk_widget_show (completion->priv->action_view);
     }
diff --git a/gtk/gtkexpander.c b/gtk/gtkexpander.c
index 9862c7b5b5..083e16f7e6 100644
--- a/gtk/gtkexpander.c
+++ b/gtk/gtkexpander.c
@@ -27,10 +27,10 @@
  * A #GtkExpander allows the user to hide or show its child by clicking
  * on an expander triangle similar to the triangles used in a #GtkTreeView.
  *
- * Normally you use an expander as you would use a descendant
- * of #GtkBin; you create the child widget and use gtk_container_add()
- * to add it to the expander. When the expander is toggled, it will take
- * care of showing and hiding the child automatically.
+ * Normally you use an expander as you would use a frame; you create
+ * the child widget and use gtk_expander_set_child() to add it to the
+ * expander. When the expander is toggled, it will take care of showing
+ * and hiding the child automatically.
  *
  * # Special Usage
  *
@@ -400,13 +400,13 @@ gtk_expander_init (GtkExpander *expander)
   gtk_widget_set_parent (expander->box, GTK_WIDGET (expander));
 
   expander->title_widget = g_object_new (GTK_TYPE_BOX,
-                                     "css-name", "title",
-                                     NULL);
-  gtk_container_add (GTK_CONTAINER (expander->box), expander->title_widget);
+                                         "css-name", "title",
+                                         NULL);
+  gtk_box_append (GTK_BOX (expander->box), expander->title_widget);
 
   expander->arrow_widget = gtk_builtin_icon_new ("expander");
   gtk_widget_add_css_class (expander->arrow_widget, GTK_STYLE_CLASS_HORIZONTAL);
-  gtk_container_add (GTK_CONTAINER (expander->title_widget), expander->arrow_widget);
+  gtk_box_append (GTK_BOX (expander->title_widget), expander->arrow_widget);
 
   controller = gtk_drop_controller_motion_new ();
   g_signal_connect (controller, "enter", G_CALLBACK (gtk_expander_drag_enter), expander);
@@ -869,13 +869,13 @@ gtk_expander_set_expanded (GtkExpander *expander,
     {
       if (expander->expanded)
         {
-          gtk_container_add (GTK_CONTAINER (expander->box), child);
+          gtk_box_append (GTK_BOX (expander->box), child);
           g_object_unref (expander->child);
         }
       else
         {
           g_object_ref (expander->child);
-          gtk_container_remove (GTK_CONTAINER (expander->box), child);
+          gtk_box_remove (GTK_BOX (expander->box), child);
         }
       gtk_expander_resize_toplevel (expander);
     }
@@ -1079,9 +1079,7 @@ gtk_expander_set_label_widget (GtkExpander *expander,
     return;
 
   if (expander->label_widget)
-    {
-      gtk_container_remove (GTK_CONTAINER (expander->title_widget), expander->label_widget);
-    }
+    gtk_box_remove (GTK_BOX (expander->title_widget), expander->label_widget);
 
   expander->label_widget = label_widget;
   widget = GTK_WIDGET (expander);
@@ -1090,7 +1088,7 @@ gtk_expander_set_label_widget (GtkExpander *expander,
     {
       expander->label_widget = label_widget;
 
-      gtk_container_add (GTK_CONTAINER (expander->title_widget), label_widget);
+      gtk_box_append (GTK_BOX (expander->title_widget), label_widget);
     }
 
   if (gtk_widget_get_visible (widget))
@@ -1174,7 +1172,7 @@ gtk_expander_set_child (GtkExpander *expander,
 
   if (expander->child)
     {
-      gtk_container_remove (GTK_CONTAINER (expander->box), expander->child);
+      gtk_box_remove (GTK_BOX (expander->box), expander->child);
       if (!expander->expanded)
         g_object_unref (expander->child);
     }
@@ -1184,7 +1182,7 @@ gtk_expander_set_child (GtkExpander *expander,
   if (expander->child)
     {
       if (expander->expanded)
-        gtk_container_add (GTK_CONTAINER (expander->box), expander->child);
+        gtk_box_append (GTK_BOX (expander->box), expander->child);
       else
         {
           if (g_object_is_floating (expander->child))
diff --git a/gtk/gtkfilechooserbutton.c b/gtk/gtkfilechooserbutton.c
index 29cc1e467f..277b3164f9 100644
--- a/gtk/gtkfilechooserbutton.c
+++ b/gtk/gtkfilechooserbutton.c
@@ -556,11 +556,11 @@ gtk_file_chooser_button_init (GtkFileChooserButton *button)
   icon = gtk_image_new_from_icon_name ("document-open-symbolic");
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_set_valign (button->image, GTK_ALIGN_BASELINE);
-  gtk_container_add (GTK_CONTAINER (box), button->image);
+  gtk_box_append (GTK_BOX (box), button->image);
   gtk_widget_set_valign (button->label, GTK_ALIGN_BASELINE);
-  gtk_container_add (GTK_CONTAINER (box), button->label);
+  gtk_box_append (GTK_BOX (box), button->label);
   gtk_widget_set_valign (icon, GTK_ALIGN_BASELINE);
-  gtk_container_add (GTK_CONTAINER (box), icon);
+  gtk_box_append (GTK_BOX (box), icon);
   gtk_button_set_child (GTK_BUTTON (button->button), box);
 
   gtk_widget_set_parent (button->button, GTK_WIDGET (button));
diff --git a/gtk/gtkfilechooserdialog.c b/gtk/gtkfilechooserdialog.c
index 2bb05003ed..24f48402c0 100644
--- a/gtk/gtkfilechooserdialog.c
+++ b/gtk/gtkfilechooserdialog.c
@@ -562,8 +562,8 @@ setup_save_entry (GtkFileChooserDialog *dialog)
       g_object_set (label, "margin-start", 6, "margin-end", 6, NULL);
       g_object_set (entry, "margin-start", 6, "margin-end", 6, NULL);
       gtk_label_set_mnemonic_widget (GTK_LABEL (label), entry);
-      gtk_container_add (GTK_CONTAINER (box), label);
-      gtk_container_add (GTK_CONTAINER (box), entry);
+      gtk_box_append (GTK_BOX (box), label);
+      gtk_box_append (GTK_BOX (box), entry);
 
       gtk_header_bar_set_title_widget (GTK_HEADER_BAR (header), box);
       gtk_file_chooser_widget_set_save_entry (GTK_FILE_CHOOSER_WIDGET (priv->widget), entry);
diff --git a/gtk/gtkfilechooserwidget.c b/gtk/gtkfilechooserwidget.c
index ca2e03a4f9..ab36bded5a 100644
--- a/gtk/gtkfilechooserwidget.c
+++ b/gtk/gtkfilechooserwidget.c
@@ -2321,7 +2321,7 @@ save_widgets_create (GtkFileChooserWidget *impl)
   gtk_widget_add_css_class (vbox, "search-bar");
 
   impl->save_widgets_table = gtk_grid_new ();
-  gtk_container_add (GTK_CONTAINER (vbox), impl->save_widgets_table);
+  gtk_box_append (GTK_BOX (vbox), impl->save_widgets_table);
   gtk_grid_set_row_spacing (GTK_GRID (impl->save_widgets_table), 12);
   gtk_grid_set_column_spacing (GTK_GRID (impl->save_widgets_table), 12);
 
@@ -2360,7 +2360,7 @@ save_widgets_destroy (GtkFileChooserWidget *impl)
   if (impl->save_widgets == NULL)
     return;
 
-  gtk_container_remove (GTK_CONTAINER (impl->box), impl->save_widgets);
+  gtk_box_remove (GTK_BOX (impl->box), impl->save_widgets);
   impl->save_widgets = NULL;
   impl->save_widgets_table = NULL;
   impl->location_entry = NULL;
@@ -2372,13 +2372,7 @@ save_widgets_destroy (GtkFileChooserWidget *impl)
 static void
 location_switch_to_path_bar (GtkFileChooserWidget *impl)
 {
-  if (impl->location_entry)
-    {
-      gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (impl->location_entry)),
-                            impl->location_entry);
-      impl->location_entry = NULL;
-    }
-
+  g_clear_pointer (&impl->location_entry, gtk_widget_unparent);
   gtk_stack_set_visible_child_name (GTK_STACK (impl->browse_header_stack), "pathbar");
 }
 
@@ -2400,7 +2394,7 @@ location_switch_to_filename_entry (GtkFileChooserWidget *impl)
   if (!impl->location_entry)
     {
       location_entry_create (impl);
-      gtk_container_add (GTK_CONTAINER (impl->location_entry_box), impl->location_entry);
+      gtk_box_append (GTK_BOX (impl->location_entry_box), impl->location_entry);
     }
 
   _gtk_file_chooser_entry_set_base_folder (GTK_FILE_CHOOSER_ENTRY (impl->location_entry), 
impl->current_folder);
@@ -2541,14 +2535,14 @@ set_extra_widget (GtkFileChooserWidget *impl,
 
   if (impl->extra_widget)
     {
-      gtk_container_remove (GTK_CONTAINER (impl->extra_align), impl->extra_widget);
+      gtk_box_remove (GTK_BOX (impl->extra_align), impl->extra_widget);
       g_object_unref (impl->extra_widget);
     }
 
   impl->extra_widget = extra_widget;
   if (impl->extra_widget)
     {
-      gtk_container_add (GTK_CONTAINER (impl->extra_align), impl->extra_widget);
+      gtk_box_append (GTK_BOX (impl->extra_align), impl->extra_widget);
       gtk_widget_show (impl->extra_align);
     }
   else
@@ -7947,11 +7941,11 @@ gtk_file_chooser_widget_add_choice (GtkFileChooser  *chooser,
       int i;
 
       box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
-      gtk_container_add (GTK_CONTAINER (box), gtk_label_new (label));
+      gtk_box_append (GTK_BOX (box), gtk_label_new (label));
 
       combo = gtk_combo_box_text_new ();
       g_hash_table_insert (impl->choices, g_strdup (id), combo);
-      gtk_container_add (GTK_CONTAINER (box), combo);
+      gtk_box_append (GTK_BOX (box), combo);
 
       for (i = 0; options[i]; i++)
         gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (combo),
@@ -7969,7 +7963,7 @@ gtk_file_chooser_widget_add_choice (GtkFileChooser  *chooser,
       widget = check;
     }
 
-  gtk_container_add (GTK_CONTAINER (impl->choice_box), widget);
+  gtk_box_append (GTK_BOX (impl->choice_box), widget);
 }
 
 static void
@@ -7984,7 +7978,7 @@ gtk_file_chooser_widget_remove_choice (GtkFileChooser  *chooser,
 
   widget = (GtkWidget *)g_hash_table_lookup (impl->choices, id);
   g_hash_table_remove (impl->choices, id);
-  gtk_container_remove (GTK_CONTAINER (impl->choice_box), widget);
+  gtk_box_remove (GTK_BOX (impl->choice_box), widget);
 
   if (g_hash_table_size (impl->choices) == 0)
     {
diff --git a/gtk/gtkfontbutton.c b/gtk/gtkfontbutton.c
index a0a9e0162f..86121c2e2a 100644
--- a/gtk/gtkfontbutton.c
+++ b/gtk/gtkfontbutton.c
@@ -552,11 +552,11 @@ gtk_font_button_init (GtkFontButton *font_button)
   font_button->font_size_box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (box), font_button->font_label);
+  gtk_box_append (GTK_BOX (box), font_button->font_label);
 
-  gtk_container_add (GTK_CONTAINER (font_button->font_size_box), gtk_separator_new 
(GTK_ORIENTATION_VERTICAL));
-  gtk_container_add (GTK_CONTAINER (font_button->font_size_box), font_button->size_label);
-  gtk_container_add (GTK_CONTAINER (box), font_button->font_size_box);
+  gtk_box_append (GTK_BOX (font_button->font_size_box), gtk_separator_new (GTK_ORIENTATION_VERTICAL));
+  gtk_box_append (GTK_BOX (font_button->font_size_box), font_button->size_label);
+  gtk_box_append (GTK_BOX (box), font_button->font_size_box);
 
   gtk_button_set_child (GTK_BUTTON (font_button->button), box);
   gtk_widget_set_parent (font_button->button, GTK_WIDGET (font_button));
diff --git a/gtk/gtkfontchooserwidget.c b/gtk/gtkfontchooserwidget.c
index bebe453a84..df72e8c3c6 100644
--- a/gtk/gtkfontchooserwidget.c
+++ b/gtk/gtkfontchooserwidget.c
@@ -1963,7 +1963,7 @@ add_check_group (GtkFontChooserWidget *fontchooser,
   pango_attr_list_insert (attrs, pango_attr_weight_new (PANGO_WEIGHT_BOLD));
   gtk_label_set_attributes (GTK_LABEL (label), attrs);
   pango_attr_list_unref (attrs);
-  gtk_container_add (GTK_CONTAINER (group), label);
+  gtk_box_append (GTK_BOX (group), label);
 
   for (i = 0; tags[i]; i++)
     {
@@ -1993,9 +1993,9 @@ add_check_group (GtkFontChooserWidget *fontchooser,
 
       box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
       gtk_box_set_homogeneous (GTK_BOX (box), TRUE);
-      gtk_container_add (GTK_CONTAINER (box), feat);
-      gtk_container_add (GTK_CONTAINER (box), example);
-      gtk_container_add (GTK_CONTAINER (group), box);
+      gtk_box_append (GTK_BOX (box), feat);
+      gtk_box_append (GTK_BOX (box), example);
+      gtk_box_append (GTK_BOX (group), box);
 
       item = g_new (FeatureItem, 1);
       item->name = tags[i];
@@ -2007,7 +2007,7 @@ add_check_group (GtkFontChooserWidget *fontchooser,
       fontchooser->feature_items = g_list_prepend (fontchooser->feature_items, item);
     }
 
-  gtk_container_add (GTK_CONTAINER (fontchooser->feature_box), group);
+  gtk_box_append (GTK_BOX (fontchooser->feature_box), group);
 }
 
 static void
@@ -2032,7 +2032,7 @@ add_radio_group (GtkFontChooserWidget *fontchooser,
   pango_attr_list_insert (attrs, pango_attr_weight_new (PANGO_WEIGHT_BOLD));
   gtk_label_set_attributes (GTK_LABEL (label), attrs);
   pango_attr_list_unref (attrs);
-  gtk_container_add (GTK_CONTAINER (group), label);
+  gtk_box_append (GTK_BOX (group), label);
 
   for (i = 0; tags[i]; i++)
     {
@@ -2060,9 +2060,9 @@ add_radio_group (GtkFontChooserWidget *fontchooser,
 
       box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
       gtk_box_set_homogeneous (GTK_BOX (box), TRUE);
-      gtk_container_add (GTK_CONTAINER (box), feat);
-      gtk_container_add (GTK_CONTAINER (box), example);
-      gtk_container_add (GTK_CONTAINER (group), box);
+      gtk_box_append (GTK_BOX (box), feat);
+      gtk_box_append (GTK_BOX (box), example);
+      gtk_box_append (GTK_BOX (group), box);
 
       item = g_new (FeatureItem, 1);
       item->name = tags[i];
@@ -2074,7 +2074,7 @@ add_radio_group (GtkFontChooserWidget *fontchooser,
       fontchooser->feature_items = g_list_prepend (fontchooser->feature_items, item);
     }
 
-  gtk_container_add (GTK_CONTAINER (fontchooser->feature_box), group);
+  gtk_box_append (GTK_BOX (fontchooser->feature_box), group);
 }
 
 static void
diff --git a/gtk/gtkgrid.c b/gtk/gtkgrid.c
index 36dfda600c..d63b686fbc 100644
--- a/gtk/gtkgrid.c
+++ b/gtk/gtkgrid.c
@@ -44,13 +44,9 @@
  *
  * Children are added using gtk_grid_attach(). They can span multiple
  * rows or columns. It is also possible to add a child next to an
- * existing child, using gtk_grid_attach_next_to(). The behaviour of
- * GtkGrid when several children occupy the same grid cell is undefined.
- *
- * GtkGrid can be used like a #GtkBox by just using gtk_container_add(),
- * which will place children next to each other in the direction determined
- * by the #GtkOrientable:orientation property. However, if all you want is a
- * single row or column, then #GtkBox is the preferred widget.
+ * existing child, using gtk_grid_attach_next_to(). To remove a child
+ * from the grid, use gtk_grid_remove(). The behaviour of GtkGrid when
+ * several children occupy the same grid cell is undefined.
  *
  * # CSS nodes
  *
@@ -726,7 +722,7 @@ gtk_grid_remove_row (GtkGrid *grid,
 
       if (height <= 0)
         {
-          gtk_container_remove (GTK_CONTAINER (grid), child);
+          gtk_grid_remove (grid, child);
         }
       else
         {
@@ -816,7 +812,7 @@ gtk_grid_remove_column (GtkGrid *grid,
 
       if (width <= 0)
         {
-          gtk_container_remove (GTK_CONTAINER (grid), child);
+          gtk_grid_remove (grid, child);
         }
       else
         {
diff --git a/gtk/gtkheaderbar.c b/gtk/gtkheaderbar.c
index c4a2a19123..881f0dde2f 100644
--- a/gtk/gtkheaderbar.c
+++ b/gtk/gtkheaderbar.c
@@ -164,7 +164,7 @@ create_window_controls (GtkHeaderBar *bar)
   g_object_bind_property (controls, "empty",
                           controls, "visible",
                           G_BINDING_SYNC_CREATE | G_BINDING_INVERT_BOOLEAN);
-  gtk_container_add (GTK_CONTAINER (priv->start_box), controls);
+  gtk_box_append (GTK_BOX (priv->start_box), controls);
   priv->start_window_controls = controls;
 
   controls = gtk_window_controls_new (GTK_PACK_END);
@@ -174,7 +174,7 @@ create_window_controls (GtkHeaderBar *bar)
   g_object_bind_property (controls, "empty",
                           controls, "visible",
                           G_BINDING_SYNC_CREATE | G_BINDING_INVERT_BOOLEAN);
-  gtk_container_add (GTK_CONTAINER (priv->end_box), controls);
+  gtk_box_append (GTK_BOX (priv->end_box), controls);
   priv->end_window_controls = controls;
 }
 
@@ -470,11 +470,11 @@ gtk_header_bar_pack (GtkHeaderBar *bar,
 
   if (pack_type == GTK_PACK_START)
     {
-      gtk_container_add (GTK_CONTAINER (priv->start_box), widget);
+      gtk_box_append (GTK_BOX (priv->start_box), widget);
     }
   else if (pack_type == GTK_PACK_END)
     {
-      gtk_container_add (GTK_CONTAINER (priv->end_box), widget);
+      gtk_box_append (GTK_BOX (priv->end_box), widget);
       gtk_box_reorder_child_after (GTK_BOX (priv->end_box), widget, NULL);
     }
 
@@ -504,12 +504,12 @@ gtk_header_bar_remove (GtkHeaderBar *bar,
 
   if (parent == priv->start_box)
     {
-      gtk_container_remove (GTK_CONTAINER (priv->start_box), child);
+      gtk_box_remove (GTK_BOX (priv->start_box), child);
       removed = TRUE;
     }
   else if (parent == priv->end_box)
     {
-      gtk_container_remove (GTK_CONTAINER (priv->end_box), child);
+      gtk_box_remove (GTK_BOX (priv->end_box), child);
       removed = TRUE;
     }
   else if (parent == GTK_WIDGET (bar) &&
diff --git a/gtk/gtkinfobar.c b/gtk/gtkinfobar.c
index 584c6fd043..c3657ece49 100644
--- a/gtk/gtkinfobar.c
+++ b/gtk/gtkinfobar.c
@@ -300,25 +300,19 @@ static GtkWidget *
 find_button (GtkInfoBar *info_bar,
              gint        response_id)
 {
-  GList *children, *list;
-  GtkWidget *child = NULL;
+  GtkWidget *child;
 
-  children = gtk_container_get_children (GTK_CONTAINER (info_bar->action_area));
-
-  for (list = children; list; list = list->next)
+  for (child = gtk_widget_get_first_child (info_bar->action_area);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
     {
-      ResponseData *rd = get_response_data (list->data, FALSE);
+      ResponseData *rd = get_response_data (child, FALSE);
 
       if (rd && rd->response_id == response_id)
-        {
-          child = list->data;
-          break;
-        }
+        return child;
     }
 
-  g_list_free (children);
-
-  return child;
+  return NULL;
 }
 
 static void
@@ -474,18 +468,18 @@ gtk_info_bar_init (GtkInfoBar *info_bar)
 
   info_bar->content_area = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_set_hexpand (info_bar->content_area, TRUE);
-  gtk_container_add (GTK_CONTAINER (main_box), info_bar->content_area);
+  gtk_box_append (GTK_BOX (main_box), info_bar->content_area);
 
   info_bar->action_area = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_set_halign (info_bar->action_area, GTK_ALIGN_END);
   gtk_widget_set_valign (info_bar->action_area, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (main_box), info_bar->action_area);
+  gtk_box_append (GTK_BOX (main_box), info_bar->action_area);
 
   info_bar->close_button = gtk_button_new_from_icon_name ("window-close-symbolic");
   gtk_widget_hide (info_bar->close_button);
   gtk_widget_set_valign (info_bar->close_button, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (info_bar->close_button, "close");
-  gtk_container_add (GTK_CONTAINER (main_box), info_bar->close_button);
+  gtk_box_append (GTK_BOX (main_box), info_bar->close_button);
   g_signal_connect (info_bar->close_button, "clicked",
                     G_CALLBACK (close_button_clicked_cb), info_bar);
 
@@ -573,7 +567,7 @@ gtk_info_bar_add_action_widget (GtkInfoBar *info_bar,
   else
     g_warning ("Only 'activatable' widgets can be packed into the action area of a GtkInfoBar");
 
-  gtk_container_add (GTK_CONTAINER (info_bar->action_area), child);
+  gtk_box_append (GTK_BOX (info_bar->action_area), child);
 }
 
 /**
@@ -595,7 +589,7 @@ gtk_info_bar_remove_action_widget (GtkInfoBar *info_bar,
 
   clear_response_data (widget);
 
-  gtk_container_remove (GTK_CONTAINER (info_bar->action_area), widget);
+  gtk_box_remove (GTK_BOX (info_bar->action_area), widget);
 }
 
 /**
@@ -758,23 +752,20 @@ gtk_info_bar_set_response_sensitive (GtkInfoBar *info_bar,
                                      gint        response_id,
                                      gboolean    setting)
 {
-  GList *children, *list;
+  GtkWidget *child;
 
   g_return_if_fail (GTK_IS_INFO_BAR (info_bar));
 
-  children = gtk_container_get_children (GTK_CONTAINER (info_bar->action_area));
-
-  for (list = children; list; list = list->next)
+  for (child = gtk_widget_get_first_child (info_bar->action_area);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
     {
-      GtkWidget *widget = list->data;
-      ResponseData *rd = get_response_data (widget, FALSE);
+      ResponseData *rd = get_response_data (child, FALSE);
 
       if (rd && rd->response_id == response_id)
-        gtk_widget_set_sensitive (widget, setting);
+        gtk_widget_set_sensitive (child, setting);
     }
 
-  g_list_free (children);
-
   if (response_id == info_bar->default_response)
     update_default_response (info_bar, response_id, setting);
 }
@@ -795,30 +786,28 @@ void
 gtk_info_bar_set_default_response (GtkInfoBar *info_bar,
                                    gint        response_id)
 {
-  GList *children, *list;
+  GtkWidget *child;
+  GtkWidget *window;
   gboolean sensitive = TRUE;
 
   g_return_if_fail (GTK_IS_INFO_BAR (info_bar));
 
-  children = gtk_container_get_children (GTK_CONTAINER (info_bar->action_area));
+  window = gtk_widget_get_ancestor (GTK_WIDGET (info_bar), GTK_TYPE_WINDOW);
 
-  for (list = children; list; list = list->next)
+  for (child = gtk_widget_get_first_child (info_bar->action_area);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
     {
-      GtkWidget *widget = list->data;
-      ResponseData *rd = get_response_data (widget, FALSE);
+      ResponseData *rd = get_response_data (child, FALSE);
 
       if (rd && rd->response_id == response_id)
         {
-          GtkWidget *window;
-
-          window = gtk_widget_get_ancestor (GTK_WIDGET (info_bar), GTK_TYPE_WINDOW);
-          gtk_window_set_default_widget (GTK_WINDOW (window), widget);
-          sensitive = gtk_widget_get_sensitive (widget);
+          gtk_window_set_default_widget (GTK_WINDOW (window), child);
+          sensitive = gtk_widget_get_sensitive (child);
+          break;
         }
     }
 
-  g_list_free (children);
-
   update_default_response (info_bar, response_id, sensitive);
 }
 
@@ -1061,7 +1050,7 @@ gtk_info_bar_buildable_add_child (GtkBuildable *buildable,
   if (!type && GTK_IS_WIDGET (child))
     gtk_info_bar_add_child (GTK_INFO_BAR (info_bar), GTK_WIDGET (child));
   else if (g_strcmp0 (type, "action") == 0)
-    gtk_container_add (GTK_CONTAINER (info_bar->action_area), GTK_WIDGET (child));
+    gtk_box_append (GTK_BOX (info_bar->action_area), GTK_WIDGET (child));
   else
     parent_buildable_iface->add_child (buildable, builder, child, type);
 }
@@ -1251,7 +1240,7 @@ gtk_info_bar_add_child (GtkInfoBar *info_bar,
   g_return_if_fail (GTK_IS_INFO_BAR (info_bar));
   g_return_if_fail (GTK_IS_WIDGET (widget));
 
-  gtk_container_add (GTK_CONTAINER (info_bar->content_area), widget);
+  gtk_box_append (GTK_BOX (info_bar->content_area), widget);
 }
 
 /**
@@ -1269,6 +1258,6 @@ gtk_info_bar_remove_child (GtkInfoBar *info_bar,
   g_return_if_fail (GTK_IS_INFO_BAR (info_bar));
   g_return_if_fail (GTK_IS_WIDGET (widget));
 
-  gtk_container_remove (GTK_CONTAINER (info_bar->content_area), widget);
+  gtk_box_remove (GTK_BOX (info_bar->content_area), widget);
 }
 
diff --git a/gtk/gtkmenubutton.c b/gtk/gtkmenubutton.c
index 464ee6a685..ebb17a01da 100644
--- a/gtk/gtkmenubutton.c
+++ b/gtk/gtkmenubutton.c
@@ -889,8 +889,8 @@ gtk_menu_button_set_label (GtkMenuButton *menu_button,
                                gtk_button_get_use_underline (GTK_BUTTON (menu_button->button)));
   gtk_widget_set_hexpand (label_widget, TRUE);
   image = gtk_image_new_from_icon_name ("pan-down-symbolic");
-  gtk_container_add (GTK_CONTAINER (box), label_widget);
-  gtk_container_add (GTK_CONTAINER (box), image);
+  gtk_box_append (GTK_BOX (box), label_widget);
+  gtk_box_append (GTK_BOX (box), image);
   gtk_button_set_child (GTK_BUTTON (menu_button->button), box);
   menu_button->label_widget = label_widget;
 
diff --git a/gtk/gtkmenusectionbox.c b/gtk/gtkmenusectionbox.c
index 072b3287ca..f014502460 100644
--- a/gtk/gtkmenusectionbox.c
+++ b/gtk/gtkmenusectionbox.c
@@ -70,18 +70,6 @@ static void        gtk_menu_section_box_new_submenu     (GtkMenuTrackerItem *ite
 static GtkWidget * gtk_menu_section_box_new_section     (GtkMenuTrackerItem *item,
                                                          GtkMenuSectionBox  *parent);
 
-static void
-gtk_menu_section_box_sync_item (GtkWidget *widget,
-                                gpointer   user_data)
-{
-  MenuData *data = (MenuData *)user_data;
-
-  if (GTK_IS_MENU_SECTION_BOX (widget))
-    gtk_menu_section_box_sync_separators (GTK_MENU_SECTION_BOX (widget), data);
-  else
-    data->n_items++;
-}
-
 /* We are trying to implement the following rules here:
  *
  * rule 1: never ever show separators for empty sections
@@ -104,11 +92,20 @@ gtk_menu_section_box_sync_separators (GtkMenuSectionBox *box,
   gboolean has_label;
   gboolean separator_condition;
   gint n_items_before;
+  GtkWidget *child;
 
   n_items_before =  data->n_items;
   previous_section_is_iconic = data->previous_is_iconic;
 
-  gtk_container_foreach (GTK_CONTAINER (box->item_box), gtk_menu_section_box_sync_item, data);
+  for (child = gtk_widget_get_first_child (GTK_WIDGET (box->item_box));
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    {
+      if (GTK_IS_MENU_SECTION_BOX (child))
+        gtk_menu_section_box_sync_separators (GTK_MENU_SECTION_BOX (child), data);
+      else
+        data->n_items++;
+    }
 
   is_not_empty_item = (data->n_items > n_items_before);
 
@@ -148,7 +145,7 @@ gtk_menu_section_box_sync_separators (GtkMenuSectionBox *box,
   if (should_have_separator)
     gtk_box_insert_child_after (GTK_BOX (box), box->separator, NULL);
   else
-    gtk_container_remove (GTK_CONTAINER (box), box->separator);
+    gtk_box_remove (GTK_BOX (box), box->separator);
 }
 
 static gboolean
@@ -212,11 +209,15 @@ gtk_menu_section_box_remove_func (gint     position,
   GtkMenuSectionBox *box = user_data;
   GtkMenuTrackerItem *item;
   GtkWidget *widget;
-  GList *children;
-
-  children = gtk_container_get_children (GTK_CONTAINER (box->item_box));
+  int pos;
 
-  widget = g_list_nth_data (children, position);
+  for (widget = gtk_widget_get_first_child (GTK_WIDGET (box->item_box)), pos = 0;
+       widget != NULL;
+       widget = gtk_widget_get_next_sibling (widget), pos++)
+    {
+      if (pos == position)
+        break;
+    }
 
   item = g_object_get_data (G_OBJECT (widget), "GtkMenuTrackerItem");
   if (gtk_menu_tracker_item_get_has_link (item, G_MENU_LINK_SUBMENU))
@@ -229,9 +230,7 @@ gtk_menu_section_box_remove_func (gint     position,
         gtk_stack_remove (GTK_STACK (stack), subbox);
     }
 
-  gtk_container_remove (GTK_CONTAINER (box->item_box),
-                        g_list_nth_data (children, position));
-  g_list_free (children);
+  gtk_box_remove (GTK_BOX (box->item_box), widget);
 
   gtk_menu_section_box_schedule_separator_sync (box);
 }
@@ -387,7 +386,7 @@ gtk_menu_section_box_insert_func (GtkMenuTrackerItem *item,
     {
       gtk_widget_set_halign (widget, GTK_ALIGN_FILL);
     }
-  gtk_container_add (GTK_CONTAINER (box->item_box), widget);
+  gtk_box_append (GTK_BOX (box->item_box), widget);
 
   if (position == 0)
     gtk_box_reorder_child_after (GTK_BOX (box->item_box), widget, NULL);
@@ -434,7 +433,7 @@ gtk_menu_section_box_init (GtkMenuSectionBox *box)
 
   item_box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   box->item_box = GTK_BOX (item_box);
-  gtk_container_add (GTK_CONTAINER (box), item_box);
+  gtk_box_append (GTK_BOX (box), item_box);
   gtk_widget_set_halign (GTK_WIDGET (item_box), GTK_ALIGN_FILL);
   gtk_widget_set_halign (GTK_WIDGET (box), GTK_ALIGN_FILL);
 }
@@ -602,7 +601,7 @@ gtk_menu_section_box_new_section (GtkMenuTrackerItem *item,
       gtk_widget_add_css_class (GTK_WIDGET (box->item_box), "inline-buttons");
 
       spacer = gtk_builtin_icon_new ("none");
-      gtk_container_add (GTK_CONTAINER (box->item_box), spacer);
+      gtk_box_append (GTK_BOX (box->item_box), spacer);
       gtk_size_group_add_widget (box->indicators, spacer);
 
       if (label != NULL)
@@ -613,11 +612,11 @@ gtk_menu_section_box_new_section (GtkMenuTrackerItem *item,
           gtk_widget_set_hexpand (title, TRUE);
           gtk_widget_set_halign (title, GTK_ALIGN_START);
           g_object_bind_property (item, "label", title, "label", G_BINDING_SYNC_CREATE);
-          gtk_container_add (GTK_CONTAINER (box->item_box), title);
+          gtk_box_append (GTK_BOX (box->item_box), title);
         }
 
       item_box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (box->item_box), item_box);
+      gtk_box_append (GTK_BOX (box->item_box), item_box);
       box->item_box = GTK_BOX (item_box);
     }
   else if (hint && g_str_equal (hint, "circular-buttons"))
@@ -639,7 +638,7 @@ gtk_menu_section_box_new_section (GtkMenuTrackerItem *item,
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
       gtk_widget_set_valign (separator, GTK_ALIGN_CENTER);
       gtk_widget_set_hexpand (separator, TRUE);
-      gtk_container_add (GTK_CONTAINER (box->separator), separator);
+      gtk_box_append (GTK_BOX (box->separator), separator);
 
       title = gtk_label_new (label);
       g_object_bind_property (item, "label", title, "label", G_BINDING_SYNC_CREATE);
@@ -647,7 +646,7 @@ gtk_menu_section_box_new_section (GtkMenuTrackerItem *item,
       gtk_widget_set_halign (title, GTK_ALIGN_START);
       gtk_label_set_xalign (GTK_LABEL (title), 0.0);
       gtk_widget_add_css_class (title, GTK_STYLE_CLASS_TITLE);
-      gtk_container_add (GTK_CONTAINER (box->separator), title);
+      gtk_box_append (GTK_BOX (box->separator), title);
     }
   else
     {
diff --git a/gtk/gtkmessagedialog.c b/gtk/gtkmessagedialog.c
index 1f6abc9e9f..be0b4afe2c 100644
--- a/gtk/gtkmessagedialog.c
+++ b/gtk/gtkmessagedialog.c
@@ -367,7 +367,7 @@ gtk_message_dialog_constructed (GObject *object)
       gtk_widget_set_halign (label, GTK_ALIGN_CENTER);
       gtk_widget_set_hexpand (label, TRUE);
       gtk_widget_add_css_class (label, "title");
-      gtk_container_add (GTK_CONTAINER (box), label);
+      gtk_box_append (GTK_BOX (box), label);
       g_signal_connect_object (dialog, "notify::title", G_CALLBACK (update_title), label, 0);
 
       gtk_window_set_titlebar (GTK_WINDOW (dialog), box);
diff --git a/gtk/gtkmodelbutton.c b/gtk/gtkmodelbutton.c
index e8fe1bebaf..a58ec5e853 100644
--- a/gtk/gtkmodelbutton.c
+++ b/gtk/gtkmodelbutton.c
@@ -509,7 +509,7 @@ update_node_name (GtkModelButton *self)
       gtk_widget_set_valign (self->start_indicator, GTK_ALIGN_CENTER);
       update_start_indicator (self);
 
-      gtk_container_add (GTK_CONTAINER (self->start_box), self->start_indicator);
+      gtk_box_append (GTK_BOX (self->start_box), self->start_indicator);
     }
   else if (start_name)
     {
@@ -517,7 +517,7 @@ update_node_name (GtkModelButton *self)
     }
   else if (self->start_indicator)
     {
-      gtk_container_remove (GTK_CONTAINER (self->start_box), self->start_indicator);
+      gtk_box_remove (GTK_BOX (self->start_box), self->start_indicator);
       self->start_indicator = NULL;
     }
 
@@ -699,7 +699,7 @@ gtk_model_button_set_iconic (GtkModelButton *self,
     {
       if (self->start_indicator)
         {
-          gtk_container_remove (GTK_CONTAINER (self->start_box), self->start_indicator);
+          gtk_box_remove (GTK_BOX (self->start_box), self->start_indicator);
           self->start_indicator = NULL;
         }
       g_clear_pointer (&self->end_indicator, gtk_widget_unparent);
diff --git a/gtk/gtkmountoperation.c b/gtk/gtkmountoperation.c
index 8b91dc6dbb..435c1409f2 100644
--- a/gtk/gtkmountoperation.c
+++ b/gtk/gtkmountoperation.c
@@ -612,17 +612,17 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
 
   /* Build contents */
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
-  gtk_container_add (GTK_CONTAINER (content_area), hbox);
+  gtk_box_append (GTK_BOX (content_area), hbox);
 
   icon = gtk_image_new_from_icon_name ("dialog-password");
   gtk_image_set_icon_size (GTK_IMAGE (icon), GTK_ICON_SIZE_LARGE);
 
   gtk_widget_set_halign (icon, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (icon, GTK_ALIGN_START);
-  gtk_container_add (GTK_CONTAINER (hbox), icon);
+  gtk_box_append (GTK_BOX (hbox), icon);
 
   main_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 18);
-  gtk_container_add (GTK_CONTAINER (hbox), main_vbox);
+  gtk_box_append (GTK_BOX (hbox), main_vbox);
 
   secondary = strstr (message, "\n");
   if (secondary != NULL)
@@ -638,7 +638,7 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
   gtk_widget_set_halign (label, GTK_ALIGN_START);
   gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
   gtk_label_set_wrap (GTK_LABEL (label), TRUE);
-  gtk_container_add (GTK_CONTAINER (main_vbox), GTK_WIDGET (label));
+  gtk_box_append (GTK_BOX (main_vbox), GTK_WIDGET (label));
   g_free (primary);
   attrs = pango_attr_list_new ();
   pango_attr_list_insert (attrs, pango_attr_weight_new (PANGO_WEIGHT_BOLD));
@@ -651,7 +651,7 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
       gtk_widget_set_halign (label, GTK_ALIGN_START);
       gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
       gtk_label_set_wrap (GTK_LABEL (label), TRUE);
-      gtk_container_add (GTK_CONTAINER (main_vbox), GTK_WIDGET (label));
+      gtk_box_append (GTK_BOX (main_vbox), GTK_WIDGET (label));
     }
 
   grid = gtk_grid_new ();
@@ -659,7 +659,7 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
   gtk_grid_set_row_spacing (GTK_GRID (grid), 12);
   gtk_grid_set_column_spacing (GTK_GRID (grid), 12);
   gtk_widget_set_margin_bottom (grid, 12);
-  gtk_container_add (GTK_CONTAINER (main_vbox), grid);
+  gtk_box_append (GTK_BOX (main_vbox), grid);
 
   can_anonymous = priv->ask_flags & G_ASK_PASSWORD_ANONYMOUS_SUPPORTED;
 
@@ -682,7 +682,7 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
       gtk_grid_attach (GTK_GRID (grid), anon_box, 1, rows++, 1, 1);
 
       choice = gtk_radio_button_new_with_mnemonic (NULL, _("_Anonymous"));
-      gtk_container_add (GTK_CONTAINER (anon_box),
+      gtk_box_append (GTK_BOX (anon_box),
                           choice);
       g_signal_connect (choice, "toggled",
                         G_CALLBACK (pw_dialog_anonymous_toggled), operation);
@@ -690,7 +690,7 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
 
       group = gtk_radio_button_get_group (GTK_RADIO_BUTTON (choice));
       choice = gtk_radio_button_new_with_mnemonic (group, _("Registered U_ser"));
-      gtk_container_add (GTK_CONTAINER (anon_box),
+      gtk_box_append (GTK_BOX (anon_box),
                           choice);
       g_signal_connect (choice, "toggled",
                         G_CALLBACK (pw_dialog_anonymous_toggled), operation);
@@ -724,10 +724,10 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
       priv->user_widgets = g_list_prepend (priv->user_widgets, volume_type_box);
 
       priv->tcrypt_hidden_toggle = gtk_check_button_new_with_mnemonic (_("_Hidden"));
-      gtk_container_add (GTK_CONTAINER (volume_type_box), priv->tcrypt_hidden_toggle);
+      gtk_box_append (GTK_BOX (volume_type_box), priv->tcrypt_hidden_toggle);
 
       priv->tcrypt_system_toggle = gtk_check_button_new_with_mnemonic (_("_Windows system"));
-      gtk_container_add (GTK_CONTAINER (volume_type_box), priv->tcrypt_system_toggle);
+      gtk_box_append (GTK_BOX (volume_type_box), priv->tcrypt_system_toggle);
 
       priv->pim_entry = table_add_entry (operation, rows++, _("_PIM"), NULL, operation);
     }
@@ -752,7 +752,7 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
       priv->user_widgets = g_list_prepend (priv->user_widgets, remember_box);
 
       label = gtk_label_new ("");
-      gtk_container_add (GTK_CONTAINER (remember_box), label);
+      gtk_box_append (GTK_BOX (remember_box), label);
 
       password_save = g_mount_operation_get_password_save (G_MOUNT_OPERATION (operation));
       priv->password_save = password_save;
@@ -764,7 +764,7 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
                          GINT_TO_POINTER (G_PASSWORD_SAVE_NEVER));
       g_signal_connect (choice, "toggled",
                         G_CALLBACK (remember_button_toggled), operation);
-      gtk_container_add (GTK_CONTAINER (remember_box), choice);
+      gtk_box_append (GTK_BOX (remember_box), choice);
 
       group = gtk_radio_button_get_group (GTK_RADIO_BUTTON (choice));
       choice = gtk_radio_button_new_with_mnemonic (group, _("Remember password until you _logout"));
@@ -774,7 +774,7 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
                          GINT_TO_POINTER (G_PASSWORD_SAVE_FOR_SESSION));
       g_signal_connect (choice, "toggled",
                         G_CALLBACK (remember_button_toggled), operation);
-      gtk_container_add (GTK_CONTAINER (remember_box), choice);
+      gtk_box_append (GTK_BOX (remember_box), choice);
 
       group = gtk_radio_button_get_group (GTK_RADIO_BUTTON (choice));
       choice = gtk_radio_button_new_with_mnemonic (group, _("Remember _forever"));
@@ -784,7 +784,7 @@ gtk_mount_operation_ask_password_do_gtk (GtkMountOperation *operation,
                          GINT_TO_POINTER (G_PASSWORD_SAVE_PERMANENTLY));
       g_signal_connect (choice, "toggled",
                         G_CALLBACK (remember_button_toggled), operation);
-      gtk_container_add (GTK_CONTAINER (remember_box), choice);
+      gtk_box_append (GTK_BOX (remember_box), choice);
     }
 
   g_signal_connect (G_OBJECT (dialog), "response",
@@ -1430,7 +1430,7 @@ do_popup_menu_for_process_tree_view (GtkWidget         *widget,
   g_signal_connect (item, "clicked",
                     G_CALLBACK (on_end_process_activated),
                     op);
-  gtk_container_add (GTK_CONTAINER (menu), item);
+  gtk_box_append (GTK_BOX (menu), item);
 
   if (event && gdk_event_triggers_context_menu (event))
     {
@@ -1538,7 +1538,7 @@ create_show_processes_dialog (GtkMountOperation *op,
 
   content_area = gtk_dialog_get_content_area (GTK_DIALOG (dialog));
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 12);
-  gtk_container_add (GTK_CONTAINER (content_area), vbox);
+  gtk_box_append (GTK_BOX (content_area), vbox);
 
   if (secondary != NULL)
     s = g_strdup_printf ("<big><b>%s</b></big>\n\n%s", primary, secondary);
@@ -1549,7 +1549,7 @@ create_show_processes_dialog (GtkMountOperation *op,
   label = gtk_label_new (NULL);
   gtk_label_set_markup (GTK_LABEL (label), s);
   g_free (s);
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   /* First count the items in the list then
    * add the buttons in reverse order
@@ -1599,7 +1599,7 @@ create_show_processes_dialog (GtkMountOperation *op,
   gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (scrolled_window), TRUE);
 
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolled_window), tree_view);
-  gtk_container_add (GTK_CONTAINER (vbox), scrolled_window);
+  gtk_box_append (GTK_BOX (vbox), scrolled_window);
 
   controller = gtk_shortcut_controller_new ();
   trigger = gtk_alternative_trigger_new (gtk_keyval_trigger_new (GDK_KEY_F10, GDK_SHIFT_MASK),
diff --git a/gtk/gtknotebook.c b/gtk/gtknotebook.c
index 9cd289538d..9fb51844f4 100644
--- a/gtk/gtknotebook.c
+++ b/gtk/gtknotebook.c
@@ -876,8 +876,7 @@ static void gtk_notebook_menu_item_create    (GtkNotebook      *notebook,
                                               GtkNotebookPage  *page);
 static void gtk_notebook_menu_item_recreate  (GtkNotebook      *notebook,
                                               GList            *list);
-static void gtk_notebook_menu_label_unparent (GtkWidget        *widget,
-                                              gpointer          data);
+static void gtk_notebook_menu_label_unparent (GtkWidget        *widget);
 
 static void gtk_notebook_update_tab_pos      (GtkNotebook      *notebook);
 
@@ -1416,7 +1415,7 @@ gtk_notebook_init (GtkNotebook *notebook)
                                          (GtkGizmoFocusFunc)gtk_widget_focus_self,
                                          (GtkGizmoGrabFocusFunc)gtk_widget_grab_focus_self);
   gtk_widget_set_hexpand (notebook->tabs_widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (notebook->header_widget), notebook->tabs_widget);
+  gtk_box_append (GTK_BOX (notebook->header_widget), notebook->tabs_widget);
 
   notebook->stack_widget = gtk_stack_new ();
   gtk_widget_set_hexpand (notebook->stack_widget, TRUE);
@@ -2657,7 +2656,7 @@ tab_drag_end (GtkNotebook     *notebook,
   if (!NOTEBOOK_IS_TAB_LABEL_PARENT (notebook, page))
     {
       g_object_ref (page->tab_label);
-      gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (page->tab_label)), page->tab_label);
+      gtk_box_remove (GTK_BOX (gtk_widget_get_parent (page->tab_label)), page->tab_label);
       gtk_widget_set_parent (page->tab_label, page->tab_widget);
       g_object_unref (page->tab_label);
     }
@@ -4107,7 +4106,7 @@ gtk_notebook_remove_tab_label (GtkNotebook     *notebook,
           /* we hit this condition during dnd of a detached tab */
           parent = gtk_widget_get_parent (page->tab_label);
           if (GTK_IS_WINDOW (parent))
-            gtk_container_remove (GTK_CONTAINER (parent), page->tab_label);
+            gtk_box_remove (GTK_BOX (parent), page->tab_label);
           else
             gtk_widget_unparent (page->tab_label);
         }
@@ -4186,7 +4185,7 @@ gtk_notebook_real_remove (GtkNotebook *notebook,
       GtkWidget *parent = gtk_widget_get_parent (page->menu_label);
 
       if (parent)
-        gtk_notebook_menu_label_unparent (parent, NULL);
+        gtk_notebook_menu_label_unparent (parent);
       gtk_popover_set_child (GTK_POPOVER (notebook->menu), NULL);
 
       gtk_widget_queue_resize (notebook->menu);
@@ -5488,7 +5487,7 @@ gtk_notebook_menu_item_create (GtkNotebook *notebook,
   menu_item = gtk_button_new ();
   gtk_button_set_has_frame (GTK_BUTTON (menu_item), FALSE);
   gtk_button_set_child (GTK_BUTTON (menu_item), page->menu_label);
-  gtk_container_add (GTK_CONTAINER (notebook->menu_box), menu_item);
+  gtk_box_append (GTK_BOX (notebook->menu_box), menu_item);
   g_signal_connect (menu_item, "clicked",
                     G_CALLBACK (gtk_notebook_menu_switch_page), page);
   if (!gtk_widget_get_visible (page->child))
@@ -5502,14 +5501,13 @@ gtk_notebook_menu_item_recreate (GtkNotebook *notebook,
   GtkNotebookPage *page = list->data;
   GtkWidget *menu_item = gtk_widget_get_parent (page->menu_label);
 
-  gtk_container_remove (GTK_CONTAINER (menu_item), page->menu_label);
+  gtk_box_remove (GTK_BOX (menu_item), page->menu_label);
   gtk_widget_unparent (menu_item);
   gtk_notebook_menu_item_create (notebook, page);
 }
 
 static void
-gtk_notebook_menu_label_unparent (GtkWidget *widget,
-                                  gpointer  data)
+gtk_notebook_menu_label_unparent (GtkWidget *widget)
 {
   gtk_button_set_child (GTK_BUTTON (widget), NULL);
 }
@@ -6331,14 +6329,17 @@ gtk_notebook_popup_enable (GtkNotebook *notebook)
 void
 gtk_notebook_popup_disable (GtkNotebook *notebook)
 {
+  GtkWidget *child;
+
   g_return_if_fail (GTK_IS_NOTEBOOK (notebook));
 
   if (!notebook->menu)
     return;
 
-  gtk_container_foreach (GTK_CONTAINER (notebook->menu_box),
-                         (GtkCallback) gtk_notebook_menu_label_unparent, NULL);
-
+  for (child = gtk_widget_get_first_child (notebook->menu_box);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    gtk_notebook_menu_label_unparent (child);
   notebook->menu = NULL;
   notebook->menu_box = NULL;
 
@@ -6993,13 +6994,13 @@ gtk_notebook_set_action_widget (GtkNotebook *notebook,
   g_return_if_fail (!widget || gtk_widget_get_parent (widget) == NULL);
 
   if (notebook->action_widget[pack_type])
-    gtk_container_remove (GTK_CONTAINER (notebook->header_widget), notebook->action_widget[pack_type]);
+    gtk_box_remove (GTK_BOX (notebook->header_widget), notebook->action_widget[pack_type]);
 
   notebook->action_widget[pack_type] = widget;
 
   if (widget)
     {
-      gtk_container_add (GTK_CONTAINER (notebook->header_widget), widget);
+      gtk_box_append (GTK_BOX (notebook->header_widget), widget);
       if (pack_type == GTK_PACK_START)
         gtk_box_reorder_child_after (GTK_BOX (notebook->header_widget), widget, NULL);
       else
diff --git a/gtk/gtkpaned.c b/gtk/gtkpaned.c
index c7aafa053b..50f4575560 100644
--- a/gtk/gtkpaned.c
+++ b/gtk/gtkpaned.c
@@ -2107,10 +2107,14 @@ get_child_panes (GtkWidget  *widget,
       *panes = g_list_prepend (*panes, widget);
       get_child_panes (priv->end_child, panes);
     }
-  else if (GTK_IS_CONTAINER (widget))
+  else
     {
-      gtk_container_forall (GTK_CONTAINER (widget),
-                            (GtkCallback)get_child_panes, panes);
+      GtkWidget *child;
+
+      for (child = gtk_widget_get_first_child (widget);
+           child != NULL;
+           child = gtk_widget_get_next_sibling (child))
+        get_child_panes (child, panes);
     }
 }
 
diff --git a/gtk/gtkpathbar.c b/gtk/gtkpathbar.c
index c794f56dc2..ce7ac14e2d 100644
--- a/gtk/gtkpathbar.c
+++ b/gtk/gtkpathbar.c
@@ -1047,8 +1047,8 @@ make_directory_button (GtkPathBar  *path_bar,
       button_data->image = gtk_image_new ();
       button_data->label = gtk_label_new (NULL);
       child = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (child), button_data->image);
-      gtk_container_add (GTK_CONTAINER (child), button_data->label);
+      gtk_box_append (GTK_BOX (child), button_data->image);
+      gtk_box_append (GTK_BOX (child), button_data->label);
       break;
     case NORMAL_BUTTON:
     default:
diff --git a/gtk/gtkplacesview.c b/gtk/gtkplacesview.c
index 94ca0d09e7..0b299bb2c1 100644
--- a/gtk/gtkplacesview.c
+++ b/gtk/gtkplacesview.c
@@ -2041,18 +2041,18 @@ listbox_header_func (GtkListBoxRow *row,
                                   "spinning",
                                   G_BINDING_SYNC_CREATE);
 
-          gtk_container_add (GTK_CONTAINER (header_name), label);
-          gtk_container_add (GTK_CONTAINER (header_name), network_header_spinner);
-          gtk_container_add (GTK_CONTAINER (header), header_name);
+          gtk_box_append (GTK_BOX (header_name), label);
+          gtk_box_append (GTK_BOX (header_name), network_header_spinner);
+          gtk_box_append (GTK_BOX (header), header_name);
         }
       else
         {
           gtk_widget_set_hexpand (label, TRUE);
           gtk_widget_set_margin_end (label, 12);
-          gtk_container_add (GTK_CONTAINER (header), label);
+          gtk_box_append (GTK_BOX (header), label);
         }
 
-      gtk_container_add (GTK_CONTAINER (header), separator);
+      gtk_box_append (GTK_BOX (header), separator);
 
       gtk_list_box_row_set_header (row, header);
 
diff --git a/gtk/gtkprintbackend.c b/gtk/gtkprintbackend.c
index 9ec37814f0..7e54470603 100644
--- a/gtk/gtkprintbackend.c
+++ b/gtk/gtkprintbackend.c
@@ -687,12 +687,12 @@ request_password (GtkPrintBackend  *backend,
 
   /* Packing */
   content_area = gtk_dialog_get_content_area (GTK_DIALOG (dialog));
-  gtk_container_add (GTK_CONTAINER (content_area), main_box);
+  gtk_box_append (GTK_BOX (content_area), main_box);
 
-  gtk_container_add (GTK_CONTAINER (main_box), icon);
-  gtk_container_add (GTK_CONTAINER (main_box), vbox);
+  gtk_box_append (GTK_BOX (main_box), icon);
+  gtk_box_append (GTK_BOX (main_box), vbox);
 
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   /* Right - 2. */
   for (i = 0; i < length; i++)
@@ -718,10 +718,10 @@ request_password (GtkPrintBackend  *backend,
           gtk_entry_set_visibility (GTK_ENTRY (entry), ai_visible[i]);
           gtk_entry_set_activates_default (GTK_ENTRY (entry), TRUE);
 
-          gtk_container_add (GTK_CONTAINER (vbox), box);
+          gtk_box_append (GTK_BOX (vbox), box);
 
-          gtk_container_add (GTK_CONTAINER (box), label);
-          gtk_container_add (GTK_CONTAINER (box), entry);
+          gtk_box_append (GTK_BOX (box), label);
+          gtk_box_append (GTK_BOX (box), entry);
 
           g_signal_connect (entry, "changed",
                             G_CALLBACK (store_entry), &(priv->auth_info[i]));
@@ -734,7 +734,7 @@ request_password (GtkPrintBackend  *backend,
       gtk_widget_set_margin_top (chkbtn, 6);
       gtk_widget_set_margin_bottom (chkbtn, 6);
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (chkbtn), FALSE);
-      gtk_container_add (GTK_CONTAINER (vbox), chkbtn);
+      gtk_box_append (GTK_BOX (vbox), chkbtn);
       g_signal_connect (chkbtn, "toggled",
                         G_CALLBACK (store_auth_info_toggled),
                         &(priv->store_auth_info));
diff --git a/gtk/gtkprinteroptionwidget.c b/gtk/gtkprinteroptionwidget.c
index 694fec9e48..66a145cffe 100644
--- a/gtk/gtkprinteroptionwidget.c
+++ b/gtk/gtkprinteroptionwidget.c
@@ -701,11 +701,14 @@ select_maybe (GtkWidget   *widget,
 
 static void
 alternative_set (GtkWidget   *box,
-                const gchar *value)
+                 const gchar *value)
 {
-  gtk_container_foreach (GTK_CONTAINER (box), 
-                        (GtkCallback) select_maybe,
-                        (gpointer) value);
+  GtkWidget *child;
+
+  for (child = gtk_widget_get_first_child (box);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    select_maybe (child, value);
 }
 
 static GSList *
@@ -720,7 +723,7 @@ alternative_append (GtkWidget              *box,
   button = gtk_radio_button_new_with_label (group, label);
   gtk_widget_show (button);
   gtk_widget_set_valign (button, GTK_ALIGN_BASELINE);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   g_object_set_data (G_OBJECT (button), "value", (gpointer)value);
   g_signal_connect (button, "toggled",
@@ -751,7 +754,7 @@ construct_widgets (GtkPrinterOptionWidget *widget)
       gtk_combo_box_set_active (GTK_COMBO_BOX (priv->combo), 0);
       gtk_widget_set_sensitive (GTK_WIDGET (widget), FALSE);
       gtk_widget_show (priv->combo);
-      gtk_container_add (GTK_CONTAINER (widget), priv->combo);
+      gtk_box_append (GTK_BOX (widget), priv->combo);
     }
   else switch (source->type)
     {
@@ -759,7 +762,7 @@ construct_widgets (GtkPrinterOptionWidget *widget)
       priv->check = gtk_check_button_new_with_mnemonic (source->display_text);
       g_signal_connect (priv->check, "toggled", G_CALLBACK (check_toggled_cb), widget);
       gtk_widget_show (priv->check);
-      gtk_container_add (GTK_CONTAINER (widget), priv->check);
+      gtk_box_append (GTK_BOX (widget), priv->check);
       break;
     case GTK_PRINTER_OPTION_TYPE_PICKONE:
     case GTK_PRINTER_OPTION_TYPE_PICKONE_PASSWORD:
@@ -791,7 +794,7 @@ construct_widgets (GtkPrinterOptionWidget *widget)
                           source->choices_display[i],
                           source->choices[i]);
       gtk_widget_show (priv->combo);
-      gtk_container_add (GTK_CONTAINER (widget), priv->combo);
+      gtk_box_append (GTK_BOX (widget), priv->combo);
       g_signal_connect (priv->combo, "changed", G_CALLBACK (combo_changed_cb), widget);
 
       text = g_strdup_printf ("%s:", source->display_text);
@@ -805,7 +808,7 @@ construct_widgets (GtkPrinterOptionWidget *widget)
       priv->box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
       gtk_widget_set_valign (priv->box, GTK_ALIGN_BASELINE);
       gtk_widget_show (priv->box);
-      gtk_container_add (GTK_CONTAINER (widget), priv->box);
+      gtk_box_append (GTK_BOX (widget), priv->box);
       for (i = 0; i < source->num_choices; i++)
         {
          group = alternative_append (priv->box,
@@ -833,7 +836,7 @@ construct_widgets (GtkPrinterOptionWidget *widget)
       gtk_entry_set_activates_default (GTK_ENTRY (priv->entry),
                                        gtk_printer_option_get_activates_default (source));
       gtk_widget_show (priv->entry);
-      gtk_container_add (GTK_CONTAINER (widget), priv->entry);
+      gtk_box_append (GTK_BOX (widget), priv->entry);
       g_signal_connect (priv->entry, "changed", G_CALLBACK (entry_changed_cb), widget);
 
       text = g_strdup_printf ("%s:", source->display_text);
@@ -846,7 +849,7 @@ construct_widgets (GtkPrinterOptionWidget *widget)
     case GTK_PRINTER_OPTION_TYPE_FILESAVE:
       priv->button = gtk_button_new ();
       gtk_widget_show (priv->button);
-      gtk_container_add (GTK_CONTAINER (widget), priv->button);
+      gtk_box_append (GTK_BOX (widget), priv->button);
       g_signal_connect (priv->button, "clicked", G_CALLBACK (filesave_choose_cb), widget);
 
       text = g_strdup_printf ("%s:", source->display_text);
@@ -859,7 +862,7 @@ construct_widgets (GtkPrinterOptionWidget *widget)
     case GTK_PRINTER_OPTION_TYPE_INFO:
       priv->info_label = gtk_label_new (NULL);
       gtk_label_set_selectable (GTK_LABEL (priv->info_label), TRUE);
-      gtk_container_add (GTK_CONTAINER (widget), priv->info_label);
+      gtk_box_append (GTK_BOX (widget), priv->info_label);
 
       text = g_strdup_printf ("%s:", source->display_text);
       priv->label = gtk_label_new_with_mnemonic (text);
@@ -872,7 +875,7 @@ construct_widgets (GtkPrinterOptionWidget *widget)
     }
 
   priv->image = gtk_image_new_from_icon_name ("dialog-warning");
-  gtk_container_add (GTK_CONTAINER (widget), priv->image);
+  gtk_box_append (GTK_BOX (widget), priv->image);
 }
 
 /*
diff --git a/gtk/gtkprintoperation-win32.c b/gtk/gtkprintoperation-win32.c
index 009dffcde4..2b9ec44b75 100644
--- a/gtk/gtkprintoperation-win32.c
+++ b/gtk/gtkprintoperation-win32.c
@@ -1423,7 +1423,7 @@ pageDlgProc (HWND wnd, UINT message, WPARAM wparam, LPARAM lparam)
 
       gtk_window_set_modal (GTK_WINDOW (plug), TRUE);
       op_win32->embed_widget = plug;
-      gtk_container_add (GTK_CONTAINER (plug), op->priv->custom_widget);
+      gtk_box_append (GTK_BOX (plug), op->priv->custom_widget);
       gtk_widget_show (op->priv->custom_widget);
       gtk_widget_show (plug);
 
diff --git a/gtk/gtkprintunixdialog.c b/gtk/gtkprintunixdialog.c
index e228db84d4..affb67cf9a 100644
--- a/gtk/gtkprintunixdialog.c
+++ b/gtk/gtkprintunixdialog.c
@@ -816,7 +816,7 @@ gtk_print_unix_dialog_constructed (GObject *object)
        button = gtk_dialog_get_widget_for_response (GTK_DIALOG (object), GTK_RESPONSE_APPLY);
        g_object_ref (button);
        parent = gtk_widget_get_ancestor (button, GTK_TYPE_HEADER_BAR);
-       gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (button)), button);
+       gtk_box_remove (GTK_BOX (gtk_widget_get_parent (button)), button);
        gtk_header_bar_pack_end (GTK_HEADER_BAR (parent), button);
        g_object_unref (button);
     }
@@ -1291,13 +1291,13 @@ wrap_in_frame (const gchar *label,
   g_free (bold_text);
 
   frame = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
-  gtk_container_add (GTK_CONTAINER (frame), label_widget);
+  gtk_box_append (GTK_BOX (frame), label_widget);
 
   gtk_widget_set_margin_start (child, 12);
   gtk_widget_set_halign (child, GTK_ALIGN_FILL);
   gtk_widget_set_valign (child, GTK_ALIGN_FILL);
 
-  gtk_container_add (GTK_CONTAINER (frame), child);
+  gtk_box_append (GTK_BOX (frame), child);
 
   gtk_widget_show (frame);
 
@@ -1341,14 +1341,14 @@ add_option_to_extension_point (GtkPrinterOption *option,
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
       gtk_widget_set_valign (hbox, GTK_ALIGN_BASELINE);
-      gtk_container_add (GTK_CONTAINER (hbox), label);
-      gtk_container_add (GTK_CONTAINER (hbox), widget);
+      gtk_box_append (GTK_BOX (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), widget);
       gtk_widget_show (hbox);
 
-      gtk_container_add (GTK_CONTAINER (extension_point), hbox);
+      gtk_box_append (GTK_BOX (extension_point), hbox);
     }
   else
-    gtk_container_add (GTK_CONTAINER (extension_point), widget);
+    gtk_box_append (GTK_BOX (extension_point), widget);
 }
 
 static gint
@@ -1521,7 +1521,7 @@ update_dialog_from_settings (GtkPrintUnixDialog *dialog)
   GtkWidget *table, *frame;
   gboolean has_advanced, has_job;
   guint nrows;
-  GList *children;
+  GtkWidget *child;
 
   if (dialog->current_printer == NULL)
     {
@@ -1579,11 +1579,9 @@ update_dialog_from_settings (GtkPrintUnixDialog *dialog)
    * This keeps the file format radios from moving as the
    * filename changes.
    */
-  children = gtk_container_get_children (GTK_CONTAINER (dialog->extension_point));
-  l = g_list_last (children);
-  if (l && l != children)
-    gtk_widget_set_halign (GTK_WIDGET (l->data), GTK_ALIGN_END);
-  g_list_free (children);
+  child = gtk_widget_get_last_child (dialog->extension_point);
+  if (child && child != gtk_widget_get_first_child (dialog->extension_point))
+    gtk_widget_set_halign (child, GTK_ALIGN_END);
 
   /* Put the rest of the groups in the advanced page */
   groups = gtk_printer_option_set_get_groups (dialog->options);
@@ -1620,7 +1618,7 @@ update_dialog_from_settings (GtkPrintUnixDialog *dialog)
         {
           has_advanced = TRUE;
           frame = wrap_in_frame (group, table);
-          gtk_container_add (GTK_CONTAINER (dialog->advanced_vbox), frame);
+          gtk_box_append (GTK_BOX (dialog->advanced_vbox), frame);
         }
     }
 
@@ -1942,9 +1940,9 @@ clear_per_printer_ui (GtkPrintUnixDialog *dialog)
   while ((child = gtk_widget_get_first_child (dialog->color_table)))
     gtk_grid_remove (GTK_GRID (dialog->color_table), child);
   while ((child = gtk_widget_get_first_child (dialog->advanced_vbox)))
-    gtk_container_remove (GTK_CONTAINER (dialog->advanced_vbox), child);
+    gtk_box_remove (GTK_BOX (dialog->advanced_vbox), child);
   while ((child = gtk_widget_get_first_child (dialog->extension_point)))
-    gtk_container_remove (GTK_CONTAINER (dialog->extension_point), child);
+    gtk_box_remove (GTK_BOX (dialog->extension_point), child);
 }
 
 static void
diff --git a/gtk/gtkradiobutton.c b/gtk/gtkradiobutton.c
index 618fb712d9..4d67d0ddca 100644
--- a/gtk/gtkradiobutton.c
+++ b/gtk/gtkradiobutton.c
@@ -104,7 +104,7 @@
  *    // Create a radio button with a GtkEntry widget
  *    radio1 = gtk_radio_button_new (NULL);
  *    entry = gtk_entry_new ();
- *    gtk_container_add (GTK_CONTAINER (radio1), entry);
+ *    gtk_box_append (GTK_BOX (radio1), entry);
  *
  *
  *    // Create a radio button with a label
@@ -112,8 +112,8 @@
  *                                                          "I’m the second radio button.");
  *
  *    // Pack them into a box, then show all the widgets
- *    gtk_container_add (GTK_CONTAINER (box), radio1);
- *    gtk_container_add (GTK_CONTAINER (box), radio2);
+ *    gtk_box_append (GTK_BOX (box), radio1);
+ *    gtk_box_append (GTK_BOX (box), radio2);
       gtk_window_set_child (GTK_WINDOW (window),box);
  *    gtk_widget_show (window);
  *    return;
diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index 24bdd5a063..2478b230b9 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -85,14 +85,14 @@
  *
  * // GtkButton is not a GtkScrollable, so GtkScrolledWindow will automatically
  * // add a GtkViewport.
- * gtk_container_add (GTK_CONTAINER (scrolled_window),
+ * gtk_box_append (GTK_BOX (scrolled_window),
  *                    child_widget);
  *
  * // Either of these will result in child_widget being unparented:
- * gtk_container_remove (GTK_CONTAINER (scrolled_window),
+ * gtk_box_remove (GTK_BOX (scrolled_window),
  *                       child_widget);
  * // or
- * gtk_container_remove (GTK_CONTAINER (scrolled_window),
+ * gtk_box_remove (GTK_BOX (scrolled_window),
  *                       gtk_bin_get_child (GTK_BIN (scrolled_window)));
  * ]|
  *
diff --git a/gtk/gtkshortcutsgroup.c b/gtk/gtkshortcutsgroup.c
index a44a37d84d..0d1cd76d42 100644
--- a/gtk/gtkshortcutsgroup.c
+++ b/gtk/gtkshortcutsgroup.c
@@ -92,49 +92,47 @@ static void
 gtk_shortcuts_group_set_accel_size_group (GtkShortcutsGroup *group,
                                           GtkSizeGroup      *size_group)
 {
-  GList *children, *l;
+  GtkWidget *child;
 
   g_set_object (&group->accel_size_group, size_group);
 
-  children = gtk_container_get_children (GTK_CONTAINER (group));
-  for (l = children; l; l = l->next)
-    gtk_shortcuts_group_apply_accel_size_group (group, GTK_WIDGET (l->data));
-  g_list_free (children);
+  for (child = gtk_widget_get_first_child (GTK_WIDGET (group));
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    gtk_shortcuts_group_apply_accel_size_group (group, child);
 }
 
 static void
 gtk_shortcuts_group_set_title_size_group (GtkShortcutsGroup *group,
                                           GtkSizeGroup      *size_group)
 {
-  GList *children, *l;
+  GtkWidget *child;
 
   g_set_object (&group->title_size_group, size_group);
 
-  children = gtk_container_get_children (GTK_CONTAINER (group));
-  for (l = children; l; l = l->next)
-    gtk_shortcuts_group_apply_title_size_group (group, GTK_WIDGET (l->data));
-  g_list_free (children);
+  for (child = gtk_widget_get_first_child (GTK_WIDGET (group));
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    gtk_shortcuts_group_apply_title_size_group (group, child);
 }
 
 static guint
 gtk_shortcuts_group_get_height (GtkShortcutsGroup *group)
 {
-  GList *children, *l;
+  GtkWidget *child;
   guint height;
 
   height = 1;
 
-  children = gtk_container_get_children (GTK_CONTAINER (group));
-  for (l = children; l; l = l->next)
+  for (child = gtk_widget_get_first_child (GTK_WIDGET (group));
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
     {
-      GtkWidget *child = l->data;
-
       if (!gtk_widget_get_visible (child))
         continue;
       else if (GTK_IS_SHORTCUTS_SHORTCUT (child))
         height += 1;
     }
-  g_list_free (children);
 
   return height;
 }
diff --git a/gtk/gtkshortcutssection.c b/gtk/gtkshortcutssection.c
index 9c2f413023..f6bfbf4d4c 100644
--- a/gtk/gtkshortcutssection.c
+++ b/gtk/gtkshortcutssection.c
@@ -143,7 +143,7 @@ gtk_shortcuts_section_remove (GtkContainer *container,
       gtk_widget_is_ancestor (child, GTK_WIDGET (container)))
     {
       self->groups = g_list_remove (self->groups, child);
-      gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (child)), child);
+      gtk_box_remove (GTK_BOX (gtk_widget_get_parent (child)), child);
     }
   else
     GTK_CONTAINER_CLASS (gtk_shortcuts_section_parent_class)->remove (container, child);
@@ -492,10 +492,10 @@ gtk_shortcuts_section_add_group (GtkShortcutsSection *self,
   if (column == NULL)
     {
       column = gtk_box_new (GTK_ORIENTATION_VERTICAL, 22);
-      gtk_container_add (GTK_CONTAINER (page), column);
+      gtk_box_append (GTK_BOX (page), column);
     }
 
-  gtk_container_add (GTK_CONTAINER (column), GTK_WIDGET (group));
+  gtk_box_append (GTK_BOX (column), GTK_WIDGET (group));
   self->groups = g_list_append (self->groups, group);
 
   gtk_shortcuts_section_reflow_groups (self);
@@ -527,18 +527,26 @@ update_group_visibility (GtkWidget *child, gpointer data)
 
       g_free (view);
     }
-  else if (GTK_IS_CONTAINER (child))
+  else
     {
-      gtk_container_foreach (GTK_CONTAINER (child), update_group_visibility, data);
+      for (child = gtk_widget_get_first_child (GTK_WIDGET (child));
+           child != NULL;
+           child = gtk_widget_get_next_sibling (child))
+        update_group_visibility (child, self);
     }
 }
 
 static void
 gtk_shortcuts_section_filter_groups (GtkShortcutsSection *self)
 {
+  GtkWidget *child;
+
   self->has_filtered_group = FALSE;
 
-  gtk_container_foreach (GTK_CONTAINER (self), update_group_visibility, self);
+  for (child = gtk_widget_get_first_child (GTK_WIDGET (self));
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    update_group_visibility (child, self);
 
   gtk_widget_set_visible (GTK_WIDGET (self->show_all), self->has_filtered_group);
   gtk_widget_set_visible (gtk_widget_get_parent (GTK_WIDGET (self->show_all)),
@@ -549,10 +557,9 @@ gtk_shortcuts_section_filter_groups (GtkShortcutsSection *self)
 static void
 gtk_shortcuts_section_reflow_groups (GtkShortcutsSection *self)
 {
-  GtkWidget *page, *column;
   GList *pages, *p;
+  GtkWidget *page;
   GList *groups, *g;
-  GList *children;
   guint n_rows;
   guint n_columns;
   guint n_pages;
@@ -564,14 +571,23 @@ gtk_shortcuts_section_reflow_groups (GtkShortcutsSection *self)
        page != NULL;
        page = gtk_widget_get_next_sibling (page))
     {
+      GtkWidget *column;
+
       for (column = gtk_widget_get_first_child (page);
            column != NULL;
            column = gtk_widget_get_next_sibling (column))
         {
-          children = gtk_container_get_children (GTK_CONTAINER (column));
-          groups = g_list_concat (groups, children);
+          GtkWidget *group;
+
+          for (group = gtk_widget_get_first_child (column);
+               group != NULL;
+               group = gtk_widget_get_next_sibling (group))
+            {
+              groups = g_list_prepend (groups, group);
+            }
         }
     }
+  groups = g_list_reverse (groups);
 
   /* create new pages */
   current_page = NULL;
@@ -614,7 +630,7 @@ gtk_shortcuts_section_reflow_groups (GtkShortcutsSection *self)
               current_page = page;
             }
 
-          gtk_container_add (GTK_CONTAINER (current_page), column_box);
+          gtk_box_append (GTK_BOX (current_page), column_box);
           current_column = column_box;
           n_columns += 1;
           n_rows = 0;
@@ -628,8 +644,8 @@ gtk_shortcuts_section_reflow_groups (GtkShortcutsSection *self)
                     NULL);
 
       g_object_ref (group);
-      gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (GTK_WIDGET (group))), GTK_WIDGET (group));
-      gtk_container_add (GTK_CONTAINER (current_column), GTK_WIDGET (group));
+      gtk_box_remove (GTK_BOX (gtk_widget_get_parent (GTK_WIDGET (group))), GTK_WIDGET (group));
+      gtk_box_append (GTK_BOX (current_column), GTK_WIDGET (group));
       g_object_unref (group);
     }
 
@@ -639,6 +655,7 @@ gtk_shortcuts_section_reflow_groups (GtkShortcutsSection *self)
       GtkWidget *column_box;
       GtkSizeGroup *size_group;
       GList *content;
+      GtkWidget *child;
       guint n;
 
       column_box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 22);
@@ -648,9 +665,14 @@ gtk_shortcuts_section_reflow_groups (GtkShortcutsSection *self)
       size_group = gtk_size_group_new (GTK_SIZE_GROUP_HORIZONTAL);
       g_object_set_data_full (G_OBJECT (column_box), "title-size-group", size_group, g_object_unref);
 
-      gtk_container_add (GTK_CONTAINER (current_page), column_box);
+      gtk_box_append (GTK_BOX (current_page), column_box);
 
-      content = gtk_container_get_children (GTK_CONTAINER (current_column));
+      content = NULL;
+      for (child = gtk_widget_get_last_child (current_column);
+           child != NULL;
+           child = gtk_widget_get_prev_sibling (child))
+        content = g_list_prepend (content, child);
+      content = g_list_reverse (content);
       n = 0;
 
       for (g = g_list_last (content); g; g = g->prev)
@@ -686,8 +708,8 @@ gtk_shortcuts_section_reflow_groups (GtkShortcutsSection *self)
                         NULL);
 
           g_object_ref (group);
-          gtk_container_remove (GTK_CONTAINER (current_column), GTK_WIDGET (group));
-          gtk_container_add (GTK_CONTAINER (column_box), GTK_WIDGET (group));
+          gtk_box_remove (GTK_BOX (current_column), GTK_WIDGET (group));
+          gtk_box_append (GTK_BOX (column_box), GTK_WIDGET (group));
           g_object_unref (group);
         }
 
@@ -742,26 +764,21 @@ gtk_shortcuts_section_change_current_page (GtkShortcutsSection *self,
                                            gint                 offset)
 {
   GtkWidget *child;
-  GList *children, *l;
 
   child = gtk_stack_get_visible_child (self->stack);
-  children = gtk_container_get_children (GTK_CONTAINER (self->stack));
-  l = g_list_find (children, child);
 
   if (offset == 1)
-    l = l->next;
+    child = gtk_widget_get_next_sibling (child);
   else if (offset == -1)
-    l = l->prev;
+    child = gtk_widget_get_prev_sibling (child);
   else
     g_assert_not_reached ();
 
-  if (l)
-    gtk_stack_set_visible_child (self->stack, GTK_WIDGET (l->data));
+  if (child)
+    gtk_stack_set_visible_child (self->stack, child);
   else
     gtk_widget_error_bell (GTK_WIDGET (self));
 
-  g_list_free (children);
-
   return TRUE;
 }
 
diff --git a/gtk/gtkshortcutsshortcut.c b/gtk/gtkshortcutsshortcut.c
index 9c4b0284ab..e7586c3cbf 100644
--- a/gtk/gtkshortcutsshortcut.c
+++ b/gtk/gtkshortcutsshortcut.c
@@ -742,13 +742,13 @@ gtk_shortcuts_shortcut_init (GtkShortcutsShortcut *self)
                               "visible", FALSE,
                               "valign", GTK_ALIGN_CENTER,
                               NULL);
-  gtk_container_add (GTK_CONTAINER (self->box), GTK_WIDGET (self->image));
+  gtk_box_append (GTK_BOX (self->box), GTK_WIDGET (self->image));
 
   self->accelerator = g_object_new (GTK_TYPE_SHORTCUT_LABEL,
                                     "visible", TRUE,
                                     "valign", GTK_ALIGN_CENTER,
                                     NULL);
-  gtk_container_add (GTK_CONTAINER (self->box), GTK_WIDGET (self->accelerator));
+  gtk_box_append (GTK_BOX (self->box), GTK_WIDGET (self->accelerator));
 
   self->title_box = g_object_new (GTK_TYPE_BOX,
                                   "visible", TRUE,
@@ -756,18 +756,18 @@ gtk_shortcuts_shortcut_init (GtkShortcutsShortcut *self)
                                   "hexpand", TRUE,
                                   "orientation", GTK_ORIENTATION_VERTICAL,
                                   NULL);
-  gtk_container_add (GTK_CONTAINER (self->box), GTK_WIDGET (self->title_box));
+  gtk_box_append (GTK_BOX (self->box), GTK_WIDGET (self->title_box));
 
   self->title = g_object_new (GTK_TYPE_LABEL,
                               "visible", TRUE,
                               "xalign", 0.0f,
                               NULL);
-  gtk_container_add (GTK_CONTAINER (self->title_box), GTK_WIDGET (self->title));
+  gtk_box_append (GTK_BOX (self->title_box), GTK_WIDGET (self->title));
 
   self->subtitle = g_object_new (GTK_TYPE_LABEL,
                                  "visible", FALSE,
                                  "xalign", 0.0f,
                                  NULL);
   gtk_widget_add_css_class (GTK_WIDGET (self->subtitle), GTK_STYLE_CLASS_DIM_LABEL);
-  gtk_container_add (GTK_CONTAINER (self->title_box), GTK_WIDGET (self->subtitle));
+  gtk_box_append (GTK_BOX (self->title_box), GTK_WIDGET (self->subtitle));
 }
diff --git a/gtk/gtkshortcutswindow.c b/gtk/gtkshortcutswindow.c
index 2ca5fb26bc..643c1b0e68 100644
--- a/gtk/gtkshortcutswindow.c
+++ b/gtk/gtkshortcutswindow.c
@@ -284,18 +284,23 @@ gtk_shortcuts_window_add_search_item (GtkWidget *child, gpointer data)
 
       g_hash_table_insert (priv->keywords, item, keywords);
       if (shortcut_type == GTK_SHORTCUT_ACCELERATOR)
-        gtk_container_add (GTK_CONTAINER (priv->search_shortcuts), item);
+        gtk_box_append (GTK_BOX (priv->search_shortcuts), item);
       else
-        gtk_container_add (GTK_CONTAINER (priv->search_gestures), item);
+        gtk_box_append (GTK_BOX (priv->search_gestures), item);
 
       g_free (title);
       g_free (accelerator);
       g_free (str);
       g_free (action_name);
     }
-  else if (GTK_IS_CONTAINER (child))
+  else
     {
-      gtk_container_foreach (GTK_CONTAINER (child), gtk_shortcuts_window_add_search_item, self);
+      GtkWidget *widget;
+
+      for (widget = gtk_widget_get_first_child (child);
+           widget != NULL;
+           widget = gtk_widget_get_next_sibling (widget))
+        gtk_shortcuts_window_add_search_item (widget, self);
     }
 }
 
@@ -337,8 +342,12 @@ gtk_shortcuts_window_add_section (GtkShortcutsWindow  *self,
   gchar *name;
   const gchar *visible_section;
   GtkWidget *label;
+  GtkWidget *child;
 
-  gtk_container_foreach (GTK_CONTAINER (section), gtk_shortcuts_window_add_search_item, self);
+  for (child = gtk_widget_get_first_child (GTK_WIDGET (section));
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    gtk_shortcuts_window_add_search_item (child, self);
 
   g_object_get (section,
                 "section-name", &name,
@@ -445,8 +454,15 @@ update_accels_cb (GtkWidget *widget,
 
   if (GTK_IS_SHORTCUTS_SHORTCUT (widget))
     gtk_shortcuts_shortcut_update_accel (GTK_SHORTCUTS_SHORTCUT (widget), priv->window);
-  else if (GTK_IS_CONTAINER (widget))
-    gtk_container_foreach (GTK_CONTAINER (widget), update_accels_cb, self);
+  else
+    {
+      GtkWidget *child;
+
+      for (child = gtk_widget_get_first_child (GTK_WIDGET (widget));
+           child != NULL;
+           child = gtk_widget_get_next_sibling (child ))
+        update_accels_cb (child, self);
+    }
 }
 
 static void
@@ -863,7 +879,7 @@ gtk_shortcuts_window_init (GtkShortcutsWindow *self)
   g_object_bind_property (priv->search_bar, "search-mode-enabled",
                           search_button, "active",
                           G_BINDING_SYNC_CREATE | G_BINDING_BIDIRECTIONAL);
-  gtk_container_add (GTK_CONTAINER (priv->main_box), GTK_WIDGET (priv->search_bar));
+  gtk_box_append (GTK_BOX (priv->main_box), GTK_WIDGET (priv->search_bar));
   gtk_search_bar_set_key_capture_widget (GTK_SEARCH_BAR (priv->search_bar),
                                          GTK_WIDGET (self));
 
@@ -874,7 +890,7 @@ gtk_shortcuts_window_init (GtkShortcutsWindow *self)
                               "vhomogeneous", TRUE,
                               "transition-type", GTK_STACK_TRANSITION_TYPE_CROSSFADE,
                               NULL);
-  gtk_container_add (GTK_CONTAINER (priv->main_box), GTK_WIDGET (priv->stack));
+  gtk_box_append (GTK_BOX (priv->main_box), GTK_WIDGET (priv->stack));
 
   priv->title_stack = g_object_new (GTK_TYPE_STACK,
                                     NULL);
@@ -944,14 +960,14 @@ gtk_shortcuts_window_init (GtkShortcutsWindow *self)
                                          "spacing", 6,
                                          "orientation", GTK_ORIENTATION_VERTICAL,
                                          NULL);
-  gtk_container_add (GTK_CONTAINER (box), GTK_WIDGET (priv->search_shortcuts));
+  gtk_box_append (GTK_BOX (box), GTK_WIDGET (priv->search_shortcuts));
 
   priv->search_gestures = g_object_new (GTK_TYPE_BOX,
                                         "halign", GTK_ALIGN_CENTER,
                                         "spacing", 6,
                                         "orientation", GTK_ORIENTATION_VERTICAL,
                                         NULL);
-  gtk_container_add (GTK_CONTAINER (box), GTK_WIDGET (priv->search_gestures));
+  gtk_box_append (GTK_BOX (box), GTK_WIDGET (priv->search_gestures));
 
   empty = g_object_new (GTK_TYPE_GRID,
                         "row-spacing", 12,
diff --git a/gtk/gtktext.c b/gtk/gtktext.c
index 9113a84575..de3b46c009 100644
--- a/gtk/gtktext.c
+++ b/gtk/gtktext.c
@@ -6006,7 +6006,7 @@ append_bubble_item (GtkText    *self,
   gtk_widget_add_css_class (item, "image-button");
   gtk_actionable_set_action_name (GTK_ACTIONABLE (item), action_name);
   gtk_widget_show (GTK_WIDGET (item));
-  gtk_container_add (GTK_CONTAINER (toolbar), item);
+  gtk_box_append (GTK_BOX (toolbar), item);
 }
 
 static gboolean
@@ -6054,7 +6054,7 @@ gtk_text_selection_bubble_popup_show (gpointer user_data)
   toolbar = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_add_css_class (toolbar, "linked");
   gtk_popover_set_child (GTK_POPOVER (priv->selection_bubble), box);
-  gtk_container_add (GTK_CONTAINER (box), toolbar);
+  gtk_box_append (GTK_BOX (box), toolbar);
 
   model = gtk_text_get_menu_model (self);
 
diff --git a/gtk/gtktextview.c b/gtk/gtktextview.c
index 2e02abea24..45f1476627 100644
--- a/gtk/gtktextview.c
+++ b/gtk/gtktextview.c
@@ -8753,7 +8753,7 @@ append_bubble_item (GtkTextView *text_view,
   gtk_widget_add_css_class (item, "image-button");
   gtk_actionable_set_action_name (GTK_ACTIONABLE (item), action_name);
 
-  gtk_container_add (GTK_CONTAINER (toolbar), item);
+  gtk_box_append (GTK_BOX (toolbar), item);
 }
 
 static gboolean
@@ -8789,7 +8789,7 @@ gtk_text_view_selection_bubble_popup_show (gpointer user_data)
   toolbar = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_add_css_class (toolbar, "linked");
   gtk_popover_set_child (GTK_POPOVER (priv->selection_bubble), box);
-  gtk_container_add (GTK_CONTAINER (box), toolbar);
+  gtk_box_append (GTK_BOX (box), toolbar);
 
   model = gtk_text_view_get_menu_model (text_view);
 
diff --git a/gtk/gtktogglebutton.c b/gtk/gtktogglebutton.c
index da5de35ae5..34b2879e63 100644
--- a/gtk/gtktogglebutton.c
+++ b/gtk/gtktogglebutton.c
@@ -84,14 +84,14 @@
  *   g_signal_connect (toggle1, "toggled",
  *                     G_CALLBACK (output_state),
  *                     NULL);
- *   gtk_container_add (GTK_CONTAINER (box), toggle1);
+ *   gtk_box_append (GTK_BOX (box), toggle1);
  *
  *   text = "Hi, I’m a toggle button.";
  *   toggle2 = gtk_toggle_button_new_with_label (text);
  *   g_signal_connect (toggle2, "toggled",
  *                     G_CALLBACK (output_state),
  *                     NULL);
- *   gtk_container_add (GTK_CONTAINER (box), toggle2);
+ *   gtk_box_append (GTK_BOX (box), toggle2);
  *
  *   gtk_window_set_child (GTK_WINDOW (window), box);
  *   gtk_widget_show (window);
diff --git a/gtk/gtktooltipwindow.c b/gtk/gtktooltipwindow.c
index 3c36b82691..5c9c4e5097 100644
--- a/gtk/gtktooltipwindow.c
+++ b/gtk/gtktooltipwindow.c
@@ -499,7 +499,7 @@ gtk_tooltip_window_set_custom_widget (GtkTooltipWindow *window,
        * gtk_tooltip_set_custom()
        */
       window->custom_widget = NULL;
-      gtk_container_remove (GTK_CONTAINER (window->box), custom);
+      gtk_box_remove (GTK_BOX (window->box), custom);
       g_object_unref (custom);
     }
 
@@ -507,7 +507,7 @@ gtk_tooltip_window_set_custom_widget (GtkTooltipWindow *window,
     {
       window->custom_widget = g_object_ref (custom_widget);
 
-      gtk_container_add (GTK_CONTAINER (window->box), custom_widget);
+      gtk_box_append (GTK_BOX (window->box), custom_widget);
       gtk_widget_show (custom_widget);
       gtk_widget_hide (window->image);
       gtk_widget_hide (window->label);
diff --git a/gtk/gtktreepopover.c b/gtk/gtktreepopover.c
index 2c26ea8234..dba7de69e0 100644
--- a/gtk/gtktreepopover.c
+++ b/gtk/gtktreepopover.c
@@ -318,8 +318,8 @@ ensure_submenu (GtkTreePopover *popover,
           GtkWidget *item;
           gtk_tree_model_get_iter (popover->model, &iter, path);
           item = gtk_tree_popover_create_item (popover, path, &iter, TRUE);
-          gtk_container_add (GTK_CONTAINER (box), item);
-          gtk_container_add (GTK_CONTAINER (box), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+          gtk_box_append (GTK_BOX (box), item);
+          gtk_box_append (GTK_BOX (box), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
         }
 
     }
@@ -407,7 +407,7 @@ row_changed_cb (GtkTreeModel   *model,
     {
       GtkWidget *box = gtk_widget_get_parent (item);
 
-      gtk_container_remove (GTK_CONTAINER (box), item);
+      gtk_box_remove (GTK_BOX (box), item);
 
       item = gtk_tree_popover_create_item (popover, path, iter, FALSE);
 
diff --git a/gtk/gtktreeviewcolumn.c b/gtk/gtktreeviewcolumn.c
index 0692717a65..e26d1a0b03 100644
--- a/gtk/gtktreeviewcolumn.c
+++ b/gtk/gtktreeviewcolumn.c
@@ -887,16 +887,16 @@ gtk_tree_view_column_create_button (GtkTreeViewColumn *tree_column)
 
   if (priv->xalign <= 0.5)
     {
-      gtk_container_add (GTK_CONTAINER (hbox), priv->frame);
-      gtk_container_add (GTK_CONTAINER (hbox), priv->arrow);
+      gtk_box_append (GTK_BOX (hbox), priv->frame);
+      gtk_box_append (GTK_BOX (hbox), priv->arrow);
     }
   else
     {
-      gtk_container_add (GTK_CONTAINER (hbox), priv->arrow);
-      gtk_container_add (GTK_CONTAINER (hbox), priv->frame);
+      gtk_box_append (GTK_BOX (hbox), priv->arrow);
+      gtk_box_append (GTK_BOX (hbox), priv->frame);
     }
 
-  gtk_container_add (GTK_CONTAINER (priv->frame), child);
+  gtk_box_append (GTK_BOX (priv->frame), child);
   gtk_button_set_child (GTK_BUTTON (priv->button), hbox);
 }
 
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 1b0ce5d61a..4e4c5cf66f 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -7099,9 +7099,7 @@ gtk_widget_dispose (GObject *object)
   if (priv->controller_observer)
     gtk_list_list_model_clear (priv->controller_observer);
 
-  if (priv->parent && GTK_IS_CONTAINER (priv->parent))
-    gtk_container_remove (GTK_CONTAINER (priv->parent), widget);
-  else if (priv->parent)
+  if (priv->parent)
     gtk_widget_unparent (widget);
   else if (_gtk_widget_get_visible (widget))
     gtk_widget_hide (widget);
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index eaa0ff11bd..124035d444 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -5830,7 +5830,7 @@ gtk_window_do_popup_fallback (GtkWindow *window,
     gtk_widget_set_sensitive (menuitem, FALSE);
   g_signal_connect (G_OBJECT (menuitem), "clicked",
                     G_CALLBACK (restore_window_clicked), window);
-  gtk_container_add (GTK_CONTAINER (box), menuitem);
+  gtk_box_append (GTK_BOX (box), menuitem);
 
   menuitem = gtk_model_button_new ();
   g_object_set (menuitem, "text", _("Move"), NULL);
@@ -5839,7 +5839,7 @@ gtk_window_do_popup_fallback (GtkWindow *window,
     gtk_widget_set_sensitive (menuitem, FALSE);
   g_signal_connect (G_OBJECT (menuitem), "clicked",
                     G_CALLBACK (move_window_clicked), window);
-  gtk_container_add (GTK_CONTAINER (box), menuitem);
+  gtk_box_append (GTK_BOX (box), menuitem);
 
   menuitem = gtk_model_button_new ();
   g_object_set (menuitem, "text", _("Resize"), NULL);
@@ -5848,7 +5848,7 @@ gtk_window_do_popup_fallback (GtkWindow *window,
     gtk_widget_set_sensitive (menuitem, FALSE);
   g_signal_connect (G_OBJECT (menuitem), "clicked",
                     G_CALLBACK (resize_window_clicked), window);
-  gtk_container_add (GTK_CONTAINER (box), menuitem);
+  gtk_box_append (GTK_BOX (box), menuitem);
 
   menuitem = gtk_model_button_new ();
   g_object_set (menuitem, "text", _("Minimize"), NULL);
@@ -5857,7 +5857,7 @@ gtk_window_do_popup_fallback (GtkWindow *window,
     gtk_widget_set_sensitive (menuitem, FALSE);
   g_signal_connect (G_OBJECT (menuitem), "clicked",
                     G_CALLBACK (minimize_window_clicked), window);
-  gtk_container_add (GTK_CONTAINER (box), menuitem);
+  gtk_box_append (GTK_BOX (box), menuitem);
 
   menuitem = gtk_model_button_new ();
   g_object_set (menuitem, "text", _("Maximize"), NULL);
@@ -5866,10 +5866,10 @@ gtk_window_do_popup_fallback (GtkWindow *window,
     gtk_widget_set_sensitive (menuitem, FALSE);
   g_signal_connect (G_OBJECT (menuitem), "clicked",
                     G_CALLBACK (maximize_window_clicked), window);
-  gtk_container_add (GTK_CONTAINER (box), menuitem);
+  gtk_box_append (GTK_BOX (box), menuitem);
 
   menuitem = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-  gtk_container_add (GTK_CONTAINER (box), menuitem);
+  gtk_box_append (GTK_BOX (box), menuitem);
 
   menuitem = gtk_model_button_new ();
   g_object_set (menuitem,
@@ -5881,10 +5881,10 @@ gtk_window_do_popup_fallback (GtkWindow *window,
     gtk_widget_set_sensitive (menuitem, FALSE);
   g_signal_connect (G_OBJECT (menuitem), "clicked",
                     G_CALLBACK (ontop_window_clicked), window);
-  gtk_container_add (GTK_CONTAINER (box), menuitem);
+  gtk_box_append (GTK_BOX (box), menuitem);
 
   menuitem = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-  gtk_container_add (GTK_CONTAINER (box), menuitem);
+  gtk_box_append (GTK_BOX (box), menuitem);
 
   menuitem = gtk_model_button_new ();
   g_object_set (menuitem, "text", _("Close"), NULL);
@@ -5893,7 +5893,7 @@ gtk_window_do_popup_fallback (GtkWindow *window,
     gtk_widget_set_sensitive (menuitem, FALSE);
   g_signal_connect (G_OBJECT (menuitem), "clicked",
                     G_CALLBACK (close_window_clicked), window);
-  gtk_container_add (GTK_CONTAINER (box), menuitem);
+  gtk_box_append (GTK_BOX (box), menuitem);
 
   g_signal_connect (priv->popup_menu, "closed",
                     G_CALLBACK (popup_menu_closed), window);
@@ -7459,7 +7459,7 @@ gtk_window_set_debugging (GdkDisplay *display,
           check = gtk_check_button_new_with_label (_("Don’t show this message again"));
           gtk_widget_set_margin_start (check, 10);
           gtk_widget_show (check);
-          gtk_container_add (GTK_CONTAINER (area), check);
+          gtk_box_append (GTK_BOX (area), check);
           g_object_set_data (G_OBJECT (dialog), "check", check);
           gtk_dialog_add_button (GTK_DIALOG (dialog), _("_Cancel"), GTK_RESPONSE_NO);
           gtk_dialog_add_button (GTK_DIALOG (dialog), _("_OK"), GTK_RESPONSE_YES);
diff --git a/gtk/inspector/action-editor.c b/gtk/inspector/action-editor.c
index fa74f2cfee..1f1606ba19 100644
--- a/gtk/inspector/action-editor.c
+++ b/gtk/inspector/action-editor.c
@@ -102,9 +102,9 @@ variant_editor_new (const GVariantType   *type,
     {
       editor = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
       entry = gtk_entry_new ();
-      gtk_container_add (GTK_CONTAINER (editor), entry);
+      gtk_box_append (GTK_BOX (editor), entry);
       label = gtk_label_new (g_variant_type_peek_string (type));
-      gtk_container_add (GTK_CONTAINER (editor), label);
+      gtk_box_append (GTK_BOX (editor), label);
       g_signal_connect (entry, "notify::text", G_CALLBACK (variant_editor_changed_cb), d);
     }
 
@@ -283,24 +283,24 @@ constructed (GObject *object)
 
   row = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
   activate = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (row), activate);
+  gtk_box_append (GTK_BOX (row), activate);
   gtk_size_group_add_widget (r->priv->sg, activate);
 
   r->priv->activate_button = gtk_button_new_with_label (_("Activate"));
   g_signal_connect (r->priv->activate_button, "clicked", G_CALLBACK (activate_action), r);
 
   gtk_widget_set_sensitive (r->priv->activate_button, r->priv->enabled);
-  gtk_container_add (GTK_CONTAINER (activate), r->priv->activate_button);
+  gtk_box_append (GTK_BOX (activate), r->priv->activate_button);
 
   r->priv->parameter_type = g_action_group_get_action_parameter_type (r->priv->group, r->priv->name);
   if (r->priv->parameter_type)
     {
       r->priv->parameter_entry = variant_editor_new (r->priv->parameter_type, parameter_changed, r);
       gtk_widget_set_sensitive (r->priv->parameter_entry, r->priv->enabled);
-      gtk_container_add (GTK_CONTAINER (activate), r->priv->parameter_entry);
+      gtk_box_append (GTK_BOX (activate), r->priv->parameter_entry);
     }
 
-  gtk_container_add (GTK_CONTAINER (r), row);
+  gtk_box_append (GTK_BOX (r), row);
 
   if (state)
     {
@@ -308,11 +308,11 @@ constructed (GObject *object)
       row = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
       label = gtk_label_new (_("Set State"));
       gtk_size_group_add_widget (r->priv->sg, label);
-      gtk_container_add (GTK_CONTAINER (row), label);
+      gtk_box_append (GTK_BOX (row), label);
       r->priv->state_entry = variant_editor_new (r->priv->state_type, state_changed, r);
       variant_editor_set_value (r->priv->state_entry, state);
-      gtk_container_add (GTK_CONTAINER (row), r->priv->state_entry);
-      gtk_container_add (GTK_CONTAINER (r), row);
+      gtk_box_append (GTK_BOX (row), r->priv->state_entry);
+      gtk_box_append (GTK_BOX (r), row);
     }
 
   g_signal_connect (r->priv->group, "action-enabled-changed",
diff --git a/gtk/inspector/actions.c b/gtk/inspector/actions.c
index 78133cb456..327bcb0476 100644
--- a/gtk/inspector/actions.c
+++ b/gtk/inspector/actions.c
@@ -94,14 +94,14 @@ add_action (GtkInspectorActions *sl,
   gtk_widget_add_css_class (label, "cell");
   gtk_label_set_xalign (GTK_LABEL (label), 0);
   gtk_size_group_add_widget (sl->priv->name, label);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   label = gtk_label_new (enabled ? "+" : "-");
   gtk_widget_add_css_class (label, "cell");
   gtk_label_set_xalign (GTK_LABEL (label), 0);
   gtk_widget_set_halign (label, GTK_ALIGN_CENTER);
   gtk_size_group_add_widget (sl->priv->enabled, label);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   g_object_set_data (G_OBJECT (row), "enabled", label);
 
@@ -109,18 +109,18 @@ add_action (GtkInspectorActions *sl,
   gtk_widget_add_css_class (label, "cell");
   gtk_label_set_xalign (GTK_LABEL (label), 0);
   gtk_size_group_add_widget (sl->priv->parameter, label);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   label = gtk_label_new (state_string);
   gtk_label_set_xalign (GTK_LABEL (label), 0);
   gtk_widget_add_css_class (label, "cell");
   gtk_size_group_add_widget (sl->priv->state, label);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
   g_object_set_data (G_OBJECT (row), "state", label);
 
   editor = gtk_inspector_action_editor_new (group, name, sl->priv->activate);
   gtk_widget_add_css_class (editor, "cell");
-  gtk_container_add (GTK_CONTAINER (box), editor);
+  gtk_box_append (GTK_BOX (box), editor);
   g_object_set_data (G_OBJECT (row), "editor", editor);
 
   gtk_list_box_insert (GTK_LIST_BOX (sl->priv->list), row, -1);
diff --git a/gtk/inspector/controllers.c b/gtk/inspector/controllers.c
index a36e1ee304..64063508a6 100644
--- a/gtk/inspector/controllers.c
+++ b/gtk/inspector/controllers.c
@@ -89,9 +89,9 @@ gtk_inspector_controllers_init (GtkInspectorControllers *sl)
   gtk_widget_set_halign (sl->priv->listbox, GTK_ALIGN_CENTER);
   g_signal_connect (sl->priv->listbox, "row-activated", G_CALLBACK (row_activated), sl);
   gtk_list_box_set_selection_mode (GTK_LIST_BOX (sl->priv->listbox), GTK_SELECTION_NONE);
-  gtk_container_add (GTK_CONTAINER (box), sl->priv->listbox);
+  gtk_box_append (GTK_BOX (box), sl->priv->listbox);
 
-  gtk_container_add (GTK_CONTAINER (sl), sw);
+  gtk_box_append (GTK_BOX (sl), sw);
 }
 
 static void
@@ -129,7 +129,7 @@ create_controller_widget (gpointer item,
   gtk_widget_set_margin_bottom (box, 10);
   label = gtk_label_new (G_OBJECT_TYPE_NAME (controller));
   g_object_set (label, "xalign", 0.0, NULL);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
   gtk_size_group_add_widget (sl->priv->sizegroup, label);
   gtk_widget_set_halign (label, GTK_ALIGN_START);
   gtk_widget_set_valign (label, GTK_ALIGN_BASELINE);
@@ -140,7 +140,7 @@ create_controller_widget (gpointer item,
   gtk_combo_box_text_insert_text (GTK_COMBO_BOX_TEXT (combo), GTK_PHASE_BUBBLE, C_("event phase", "Bubble"));
   gtk_combo_box_text_insert_text (GTK_COMBO_BOX_TEXT (combo), GTK_PHASE_TARGET, C_("event phase", "Target"));
   gtk_combo_box_set_active (GTK_COMBO_BOX (combo), gtk_event_controller_get_propagation_phase (controller));
-  gtk_container_add (GTK_CONTAINER (box), combo);
+  gtk_box_append (GTK_BOX (box), combo);
   gtk_widget_set_halign (label, GTK_ALIGN_END);
   gtk_widget_set_valign (label, GTK_ALIGN_BASELINE);
 
diff --git a/gtk/inspector/general.c b/gtk/inspector/general.c
index 36b6ad0b9a..09afdbb271 100644
--- a/gtk/inspector/general.c
+++ b/gtk/inspector/general.c
@@ -175,13 +175,13 @@ add_check_row (GtkInspectorGeneral *gen,
   gtk_widget_set_valign (label, GTK_ALIGN_BASELINE);
   gtk_label_set_xalign (GTK_LABEL (label), 0.0);
   gtk_widget_set_hexpand (label, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   check = gtk_image_new_from_icon_name ("object-select-symbolic");
   gtk_widget_set_halign (check, GTK_ALIGN_END);
   gtk_widget_set_valign (check, GTK_ALIGN_BASELINE);
   gtk_widget_set_opacity (check, value ? 1.0 : 0.0);
-  gtk_container_add (GTK_CONTAINER (box), check);
+  gtk_box_append (GTK_BOX (box), check);
 
   row = gtk_list_box_row_new ();
   gtk_list_box_row_set_child (GTK_LIST_BOX_ROW (row), box);
@@ -217,14 +217,14 @@ add_label_row (GtkInspectorGeneral *gen,
   gtk_widget_set_valign (label, GTK_ALIGN_BASELINE);
   gtk_label_set_xalign (GTK_LABEL (label), 0.0);
   gtk_widget_set_hexpand (label, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   label = gtk_label_new (value);
   gtk_label_set_selectable (GTK_LABEL (label), TRUE);
   gtk_widget_set_halign (label, GTK_ALIGN_END);
   gtk_widget_set_valign (label, GTK_ALIGN_BASELINE);
   gtk_label_set_xalign (GTK_LABEL (label), 1.0);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   row = gtk_list_box_row_new ();
   gtk_list_box_row_set_child (GTK_LIST_BOX_ROW (row), box);
diff --git a/gtk/inspector/misc-info.c b/gtk/inspector/misc-info.c
index 54d7e993bb..efd9e602bf 100644
--- a/gtk/inspector/misc-info.c
+++ b/gtk/inspector/misc-info.c
@@ -332,7 +332,7 @@ update_info (gpointer data)
       GList *list, *l;
 
        while ((child = gtk_widget_get_first_child (sl->priv->mnemonic_label)))
-         gtk_widget_unparent (child);
+         gtk_box_remove (GTK_BOX (sl->priv->mnemonic_label), child);
 
       list = gtk_widget_list_mnemonic_labels (GTK_WIDGET (sl->priv->object));
       for (l = list; l; l = l->next)
@@ -343,7 +343,7 @@ update_info (gpointer data)
           button = gtk_button_new_with_label (tmp);
           g_free (tmp);
           gtk_widget_show (button);
-          gtk_container_add (GTK_CONTAINER (sl->priv->mnemonic_label), button);
+          gtk_box_append (GTK_BOX (sl->priv->mnemonic_label), button);
           g_object_set_data (G_OBJECT (button), "mnemonic-label", l->data);
           g_signal_connect (button, "clicked", G_CALLBACK (show_mnemonic_label), sl);
         }
diff --git a/gtk/inspector/object-tree.c b/gtk/inspector/object-tree.c
index 239f70358a..0de34cf583 100644
--- a/gtk/inspector/object-tree.c
+++ b/gtk/inspector/object-tree.c
@@ -1003,7 +1003,7 @@ gtk_inspector_object_tree_create_list_widget (gpointer row_item,
 
   column = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_size_group_add_widget (wt->priv->type_size_group, column);
-  gtk_container_add (GTK_CONTAINER (box), column);
+  gtk_box_append (GTK_BOX (box), column);
 
   /* expander */
   depth = gtk_tree_list_row_get_depth (row_item);
@@ -1011,7 +1011,7 @@ gtk_inspector_object_tree_create_list_widget (gpointer row_item,
     {
       child = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
       gtk_widget_set_size_request (child, 16 * depth, 0);
-      gtk_container_add (GTK_CONTAINER (column), child);
+      gtk_box_append (GTK_BOX (column), child);
     }
   if (gtk_tree_list_row_is_expandable (row_item))
     {
@@ -1022,7 +1022,7 @@ gtk_inspector_object_tree_create_list_widget (gpointer row_item,
       title = g_object_new (GTK_TYPE_TOGGLE_BUTTON, "css-name", "title", NULL);
       gtk_button_set_has_frame (GTK_BUTTON (title), FALSE);
       g_object_bind_property (row_item, "expanded", title, "active", G_BINDING_BIDIRECTIONAL | 
G_BINDING_SYNC_CREATE);
-      gtk_container_add (GTK_CONTAINER (child), title);
+      gtk_box_append (GTK_BOX (child), title);
 
       arrow = gtk_builtin_icon_new ("expander");
       gtk_button_set_child (GTK_BUTTON (title), arrow);
@@ -1031,20 +1031,20 @@ gtk_inspector_object_tree_create_list_widget (gpointer row_item,
     {
       child = gtk_image_new (); /* empty whatever */
     }
-  gtk_container_add (GTK_CONTAINER (column), child);
+  gtk_box_append (GTK_BOX (column), child);
 
   /* 1st column: type name */
   child = gtk_label_new (G_OBJECT_TYPE_NAME (item));
   gtk_label_set_width_chars (GTK_LABEL (child), 30);
   gtk_label_set_xalign (GTK_LABEL (child), 0.0);
-  gtk_container_add (GTK_CONTAINER (column), child);
+  gtk_box_append (GTK_BOX (column), child);
 
   /* 2nd column: name */
   child = gtk_label_new (gtk_inspector_get_object_name (item));
   gtk_label_set_width_chars (GTK_LABEL (child), 15);
   gtk_label_set_xalign (GTK_LABEL (child), 0.0);
   gtk_size_group_add_widget (wt->priv->name_size_group, child);
-  gtk_container_add (GTK_CONTAINER (box), child);
+  gtk_box_append (GTK_BOX (box), child);
 
   /* 3rd column: label */
   child = gtk_label_new (NULL);
@@ -1059,7 +1059,7 @@ gtk_inspector_object_tree_create_list_widget (gpointer row_item,
   gtk_label_set_width_chars (GTK_LABEL (child), 15);
   gtk_label_set_xalign (GTK_LABEL (child), 0.0);
   gtk_size_group_add_widget (wt->priv->label_size_group, child);
-  gtk_container_add (GTK_CONTAINER (box), child);
+  gtk_box_append (GTK_BOX (box), child);
 
   g_object_unref (item);
 
diff --git a/gtk/inspector/prop-editor.c b/gtk/inspector/prop-editor.c
index ff8f18cc81..3504ec2383 100644
--- a/gtk/inspector/prop-editor.c
+++ b/gtk/inspector/prop-editor.c
@@ -794,8 +794,8 @@ create_row (gpointer item,
   g_signal_connect (button, "clicked", G_CALLBACK (item_properties), user_data);
 
   row = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
-  gtk_container_add (GTK_CONTAINER (row), label);
-  gtk_container_add (GTK_CONTAINER (row), button);
+  gtk_box_append (GTK_BOX (row), label);
+  gtk_box_append (GTK_BOX (row), button);
 
   return row;
 }
@@ -969,7 +969,7 @@ property_editor (GObject                *object,
             b = gtk_check_button_new_with_label (fclass->values[j].value_nick);
             g_object_set_data (G_OBJECT (b), "index", GINT_TO_POINTER (j));
             gtk_widget_show (b);
-            gtk_container_add (GTK_CONTAINER (box), b);
+            gtk_box_append (GTK_BOX (box), b);
             connect_controller (G_OBJECT (b), "toggled",
                                 object, spec, G_CALLBACK (flags_modified));
           }
@@ -1048,8 +1048,8 @@ property_editor (GObject                *object,
       g_signal_connect_swapped (button, "clicked",
                                 G_CALLBACK (object_properties),
                                 editor);
-      gtk_container_add (GTK_CONTAINER (prop_edit), label);
-      gtk_container_add (GTK_CONTAINER (prop_edit), button);
+      gtk_box_append (GTK_BOX (prop_edit), label);
+      gtk_box_append (GTK_BOX (prop_edit), button);
       gtk_widget_show (label);
       gtk_widget_show (button);
 
@@ -1218,14 +1218,14 @@ attribute_editor (GObject                *object,
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
 
   label = gtk_label_new (_("Attribute:"));
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   button = gtk_button_new_with_label (_("Model"));
   g_object_set_data (G_OBJECT (button), "model", model);
   g_signal_connect (button, "clicked", G_CALLBACK (model_properties), editor);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
-  gtk_container_add (GTK_CONTAINER (box), gtk_label_new (_("Column:")));
+  gtk_box_append (GTK_BOX (box), gtk_label_new (_("Column:")));
   store = gtk_list_store_new (2, G_TYPE_STRING, G_TYPE_BOOLEAN);
   combo = gtk_combo_box_new_with_model (GTK_TREE_MODEL (store));
   renderer = gtk_cell_renderer_text_new ();
@@ -1249,7 +1249,7 @@ attribute_editor (GObject                *object,
   attribute_mapping_changed (GTK_COMBO_BOX (combo), editor);
   g_signal_connect (combo, "changed",
                     G_CALLBACK (attribute_mapping_changed), editor);
-  gtk_container_add (GTK_CONTAINER (box), combo);
+  gtk_box_append (GTK_BOX (box), combo);
 
   return box;
 }
@@ -1317,13 +1317,13 @@ action_editor (GObject                *object,
     {
       text = g_strdup_printf (_("Action from: %p (%s)"),
                               owner, g_type_name_from_instance ((GTypeInstance *)owner));
-      gtk_container_add (GTK_CONTAINER (box), gtk_label_new (text));
+      gtk_box_append (GTK_BOX (box), gtk_label_new (text));
       g_free (text);
       button = gtk_button_new_with_label (_("Properties"));
       g_object_set_data (G_OBJECT (button), "owner", owner);
       g_signal_connect (button, "clicked",
                         G_CALLBACK (show_action_owner), editor);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
     }
 
   return box;
@@ -1379,7 +1379,7 @@ add_attribute_info (GtkInspectorPropEditor *editor,
                     GParamSpec             *spec)
 {
   if (GTK_IS_CELL_RENDERER (editor->priv->object))
-    gtk_container_add (GTK_CONTAINER (editor),
+    gtk_box_append (GTK_BOX (editor),
                        attribute_editor (editor->priv->object, spec, editor));
 }
 
@@ -1388,7 +1388,7 @@ add_actionable_info (GtkInspectorPropEditor *editor)
 {
   if (GTK_IS_ACTIONABLE (editor->priv->object) &&
       g_strcmp0 (editor->priv->name, "action-name") == 0)
-    gtk_container_add (GTK_CONTAINER (editor),
+    gtk_box_append (GTK_BOX (editor),
                        action_editor (editor->priv->object, editor));
 }
 
@@ -1437,20 +1437,20 @@ add_settings_info (GtkInspectorPropEditor *editor)
     }
 
   row = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (row), gtk_label_new (_("Setting:")));
+  gtk_box_append (GTK_BOX (row), gtk_label_new (_("Setting:")));
   label = gtk_label_new (direction);
   if (tip)
     gtk_widget_set_tooltip_text (label, tip);
-  gtk_container_add (GTK_CONTAINER (row), label);
+  gtk_box_append (GTK_BOX (row), label);
   
   str = g_strdup_printf ("%s %s",
                          g_settings_schema_get_id (binding->key.schema),
                          binding->key.name);
   label = gtk_label_new (str);
-  gtk_container_add (GTK_CONTAINER (row), label);
+  gtk_box_append (GTK_BOX (row), label);
   g_free (str);
 
-  gtk_container_add (GTK_CONTAINER (editor), row);
+  gtk_box_append (GTK_BOX (editor), row);
 }
 
 static void
@@ -1478,7 +1478,7 @@ add_gtk_settings_info (GtkInspectorPropEditor *editor)
   row = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
 
   button = gtk_button_new_with_label (_("Reset"));
-  gtk_container_add (GTK_CONTAINER (row), button);
+  gtk_box_append (GTK_BOX (row), button);
   gtk_widget_set_sensitive (button, FALSE);
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (reset_setting), editor);
 
@@ -1501,10 +1501,10 @@ add_gtk_settings_info (GtkInspectorPropEditor *editor)
       source = _("Unknown");
       break;
     }
-  gtk_container_add (GTK_CONTAINER (row), gtk_label_new (_("Source:")));
-  gtk_container_add (GTK_CONTAINER (row), gtk_label_new (source));
+  gtk_box_append (GTK_BOX (row), gtk_label_new (_("Source:")));
+  gtk_box_append (GTK_BOX (row), gtk_label_new (source));
 
-  gtk_container_add (GTK_CONTAINER (editor), row);
+  gtk_box_append (GTK_BOX (editor), row);
 }
 
 static void
@@ -1553,7 +1553,7 @@ constructed (GObject *object)
   if (label)
     {
       gtk_widget_add_css_class (label, GTK_STYLE_CLASS_DIM_LABEL);
-      gtk_container_add (GTK_CONTAINER (box), label);
+      gtk_box_append (GTK_BOX (box), label);
     }
 
   /* By reaching this, we already know the property is readable.
@@ -1567,7 +1567,7 @@ constructed (GObject *object)
     {
       label = gtk_label_new ("");
       gtk_widget_add_css_class (label, GTK_STYLE_CLASS_DIM_LABEL);
-      gtk_container_add (GTK_CONTAINER (box), label);
+      gtk_box_append (GTK_BOX (box), label);
 
       readonly_changed (editor->priv->object, spec, label);
       g_object_connect_property (editor->priv->object, spec,
@@ -1576,15 +1576,15 @@ constructed (GObject *object)
 
       if (editor->priv->size_group)
         gtk_size_group_add_widget (editor->priv->size_group, box);
-      gtk_container_add (GTK_CONTAINER (editor), box);
+      gtk_box_append (GTK_BOX (editor), box);
       return;
     }
 
   editor->priv->editor = property_editor (editor->priv->object, spec, editor);
-  gtk_container_add (GTK_CONTAINER (box), editor->priv->editor);
+  gtk_box_append (GTK_BOX (box), editor->priv->editor);
   if (editor->priv->size_group)
     gtk_size_group_add_widget (editor->priv->size_group, box);
-  gtk_container_add (GTK_CONTAINER (editor), box);
+  gtk_box_append (GTK_BOX (editor), box);
 
   add_attribute_info (editor, spec);
   add_actionable_info (editor);
diff --git a/gtk/inspector/prop-list.c b/gtk/inspector/prop-list.c
index a0d1d76435..d143da83df 100644
--- a/gtk/inspector/prop-list.c
+++ b/gtk/inspector/prop-list.c
@@ -536,25 +536,25 @@ gtk_inspector_prop_list_create_row (GtkInspectorPropList *pl,
   gtk_widget_set_sensitive (label, writable);
   gtk_label_set_xalign (GTK_LABEL (label), 0);
   gtk_size_group_add_widget (pl->priv->names, label);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   label = gtk_label_new (type ? type : "");
   gtk_widget_add_css_class (label, "cell");
   gtk_widget_set_sensitive (label, writable);
   gtk_label_set_xalign (GTK_LABEL (label), 0);
   gtk_size_group_add_widget (pl->priv->types, label);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   label = gtk_label_new (g_type_name (prop->owner_type));
   gtk_widget_add_css_class (label, "cell");
   gtk_widget_set_sensitive (label, writable);
   gtk_label_set_xalign (GTK_LABEL (label), 0);
   gtk_size_group_add_widget (pl->priv->origins, label);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   widget = gtk_inspector_prop_editor_new (pl->priv->object, prop->name, pl->priv->values);
   gtk_widget_add_css_class (widget, "cell");
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
   g_signal_connect (widget, "show-object", G_CALLBACK (show_object), pl);
 
   g_free (value);
@@ -601,7 +601,7 @@ gtk_inspector_prop_list_set_object (GtkInspectorPropList *pl,
   pl->priv->object = object;
 
   while ((w = gtk_widget_get_first_child (pl->priv->list2)))
-    gtk_container_remove (GTK_CONTAINER (pl->priv->list2), w);
+    gtk_list_box_remove (GTK_LIST_BOX (pl->priv->list2), w);
 
   for (i = 0; i < num_properties; i++)
     {
diff --git a/gtk/inspector/recorder.c b/gtk/inspector/recorder.c
index 784e66b269..1717ddc587 100644
--- a/gtk/inspector/recorder.c
+++ b/gtk/inspector/recorder.c
@@ -316,7 +316,7 @@ create_widget_for_render_node (gpointer row_item,
     {
       child = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
       gtk_widget_set_size_request (child, 16 * depth, 0);
-      gtk_container_add (GTK_CONTAINER (box), child);
+      gtk_box_append (GTK_BOX (box), child);
     }
   if (gtk_tree_list_row_is_expandable (row_item))
     {
@@ -327,7 +327,7 @@ create_widget_for_render_node (gpointer row_item,
       title = g_object_new (GTK_TYPE_TOGGLE_BUTTON, "css-name", "title", NULL);
       gtk_button_set_has_frame (GTK_BUTTON (title), FALSE);
       g_object_bind_property (row_item, "expanded", title, "active", G_BINDING_BIDIRECTIONAL | 
G_BINDING_SYNC_CREATE);
-      gtk_container_add (GTK_CONTAINER (child), title);
+      gtk_box_append (GTK_BOX (child), title);
       g_object_set_data_full (G_OBJECT (row), "make-sure-its-not-unreffed", g_object_ref (row_item), 
g_object_unref);
 
       arrow = gtk_builtin_icon_new ("expander");
@@ -337,17 +337,17 @@ create_widget_for_render_node (gpointer row_item,
     {
       child = gtk_image_new (); /* empty whatever */
     }
-  gtk_container_add (GTK_CONTAINER (box), child);
+  gtk_box_append (GTK_BOX (box), child);
 
   /* icon */
   child = gtk_image_new_from_paintable (paintable);
-  gtk_container_add (GTK_CONTAINER (box), child);
+  gtk_box_append (GTK_BOX (box), child);
 
   /* name */
   name = node_name (node);
   child = gtk_label_new (name);
   g_free (name);
-  gtk_container_add (GTK_CONTAINER (box), child);
+  gtk_box_append (GTK_BOX (box), child);
 
   g_object_unref (paintable);
 
@@ -1074,7 +1074,7 @@ gtk_inspector_recorder_recordings_list_create_widget (gpointer item,
       widget = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
-      gtk_container_add (GTK_CONTAINER (widget), hbox);
+      gtk_box_append (GTK_BOX (widget), hbox);
 
       for (i = 0; i < g_list_model_get_n_items (priv->recordings); i++)
         {
@@ -1115,17 +1115,17 @@ gtk_inspector_recorder_recordings_list_create_widget (gpointer item,
       label = gtk_label_new (str);
       gtk_label_set_use_markup (GTK_LABEL (label), TRUE);
       g_free (str);
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       button = gtk_toggle_button_new ();
       gtk_button_set_has_frame (GTK_BUTTON (button), FALSE);
       gtk_button_set_icon_name (GTK_BUTTON (button), "view-more-symbolic");
 
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
       label = gtk_label_new (gtk_inspector_render_recording_get_profiler_info 
(GTK_INSPECTOR_RENDER_RECORDING (recording)));
       gtk_widget_hide (label);
-      gtk_container_add (GTK_CONTAINER (widget), label);
+      gtk_box_append (GTK_BOX (widget), label);
       g_object_bind_property (button, "active", label, "visible", 0);
     }
   else
diff --git a/gtk/inspector/shortcuts.c b/gtk/inspector/shortcuts.c
index 3f708371cd..4e4fa67855 100644
--- a/gtk/inspector/shortcuts.c
+++ b/gtk/inspector/shortcuts.c
@@ -67,14 +67,14 @@ create_row (gpointer item,
   label = gtk_label_new (s);
   gtk_label_set_xalign (GTK_LABEL (label), 0.0);
   g_free (s);
-  gtk_container_add (GTK_CONTAINER (row), label);
+  gtk_box_append (GTK_BOX (row), label);
   gtk_size_group_add_widget (sl->trigger, label);
 
   s = gtk_shortcut_action_to_string (action);
   label = gtk_label_new (s);
   gtk_label_set_xalign (GTK_LABEL (label), 0.0);
   g_free (s);
-  gtk_container_add (GTK_CONTAINER (row), label);
+  gtk_box_append (GTK_BOX (row), label);
   gtk_size_group_add_widget (sl->action, label);
 
   return row;
diff --git a/gtk/inspector/size-groups.c b/gtk/inspector/size-groups.c
index 19946541ca..0e552fe063 100644
--- a/gtk/inspector/size-groups.c
+++ b/gtk/inspector/size-groups.c
@@ -86,7 +86,7 @@ size_group_row_widget_destroyed (GtkWidget *widget, SizeGroupRow *row)
 
   parent = gtk_widget_get_parent (GTK_WIDGET (row));
   if (parent)
-    gtk_container_remove (GTK_CONTAINER (parent), GTK_WIDGET (row));
+    gtk_box_remove (GTK_BOX (parent), GTK_WIDGET (row));
 }
 
 static void
@@ -186,7 +186,7 @@ clear_view (GtkInspectorSizeGroups *sl)
   GtkWidget *child;
 
   while ((child = gtk_widget_get_first_child (GTK_WIDGET (sl))))
-    gtk_container_remove (GTK_CONTAINER (sl), child);
+    gtk_box_remove (GTK_BOX (sl), child);
 }
 
 static void
@@ -222,13 +222,13 @@ add_size_group (GtkInspectorSizeGroups *sl,
   GtkWidget *listbox;
 
   frame = gtk_frame_new (NULL);
-  gtk_container_add (GTK_CONTAINER (sl), frame);
+  gtk_box_append (GTK_BOX (sl), frame);
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   gtk_widget_add_css_class (box, GTK_STYLE_CLASS_VIEW);
   gtk_frame_set_child (GTK_FRAME (frame), box);
 
   box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (box), box2);
+  gtk_box_append (GTK_BOX (box), box2);
 
   label = gtk_label_new (_("Mode"));
   gtk_widget_set_margin_start (label, 10);
@@ -237,7 +237,7 @@ add_size_group (GtkInspectorSizeGroups *sl,
   gtk_widget_set_margin_bottom (label, 10);
   gtk_widget_set_halign (label, GTK_ALIGN_START);
   gtk_widget_set_valign (label, GTK_ALIGN_BASELINE);
-  gtk_container_add (GTK_CONTAINER (box2), label);
+  gtk_box_append (GTK_BOX (box2), label);
 
   combo = gtk_combo_box_text_new ();
   gtk_widget_set_margin_start (combo, 10);
@@ -253,10 +253,10 @@ add_size_group (GtkInspectorSizeGroups *sl,
   g_object_bind_property (group, "mode",
                           combo, "active",
                           G_BINDING_BIDIRECTIONAL | G_BINDING_SYNC_CREATE);
-  gtk_container_add (GTK_CONTAINER (box2), combo);
+  gtk_box_append (GTK_BOX (box2), combo);
 
   listbox = gtk_list_box_new ();
-  gtk_container_add (GTK_CONTAINER (box), listbox);
+  gtk_box_append (GTK_BOX (box), listbox);
   gtk_list_box_set_selection_mode (GTK_LIST_BOX (listbox), GTK_SELECTION_NONE);
 
   widgets = gtk_size_group_get_widgets (group);
diff --git a/gtk/inspector/strv-editor.c b/gtk/inspector/strv-editor.c
index 77cb5551e8..c8b19d6dda 100644
--- a/gtk/inspector/strv-editor.c
+++ b/gtk/inspector/strv-editor.c
@@ -52,7 +52,7 @@ remove_string (GtkButton              *button,
   GtkWidget *row;
 
   row = gtk_widget_get_parent (GTK_WIDGET (button));
-  gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (row)), row);
+  gtk_box_remove (GTK_BOX (gtk_widget_get_parent (row)), row);
   emit_changed (editor);
 }
 
@@ -71,17 +71,17 @@ add_string (GtkInspectorStrvEditor *editor,
   entry = gtk_entry_new ();
   gtk_editable_set_text (GTK_EDITABLE (entry), str);
   gtk_widget_show (entry);
-  gtk_container_add (GTK_CONTAINER (box), entry);
+  gtk_box_append (GTK_BOX (box), entry);
   g_object_set_data (G_OBJECT (box), "entry", entry);
   g_signal_connect_swapped (entry, "notify::text", G_CALLBACK (emit_changed), editor);
 
   button = gtk_button_new_from_icon_name ("user-trash-symbolic");
   gtk_widget_add_css_class (button, "image-button");
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
   g_signal_connect (button, "clicked", G_CALLBACK (remove_string), editor);
 
-  gtk_container_add (GTK_CONTAINER (editor->box), box);
+  gtk_box_append (GTK_BOX (editor->box), box);
 
   gtk_widget_grab_focus (entry);
 
@@ -110,8 +110,8 @@ gtk_inspector_strv_editor_init (GtkInspectorStrvEditor *editor)
   gtk_widget_show (editor->button);
   g_signal_connect (editor->button, "clicked", G_CALLBACK (add_cb), editor);
 
-  gtk_container_add (GTK_CONTAINER (editor), editor->box);
-  gtk_container_add (GTK_CONTAINER (editor), editor->button);
+  gtk_box_append (GTK_BOX (editor), editor->box);
+  gtk_box_append (GTK_BOX (editor), editor->button);
 }
 
 static void
@@ -137,7 +137,7 @@ gtk_inspector_strv_editor_set_strv (GtkInspectorStrvEditor  *editor,
   editor->blocked = TRUE;
 
   while ((child = gtk_widget_get_first_child (GTK_WIDGET (editor->box))))
-    gtk_container_remove (GTK_CONTAINER (editor->box), child);
+    gtk_box_remove (GTK_BOX (editor->box), child);
 
   if (strv)
     {
diff --git a/gtk/tools/gtk-builder-tool-preview.c b/gtk/tools/gtk-builder-tool-preview.c
index 70ca1fac28..bac6c0b871 100644
--- a/gtk/tools/gtk-builder-tool-preview.c
+++ b/gtk/tools/gtk-builder-tool-preview.c
@@ -136,7 +136,7 @@ preview_file (const char *filename,
 
       g_object_ref (widget);
       if (gtk_widget_get_parent (widget) != NULL)
-        gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (widget)), widget);
+        gtk_box_remove (GTK_BOX (gtk_widget_get_parent (widget)), widget);
       gtk_window_set_child (GTK_WINDOW (window), widget);
       g_object_unref (widget);
     }
diff --git a/tests/gdkgears.c b/tests/gdkgears.c
index 853c5cb1ab..6b71f33c18 100644
--- a/tests/gdkgears.c
+++ b/tests/gdkgears.c
@@ -65,7 +65,7 @@ create_axis_slider (GtkGears *gears,
     }
 
   label = gtk_label_new (text);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
   gtk_widget_show (label);
 
   adj = gtk_adjustment_new (gtk_gears_get_axis (gears, axis), 0.0, 360.0, 1.0, 12.0, 0.0);
@@ -75,7 +75,7 @@ create_axis_slider (GtkGears *gears,
                     gears);
   slider = gtk_scale_new (GTK_ORIENTATION_VERTICAL, adj);
   gtk_scale_set_draw_value (GTK_SCALE (slider), FALSE);
-  gtk_container_add (GTK_CONTAINER (box), slider);
+  gtk_box_append (GTK_BOX (box), slider);
   gtk_widget_set_vexpand (slider, TRUE);
   gtk_widget_show (slider);
 
@@ -87,22 +87,20 @@ create_axis_slider (GtkGears *gears,
 static void
 moar_gears (GtkButton *button, gpointer data)
 {
-  GtkContainer *container = GTK_CONTAINER (data);
   GtkWidget *gears;
 
   gears = gtk_gears_new ();
   gtk_widget_set_size_request (gears, 100, 100);
-  gtk_container_add (container, gears);
+  gtk_box_append (GTK_BOX (data), gears);
   gtk_widget_show (gears);
 }
 
 static void
 less_gears (GtkButton *button, gpointer data)
 {
-  GtkContainer *container = GTK_CONTAINER (data);
   GtkWidget *gears;
 
-  gears = gtk_widget_get_last_child (GTK_WIDGET (container));
+  gears = gtk_widget_get_last_child (GTK_WIDGET (data));
   if (gears)
     gtk_container_remove (container, gears);
 }
@@ -161,7 +159,7 @@ main (int argc, char *argv[])
   gtk_widget_show (hbox);
 
   label = gtk_label_new ("This is a transparent overlay widget!!!!\nAmazing, eh?");
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
   gtk_widget_show (label);
 
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, FALSE);
@@ -171,27 +169,27 @@ main (int argc, char *argv[])
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, FALSE);
   gtk_box_set_spacing (GTK_BOX (box), 6);
-  gtk_container_add (GTK_CONTAINER (box), hbox);
+  gtk_box_append (GTK_BOX (box), hbox);
   gtk_widget_show (hbox);
 
   gears = gtk_gears_new ();
   gtk_widget_set_hexpand (gears, TRUE);
   gtk_widget_set_vexpand (gears, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), gears);
+  gtk_box_append (GTK_BOX (hbox), gears);
   gtk_widget_show (gears);
 
   for (i = 0; i < GTK_GEARS_N_AXIS; i++)
-    gtk_container_add (GTK_CONTAINER (hbox), create_axis_slider (GTK_GEARS (gears), i));
+    gtk_box_append (GTK_BOX (hbox), create_axis_slider (GTK_GEARS (gears), i));
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, FALSE);
   gtk_box_set_spacing (GTK_BOX (hbox), 6);
-  gtk_container_add (GTK_CONTAINER (box), hbox);
+  gtk_box_append (GTK_BOX (box), hbox);
   gtk_widget_show (hbox);
 
   fps_label = gtk_label_new ("");
   gtk_widget_set_hexpand (fps_label, TRUE);
   gtk_widget_set_halign (fps_label, GTK_ALIGN_START);
-  gtk_container_add (GTK_CONTAINER (hbox), fps_label);
+  gtk_box_append (GTK_BOX (hbox), fps_label);
   gtk_gears_set_fps_label (GTK_GEARS (gears), GTK_LABEL (fps_label));
 
 
@@ -202,10 +200,10 @@ main (int argc, char *argv[])
   gtk_popover_set_child (GTK_POPOVER (popover), label);
 
   gtk_menu_button_set_popover (GTK_MENU_BUTTON (button), popover);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   check = gtk_check_button_new_with_label ("Overlay");
-  gtk_container_add (GTK_CONTAINER (hbox), check);
+  gtk_box_append (GTK_BOX (hbox), check);
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check), FALSE);
   g_signal_connect (check, "toggled",
                     G_CALLBACK (toggle_overlay), revealer);
@@ -213,12 +211,12 @@ main (int argc, char *argv[])
 
 
   check = gtk_check_button_new_with_label ("Animate spinner");
-  gtk_container_add (GTK_CONTAINER (hbox), check);
+  gtk_box_append (GTK_BOX (hbox), check);
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check), TRUE);
 
 
   spinner = gtk_spinner_new ();
-  gtk_container_add (GTK_CONTAINER (hbox), spinner);
+  gtk_box_append (GTK_BOX (hbox), spinner);
   gtk_spinner_start (GTK_SPINNER (spinner));
   g_signal_connect (check, "toggled",
                     G_CALLBACK (toggle_spin), spinner);
@@ -228,7 +226,7 @@ main (int argc, char *argv[])
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled),
                                   GTK_POLICY_AUTOMATIC,
                                   GTK_POLICY_NEVER);
-  gtk_container_add (GTK_CONTAINER (box), scrolled);
+  gtk_box_append (GTK_BOX (box), scrolled);
   gtk_widget_show (scrolled);
 
   extra_hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, FALSE);
@@ -238,22 +236,22 @@ main (int argc, char *argv[])
 
   bbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_box_set_spacing (GTK_BOX (bbox), 6);
-  gtk_container_add (GTK_CONTAINER (box), bbox);
+  gtk_box_append (GTK_BOX (box), bbox);
   gtk_widget_show (bbox);
 
   button = gtk_button_new_with_label ("Moar gears!");
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (moar_gears), extra_hbox);
   gtk_widget_show (button);
 
   button = gtk_button_new_with_label ("Less gears!");
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (less_gears), extra_hbox);
   gtk_widget_show (button);
 
   button = gtk_button_new_with_label ("Quit");
   gtk_widget_set_hexpand (button, TRUE);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (gtk_window_destroy), window);
   gtk_widget_show (button);
 
diff --git a/tests/motion-compression.c b/tests/motion-compression.c
index caba2bca3f..33be6b617e 100644
--- a/tests/motion-compression.c
+++ b/tests/motion-compression.c
@@ -67,15 +67,15 @@ main (int argc, char **argv)
   da = gtk_drawing_area_new ();
   gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (da), on_draw, NULL, NULL);
   gtk_widget_set_vexpand (da, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), da);
+  gtk_box_append (GTK_BOX (vbox), da);
 
   label = gtk_label_new ("Event processing time (ms):");
   gtk_widget_set_halign (label, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   adjustment = gtk_adjustment_new (20, 0, 200, 1, 10, 0);
   scale = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL, adjustment);
-  gtk_container_add (GTK_CONTAINER (vbox), scale);
+  gtk_box_append (GTK_BOX (vbox), scale);
 
   controller = gtk_event_controller_motion_new ();
   g_signal_connect (controller, "motion",
diff --git a/tests/overlayscroll.c b/tests/overlayscroll.c
index 2aaabb3710..5a4b2fa018 100644
--- a/tests/overlayscroll.c
+++ b/tests/overlayscroll.c
@@ -77,7 +77,7 @@ main (int argc, char *argv[])
                                   GTK_POLICY_NEVER,
                                   GTK_POLICY_AUTOMATIC);
 
-  gtk_container_add (GTK_CONTAINER (box), sw);
+  gtk_box_append (GTK_BOX (box), sw);
 
   content = get_content ();
 
@@ -97,10 +97,10 @@ main (int argc, char *argv[])
   g_signal_connect (combo, "changed", G_CALLBACK (mode_changed), sw);
   gtk_combo_box_set_active (GTK_COMBO_BOX (combo), 1);
 
-  gtk_container_add (GTK_CONTAINER (box), combo);
+  gtk_box_append (GTK_BOX (box), combo);
 
   sb2 = gtk_scrollbar_new (GTK_ORIENTATION_VERTICAL, adj);
-  gtk_container_add (GTK_CONTAINER (box), sb2);
+  gtk_box_append (GTK_BOX (box), sb2);
 
   gtk_widget_show (window);
 
diff --git a/tests/print-editor.c b/tests/print-editor.c
index acebfdc06b..c296026d91 100644
--- a/tests/print-editor.c
+++ b/tests/print-editor.c
@@ -341,15 +341,15 @@ create_custom_widget (GtkPrintOperation *operation,
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
   gtk_widget_show (hbox);
 
   label = gtk_label_new ("Font:");
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
   gtk_widget_show (label);
 
   font = gtk_font_button_new_with_font  (data->font);
-  gtk_container_add (GTK_CONTAINER (hbox), font);
+  gtk_box_append (GTK_BOX (hbox), font);
   gtk_widget_show (font);
   data->font_button = font;
 
@@ -748,7 +748,7 @@ activate (GApplication *app)
   update_title (GTK_WINDOW (main_window));
 
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (main_window), box);
+  gtk_box_append (GTK_BOX (main_window), box);
 
   /* Create document  */
   sw = gtk_scrolled_window_new (NULL, NULL);
@@ -760,7 +760,7 @@ activate (GApplication *app)
   gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (sw), TRUE);
 
   gtk_widget_set_vexpand (sw, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), sw);
+  gtk_box_append (GTK_BOX (box), sw);
 
   contents = gtk_text_view_new ();
   gtk_widget_grab_focus (contents);
@@ -770,7 +770,7 @@ activate (GApplication *app)
 
   /* Create statusbar */
   statusbar = gtk_statusbar_new ();
-  gtk_container_add (GTK_CONTAINER (box), statusbar);
+  gtk_box_append (GTK_BOX (box), statusbar);
 
   /* Show text widget info in the statusbar */
   buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (contents));
diff --git a/tests/scrolling-performance.c b/tests/scrolling-performance.c
index 96fc298542..033bd31fd4 100644
--- a/tests/scrolling-performance.c
+++ b/tests/scrolling-performance.c
@@ -45,7 +45,7 @@ create_widget_factory_content (void)
 
   result = GTK_WIDGET (gtk_builder_get_object (builder, "box1"));
   g_object_ref (result);
-  gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (result)),
+  gtk_box_remove (GTK_BOX (gtk_widget_get_parent (result)),
                         result);
   g_object_unref (builder);
 
diff --git a/tests/showrendernode.c b/tests/showrendernode.c
index 1f54217073..538f7288ae 100644
--- a/tests/showrendernode.c
+++ b/tests/showrendernode.c
@@ -216,8 +216,8 @@ main (int argc, char **argv)
                                    gdk_texture_get_width (texture),
                                    gdk_texture_get_height (texture));
 
-      gtk_container_add (GTK_CONTAINER (box), nodeview);
-      gtk_container_add (GTK_CONTAINER (box), image);
+      gtk_box_append (GTK_BOX (box), nodeview);
+      gtk_box_append (GTK_BOX (box), image);
       gtk_window_set_child (GTK_WINDOW (window), box);
 
       gsk_renderer_unrealize (renderer);
diff --git a/tests/syncscroll.c b/tests/syncscroll.c
index 4a0a8c6103..b9af802331 100644
--- a/tests/syncscroll.c
+++ b/tests/syncscroll.c
@@ -32,7 +32,7 @@ main (int argc, char *argv[])
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                   GTK_POLICY_NEVER,
                                   GTK_POLICY_EXTERNAL);
-  gtk_container_add (GTK_CONTAINER (box), sw);
+  gtk_box_append (GTK_BOX (box), sw);
   tv = gtk_text_view_new ();
   fill_text_view (tv, "Left");
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), tv);
@@ -43,7 +43,7 @@ main (int argc, char *argv[])
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                   GTK_POLICY_NEVER,
                                   GTK_POLICY_EXTERNAL);
-  gtk_container_add (GTK_CONTAINER (box), sw);
+  gtk_box_append (GTK_BOX (box), sw);
   tv = gtk_text_view_new ();
   fill_text_view (tv, "Middle");
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), tv);
@@ -52,14 +52,14 @@ main (int argc, char *argv[])
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                   GTK_POLICY_NEVER,
                                   GTK_POLICY_EXTERNAL);
-  gtk_container_add (GTK_CONTAINER (box), sw);
+  gtk_box_append (GTK_BOX (box), sw);
   tv = gtk_text_view_new ();
   fill_text_view (tv, "Right");
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), tv);
 
   sb = gtk_scrollbar_new (GTK_ORIENTATION_VERTICAL, adj);
 
-  gtk_container_add (GTK_CONTAINER (box), sb);
+  gtk_box_append (GTK_BOX (box), sb);
 
   gtk_widget_show (win);
 
diff --git a/tests/testaccel.c b/tests/testaccel.c
index 5a7ddd140c..1b4f419df3 100644
--- a/tests/testaccel.c
+++ b/tests/testaccel.c
@@ -75,7 +75,7 @@ key_test (void)
         box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
         gtk_widget_show (box);
         gtk_window_set_child (GTK_WINDOW (window), box);
-        gtk_container_add (GTK_CONTAINER (box), sw);
+        gtk_box_append (GTK_BOX (box), sw);
 
        store = gtk_list_store_new (3, G_TYPE_INT, G_TYPE_UINT, G_TYPE_UINT);
        tv = gtk_tree_view_new_with_model (GTK_TREE_MODEL (store));
@@ -112,7 +112,7 @@ key_test (void)
 
         entry = gtk_entry_new ();
         gtk_widget_show (entry);
-        gtk_container_add (GTK_CONTAINER (box), entry);
+        gtk_box_append (GTK_BOX (box), entry);
  
        return window;
 }
diff --git a/tests/testadjustsize.c b/tests/testadjustsize.c
index 2e3c251f16..ff7657825a 100644
--- a/tests/testadjustsize.c
+++ b/tests/testadjustsize.c
@@ -153,14 +153,14 @@ open_control_window (void)
   g_signal_connect (G_OBJECT (toggle),
                     "toggled", G_CALLBACK (on_set_small_size_requests),
                     NULL);
-  gtk_container_add (GTK_CONTAINER (box), toggle);
+  gtk_box_append (GTK_BOX (box), toggle);
 
   toggle =
     gtk_toggle_button_new_with_label ("Set large size requests");
   g_signal_connect (G_OBJECT (toggle),
                     "toggled", G_CALLBACK (on_set_large_size_requests),
                     NULL);
-  gtk_container_add (GTK_CONTAINER (box), toggle);
+  gtk_box_append (GTK_BOX (box), toggle);
 
 
   gtk_widget_show (window);
@@ -182,16 +182,16 @@ create_widget_visible_border (const char *text)
   inner_box = gtk_overlay_new ();
   gtk_widget_add_css_class (inner_box, "blue-bg");
 
-  gtk_container_add (GTK_CONTAINER (outer_box), inner_box);
+  gtk_box_append (GTK_BOX (outer_box), inner_box);
 
 
   test_widget = gtk_overlay_new ();
   gtk_widget_add_css_class (test_widget, "red-bg");
 
-  gtk_container_add (GTK_CONTAINER (inner_box), test_widget);
+  gtk_box_append (GTK_BOX (inner_box), test_widget);
 
   label = gtk_label_new (text);
-  gtk_container_add (GTK_CONTAINER (test_widget), label);
+  gtk_box_append (GTK_BOX (test_widget), label);
 
   g_assert (TEST_WIDGET (outer_box) == test_widget);
 
@@ -315,7 +315,7 @@ open_margin_window (void)
       GtkWidget *child =
         create_margined(margins[i]);
 
-      gtk_container_add (GTK_CONTAINER (box), child);
+      gtk_box_append (GTK_BOX (box), child);
     }
 
   gtk_widget_show (test_window);
@@ -336,7 +336,7 @@ open_valigned_label_window (void)
 
   label = gtk_label_new ("Both labels expand");
   gtk_widget_show (label);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
   label = gtk_label_new ("Some wrapping text with width-chars = 15 and max-width-chars = 35");
   gtk_label_set_wrap  (GTK_LABEL (label), TRUE);
@@ -352,7 +352,7 @@ open_valigned_label_window (void)
   gtk_widget_set_valign (frame, GTK_ALIGN_CENTER);
   gtk_widget_set_halign (frame, GTK_ALIGN_CENTER);
 
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
 
   gtk_window_present (GTK_WINDOW (window));
 }
diff --git a/tests/testappchooser.c b/tests/testappchooser.c
index df3ffa8758..e6fa88595e 100644
--- a/tests/testappchooser.c
+++ b/tests/testappchooser.c
@@ -230,7 +230,7 @@ main (int argc, char **argv)
   g_signal_connect (open, "clicked",
                     G_CALLBACK (display_dialog), NULL);
 
-  gtk_container_add (GTK_CONTAINER (toplevel), grid);
+  gtk_box_append (GTK_BOX (toplevel), grid);
 
   gtk_widget_show (toplevel);
   g_signal_connect (toplevel, "destroy", G_CALLBACK (quit_cb), &done);
diff --git a/tests/testappchooserbutton.c b/tests/testappchooserbutton.c
index 9d69ce0189..467da85464 100644
--- a/tests/testappchooserbutton.c
+++ b/tests/testappchooserbutton.c
@@ -83,25 +83,25 @@ main (int argc,
   toplevel = gtk_window_new ();
 
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
-  gtk_container_add (GTK_CONTAINER (toplevel), box);
+  gtk_box_append (GTK_BOX (toplevel), box);
 
   button = gtk_app_chooser_button_new ("image/jpeg");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   g_signal_connect (button, "changed",
                     G_CALLBACK (combo_changed_cb), NULL);
 
   w = gtk_label_new (NULL);
   gtk_label_set_markup (GTK_LABEL (w), "<b>Selected app info</b>");
-  gtk_container_add (GTK_CONTAINER (box), w);
+  gtk_box_append (GTK_BOX (box), w);
 
   w = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
-  gtk_container_add (GTK_CONTAINER (box), w);
+  gtk_box_append (GTK_BOX (box), w);
 
   sel_image = gtk_image_new ();
-  gtk_container_add (GTK_CONTAINER (w), sel_image);
+  gtk_box_append (GTK_BOX (w), sel_image);
   sel_name = gtk_label_new (NULL);
-  gtk_container_add (GTK_CONTAINER (w), sel_name);
+  gtk_box_append (GTK_BOX (w), sel_name);
 
   gtk_app_chooser_button_set_heading (GTK_APP_CHOOSER_BUTTON (button), "Choose one, <i>not</i> two");
   gtk_app_chooser_button_append_separator (GTK_APP_CHOOSER_BUTTON (button));
diff --git a/tests/testassistant.c b/tests/testassistant.c
index 42a105eb8b..e4964ab10b 100644
--- a/tests/testassistant.c
+++ b/tests/testassistant.c
@@ -61,8 +61,8 @@ add_completion_test_page (GtkWidget   *assistant,
   page = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   check = gtk_check_button_new_with_label ("Complete");
 
-  gtk_container_add (GTK_CONTAINER (page), gtk_label_new (text));
-  gtk_container_add (GTK_CONTAINER (page), check);
+  gtk_box_append (GTK_BOX (page), gtk_label_new (text));
+  gtk_box_append (GTK_BOX (page), check);
   
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check), complete);
 
@@ -277,7 +277,7 @@ create_generous_assistant (GtkWidget *widget)
       g_signal_connect (G_OBJECT (check), "toggled", 
                        G_CALLBACK (visible_cb), next);
       gtk_widget_show (check);
-      gtk_container_add (GTK_CONTAINER (page), check);
+      gtk_box_append (GTK_BOX (page), check);
       
       add_completion_test_page (assistant, "Even More Content", TRUE, TRUE);
 
@@ -377,13 +377,13 @@ create_nonlinear_assistant (GtkWidget *widget)
       page = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
 
       button = gtk_radio_button_new_with_label (NULL, "branch A");
-      gtk_container_add (GTK_CONTAINER (page), button);
+      gtk_box_append (GTK_BOX (page), button);
       g_signal_connect (G_OBJECT (button), "toggled", G_CALLBACK (select_branch), GINT_TO_POINTER ('A'));
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
 
       button = gtk_radio_button_new_with_label (gtk_radio_button_get_group (GTK_RADIO_BUTTON (button)),
                                                "branch B");
-      gtk_container_add (GTK_CONTAINER (page), button);
+      gtk_box_append (GTK_BOX (page), button);
       g_signal_connect (G_OBJECT (button), "toggled", G_CALLBACK (select_branch), GINT_TO_POINTER ('B'));
 
       gtk_assistant_append_page (GTK_ASSISTANT (assistant), page);
@@ -647,7 +647,7 @@ create_page_flipping_assistant (GtkWidget *widget)
       gtk_assistant_set_page_complete (GTK_ASSISTANT (assistant), page, TRUE);
 
       page = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-      gtk_container_add (GTK_CONTAINER (page),
+      gtk_box_append (GTK_BOX (page),
                           get_test_page ("Page 2"));
       gtk_assistant_append_page (GTK_ASSISTANT (assistant), page);
       gtk_assistant_set_page_title (GTK_ASSISTANT (assistant), page, "Page 2");
@@ -729,7 +729,7 @@ main (int argc, gchar *argv[])
        g_signal_connect (G_OBJECT (button), "clicked",
                          G_CALLBACK (buttons[i].func), NULL);
 
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
     }
 
   gtk_widget_show (window);
diff --git a/tests/testbaseline.c b/tests/testbaseline.c
index ba1129d4cc..f229a9b660 100644
--- a/tests/testbaseline.c
+++ b/tests/testbaseline.c
@@ -112,13 +112,13 @@ main (int    argc,
   for (j = 0; j < 2; j++)
     {
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       const char *aligns_names[] = { "FILL", "BASELINE" };
       GtkAlign aligns[] = { GTK_ALIGN_FILL, GTK_ALIGN_BASELINE};
 
       label = gtk_label_new (aligns_names[j]);
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       for (i = 0; i < 3; i++) {
        label = gtk_label_new ("│XYyj,Ö...");
@@ -127,7 +127,7 @@ main (int    argc,
 
        gtk_widget_set_valign (label, aligns[j]);
 
-       gtk_container_add (GTK_CONTAINER (hbox), label);
+       gtk_box_append (GTK_BOX (hbox), label);
       }
 
       for (i = 0; i < 3; i++) {
@@ -138,33 +138,33 @@ main (int    argc,
 
        gtk_widget_set_valign (entry, aligns[j]);
 
-       gtk_container_add (GTK_CONTAINER (hbox), entry);
+       gtk_box_append (GTK_BOX (hbox), entry);
       }
 
       spin = gtk_spin_button_new (NULL, 0, 1);
       gtk_orientable_set_orientation (GTK_ORIENTABLE (spin), GTK_ORIENTATION_VERTICAL);
       gtk_widget_set_valign (spin, aligns[j]);
-      gtk_container_add (GTK_CONTAINER (hbox), spin);
+      gtk_box_append (GTK_BOX (hbox), spin);
 
       spin = gtk_spin_button_new (NULL, 0, 1);
       gtk_widget_set_valign (spin, aligns[j]);
-      gtk_container_add (GTK_CONTAINER (hbox), spin);
+      gtk_box_append (GTK_BOX (hbox), spin);
     }
 
   grid_hbox = hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   combo = gtk_combo_box_text_new ();
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo), baseline_pos_str[0]);
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo), baseline_pos_str[1]);
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo), baseline_pos_str[2]);
   gtk_combo_box_set_active (GTK_COMBO_BOX (combo), 1);
-  gtk_container_add (GTK_CONTAINER (hbox), combo);
+  gtk_box_append (GTK_BOX (hbox), combo);
 
   for (j = 0; j < 2; j++)
     {
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       g_signal_connect (G_OBJECT (combo), "changed",
                        G_CALLBACK (baseline_position_changed), hbox);
@@ -173,7 +173,7 @@ main (int    argc,
        label = gtk_label_new ("Baseline:");
       else
        label = gtk_label_new ("Normal:");
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       for (i = 0; i < 3; i++)
        {
@@ -184,7 +184,7 @@ main (int    argc,
          if (j == 0)
            gtk_widget_set_valign (button, GTK_ALIGN_BASELINE);
 
-         gtk_container_add (GTK_CONTAINER (hbox), button);
+         gtk_box_append (GTK_BOX (hbox), button);
        }
 
       for (i = 0; i < 3; i++)
@@ -192,8 +192,8 @@ main (int    argc,
           GtkWidget *box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL,  6);
           button = gtk_button_new ();
 
-          gtk_container_add (GTK_CONTAINER (box), gtk_label_new ("│Xyj,Ö"));
-          gtk_container_add (GTK_CONTAINER (box), gtk_image_new_from_icon_name ("face-sad"));
+          gtk_box_append (GTK_BOX (box), gtk_label_new ("│Xyj,Ö"));
+          gtk_box_append (GTK_BOX (box), gtk_image_new_from_icon_name ("face-sad"));
           gtk_button_set_child (GTK_BUTTON (button), box);
 
           set_font_size (button, i);
@@ -201,34 +201,34 @@ main (int    argc,
          if (j == 0)
            gtk_widget_set_valign (button, GTK_ALIGN_BASELINE);
 
-         gtk_container_add (GTK_CONTAINER (hbox), button);
+         gtk_box_append (GTK_BOX (hbox), button);
        }
 
       image = gtk_image_new_from_icon_name ("face-sad");
       gtk_image_set_pixel_size (GTK_IMAGE (image), 34);
       if (j == 0)
        gtk_widget_set_valign (image, GTK_ALIGN_BASELINE);
-      gtk_container_add (GTK_CONTAINER (hbox), image);
+      gtk_box_append (GTK_BOX (hbox), image);
 
       button = gtk_toggle_button_new_with_label ("│Xyj,Ö");
       if (j == 0)
        gtk_widget_set_valign (button, GTK_ALIGN_BASELINE);
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
       button = gtk_toggle_button_new_with_label ("│Xyj,Ö");
       if (j == 0)
        gtk_widget_set_valign (button, GTK_ALIGN_BASELINE);
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
       button = gtk_check_button_new_with_label ("│Xyj,Ö");
       if (j == 0)
        gtk_widget_set_valign (button, GTK_ALIGN_BASELINE);
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
       button = gtk_radio_button_new_with_label (NULL, "│Xyj,Ö");
       if (j == 0)
        gtk_widget_set_valign (button, GTK_ALIGN_BASELINE);
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
     }
 
 
@@ -237,12 +237,12 @@ main (int    argc,
                            vbox, gtk_label_new ("grid"));
 
   grid_hbox = hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   label = gtk_label_new ("Align me:");
   gtk_widget_set_valign (label, GTK_ALIGN_BASELINE);
 
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
 
   grid = gtk_grid_new ();
   gtk_widget_set_valign (grid, GTK_ALIGN_BASELINE);
@@ -284,8 +284,8 @@ main (int    argc,
           GtkWidget *box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL,  6);
           button = gtk_button_new ();
 
-          gtk_container_add (GTK_CONTAINER (box), gtk_label_new ("│Xyj,Ö"));
-          gtk_container_add (GTK_CONTAINER (box), gtk_image_new_from_icon_name ("face-sad"));
+          gtk_box_append (GTK_BOX (box), gtk_label_new ("│Xyj,Ö"));
+          gtk_box_append (GTK_BOX (box), gtk_image_new_from_icon_name ("face-sad"));
           gtk_button_set_child (GTK_BUTTON (button), box);
 
           set_font_size (button, i);
@@ -301,19 +301,19 @@ main (int    argc,
 
     }
 
-  gtk_container_add (GTK_CONTAINER (hbox), grid);
+  gtk_box_append (GTK_BOX (hbox), grid);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   adjustment = gtk_adjustment_new (0.0, -1.0, 5.0, 1.0, 1.0, 0.0);
   spin = gtk_spin_button_new (adjustment, 1.0, 0);
   g_signal_connect (spin, "value-changed", (GCallback)baseline_row_value_changed, grid);
-  gtk_container_add (GTK_CONTAINER (hbox), spin);
+  gtk_box_append (GTK_BOX (hbox), spin);
 
   toggle = gtk_toggle_button_new_with_label ("Homogeneous");
   g_signal_connect (toggle, "toggled", (GCallback)homogeneous_changed, grid);
-  gtk_container_add (GTK_CONTAINER (hbox), toggle);
+  gtk_box_append (GTK_BOX (hbox), toggle);
 
   combo = gtk_combo_box_text_new ();
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo), baseline_pos_str[0]);
@@ -322,37 +322,37 @@ main (int    argc,
   gtk_combo_box_set_active (GTK_COMBO_BOX (combo), 1);
   g_signal_connect (G_OBJECT (combo), "changed",
                    G_CALLBACK (baseline_position_changed), grid_hbox);
-  gtk_container_add (GTK_CONTAINER (hbox), combo);
+  gtk_box_append (GTK_BOX (hbox), combo);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   gtk_notebook_append_page (GTK_NOTEBOOK (notebook),
                            vbox, gtk_label_new ("button box"));
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   adjustment = gtk_adjustment_new (34.0, 1.0, 64.0, 1.0, 1.0, 0.0);
   spin = gtk_spin_button_new (adjustment, 1.0, 0);
-  gtk_container_add (GTK_CONTAINER (hbox), spin);
+  gtk_box_append (GTK_BOX (hbox), spin);
 
   adjustment = gtk_adjustment_new (16.0, 1.0, 64.0, 1.0, 1.0, 0.0);
   spin2 = gtk_spin_button_new (adjustment, 1.0, 0);
-  gtk_container_add (GTK_CONTAINER (hbox), spin2);
+  gtk_box_append (GTK_BOX (hbox), spin2);
 
   for (j = 0; j < 3; j++)
     {
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       gtk_box_set_baseline_position (GTK_BOX (hbox), j);
 
       label = gtk_label_new (baseline_pos_str[j]);
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
       gtk_widget_set_vexpand (label, TRUE);
 
       image = gtk_image_new_from_icon_name ("face-sad");
       gtk_image_set_pixel_size (GTK_IMAGE (image), 34);
-      gtk_container_add (GTK_CONTAINER (hbox), image);
+      gtk_box_append (GTK_BOX (hbox), image);
 
       g_signal_connect (spin, "value-changed", (GCallback)image_size_value_changed, image);
 
@@ -365,7 +365,7 @@ main (int    argc,
          if (i != 0)
            gtk_widget_set_valign (button, GTK_ALIGN_BASELINE);
 
-         gtk_container_add (GTK_CONTAINER (hbox), button);
+         gtk_box_append (GTK_BOX (hbox), button);
        }
 
       for (i = 0; i < 3; i++)
@@ -373,10 +373,10 @@ main (int    argc,
           GtkWidget *box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL,  6);
           button = gtk_button_new ();
 
-          gtk_container_add (GTK_CONTAINER (box), gtk_label_new ("│Xyj,Ö"));
+          gtk_box_append (GTK_BOX (box), gtk_label_new ("│Xyj,Ö"));
           image = gtk_image_new_from_icon_name ("face-sad");
           gtk_image_set_pixel_size (GTK_IMAGE (image), 16);
-          gtk_container_add (GTK_CONTAINER (box), image);
+          gtk_box_append (GTK_BOX (box), image);
           gtk_button_set_child (GTK_BUTTON (button), box);
 
          if (i == 0)
@@ -386,7 +386,7 @@ main (int    argc,
 
          gtk_widget_set_valign (button, GTK_ALIGN_BASELINE);
 
-         gtk_container_add (GTK_CONTAINER (hbox), button);
+         gtk_box_append (GTK_BOX (hbox), button);
        }
     }
 
diff --git a/tests/testblur.c b/tests/testblur.c
index 21fa7774ae..618862cf1c 100644
--- a/tests/testblur.c
+++ b/tests/testblur.c
@@ -112,7 +112,7 @@ main (int argc, char **argv)
     gtk_label_set_attributes (GTK_LABEL (value_label), attrs);
     pango_attr_list_unref (attrs);
   }
-  gtk_container_add (GTK_CONTAINER (blur_box), value_label);
+  gtk_box_append (GTK_BOX (blur_box), value_label);
 
 
   scale = gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0, 10, 0.05);
@@ -123,7 +123,7 @@ main (int argc, char **argv)
   g_signal_connect (scale, "value-changed", G_CALLBACK (value_changed_cb), blur_box);
   g_signal_connect (scale, "value-changed", G_CALLBACK (value_changed_cb2), value_label);
 
-  gtk_container_add (GTK_CONTAINER (blur_box), scale);
+  gtk_box_append (GTK_BOX (blur_box), scale);
   gtk_window_set_child (GTK_WINDOW (window), blur_box);
 
   gtk_widget_show (window);
diff --git a/tests/testborderdrawing.c b/tests/testborderdrawing.c
index 96c3246bb3..fa5b3125af 100644
--- a/tests/testborderdrawing.c
+++ b/tests/testborderdrawing.c
@@ -118,52 +118,52 @@ main (int argc, char **argv)
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "one");
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "two");
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "three");
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "four");
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "five");
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
 
   /* Bottom */
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "b1");
-  gtk_container_add (GTK_CONTAINER (bottom), w);
+  gtk_box_append (GTK_BOX (bottom), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "b2");
-  gtk_container_add (GTK_CONTAINER (bottom), w);
+  gtk_box_append (GTK_BOX (bottom), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "b3");
-  gtk_container_add (GTK_CONTAINER (bottom), w);
+  gtk_box_append (GTK_BOX (bottom), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "b4");
-  gtk_container_add (GTK_CONTAINER (bottom), w);
+  gtk_box_append (GTK_BOX (bottom), w);
 
-  gtk_container_add (GTK_CONTAINER (box), top);
-  gtk_container_add (GTK_CONTAINER (box), bottom);
+  gtk_box_append (GTK_BOX (box), top);
+  gtk_box_append (GTK_BOX (box), bottom);
   gtk_window_set_child (GTK_WINDOW (window), box);
   g_signal_connect (window, "destroy", G_CALLBACK (quit_cb), &done);
   gtk_widget_show (window);
diff --git a/tests/testbox.c b/tests/testbox.c
index 1d91d6714d..82160c981c 100644
--- a/tests/testbox.c
+++ b/tests/testbox.c
@@ -27,7 +27,7 @@ edit_widget (GtkWidget *button)
                     "row-spacing", 10,
                     "column-spacing", 10,
                     NULL);
-      gtk_container_add (GTK_CONTAINER (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), grid);
+      gtk_box_append (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), grid);
 
       label = gtk_label_new ("Label:");
       gtk_widget_set_halign (label, GTK_ALIGN_END);
@@ -92,14 +92,14 @@ main (int argc, char *argv[])
   gtk_window_set_child (GTK_WINDOW (window), vbox);
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (box), test_widget ("1"));
-  gtk_container_add (GTK_CONTAINER (box), test_widget ("2"));
-  gtk_container_add (GTK_CONTAINER (box), test_widget ("3"));
-  gtk_container_add (GTK_CONTAINER (box), test_widget ("4"));
-  gtk_container_add (GTK_CONTAINER (box), test_widget ("5"));
-  gtk_container_add (GTK_CONTAINER (box), test_widget ("6"));
+  gtk_box_append (GTK_BOX (box), test_widget ("1"));
+  gtk_box_append (GTK_BOX (box), test_widget ("2"));
+  gtk_box_append (GTK_BOX (box), test_widget ("3"));
+  gtk_box_append (GTK_BOX (box), test_widget ("4"));
+  gtk_box_append (GTK_BOX (box), test_widget ("5"));
+  gtk_box_append (GTK_BOX (box), test_widget ("6"));
 
-  gtk_container_add (GTK_CONTAINER (vbox), box);
+  gtk_box_append (GTK_BOX (vbox), box);
 
   check = gtk_check_button_new_with_label ("Homogeneous");
   g_object_bind_property (box, "homogeneous",
@@ -111,7 +111,7 @@ main (int argc, char *argv[])
   gtk_widget_set_margin_bottom (check, 10);
   gtk_widget_set_halign (check, GTK_ALIGN_CENTER);
   gtk_widget_show (check);
-  gtk_container_add (GTK_CONTAINER (vbox), check);
+  gtk_box_append (GTK_BOX (vbox), check);
 
   b = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
   gtk_widget_set_margin_start (b, 10);
@@ -121,15 +121,15 @@ main (int argc, char *argv[])
   gtk_widget_set_halign (b, GTK_ALIGN_CENTER);
   label = gtk_label_new ("Spacing:");
   gtk_widget_set_halign (label, GTK_ALIGN_END);
-  gtk_container_add (GTK_CONTAINER (b), label);
+  gtk_box_append (GTK_BOX (b), label);
 
   spin = gtk_spin_button_new_with_range (0, 10, 1);
   gtk_spin_button_set_numeric (GTK_SPIN_BUTTON (spin), TRUE);
   gtk_widget_set_halign (spin, GTK_ALIGN_START);
   g_signal_connect (spin, "value-changed",
                     G_CALLBACK (spacing_changed), box);
-  gtk_container_add (GTK_CONTAINER (b), spin);
-  gtk_container_add (GTK_CONTAINER (vbox), b);
+  gtk_box_append (GTK_BOX (b), spin);
+  gtk_box_append (GTK_BOX (vbox), b);
 
   gtk_widget_show (window);
 
diff --git a/tests/testbuttons.c b/tests/testbuttons.c
index 08f4418e29..cac1b578a0 100644
--- a/tests/testbuttons.c
+++ b/tests/testbuttons.c
@@ -36,11 +36,11 @@ int main (int argc, char *argv[])
         gtk_window_set_child (GTK_WINDOW (window), box);
 
        hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-       gtk_container_add (GTK_CONTAINER (box), hbox);
+       gtk_box_append (GTK_BOX (box), hbox);
        button = g_object_new (GTK_TYPE_BUTTON,
                                "label", "document-save",
                               NULL);
-       gtk_container_add (GTK_CONTAINER (hbox), button);
+       gtk_box_append (GTK_BOX (hbox), button);
 
        g_object_get (button,
                       "label", &text,
@@ -50,12 +50,12 @@ int main (int argc, char *argv[])
        text = g_strdup_printf ("label: \"%s\" icon-name: \"%s\" use-underline: %s\n", text, icon_name, 
use_underline ? "TRUE" : "FALSE");
        label = gtk_label_new (text);
        g_free (text);
-       gtk_container_add (GTK_CONTAINER (hbox), label);
+       gtk_box_append (GTK_BOX (hbox), label);
 
        hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-       gtk_container_add (GTK_CONTAINER (box), hbox);
+       gtk_box_append (GTK_BOX (box), hbox);
        button = gtk_button_new_with_label ("_Save");
-       gtk_container_add (GTK_CONTAINER (hbox), button);
+       gtk_box_append (GTK_BOX (hbox), button);
 
        g_object_get (button,
                       "label", &text,
@@ -65,12 +65,12 @@ int main (int argc, char *argv[])
        text = g_strdup_printf ("label: \"%s\" icon-name: \"%s\" use-underline: %s\n", text, icon_name, 
use_underline ? "TRUE" : "FALSE");
        label = gtk_label_new (text);
        g_free (text);
-       gtk_container_add (GTK_CONTAINER (hbox), label);
+       gtk_box_append (GTK_BOX (hbox), label);
 
        hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-       gtk_container_add (GTK_CONTAINER (box), hbox);
+       gtk_box_append (GTK_BOX (box), hbox);
        button = gtk_button_new_with_mnemonic ("_Save");
-       gtk_container_add (GTK_CONTAINER (hbox), button);
+       gtk_box_append (GTK_BOX (hbox), button);
 
        g_object_get (button,
                       "label", &text,
@@ -80,12 +80,12 @@ int main (int argc, char *argv[])
        text = g_strdup_printf ("label: \"%s\" icon-name: \"%s\" use-underline: %s\n", text, icon_name, 
use_underline ? "TRUE" : "FALSE");
        label = gtk_label_new (text);
        g_free (text);
-       gtk_container_add (GTK_CONTAINER (hbox), label);
+       gtk_box_append (GTK_BOX (hbox), label);
 
        hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-       gtk_container_add (GTK_CONTAINER (box), hbox);
+       gtk_box_append (GTK_BOX (box), hbox);
        button = gtk_button_new_from_icon_name ("help-about");
-       gtk_container_add (GTK_CONTAINER (hbox), button);
+       gtk_box_append (GTK_BOX (hbox), button);
 
        g_object_get (button,
                       "label", &text,
@@ -95,14 +95,14 @@ int main (int argc, char *argv[])
        text = g_strdup_printf ("label: \"%s\" icon-name: \"%s\" use-underline: %s\n", text, icon_name, 
use_underline ? "TRUE" : "FALSE");
        label = gtk_label_new (text);
        g_free (text);
-       gtk_container_add (GTK_CONTAINER (hbox), label);
+       gtk_box_append (GTK_BOX (hbox), label);
 
        hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-       gtk_container_add (GTK_CONTAINER (box), hbox);
+       gtk_box_append (GTK_BOX (box), hbox);
         button = gtk_button_new ();
         gtk_button_set_icon_name (GTK_BUTTON (button), "help-about");
         gtk_button_set_use_underline (GTK_BUTTON (button), TRUE);
-       gtk_container_add (GTK_CONTAINER (hbox), button);
+       gtk_box_append (GTK_BOX (hbox), button);
        g_object_get (button,
                       "label", &text,
                       "use-underline", &use_underline,
@@ -111,7 +111,7 @@ int main (int argc, char *argv[])
        text = g_strdup_printf ("label: \"%s\" icon-name: \"%s\" use-underline: %s\n", text, icon_name, 
use_underline ? "TRUE" : "FALSE");
        label = gtk_label_new (text);
        g_free (text);
-       gtk_container_add (GTK_CONTAINER (hbox), label);
+       gtk_box_append (GTK_BOX (hbox), label);
 
        gtk_widget_show (window);
 
diff --git a/tests/testcalendar.c b/tests/testcalendar.c
index 7645d887db..7d723326c4 100644
--- a/tests/testcalendar.c
+++ b/tests/testcalendar.c
@@ -234,24 +234,24 @@ create_calendar(void)
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, DEF_PAD_SMALL);
   frame = create_frame ("<b>Options</b>", vbox, GTK_ALIGN_FILL, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (rpane), frame);
+  gtk_box_append (GTK_BOX (rpane), frame);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, DEF_PAD_SMALL);
   gtk_widget_set_halign (hbox, GTK_ALIGN_START);
   gtk_widget_set_valign (hbox, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   /* Build the Right frame with the flags in */
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (rpane), vbox);
+  gtk_box_append (GTK_BOX (rpane), vbox);
 
   for (i = 0; i < G_N_ELEMENTS (flags); i++)
     {
       GtkWidget *toggle = gtk_check_button_new_with_mnemonic (flags[i].label);
       gboolean value;
 
-      gtk_container_add (GTK_CONTAINER (vbox), toggle);
+      gtk_box_append (GTK_BOX (vbox), toggle);
 
       g_object_get (G_OBJECT (calendar), flags[i].prop_name, &value, NULL);
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (toggle), value);
@@ -268,25 +268,25 @@ create_calendar(void)
   frame = create_frame ("<b>Signal Events</b>", vbox, GTK_ALIGN_FILL, GTK_ALIGN_CENTER);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 3);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
   label = gtk_label_new ("Signal:");
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
   calendar_data.last_sig = gtk_label_new ("");
-  gtk_container_add (GTK_CONTAINER (hbox), calendar_data.last_sig);
+  gtk_box_append (GTK_BOX (hbox), calendar_data.last_sig);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 3);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
   label = gtk_label_new ("Previous signal:");
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
   calendar_data.prev_sig = gtk_label_new ("");
-  gtk_container_add (GTK_CONTAINER (hbox), calendar_data.prev_sig);
+  gtk_box_append (GTK_BOX (hbox), calendar_data.prev_sig);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 3);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
   label = gtk_label_new ("Second previous signal:");
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
   calendar_data.prev2_sig = gtk_label_new ("");
-  gtk_container_add (GTK_CONTAINER (hbox), calendar_data.prev2_sig);
+  gtk_box_append (GTK_BOX (hbox), calendar_data.prev2_sig);
 
   /*
    *  Glue everything together
@@ -297,15 +297,15 @@ create_calendar(void)
 
   button = gtk_button_new_with_label ("Close");
   g_signal_connect (button, "clicked", G_CALLBACK (quit_cb), &done);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, DEF_PAD_SMALL);
 
-  gtk_container_add (GTK_CONTAINER (vbox), hpaned);
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
-  gtk_container_add (GTK_CONTAINER (vbox), frame);
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
-  gtk_container_add (GTK_CONTAINER (vbox), bbox);
+  gtk_box_append (GTK_BOX (vbox), hpaned);
+  gtk_box_append (GTK_BOX (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+  gtk_box_append (GTK_BOX (vbox), frame);
+  gtk_box_append (GTK_BOX (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+  gtk_box_append (GTK_BOX (vbox), bbox);
 
   gtk_window_set_child (GTK_WINDOW (window), vbox);
 
diff --git a/tests/testcellarea.c b/tests/testcellarea.c
index 1726b15807..1e0b424390 100644
--- a/tests/testcellarea.c
+++ b/tests/testcellarea.c
@@ -197,16 +197,16 @@ simple_cell_area (void)
 
   /* Now add some controls */
   vbox  = gtk_box_new (GTK_ORIENTATION_VERTICAL, 4);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
 
-  gtk_container_add (GTK_CONTAINER (hbox), frame);
+  gtk_box_append (GTK_BOX (hbox), frame);
 
   widget = gtk_combo_box_text_new ();
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (widget), "Horizontal");
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (widget), "Vertical");
   gtk_combo_box_set_active (GTK_COMBO_BOX (widget), 0);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (orientation_changed), iconview);
@@ -214,7 +214,7 @@ simple_cell_area (void)
   widget = gtk_check_button_new_with_label ("Align 2nd Cell");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), FALSE);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (align_cell_2_toggled), iconview);
@@ -222,7 +222,7 @@ simple_cell_area (void)
   widget = gtk_check_button_new_with_label ("Align 3rd Cell");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), TRUE);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (align_cell_3_toggled), iconview);
@@ -231,7 +231,7 @@ simple_cell_area (void)
   widget = gtk_check_button_new_with_label ("Expand 1st Cell");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), FALSE);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (expand_cell_1_toggled), iconview);
@@ -239,7 +239,7 @@ simple_cell_area (void)
   widget = gtk_check_button_new_with_label ("Expand 2nd Cell");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), TRUE);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (expand_cell_2_toggled), iconview);
@@ -247,7 +247,7 @@ simple_cell_area (void)
   widget = gtk_check_button_new_with_label ("Expand 3rd Cell");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), FALSE);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (expand_cell_3_toggled), iconview);
@@ -441,15 +441,15 @@ focus_cell_area (void)
 
   /* Now add some controls */
   vbox  = gtk_box_new (GTK_ORIENTATION_VERTICAL, 4);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
-  gtk_container_add (GTK_CONTAINER (hbox), frame);
+  gtk_box_append (GTK_BOX (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), frame);
 
   widget = gtk_combo_box_text_new ();
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (widget), "Horizontal");
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (widget), "Vertical");
   gtk_combo_box_set_active (GTK_COMBO_BOX (widget), 0);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (orientation_changed), iconview);
@@ -457,7 +457,7 @@ focus_cell_area (void)
   widget = gtk_check_button_new_with_label ("Focus Sibling");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), TRUE);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (focus_sibling_toggled), iconview);
@@ -526,7 +526,7 @@ background_area (void)
                         "prepended space distributed to the background area.");
   gtk_label_set_wrap (GTK_LABEL (label), TRUE);
   gtk_label_set_width_chars (GTK_LABEL (label), 40);
-  gtk_container_add (GTK_CONTAINER (main_vbox), label);
+  gtk_box_append (GTK_BOX (main_vbox), label);
 
   iconview = focus_iconview (TRUE, NULL, NULL);
 
@@ -540,17 +540,17 @@ background_area (void)
 
   /* Now add some controls */
   vbox  = gtk_box_new (GTK_ORIENTATION_VERTICAL, 4);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
-  gtk_container_add (GTK_CONTAINER (hbox), frame);
+  gtk_box_append (GTK_BOX (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), frame);
 
-  gtk_container_add (GTK_CONTAINER (main_vbox), hbox);
+  gtk_box_append (GTK_BOX (main_vbox), hbox);
 
   widget = gtk_combo_box_text_new ();
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (widget), "Horizontal");
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (widget), "Vertical");
   gtk_combo_box_set_active (GTK_COMBO_BOX (widget), 0);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (vbox), widget);
+  gtk_box_append (GTK_BOX (vbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (orientation_changed), iconview);
@@ -559,9 +559,9 @@ background_area (void)
   label = gtk_label_new ("Cell spacing");
   gtk_widget_set_hexpand (label, TRUE);
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
-  gtk_container_add (GTK_CONTAINER (hbox), label);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   g_signal_connect (G_OBJECT (widget), "value-changed",
                     G_CALLBACK (cell_spacing_changed), iconview);
@@ -572,9 +572,9 @@ background_area (void)
   label = gtk_label_new ("Row spacing");
   gtk_widget_set_hexpand (label, TRUE);
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
-  gtk_container_add (GTK_CONTAINER (hbox), label);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   g_signal_connect (G_OBJECT (widget), "value-changed",
                     G_CALLBACK (row_spacing_changed), iconview);
@@ -584,9 +584,9 @@ background_area (void)
   gtk_widget_set_hexpand (label, TRUE);
   gtk_spin_button_set_value (GTK_SPIN_BUTTON (widget), gtk_icon_view_get_item_padding (GTK_ICON_VIEW 
(iconview)));
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
-  gtk_container_add (GTK_CONTAINER (hbox), label);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   g_signal_connect (G_OBJECT (widget), "value-changed",
                     G_CALLBACK (item_padding_changed), iconview);
diff --git a/tests/testcellrenderertext.c b/tests/testcellrenderertext.c
index 87f424330c..ca558dc51a 100644
--- a/tests/testcellrenderertext.c
+++ b/tests/testcellrenderertext.c
@@ -278,20 +278,20 @@ main (int argc, char **argv)
   /* LTR */
 
   label = gtk_label_new ("Left to right");
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   tree = create_tree (FALSE);
   gtk_widget_set_vexpand (tree, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), tree);
+  gtk_box_append (GTK_BOX (vbox), tree);
 
   /* RTL */
 
   label = gtk_label_new ("Right to left");
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   tree = create_tree (TRUE);
   gtk_widget_set_vexpand (tree, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), tree);
+  gtk_box_append (GTK_BOX (vbox), tree);
 
   gtk_widget_show (window);
 
diff --git a/tests/testclipboard2.c b/tests/testclipboard2.c
index a7d61be95b..40c91b2b72 100644
--- a/tests/testclipboard2.c
+++ b/tests/testclipboard2.c
@@ -204,7 +204,7 @@ format_list_add_row (GtkWidget         *list,
   GtkWidget *box;
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
-  gtk_container_add (GTK_CONTAINER (box), gtk_label_new (format_name));
+  gtk_box_append (GTK_BOX (box), gtk_label_new (format_name));
 
   gdk_content_formats_unref (formats);
   gtk_list_box_insert (GTK_LIST_BOX (list), box, -1);
@@ -303,7 +303,7 @@ add_provider_button (GtkWidget          *box,
   if (provider)
     g_object_set_data_full (G_OBJECT (button), "provider", provider, g_object_unref);
 
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 }
 
 static GtkWidget *
@@ -320,7 +320,7 @@ get_button_list (GdkClipboard *clipboard,
 
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 
-  gtk_container_add (GTK_CONTAINER (box), gtk_label_new (info));
+  gtk_box_append (GTK_BOX (box), gtk_label_new (info));
 
   add_provider_button (box,
                        NULL,
@@ -388,16 +388,16 @@ get_clipboard_widget (GdkClipboard *clipboard,
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new (name));
+  gtk_box_append (GTK_BOX (hbox), vbox);
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new (name));
   switcher = gtk_stack_switcher_new ();
-  gtk_container_add (GTK_CONTAINER (vbox), switcher);
+  gtk_box_append (GTK_BOX (vbox), switcher);
   stack = get_contents_widget (clipboard);
-  gtk_container_add (GTK_CONTAINER (vbox), stack);
+  gtk_box_append (GTK_BOX (vbox), stack);
   gtk_stack_switcher_set_stack (GTK_STACK_SWITCHER (switcher), GTK_STACK (stack));
-  gtk_container_add (GTK_CONTAINER (hbox), get_button_list (clipboard, "Set Locally:"));
+  gtk_box_append (GTK_BOX (hbox), get_button_list (clipboard, "Set Locally:"));
   if (clipboard != alt_clipboard)
-    gtk_container_add (GTK_CONTAINER (hbox), get_button_list (alt_clipboard, "Set Remotely:"));
+    gtk_box_append (GTK_BOX (hbox), get_button_list (alt_clipboard, "Set Remotely:"));
 
   return hbox;
 }
@@ -410,11 +410,11 @@ get_window_contents (GdkDisplay *display,
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
   gtk_box_set_homogeneous (GTK_BOX (box), TRUE);
-  gtk_container_add (GTK_CONTAINER (box),
+  gtk_box_append (GTK_BOX (box),
                      get_clipboard_widget (gdk_display_get_clipboard (display),
                                            gdk_display_get_clipboard (alt_display),
                                            "Clipboard"));
-  gtk_container_add (GTK_CONTAINER (box),
+  gtk_box_append (GTK_BOX (box),
                      get_clipboard_widget (gdk_display_get_primary_clipboard (display),
                                            gdk_display_get_primary_clipboard (alt_display),
                                            "Primary Clipboard"));
diff --git a/tests/testcombo.c b/tests/testcombo.c
index 42a14750b9..afec47e892 100644
--- a/tests/testcombo.c
+++ b/tests/testcombo.c
@@ -958,10 +958,10 @@ main (int argc, char **argv)
 
         /* GtkCellView */
         tmp = gtk_frame_new ("GtkCellView");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
         cellview = gtk_cell_view_new ();
         renderer = gtk_cell_renderer_pixbuf_new ();
@@ -975,19 +975,19 @@ main (int argc, char **argv)
                                     renderer,
                                     TRUE);
         g_object_set (renderer, "text", "la la la", NULL);
-        gtk_container_add (GTK_CONTAINER (boom), cellview);
+        gtk_box_append (GTK_BOX (boom), cellview);
 
         /* GtkComboBox list */
         tmp = gtk_frame_new ("GtkComboBox (list)");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
         model = create_list_blaat ();
         combobox = gtk_combo_box_new_with_model (model);
         g_object_unref (model);
-        gtk_container_add (GTK_CONTAINER (boom), combobox);
+        gtk_box_append (GTK_BOX (boom), combobox);
 
         renderer = gtk_cell_renderer_pixbuf_new ();
         gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combobox),
@@ -1019,10 +1019,10 @@ main (int argc, char **argv)
 
         /* GtkComboBox dynamic list */
         tmp = gtk_frame_new ("GtkComboBox (dynamic list)");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
         model = create_empty_list_blaat ();
         combobox = gtk_combo_box_new_with_model (model);
@@ -1030,7 +1030,7 @@ main (int argc, char **argv)
                          G_CALLBACK (populate_list_blaat), combobox);
 
         g_object_unref (model);
-        gtk_container_add (GTK_CONTAINER (boom), combobox);
+        gtk_box_append (GTK_BOX (boom), combobox);
 
         renderer = gtk_cell_renderer_pixbuf_new ();
         gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combobox),
@@ -1062,15 +1062,15 @@ main (int argc, char **argv)
 
         /* GtkComboBox custom entry */
         tmp = gtk_frame_new ("GtkComboBox (custom)");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
         model = create_list_blaat ();
         combobox = gtk_combo_box_new_with_model (model);
         g_object_unref (model);
-        gtk_container_add (GTK_CONTAINER (boom), combobox);
+        gtk_box_append (GTK_BOX (boom), combobox);
 
         renderer = gtk_cell_renderer_pixbuf_new ();
         gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combobox),
@@ -1116,15 +1116,15 @@ main (int argc, char **argv)
 
         /* GtkComboBox tree */
         tmp = gtk_frame_new ("GtkComboBox (tree)");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
         model = create_tree_blaat ();
         combobox = gtk_combo_box_new_with_model (model);
         g_object_unref (model);
-        gtk_container_add (GTK_CONTAINER (boom), combobox);
+        gtk_box_append (GTK_BOX (boom), combobox);
 
         renderer = gtk_cell_renderer_pixbuf_new ();
         gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combobox),
@@ -1159,35 +1159,35 @@ main (int argc, char **argv)
 
         /* GtkComboBox (grid mode) */
         tmp = gtk_frame_new ("GtkComboBox (grid mode)");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
 
         /* GtkComboBoxEntry */
         tmp = gtk_frame_new ("GtkComboBox with entry");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
         comboboxtext = gtk_combo_box_text_new_with_entry ();
         setup_combo_entry (GTK_COMBO_BOX_TEXT (comboboxtext));
-        gtk_container_add (GTK_CONTAINER (boom), comboboxtext);
+        gtk_box_append (GTK_BOX (boom), comboboxtext);
 
 
         /* Phylogenetic tree */
         tmp = gtk_frame_new ("What are you ?");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
         model = create_phylogenetic_tree ();
         combobox = gtk_combo_box_new_with_model (model);
         g_object_unref (model);
-        gtk_container_add (GTK_CONTAINER (boom), combobox);
+        gtk_box_append (GTK_BOX (boom), combobox);
 
         renderer = gtk_cell_renderer_text_new ();
         gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combobox),
@@ -1201,15 +1201,15 @@ main (int argc, char **argv)
 
         /* Capitals */
         tmp = gtk_frame_new ("Where are you ?");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
         model = create_capital_tree ();
        combobox = gtk_combo_box_new_with_model (model);
         g_object_unref (model);
-        gtk_container_add (GTK_CONTAINER (boom), combobox);
+        gtk_box_append (GTK_BOX (boom), combobox);
         renderer = gtk_cell_renderer_text_new ();
         gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (combobox),
                                     renderer,
@@ -1232,15 +1232,15 @@ main (int argc, char **argv)
 
         /* Aligned Food */
         tmp = gtk_frame_new ("Hungry ?");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
         model = create_food_list ();
        combobox = gtk_combo_box_new_with_model (model);
         g_object_unref (model);
-        gtk_container_add (GTK_CONTAINER (boom), combobox);
+        gtk_box_append (GTK_BOX (boom), combobox);
 
        area = gtk_cell_layout_get_area (GTK_CELL_LAYOUT (combobox));
 
@@ -1266,15 +1266,15 @@ main (int argc, char **argv)
 
        /* Ellipsizing growing combos */
         tmp = gtk_frame_new ("Unconstrained Menu");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
 
         boom = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-        gtk_container_add (GTK_CONTAINER (tmp), boom);
+        gtk_box_append (GTK_BOX (tmp), boom);
 
        model = create_list_long ();
        combobox = gtk_combo_box_new_with_model (model);
         g_object_unref (model);
-        gtk_container_add (GTK_CONTAINER (boom), combobox);
+        gtk_box_append (GTK_BOX (boom), combobox);
         renderer = gtk_cell_renderer_text_new ();
        g_object_set (G_OBJECT (renderer), "ellipsize", PANGO_ELLIPSIZE_END, NULL);
 
@@ -1285,7 +1285,7 @@ main (int argc, char **argv)
        gtk_combo_box_set_popup_fixed_width (GTK_COMBO_BOX (combobox), FALSE);
 
         tmp = gtk_frame_new ("Looong");
-        gtk_container_add (GTK_CONTAINER (mainbox), tmp);
+        gtk_box_append (GTK_BOX (mainbox), tmp);
         combobox = gtk_combo_box_text_new ();
         for (i = 0; i < 200; i++)
           {
@@ -1294,7 +1294,7 @@ main (int argc, char **argv)
             g_free (text);
           }
         gtk_combo_box_set_active (GTK_COMBO_BOX (combobox), 53);
-        gtk_container_add (GTK_CONTAINER (tmp), combobox);
+        gtk_box_append (GTK_BOX (tmp), combobox);
 
         gtk_widget_show (window);
 
diff --git a/tests/testcombochange.c b/tests/testcombochange.c
index 57f2c5bdd9..fe68fee232 100644
--- a/tests/testcombochange.c
+++ b/tests/testcombochange.c
@@ -249,30 +249,30 @@ main (int argc, char **argv)
   content_area = gtk_dialog_get_content_area (GTK_DIALOG (dialog));
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
-  gtk_container_add (GTK_CONTAINER (content_area), hbox);
+  gtk_box_append (GTK_BOX (content_area), hbox);
 
   combo_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-  gtk_container_add (GTK_CONTAINER (hbox), combo_vbox);
+  gtk_box_append (GTK_BOX (hbox), combo_vbox);
 
   label = gtk_label_new (NULL);
   gtk_label_set_markup (GTK_LABEL (label), "<b>Menu mode</b>");
-  gtk_container_add (GTK_CONTAINER (combo_vbox), label);
+  gtk_box_append (GTK_BOX (combo_vbox), label);
 
   menu_combo = create_combo ("menu-combo", FALSE);
   gtk_widget_set_margin_start (menu_combo, 12);
-  gtk_container_add (GTK_CONTAINER (combo_vbox), menu_combo);
+  gtk_box_append (GTK_BOX (combo_vbox), menu_combo);
 
   label = gtk_label_new (NULL);
   gtk_label_set_markup (GTK_LABEL (label), "<b>List mode</b>");
-  gtk_container_add (GTK_CONTAINER (combo_vbox), label);
+  gtk_box_append (GTK_BOX (combo_vbox), label);
 
   list_combo = create_combo ("list-combo", TRUE);
   gtk_widget_set_margin_start (list_combo, 12);
-  gtk_container_add (GTK_CONTAINER (combo_vbox), list_combo);
+  gtk_box_append (GTK_BOX (combo_vbox), list_combo);
 
   scrolled_window = gtk_scrolled_window_new (NULL, NULL);
   gtk_widget_set_hexpand (scrolled_window, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), scrolled_window);
+  gtk_box_append (GTK_BOX (hbox), scrolled_window);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window),
                                   GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
 
@@ -283,24 +283,24 @@ main (int argc, char **argv)
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolled_window), text_view);
 
   button_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-  gtk_container_add (GTK_CONTAINER (hbox), button_vbox);
+  gtk_box_append (GTK_BOX (hbox), button_vbox);
 
   gtk_window_set_default_size (GTK_WINDOW (dialog), 500, 300);
 
   button = gtk_button_new_with_label ("Insert");
-  gtk_container_add (GTK_CONTAINER (button_vbox), button);
+  gtk_box_append (GTK_BOX (button_vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (on_insert), NULL);
 
   button = gtk_button_new_with_label ("Delete");
-  gtk_container_add (GTK_CONTAINER (button_vbox), button);
+  gtk_box_append (GTK_BOX (button_vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (on_delete), NULL);
 
   button = gtk_button_new_with_label ("Reorder");
-  gtk_container_add (GTK_CONTAINER (button_vbox), button);
+  gtk_box_append (GTK_BOX (button_vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (on_reorder), NULL);
 
   button = gtk_button_new_with_label ("Animate");
-  gtk_container_add (GTK_CONTAINER (button_vbox), button);
+  gtk_box_append (GTK_BOX (button_vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (on_animate), NULL);
 
   gtk_widget_show (dialog);
diff --git a/tests/testdialog.c b/tests/testdialog.c
index 7b2cc418a2..d0f1edd9a0 100644
--- a/tests/testdialog.c
+++ b/tests/testdialog.c
@@ -101,7 +101,7 @@ add_content (GtkWidget *dialog)
   gtk_widget_set_margin_bottom (label, 50);
   gtk_widget_show (label);
 
-  gtk_container_add (GTK_CONTAINER (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), label);
+  gtk_box_append (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), label);
 }
 
 static void
@@ -341,74 +341,74 @@ main (int argc, char *argv[])
   gtk_flow_box_set_selection_mode (GTK_FLOW_BOX (box), GTK_SELECTION_NONE);
   gtk_widget_set_hexpand (box, TRUE);
   gtk_widget_show (box);
-  gtk_container_add (GTK_CONTAINER (vbox), box);
+  gtk_box_append (GTK_BOX (vbox), box);
 
   button = gtk_button_new_with_label ("Message dialog");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_message_dialog1), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Message with icon");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_message_dialog1a), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Confirmation dialog");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_message_dialog2), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Builtin");
   button = gtk_button_new_with_label ("Builtin");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_color_chooser), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Generic Builtin");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_color_chooser_generic), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Simple");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_dialog), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("With Header");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_dialog_with_header), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("With Buttons");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_dialog_with_buttons), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Header & Buttons");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_dialog_with_header_buttons), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Header & Buttons & Builder");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_dialog_with_header_buttons2), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Template");
   button = gtk_button_new_with_label ("Template");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_dialog_from_template), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Template With Header");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_dialog_from_template_with_header), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Flexible Template");
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (show_dialog_flex_template), window);
   gtk_widget_show (button);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_check_button_new_with_label ("Dialogs have headers");
   g_object_bind_property (gtk_settings_get_default (), "gtk-dialogs-use-header",
@@ -416,13 +416,13 @@ main (int argc, char *argv[])
                           G_BINDING_BIDIRECTIONAL|G_BINDING_SYNC_CREATE);
   gtk_widget_show (button);
   gtk_widget_set_halign (button, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_spinner_new ();
   gtk_spinner_start (GTK_SPINNER (button));
   gtk_widget_show (button);
   gtk_widget_set_halign (button, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   gtk_widget_show (window);
   while (TRUE)
diff --git a/tests/testdnd.c b/tests/testdnd.c
index f6659a54c4..eb29ea5982 100644
--- a/tests/testdnd.c
+++ b/tests/testdnd.c
@@ -463,7 +463,7 @@ popup_cb (gpointer data)
                g_signal_connect (dest, "drop", G_CALLBACK (popup_drop), NULL);
                 gtk_widget_add_controller (button, GTK_EVENT_CONTROLLER (dest));
              }
-         gtk_container_add (GTK_CONTAINER (popup_window), grid);
+         gtk_box_append (GTK_BOX (popup_window), grid);
        }
       gtk_widget_show (popup_window);
       popped_up = TRUE;
diff --git a/tests/testdnd2.c b/tests/testdnd2.c
index e02dea97a4..a393bd9393 100644
--- a/tests/testdnd2.c
+++ b/tests/testdnd2.c
@@ -180,13 +180,13 @@ ask_actions (GdkDrop *drop,
       gtk_popover_set_child (GTK_POPOVER (popover), box);
       button = gtk_button_new_with_label ("Copy");
       g_signal_connect (button, "clicked", G_CALLBACK (do_copy), NULL);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
       button = gtk_button_new_with_label ("Move");
       g_signal_connect (button, "clicked", G_CALLBACK (do_copy), NULL);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
       button = gtk_button_new_with_label ("Cancel");
       g_signal_connect (button, "clicked", G_CALLBACK (do_cancel), NULL);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
     }
   gtk_popover_popup (GTK_POPOVER (popover));
 }
diff --git a/tests/testdnd3.c b/tests/testdnd3.c
index ac73b5bee4..3dd96bb35c 100644
--- a/tests/testdnd3.c
+++ b/tests/testdnd3.c
@@ -275,10 +275,10 @@ int main (int argc, char *argv[])
   gtk_window_set_child (GTK_WINDOW (window), box);
 
   box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (box), box2);
+  gtk_box_append (GTK_BOX (box), box2);
 
   canvas = canvas_new ();
-  gtk_container_add (GTK_CONTAINER (box2), canvas);
+  gtk_box_append (GTK_BOX (box2), canvas);
 
   x = y = 40;
   for (i = 0; i < 4; i++)
@@ -286,7 +286,7 @@ int main (int argc, char *argv[])
       GtkWidget *item;
 
       item = canvas_item_new (i, x, y, 0);
-      gtk_container_add (GTK_CONTAINER (canvas), item);
+      gtk_box_append (GTK_BOX (canvas), item);
       apply_transform (item);
 
       x += 150;
@@ -297,7 +297,7 @@ int main (int argc, char *argv[])
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
                                   GTK_POLICY_AUTOMATIC,
                                   GTK_POLICY_NEVER);
-  gtk_container_add (GTK_CONTAINER (box), sw);
+  gtk_box_append (GTK_BOX (box), sw);
 
   box3 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_add_css_class (box3, "linked");
@@ -314,7 +314,7 @@ int main (int argc, char *argv[])
                              "rgba", &rgba,
                              "selectable", FALSE,
                              NULL);
-      gtk_container_add (GTK_CONTAINER (box3), swatch);
+      gtk_box_append (GTK_BOX (box3), swatch);
     }
 
   gtk_widget_show (window);
diff --git a/tests/testellipsise.c b/tests/testellipsise.c
index 6a8263a9ce..70f5be1385 100644
--- a/tests/testellipsise.c
+++ b/tests/testellipsise.c
@@ -143,9 +143,9 @@ main (int argc, char *argv[])
   gtk_widget_set_vexpand (overlay, TRUE);
   gtk_overlay_add_overlay (GTK_OVERLAY (overlay), label);
 
-  gtk_container_add (GTK_CONTAINER (vbox), combo);
-  gtk_container_add (GTK_CONTAINER (vbox), scale);
-  gtk_container_add (GTK_CONTAINER (vbox), overlay);
+  gtk_box_append (GTK_BOX (vbox), combo);
+  gtk_box_append (GTK_BOX (vbox), scale);
+  gtk_box_append (GTK_BOX (vbox), overlay);
 
   g_object_set_data (G_OBJECT (label), "combo", combo);
 
diff --git a/tests/testentrycompletion.c b/tests/testentrycompletion.c
index 2f726b53ef..a6c5e4f128 100644
--- a/tests/testentrycompletion.c
+++ b/tests/testentrycompletion.c
@@ -319,7 +319,7 @@ main (int argc, char *argv[])
   label = gtk_label_new (NULL);
 
   gtk_label_set_markup (GTK_LABEL (label), "Completion demo, try writing <b>total</b> or <b>gnome</b> for 
example.");
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   /* Create our first entry */
   entry = gtk_entry_new ();
@@ -332,7 +332,7 @@ main (int argc, char *argv[])
   gtk_entry_set_completion (GTK_ENTRY (entry), completion);
   g_object_unref (completion);
   
-  gtk_container_add (GTK_CONTAINER (vbox), entry);
+  gtk_box_append (GTK_BOX (vbox), entry);
 
   /* Create a tree model and use it as the completion model */
   completion_model = create_simple_completion_model ();
@@ -352,7 +352,7 @@ main (int argc, char *argv[])
   gtk_entry_set_completion (GTK_ENTRY (entry), completion);
   g_object_unref (completion);
   
-  gtk_container_add (GTK_CONTAINER (vbox), entry);
+  gtk_box_append (GTK_BOX (vbox), entry);
 
   /* Create a tree model and use it as the completion model */
   completion_model = create_completion_model ();
@@ -389,7 +389,7 @@ main (int argc, char *argv[])
   gtk_entry_set_completion (GTK_ENTRY (entry), completion);
   g_object_unref (completion);
   
-  gtk_container_add (GTK_CONTAINER (vbox), entry);
+  gtk_box_append (GTK_BOX (vbox), entry);
 
   /* Create a tree model and use it as the completion model */
   completion_model = GTK_TREE_MODEL (gtk_list_store_new (1, G_TYPE_STRING));
@@ -404,7 +404,7 @@ main (int argc, char *argv[])
   g_timeout_add (1000, (GSourceFunc) animation_timer, completion);
 
   /* Fourth entry */
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new ("Model-less entry completion"));
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new ("Model-less entry completion"));
 
   entry = gtk_entry_new ();
 
@@ -415,7 +415,7 @@ main (int argc, char *argv[])
   gtk_entry_set_completion (GTK_ENTRY (entry), completion);
   g_object_unref (completion);
 
-  gtk_container_add (GTK_CONTAINER (vbox), entry);
+  gtk_box_append (GTK_BOX (vbox), entry);
 
   gtk_widget_show (window);
 
diff --git a/tests/testentryicons.c b/tests/testentryicons.c
index 3d6a4fdbea..9d8bf7fd1f 100644
--- a/tests/testentryicons.c
+++ b/tests/testentryicons.c
@@ -241,22 +241,22 @@ main (int argc, char **argv)
   button1 = gtk_radio_button_new_with_label (NULL, "Blank");
   gtk_widget_set_valign (button1, GTK_ALIGN_START);
   g_signal_connect (button1, "toggled", G_CALLBACK (set_blank), entry);
-  gtk_container_add (GTK_CONTAINER (box), button1);
+  gtk_box_append (GTK_BOX (box), button1);
   button2 = gtk_radio_button_new_with_label (NULL, "Icon Name");
   gtk_widget_set_valign (button2, GTK_ALIGN_START);
   gtk_radio_button_join_group (GTK_RADIO_BUTTON (button2), GTK_RADIO_BUTTON (button1));
   g_signal_connect (button2, "toggled", G_CALLBACK (set_icon_name), entry);
-  gtk_container_add (GTK_CONTAINER (box), button2);
+  gtk_box_append (GTK_BOX (box), button2);
   button3 = gtk_radio_button_new_with_label (NULL, "GIcon");
   gtk_widget_set_valign (button3, GTK_ALIGN_START);
   gtk_radio_button_join_group (GTK_RADIO_BUTTON (button3), GTK_RADIO_BUTTON (button1));
   g_signal_connect (button3, "toggled", G_CALLBACK (set_gicon), entry);
-  gtk_container_add (GTK_CONTAINER (box), button3);
+  gtk_box_append (GTK_BOX (box), button3);
   button4 = gtk_radio_button_new_with_label (NULL, "Texture");
   gtk_widget_set_valign (button4, GTK_ALIGN_START);
   gtk_radio_button_join_group (GTK_RADIO_BUTTON (button4), GTK_RADIO_BUTTON (button1));
   g_signal_connect (button4, "toggled", G_CALLBACK (set_texture), entry);
-  gtk_container_add (GTK_CONTAINER (box), button4);
+  gtk_box_append (GTK_BOX (box), button4);
 
   label = gtk_label_new ("Emoji:");
   gtk_grid_attach (GTK_GRID (grid), label, 0, 6, 1, 1);
@@ -274,7 +274,7 @@ main (int argc, char **argv)
   gtk_widget_set_cursor_from_name (box, "text");
   entry = gtk_entry_new ();
   gtk_widget_set_hexpand (entry, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), entry);
+  gtk_box_append (GTK_BOX (box), entry);
   image = gtk_image_new_from_icon_name ("edit-find-symbolic");
   gtk_widget_set_cursor_from_name (image, "default");
   gtk_widget_set_margin_start (image, 6);
@@ -287,13 +287,13 @@ main (int argc, char **argv)
   gesture = gtk_gesture_click_new ();
   g_signal_connect (gesture, "pressed", G_CALLBACK (icon_pressed_cb), NULL);
   gtk_widget_add_controller (image, GTK_EVENT_CONTROLLER (gesture));
-  gtk_container_add (GTK_CONTAINER (box), image);
+  gtk_box_append (GTK_BOX (box), image);
   image = gtk_image_new_from_icon_name ("document-save-symbolic");
   gtk_widget_set_margin_start (image, 6);
   gtk_widget_set_margin_end (image, 6);
   gtk_widget_set_margin_top (image, 6);
   gtk_widget_set_margin_bottom (image, 6);
-  gtk_container_add (GTK_CONTAINER (box), image);
+  gtk_box_append (GTK_BOX (box), image);
   gtk_grid_attach (GTK_GRID (grid), box, 1, 7, 1, 1);
 
   GtkCssProvider *provider;
diff --git a/tests/testexpand.c b/tests/testexpand.c
index 131eea5b2d..03b18bebc3 100644
--- a/tests/testexpand.c
+++ b/tests/testexpand.c
@@ -53,21 +53,21 @@ create_box_window (void)
   box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   box3 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 
-  gtk_container_add (GTK_CONTAINER (box1),
+  gtk_box_append (GTK_BOX (box1),
                       gtk_label_new ("VBox 1 Top"));
-  gtk_container_add (GTK_CONTAINER (box1),
+  gtk_box_append (GTK_BOX (box1),
                       box2);
-  gtk_container_add (GTK_CONTAINER(box1),
+  gtk_box_append (GTK_BOX(box1),
                      gtk_label_new ("VBox 1 Bottom"));
 
-  gtk_container_add (GTK_CONTAINER (box2),
+  gtk_box_append (GTK_BOX (box2),
                       gtk_label_new ("HBox 2 Left"));
-  gtk_container_add (GTK_CONTAINER (box2),
+  gtk_box_append (GTK_BOX (box2),
                       box3);
-  gtk_container_add (GTK_CONTAINER(box2),
+  gtk_box_append (GTK_BOX(box2),
                      gtk_label_new ("HBox 2 Right"));
 
-  gtk_container_add (GTK_CONTAINER (box3),
+  gtk_box_append (GTK_BOX (box3),
                       gtk_label_new ("VBox 3 Top"));
 
   colorbox = gtk_frame_new (NULL);
@@ -83,7 +83,7 @@ create_box_window (void)
                     G_CALLBACK (on_toggle_hexpand), NULL);
   gtk_frame_set_child (GTK_FRAME (colorbox), toggle);
 
-  gtk_container_add (GTK_CONTAINER (box3), colorbox);
+  gtk_box_append (GTK_BOX (box3), colorbox);
 
   colorbox = gtk_frame_new (NULL);
 
@@ -97,8 +97,8 @@ create_box_window (void)
   g_signal_connect (G_OBJECT (toggle), "toggled",
                     G_CALLBACK (on_toggle_vexpand), NULL);
   gtk_frame_set_child (GTK_FRAME (colorbox), toggle);
-  gtk_container_add (GTK_CONTAINER (box3), colorbox);
-  gtk_container_add (GTK_CONTAINER (box3),
+  gtk_box_append (GTK_BOX (box3), colorbox);
+  gtk_box_append (GTK_BOX (box3),
                      gtk_label_new ("VBox 3 Bottom"));
 
   gtk_window_set_child (GTK_WINDOW (window), box1);
diff --git a/tests/testexpander.c b/tests/testexpander.c
index e9d6e7b745..d76619b912 100644
--- a/tests/testexpander.c
+++ b/tests/testexpander.c
@@ -6,11 +6,6 @@ expander_cb (GtkExpander *expander, GParamSpec *pspec, GtkWindow *dialog)
   gtk_window_set_resizable (dialog, gtk_expander_get_expanded (expander));
 }
 
-static void
-do_not_expand (GtkWidget *child, gpointer data)
-{
-}
-
 static void
 response_cb (GtkDialog *dialog, gint response_id, gpointer data)
 {
@@ -45,8 +40,6 @@ main (int argc, char *argv[])
                                             "but not the full story.");
 
   area = gtk_message_dialog_get_message_area (GTK_MESSAGE_DIALOG (dialog));
-  /* make the labels not expand */
-  gtk_container_foreach (GTK_CONTAINER (area), do_not_expand, NULL);
 
   expander = gtk_expander_new ("Details:");
   sw = gtk_scrolled_window_new (NULL, NULL);
@@ -72,7 +65,7 @@ main (int argc, char *argv[])
   gtk_expander_set_child (GTK_EXPANDER (expander), sw);
   gtk_widget_set_hexpand (expander, TRUE);
   gtk_widget_set_vexpand (expander, TRUE);
-  gtk_container_add (GTK_CONTAINER (area), expander);
+  gtk_box_append (GTK_BOX (area), expander);
   g_signal_connect (expander, "notify::expanded",
                     G_CALLBACK (expander_cb), dialog);
 
diff --git a/tests/testfilechooser.c b/tests/testfilechooser.c
index b8da58f500..6cfc5b3110 100644
--- a/tests/testfilechooser.c
+++ b/tests/testfilechooser.c
@@ -451,53 +451,53 @@ main (int argc, char **argv)
   control_window = gtk_window_new ();
 
   vbbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (control_window), vbbox);
+  gtk_box_append (GTK_BOX (control_window), vbbox);
 
   button = gtk_button_new_with_mnemonic ("_Select all");
   gtk_widget_set_sensitive (button, multiple);
-  gtk_container_add (GTK_CONTAINER (vbbox), button);
+  gtk_box_append (GTK_BOX (vbbox), button);
   g_signal_connect_swapped (button, "clicked",
                            G_CALLBACK (gtk_file_chooser_select_all), dialog);
   g_signal_connect (dialog, "notify::select-multiple",
                    G_CALLBACK (notify_multiple_cb), button);
 
   button = gtk_button_new_with_mnemonic ("_Unselect all");
-  gtk_container_add (GTK_CONTAINER (vbbox), button);
+  gtk_box_append (GTK_BOX (vbbox), button);
   g_signal_connect_swapped (button, "clicked",
                            G_CALLBACK (gtk_file_chooser_unselect_all), dialog);
 
   button = gtk_button_new_with_label ("set_current_folder (\"/nonexistent\")");
-  gtk_container_add (GTK_CONTAINER (vbbox), button);
+  gtk_box_append (GTK_BOX (vbbox), button);
   g_signal_connect (button, "clicked",
                    G_CALLBACK (set_folder_nonexistent_cb), dialog);
 
   button = gtk_button_new_with_label ("set_current_folder (\"/usr/nonexistent\")");
-  gtk_container_add (GTK_CONTAINER (vbbox), button);
+  gtk_box_append (GTK_BOX (vbbox), button);
   g_signal_connect (button, "clicked",
                    G_CALLBACK (set_folder_existing_nonexistent_cb), dialog);
 
   button = gtk_button_new_with_label ("set_filename (\"/nonexistent\")");
-  gtk_container_add (GTK_CONTAINER (vbbox), button);
+  gtk_box_append (GTK_BOX (vbbox), button);
   g_signal_connect (button, "clicked",
                    G_CALLBACK (set_filename_nonexistent_cb), dialog);
 
   button = gtk_button_new_with_label ("set_filename (\"/usr/nonexistent\")");
-  gtk_container_add (GTK_CONTAINER (vbbox), button);
+  gtk_box_append (GTK_BOX (vbbox), button);
   g_signal_connect (button, "clicked",
                    G_CALLBACK (set_filename_existing_nonexistent_cb), dialog);
 
   button = gtk_button_new_with_label ("Get selection");
-  gtk_container_add (GTK_CONTAINER (vbbox), button);
+  gtk_box_append (GTK_BOX (vbbox), button);
   g_signal_connect (button, "clicked",
                    G_CALLBACK (get_selection_cb), dialog);
 
   button = gtk_button_new_with_label ("Get current name");
-  gtk_container_add (GTK_CONTAINER (vbbox), button);
+  gtk_box_append (GTK_BOX (vbbox), button);
   g_signal_connect (button, "clicked",
                    G_CALLBACK (get_current_name_cb), dialog);
 
   button = gtk_button_new_with_label ("Unmap and remap");
-  gtk_container_add (GTK_CONTAINER (vbbox), button);
+  gtk_box_append (GTK_BOX (vbbox), button);
   g_signal_connect (button, "clicked",
                    G_CALLBACK (unmap_and_remap_cb), dialog);
 
diff --git a/tests/testfilechooserbutton.c b/tests/testfilechooserbutton.c
index 196cebf764..f5ae97bb46 100644
--- a/tests/testfilechooserbutton.c
+++ b/tests/testfilechooserbutton.c
@@ -131,31 +131,31 @@ tests_button_clicked_cb (GtkButton *real_button,
                                    GTK_WINDOW (gtk_widget_get_root (user_data)));
 
       box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-      gtk_container_add (GTK_CONTAINER (tests), box);
+      gtk_box_append (GTK_BOX (tests), box);
       gtk_widget_show (box);
 
       button = gtk_button_new_with_label ("Print Selected Path");
       g_signal_connect (button, "clicked",
                        G_CALLBACK (print_selected_path_clicked_cb), user_data);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
       gtk_widget_show (button);
 
       button = gtk_button_new_with_label ("Add $PWD's Parent as Shortcut");
       g_signal_connect (button, "clicked",
                        G_CALLBACK (add_pwds_parent_as_shortcut_clicked_cb), user_data);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
       gtk_widget_show (button);
 
       button = gtk_button_new_with_label ("Remove $PWD's Parent as Shortcut");
       g_signal_connect (button, "clicked",
                        G_CALLBACK (del_pwds_parent_as_shortcut_clicked_cb), user_data);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
       gtk_widget_show (button);
 
       button = gtk_button_new_with_label ("Unselect all");
       g_signal_connect (button, "clicked",
                        G_CALLBACK (unselect_all_clicked_cb), user_data);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
       gtk_widget_show (button);
 
       g_object_set_data (user_data, "tests-dialog", tests);
@@ -234,12 +234,12 @@ add_new_filechooser_button (const gchar          *mnemonic,
   GFile *path;
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
-  gtk_container_add (GTK_CONTAINER (group_box), hbox);
+  gtk_box_append (GTK_BOX (group_box), hbox);
 
   label = gtk_label_new_with_mnemonic (mnemonic);
   gtk_size_group_add_widget (GTK_SIZE_GROUP (label_group), label);
   gtk_label_set_xalign (GTK_LABEL (label), 0.0);
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
 
   chooser = gtk_file_chooser_button_new (g_strconcat(chooser_title,
                                                      " - testfilechooserbutton", NULL),
@@ -256,11 +256,11 @@ add_new_filechooser_button (const gchar          *mnemonic,
                    G_CALLBACK (chooser_current_folder_changed_cb), NULL);
   g_signal_connect (chooser, "selection-changed", G_CALLBACK (chooser_selection_changed_cb), NULL);
   g_signal_connect (chooser, "file-activated", G_CALLBACK (chooser_file_activated_cb), NULL);
-  gtk_container_add (GTK_CONTAINER (hbox), chooser);
+  gtk_box_append (GTK_BOX (hbox), chooser);
 
   button = gtk_button_new_with_label ("Tests");
   g_signal_connect (button, "clicked", G_CALLBACK (tests_button_clicked_cb), chooser);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 }
 
 static void
@@ -308,11 +308,11 @@ main (int   argc,
   gtk_widget_set_margin_end (vbox, 6);
   gtk_widget_set_margin_top (vbox, 6);
   gtk_widget_set_margin_bottom (vbox, 6);
-  gtk_container_add (GTK_CONTAINER (gtk_dialog_get_content_area (GTK_DIALOG (win))), vbox);
+  gtk_box_append (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (win))), vbox);
 
   frame = gtk_frame_new ("<b>GtkFileChooserButton</b>");
   gtk_label_set_use_markup (GTK_LABEL (gtk_frame_get_label_widget (GTK_FRAME (frame))), TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), frame);
+  gtk_box_append (GTK_BOX (vbox), frame);
 
   gtk_widget_set_halign (frame, GTK_ALIGN_FILL);
   gtk_widget_set_valign (frame, GTK_ALIGN_FILL);
diff --git a/tests/testflowbox.c b/tests/testflowbox.c
index 39c39afc55..17f72484ef 100644
--- a/tests/testflowbox.c
+++ b/tests/testflowbox.c
@@ -76,7 +76,7 @@ populate_flowbox_focus (GtkFlowBox *flowbox)
       gtk_frame_set_child (GTK_FRAME (frame), box);
 
       widget = gtk_label_new ("Label");
-      gtk_container_add (GTK_CONTAINER (box), widget);
+      gtk_box_append (GTK_BOX (box), widget);
 
       switch (i % 4)
         {
@@ -97,10 +97,10 @@ populate_flowbox_focus (GtkFlowBox *flowbox)
           g_assert_not_reached ();
         }
 
-      gtk_container_add (GTK_CONTAINER (box), widget);
+      gtk_box_append (GTK_BOX (box), widget);
 
       if (i % 5 == 0)
-        gtk_container_add (GTK_CONTAINER (box), gtk_switch_new ());
+        gtk_box_append (GTK_BOX (box), gtk_switch_new ());
 
       gtk_flow_box_insert (GTK_FLOW_BOX (flowbox), frame, -1);
       if (!sensitive)
@@ -177,11 +177,11 @@ populate_flowbox_images (GtkFlowBox *flowbox)
 
       label = gtk_label_new (text);
 
-      gtk_container_add (GTK_CONTAINER (widget), image);
-      gtk_container_add (GTK_CONTAINER (widget), label);
+      gtk_box_append (GTK_BOX (widget), image);
+      gtk_box_append (GTK_BOX (widget), label);
 
       g_object_set_data_full (G_OBJECT (widget), "id", (gpointer)g_strdup (text), g_free);
-      gtk_container_add (GTK_CONTAINER (flowbox), widget);
+      gtk_box_append (GTK_BOX (flowbox), widget);
 
       g_free (text);
     }
@@ -380,7 +380,7 @@ create_window (void)
   gtk_widget_show (vbox);
   gtk_widget_show (hbox);
   gtk_window_set_child (GTK_WINDOW (window), hbox);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
 
   swindow = gtk_scrolled_window_new (NULL, NULL);
   gtk_widget_set_hexpand (swindow, TRUE);
@@ -388,7 +388,7 @@ create_window (void)
                                   GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
 
   gtk_widget_show (swindow);
-  gtk_container_add (GTK_CONTAINER (hbox), swindow);
+  gtk_box_append (GTK_BOX (hbox), swindow);
 
   flowbox = gtk_flow_box_new ();
   gtk_widget_set_halign (flowbox, GTK_ALIGN_END);
@@ -417,14 +417,14 @@ create_window (void)
   gtk_widget_show (flowbox_cntl);
   gtk_widget_show (expander);
   gtk_expander_set_child (GTK_EXPANDER (expander), flowbox_cntl);
-  gtk_container_add (GTK_CONTAINER (vbox), expander);
+  gtk_box_append (GTK_BOX (vbox), expander);
 
   widget = gtk_check_button_new_with_label ("Homogeneous");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), FALSE);
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set whether the items should be displayed at the same size");
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (homogeneous_toggled), flowbox);
@@ -435,7 +435,7 @@ create_window (void)
                           flowbox, "activate-on-single-click",
                           G_BINDING_SYNC_CREATE);
   gtk_widget_show (widget);
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   /* Add alignment controls */
   widget = gtk_combo_box_text_new ();
@@ -447,7 +447,7 @@ create_window (void)
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set the horizontal alignment policy");
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (horizontal_alignment_changed), flowbox);
@@ -461,7 +461,7 @@ create_window (void)
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set the vertical alignment policy");
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (vertical_alignment_changed), flowbox);
@@ -474,7 +474,7 @@ create_window (void)
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set the flowbox orientation");
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (orientation_changed), flowbox);
@@ -489,7 +489,7 @@ create_window (void)
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set the selection mode");
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (selection_mode_changed), flowbox);
@@ -500,7 +500,7 @@ create_window (void)
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set the minimum amount of items per line before wrapping");
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (line_length_changed), flowbox);
@@ -513,7 +513,7 @@ create_window (void)
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set the natural amount of items per line ");
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (max_line_length_changed), flowbox);
@@ -525,41 +525,41 @@ create_window (void)
   gtk_widget_show (hbox);
 
   widget = gtk_label_new ("H Spacing");
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   widget = gtk_spin_button_new_with_range (0, 30, 1);
   gtk_spin_button_set_value (GTK_SPIN_BUTTON (widget), INITIAL_CSPACING);
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set the horizontal spacing between children");
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (spacing_changed), GINT_TO_POINTER (GTK_ORIENTATION_HORIZONTAL));
   g_signal_connect (G_OBJECT (widget), "value-changed",
                     G_CALLBACK (spacing_changed), GINT_TO_POINTER (GTK_ORIENTATION_HORIZONTAL));
 
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), hbox);
+  gtk_box_append (GTK_BOX (flowbox_cntl), hbox);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 2);
   gtk_widget_show (hbox);
 
   widget = gtk_label_new ("V Spacing");
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   widget = gtk_spin_button_new_with_range (0, 30, 1);
   gtk_spin_button_set_value (GTK_SPIN_BUTTON (widget), INITIAL_RSPACING);
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set the vertical spacing between children");
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (spacing_changed), GINT_TO_POINTER (GTK_ORIENTATION_VERTICAL));
   g_signal_connect (G_OBJECT (widget), "value-changed",
                     G_CALLBACK (spacing_changed), GINT_TO_POINTER (GTK_ORIENTATION_VERTICAL));
 
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), hbox);
+  gtk_box_append (GTK_BOX (flowbox_cntl), hbox);
 
   /* filtering and sorting */
 
@@ -568,7 +568,7 @@ create_window (void)
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set whether some items should be filtered out");
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (filter_toggled), flowbox);
@@ -578,7 +578,7 @@ create_window (void)
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set whether items should be sorted");
-  gtk_container_add (GTK_CONTAINER (flowbox_cntl), widget);
+  gtk_box_append (GTK_BOX (flowbox_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (sort_toggled), flowbox);
@@ -591,7 +591,7 @@ create_window (void)
   gtk_widget_show (items_cntl);
   gtk_widget_show (expander);
   gtk_expander_set_child (GTK_EXPANDER (expander), items_cntl);
-  gtk_container_add (GTK_CONTAINER (vbox), expander);
+  gtk_box_append (GTK_BOX (vbox), expander);
 
   /* Add Items control */
   widget = gtk_combo_box_text_new ();
@@ -604,7 +604,7 @@ create_window (void)
   gtk_widget_show (widget);
 
   gtk_widget_set_tooltip_text (widget, "Set the item set to use");
-  gtk_container_add (GTK_CONTAINER (items_cntl), widget);
+  gtk_box_append (GTK_BOX (items_cntl), widget);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (items_changed), flowbox);
diff --git a/tests/testfontchooser.c b/tests/testfontchooser.c
index dedb011f9b..07b87f669f 100644
--- a/tests/testfontchooser.c
+++ b/tests/testfontchooser.c
@@ -81,7 +81,7 @@ main (int argc, char *argv[])
   gtk_widget_set_size_request (window, 600, 600);
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
   gtk_window_set_child (GTK_WINDOW (window), box);
-  gtk_container_add (GTK_CONTAINER (box), fontchooser);
+  gtk_box_append (GTK_BOX (box), fontchooser);
 
   gtk_widget_show (window);
 
diff --git a/tests/testframe.c b/tests/testframe.c
index f52e0caeba..36464daab2 100644
--- a/tests/testframe.c
+++ b/tests/testframe.c
@@ -79,7 +79,7 @@ int main (int argc, char **argv)
 
   frame = GTK_FRAME (gtk_frame_new ("Test GtkFrame"));
   gtk_widget_set_vexpand (GTK_WIDGET (frame), TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), GTK_WIDGET (frame));
+  gtk_box_append (GTK_BOX (vbox), GTK_WIDGET (frame));
 
   widget = gtk_button_new_with_label ("Hello!");
   gtk_frame_set_child (GTK_FRAME (frame), widget);
@@ -87,7 +87,7 @@ int main (int argc, char **argv)
   grid = GTK_GRID (gtk_grid_new ());
   gtk_grid_set_row_spacing (grid, 12);
   gtk_grid_set_column_spacing (grid, 6);
-  gtk_container_add (GTK_CONTAINER (vbox), GTK_WIDGET (grid));
+  gtk_box_append (GTK_BOX (vbox), GTK_WIDGET (grid));
 
   xalign = gtk_frame_get_label_align (frame);
 
diff --git a/tests/testfullscreen.c b/tests/testfullscreen.c
index 4a1e2ec2ec..c7deda5e92 100644
--- a/tests/testfullscreen.c
+++ b/tests/testfullscreen.c
@@ -78,15 +78,15 @@ main (int argc, char *argv[])
 
   button = gtk_button_new_with_label ("Fullscreen on current monitor");
   g_signal_connect (button, "clicked", G_CALLBACK (set_fullscreen_monitor_cb), GINT_TO_POINTER 
(GDK_FULLSCREEN_ON_CURRENT_MONITOR));
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Fullscreen on all monitors");
   g_signal_connect (button, "clicked", G_CALLBACK (set_fullscreen_monitor_cb), GINT_TO_POINTER 
(GDK_FULLSCREEN_ON_ALL_MONITORS));
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Un-fullscreen");
   g_signal_connect (button, "clicked", G_CALLBACK (remove_fullscreen_cb), NULL);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   gtk_widget_show (window);
 
diff --git a/tests/testgaction.c b/tests/testgaction.c
index 616fee0bf6..3a28d0b465 100644
--- a/tests/testgaction.c
+++ b/tests/testgaction.c
@@ -126,7 +126,7 @@ int main (int argc, char **argv)
   label = gtk_label_new ("Initial Text");
   gtk_widget_set_margin_top (label, 12);
   gtk_widget_set_margin_bottom (label, 12);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
   gtk_widget_set_halign (menubutton, GTK_ALIGN_CENTER);
   {
     GMenuModel *menu_model;
@@ -137,10 +137,10 @@ int main (int argc, char **argv)
 
   }
   gtk_menu_button_set_popover (GTK_MENU_BUTTON (menubutton), menu);
-  gtk_container_add (GTK_CONTAINER (box), menubutton);
+  gtk_box_append (GTK_BOX (box), menubutton);
   gtk_widget_set_halign (button1, GTK_ALIGN_CENTER);
   gtk_actionable_set_action_name (GTK_ACTIONABLE (button1), "win.change-label-button");
-  gtk_container_add (GTK_CONTAINER (box), button1);
+  gtk_box_append (GTK_BOX (box), button1);
 
   gtk_window_set_child (GTK_WINDOW (window), box);
 
diff --git a/tests/testgiconpixbuf.c b/tests/testgiconpixbuf.c
index 0a52da4b4d..cfb53a48c0 100644
--- a/tests/testgiconpixbuf.c
+++ b/tests/testgiconpixbuf.c
@@ -50,35 +50,35 @@ main (int argc,
   pixbuf = gdk_pixbuf_new_from_file ("apple-red.png", NULL);
   toplevel = gtk_window_new ();
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
-  gtk_container_add (GTK_CONTAINER (toplevel), hbox);
+  gtk_box_append (GTK_BOX (toplevel), hbox);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 12);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
 
   image = gtk_image_new_from_gicon (G_ICON (pixbuf));
   gtk_image_set_icon_size (GTK_IMAGE (image), GTK_ICON_SIZE_LARGE);
-  gtk_container_add (GTK_CONTAINER (vbox), image);
+  gtk_box_append (GTK_BOX (vbox), image);
 
   label = gtk_label_new (NULL);
   str = g_strdup_printf ("Normal icon, hash %u", g_icon_hash (G_ICON (pixbuf)));
   gtk_label_set_label (GTK_LABEL (label), str);
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   otherpix = gdk_pixbuf_new_from_file ("gnome-textfile.png", NULL);
   emblem = g_emblem_new (G_ICON (otherpix));
   emblemed = g_emblemed_icon_new (G_ICON (pixbuf), emblem);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 12);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
 
   image2 = gtk_image_new_from_gicon (emblemed);
   gtk_image_set_icon_size (GTK_IMAGE (image2), GTK_ICON_SIZE_LARGE);
-  gtk_container_add (GTK_CONTAINER (vbox), image2);
+  gtk_box_append (GTK_BOX (vbox), image2);
 
   label = gtk_label_new (NULL);
   str = g_strdup_printf ("Emblemed icon, hash %u", g_icon_hash (emblemed));
   gtk_label_set_label (GTK_LABEL (label), str);
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   gtk_widget_show (toplevel);
 
diff --git a/tests/testglarea.c b/tests/testglarea.c
index f39f005d17..8054aebb76 100644
--- a/tests/testglarea.c
+++ b/tests/testglarea.c
@@ -374,7 +374,7 @@ create_axis_slider (int axis)
     }
 
   label = gtk_label_new (text);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
   gtk_widget_show (label);
 
   adj = gtk_adjustment_new (0.0, 0.0, 360.0, 1.0, 12.0, 0.0);
@@ -382,7 +382,7 @@ create_axis_slider (int axis)
                     G_CALLBACK (on_axis_value_change),
                     GINT_TO_POINTER (axis));
   slider = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL, adj);
-  gtk_container_add (GTK_CONTAINER (box), slider);
+  gtk_box_append (GTK_BOX (box), slider);
   gtk_widget_set_hexpand (slider, TRUE);
   gtk_widget_show (slider);
 
@@ -428,23 +428,23 @@ main (int argc, char *argv[])
   gl_area = gtk_gl_area_new ();
   gtk_widget_set_hexpand (gl_area, TRUE);
   gtk_widget_set_vexpand (gl_area, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), gl_area);
+  gtk_box_append (GTK_BOX (box), gl_area);
   g_signal_connect (gl_area, "realize", G_CALLBACK (realize), NULL);
   g_signal_connect (gl_area, "unrealize", G_CALLBACK (unrealize), NULL);
   g_signal_connect (gl_area, "render", G_CALLBACK (render), NULL);
   gtk_widget_show (gl_area);
 
   controls = gtk_box_new (GTK_ORIENTATION_VERTICAL, FALSE);
-  gtk_container_add (GTK_CONTAINER (box), controls);
+  gtk_box_append (GTK_BOX (box), controls);
   gtk_widget_set_hexpand (controls, TRUE);
   gtk_widget_show (controls);
 
   for (i = 0; i < N_AXIS; i++)
-    gtk_container_add (GTK_CONTAINER (controls), create_axis_slider (i));
+    gtk_box_append (GTK_BOX (controls), create_axis_slider (i));
 
   button = gtk_button_new_with_label ("Quit");
   gtk_widget_set_hexpand (button, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
   g_signal_connect_swapped (button, "clicked", G_CALLBACK (gtk_window_destroy), window);
   gtk_widget_show (button);
 
diff --git a/tests/testgmenu.c b/tests/testgmenu.c
index f435560967..e1193a9b6f 100644
--- a/tests/testgmenu.c
+++ b/tests/testgmenu.c
@@ -564,7 +564,7 @@ create_add_remove_buttons (GActionGroup *group,
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
 
   button = gtk_check_button_new_with_label ("Add Italic");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   g_object_set_data  (G_OBJECT (button), "group", group);
   g_object_set_data  (G_OBJECT (button), "model", model);
@@ -573,7 +573,7 @@ create_add_remove_buttons (GActionGroup *group,
                     G_CALLBACK (toggle_italic), treeview);
 
   button = gtk_check_button_new_with_label ("Add Sumerian");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   g_object_set_data  (G_OBJECT (button), "group", group);
   g_object_set_data  (G_OBJECT (button), "model", model);
@@ -582,7 +582,7 @@ create_add_remove_buttons (GActionGroup *group,
                     G_CALLBACK (toggle_sumerian), NULL);
 
   button = gtk_check_button_new_with_label ("Add Speed");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   g_object_set_data  (G_OBJECT (button), "group", group);
   g_object_set_data  (G_OBJECT (button), "model", model);
@@ -661,9 +661,9 @@ main (int argc, char *argv[])
       model = get_model ();
 
       tv = create_action_treeview (group);
-      gtk_container_add (GTK_CONTAINER (box), tv);
+      gtk_box_append (GTK_BOX (box), tv);
       buttons = create_add_remove_buttons (group, model, tv);
-      gtk_container_add (GTK_CONTAINER (box), buttons);
+      gtk_box_append (GTK_BOX (box), buttons);
     }
 
   if (do_export)
@@ -688,7 +688,7 @@ main (int argc, char *argv[])
       gtk_button_set_label (GTK_BUTTON (button), "Click here");
       gtk_menu_button_set_menu_model (GTK_MENU_BUTTON (button), model);
       gtk_widget_insert_action_group (button, "actions", group);
-      gtk_container_add (GTK_CONTAINER (box), button);
+      gtk_box_append (GTK_BOX (box), button);
     }
 
   gtk_widget_show (window);
diff --git a/tests/testgrid.c b/tests/testgrid.c
index 713e0ca9c0..fefa6b3876 100644
--- a/tests/testgrid.c
+++ b/tests/testgrid.c
@@ -18,7 +18,7 @@ oriented_test_widget (const gchar *label, const gchar *color)
                                   GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
   g_free (data);
   g_object_unref (provider);
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
 
   return box;
 }
@@ -110,11 +110,11 @@ text_grid (void)
 
   grid = gtk_grid_new ();
   gtk_orientable_set_orientation (GTK_ORIENTABLE (grid), GTK_ORIENTATION_VERTICAL);
-  gtk_container_add (GTK_CONTAINER (box), gtk_label_new ("Above"));
-  gtk_container_add (GTK_CONTAINER (box), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
-  gtk_container_add (GTK_CONTAINER (box), grid);
-  gtk_container_add (GTK_CONTAINER (box), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
-  gtk_container_add (GTK_CONTAINER (box), gtk_label_new ("Below"));
+  gtk_box_append (GTK_BOX (box), gtk_label_new ("Above"));
+  gtk_box_append (GTK_BOX (box), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+  gtk_box_append (GTK_BOX (box), grid);
+  gtk_box_append (GTK_BOX (box), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+  gtk_box_append (GTK_BOX (box), gtk_label_new ("Below"));
 
   label = gtk_label_new ("Some text that may wrap if it has to");
   gtk_label_set_width_chars (GTK_LABEL (label), 10);
@@ -146,32 +146,32 @@ box_comparison (void)
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
   gtk_window_set_child (GTK_WINDOW (window), vbox);
 
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new ("Above"));
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new ("Above"));
+  gtk_box_append (GTK_BOX (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (vbox), box);
+  gtk_box_append (GTK_BOX (vbox), box);
 
-  gtk_container_add (GTK_CONTAINER (box), test_widget ("1", "white"));
+  gtk_box_append (GTK_BOX (box), test_widget ("1", "white"));
 
   label = gtk_label_new ("Some ellipsizing text");
   gtk_label_set_ellipsize (GTK_LABEL (label), PANGO_ELLIPSIZE_END);
   gtk_label_set_width_chars (GTK_LABEL (label), 10);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
-  gtk_container_add (GTK_CONTAINER (box), test_widget ("2", "green"));
+  gtk_box_append (GTK_BOX (box), test_widget ("2", "green"));
 
   label = gtk_label_new ("Some text that may wrap if needed");
   gtk_label_set_wrap (GTK_LABEL (label), TRUE);
   gtk_label_set_width_chars (GTK_LABEL (label), 10);
-  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_box_append (GTK_BOX (box), label);
 
-  gtk_container_add (GTK_CONTAINER (box), test_widget ("3", "red"));
+  gtk_box_append (GTK_BOX (box), test_widget ("3", "red"));
 
   grid = gtk_grid_new ();
   gtk_orientable_set_orientation (GTK_ORIENTABLE (grid), GTK_ORIENTATION_VERTICAL);
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
-  gtk_container_add (GTK_CONTAINER (vbox), grid);
+  gtk_box_append (GTK_BOX (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+  gtk_box_append (GTK_BOX (vbox), grid);
 
   gtk_grid_attach (GTK_GRID (grid), test_widget ("1", "white"), 0, 0, 1, 1);
 
@@ -191,8 +191,8 @@ box_comparison (void)
 
   gtk_grid_attach (GTK_GRID (grid), test_widget ("3", "red"), 4, 0, 1, 1);
 
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new ("Below"));
+  gtk_box_append (GTK_BOX (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new ("Below"));
 
   gtk_widget_show (window);
 }
diff --git a/tests/testgtk.c b/tests/testgtk.c
index 32e0187ed7..800ee3af17 100644
--- a/tests/testgtk.c
+++ b/tests/testgtk.c
@@ -154,10 +154,10 @@ build_alpha_widgets (void)
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   label = gtk_label_new (NULL);
   gtk_label_set_markup (GTK_LABEL (label), "<i>Entry: </i>");
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
   entry = gtk_entry_new ();
   gtk_widget_set_hexpand (entry, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), entry);
+  gtk_box_append (GTK_BOX (hbox), entry);
   gtk_widget_set_hexpand (hbox, TRUE);
   gtk_grid_attach (GTK_GRID (grid), hbox, 0, 3, 2, 1);
 
@@ -211,18 +211,18 @@ create_alpha_window (GtkWidget *widget)
       content_area = gtk_dialog_get_content_area (GTK_DIALOG (window));
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-      gtk_container_add (GTK_CONTAINER (content_area), vbox);
+      gtk_box_append (GTK_BOX (content_area), vbox);
 
       label = gtk_label_new (NULL);
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
       
       label = gtk_label_new (NULL);
-      gtk_container_add (GTK_CONTAINER (vbox), label);
+      gtk_box_append (GTK_BOX (vbox), label);
       display = gtk_widget_get_display (window);
       on_composited_changed (display, NULL, GTK_LABEL (label));
       g_signal_connect (display, "notify::composited", G_CALLBACK (on_composited_changed), label);
 
-      gtk_container_add (GTK_CONTAINER (vbox), build_alpha_widgets ());
+      gtk_box_append (GTK_BOX (vbox), build_alpha_widgets ());
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
       g_signal_connect (window, "response",
@@ -278,7 +278,7 @@ create_buttons (GtkWidget *widget)
       grid = gtk_grid_new ();
       gtk_grid_set_row_spacing (GTK_GRID (grid), 5);
       gtk_grid_set_column_spacing (GTK_GRID (grid), 5);
-      gtk_container_add (GTK_CONTAINER (box1), grid);
+      gtk_box_append (GTK_BOX (box1), grid);
 
       button[0] = gtk_button_new_with_label ("button1");
       button[1] = gtk_button_new_with_mnemonic ("_button2");
@@ -303,16 +303,16 @@ create_buttons (GtkWidget *widget)
         }
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button[9] = gtk_button_new_with_label ("close");
       g_signal_connect_swapped (button[9], "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (box2), button[9]);
+      gtk_box_append (GTK_BOX (box2), button[9]);
       gtk_window_set_default_widget (GTK_WINDOW (window), button[9]);
     }
 
@@ -348,28 +348,28 @@ create_toggle_buttons (GtkWidget *widget)
       gtk_window_set_child (GTK_WINDOW (window), box1);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_toggle_button_new_with_label ("button1");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_toggle_button_new_with_label ("button2");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_toggle_button_new_with_label ("button3");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_button_new_with_label ("close");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       gtk_window_set_default_widget (GTK_WINDOW (window), button);
     }
 
@@ -464,26 +464,26 @@ create_check_buttons (GtkWidget *widget)
       box1 = gtk_dialog_get_content_area (GTK_DIALOG (window));
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_check_button_new_with_mnemonic ("_button1");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_check_button_new_with_label ("button2");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_check_button_new_with_label ("button3");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_check_button_new_with_label ("inconsistent");
       gtk_check_button_set_inconsistent (GTK_CHECK_BUTTON (button), TRUE);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       table = create_widget_grid (GTK_TYPE_CHECK_BUTTON);
-      gtk_container_add (GTK_CONTAINER (box1), table);
+      gtk_box_append (GTK_BOX (box1), table);
     }
 
   if (!gtk_widget_get_visible (window))
@@ -524,53 +524,53 @@ create_radio_buttons (GtkWidget *widget)
       box1 = gtk_dialog_get_content_area (GTK_DIALOG (window));
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_radio_button_new_with_label (NULL, "button1");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_radio_button_new_with_label (
                 gtk_radio_button_get_group (GTK_RADIO_BUTTON (button)),
                 "button2");
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_radio_button_new_with_label (
                  gtk_radio_button_get_group (GTK_RADIO_BUTTON (button)),
                 "button3");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_radio_button_new_with_label (
                  gtk_radio_button_get_group (GTK_RADIO_BUTTON (button)),
                 "inconsistent");
       gtk_check_button_set_inconsistent (GTK_CHECK_BUTTON (button), TRUE);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_radio_button_new_with_label (NULL, "button4");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_radio_button_new_with_label (
                 gtk_radio_button_get_group (GTK_RADIO_BUTTON (button)),
                 "button5");
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_radio_button_new_with_label (
                  gtk_radio_button_get_group (GTK_RADIO_BUTTON (button)),
                 "button6");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       table = create_widget_grid (GTK_TYPE_RADIO_BUTTON);
-      gtk_container_add (GTK_CONTAINER (box1), table);
+      gtk_box_append (GTK_BOX (box1), table);
     }
 
   if (!gtk_widget_get_visible (window))
@@ -710,7 +710,7 @@ create_statusbar (GtkWidget *widget)
       gtk_window_set_child (GTK_WINDOW (window), box1);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       statusbar = gtk_statusbar_new ();
       g_signal_connect (statusbar,
@@ -721,7 +721,7 @@ create_statusbar (GtkWidget *widget)
       button = g_object_new (gtk_button_get_type (),
                               "label", "push something",
                               NULL);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       g_object_connect (button,
                        "signal::clicked", statusbar_push, statusbar,
                        NULL);
@@ -731,41 +731,41 @@ create_statusbar (GtkWidget *widget)
                                                 NULL),
                                 "signal_after::clicked", statusbar_pop, statusbar,
                                 NULL);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = g_object_connect (g_object_new (gtk_button_get_type (),
                                                 "label", "steal #4",
                                                 NULL),
                                 "signal_after::clicked", statusbar_steal, statusbar,
                                 NULL);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = g_object_connect (g_object_new (gtk_button_get_type (),
                                                 "label", "test contexts",
                                                 NULL),
                                 "swapped_signal_after::clicked", statusbar_contexts, statusbar,
                                 NULL);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = g_object_connect (g_object_new (gtk_button_get_type (),
                                                 "label", "push something long",
                                                 NULL),
                                 "signal_after::clicked", statusbar_push_long, statusbar,
                                 NULL);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
-      gtk_container_add (GTK_CONTAINER (box1), statusbar);
+      gtk_box_append (GTK_BOX (box1), box2);
+      gtk_box_append (GTK_BOX (box1), statusbar);
 
       button = gtk_button_new_with_label ("close");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       gtk_window_set_default_widget (GTK_WINDOW (window), button);
     }
 
@@ -810,24 +810,16 @@ static void
 set_selectable_recursive (GtkWidget *widget,
                           gboolean   setting)
 {
-  if (GTK_IS_CONTAINER (widget))
+  if (GTK_IS_LABEL (widget))
+    gtk_label_set_selectable (GTK_LABEL (widget), setting);
+  else
     {
-      GList *children;
-      GList *tmp;
-      
-      children = gtk_container_get_children (GTK_CONTAINER (widget));
-      tmp = children;
-      while (tmp)
-        {
-          set_selectable_recursive (tmp->data, setting);
+      GtkWidget *child;
 
-          tmp = tmp->next;
-        }
-      g_list_free (children);
-    }
-  else if (GTK_IS_LABEL (widget))
-    {
-      gtk_label_set_selectable (GTK_LABEL (widget), setting);
+      for (child = gtk_widget_get_first_child (widget);
+           child != NULL;
+           child = gtk_widget_get_next_sibling (child))
+        set_selectable_recursive (child, setting);
     }
 }
 
@@ -925,42 +917,42 @@ static void create_labels (GtkWidget *widget)
 
       button = create_sensitivity_control (hbox);
 
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
 
       button = create_selectable_control (hbox);
 
-      gtk_container_add (GTK_CONTAINER (vbox), button);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
 
-      gtk_container_add (GTK_CONTAINER (hbox), vbox);
+      gtk_box_append (GTK_BOX (hbox), vbox);
 
       frame = gtk_frame_new ("Normal Label");
       label = gtk_label_new ("This is a Normal label");
       gtk_label_set_ellipsize (GTK_LABEL (label), PANGO_ELLIPSIZE_START);
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       frame = gtk_frame_new ("Multi-line Label");
       label = gtk_label_new ("This is a Multi-line label.\nSecond line\nThird line");
       gtk_label_set_ellipsize (GTK_LABEL (label), PANGO_ELLIPSIZE_END);
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       frame = gtk_frame_new ("Left Justified Label");
       label = gtk_label_new ("This is a Left-Justified\nMulti-line label.\nThird      line");
       gtk_label_set_ellipsize (GTK_LABEL (label), PANGO_ELLIPSIZE_MIDDLE);
       gtk_label_set_justify (GTK_LABEL (label), GTK_JUSTIFY_LEFT);
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       frame = gtk_frame_new ("Right Justified Label");
       gtk_label_set_ellipsize (GTK_LABEL (label), PANGO_ELLIPSIZE_START);
       label = gtk_label_new ("This is a Right-Justified\nMulti-line label.\nFourth line, (j/k)");
       gtk_label_set_justify (GTK_LABEL (label), GTK_JUSTIFY_RIGHT);
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       frame = gtk_frame_new ("Internationalized Label");
       label = gtk_label_new (NULL);
@@ -973,13 +965,13 @@ static void create_labels (GtkWidget *widget)
                            "Japanese <span lang=\"ja\">\345\205\203\346\260\227        
\351\226\213\347\231\272</span>");
       gtk_label_set_justify (GTK_LABEL (label), GTK_JUSTIFY_LEFT);
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       frame = gtk_frame_new ("Bidirection Label");
       label = gtk_label_new ("\342\200\217Arabic       \330\247\331\204\330\263\331\204\330\247\331\205 
\330\271\331\204\331\212\331\203\331\205\n"
                             "\342\200\217Hebrew        \327\251\327\234\327\225\327\235");
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       frame = gtk_frame_new ("Links in a label");
       label = gtk_label_new ("Some <a href=\"http://en.wikipedia.org/wiki/Text\"; title=\"plain 
text\">text</a> may be marked up\n"
@@ -987,11 +979,11 @@ static void create_labels (GtkWidget *widget)
                              "or activated via <a href=\"keynav\">keynav</a>");
       gtk_label_set_use_markup (GTK_LABEL (label), TRUE);
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
       g_signal_connect (label, "activate-link", G_CALLBACK (activate_link), NULL);
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox);
+      gtk_box_append (GTK_BOX (hbox), vbox);
       frame = gtk_frame_new ("Line wrapped label");
       label = gtk_label_new ("This is an example of a line-wrapped label.  It should not be taking "\
                             "up the entire             "/* big space to test spacing */\
@@ -1003,7 +995,7 @@ static void create_labels (GtkWidget *widget)
 
       gtk_label_set_wrap (GTK_LABEL (label), TRUE);
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       frame = gtk_frame_new ("Filled, wrapped label");
       label = gtk_label_new ("This is an example of a line-wrapped, filled label.  It should be taking "\
@@ -1016,14 +1008,14 @@ static void create_labels (GtkWidget *widget)
       gtk_label_set_justify (GTK_LABEL (label), GTK_JUSTIFY_FILL);
       gtk_label_set_wrap (GTK_LABEL (label), TRUE);
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       frame = gtk_frame_new ("Underlined label");
       label = gtk_label_new ("This label is underlined!\n"
                             "This one is underlined 
(\343\201\223\343\202\223\343\201\253\343\201\241\343\201\257) in quite a funky fashion");
       gtk_label_set_justify (GTK_LABEL (label), GTK_JUSTIFY_LEFT);
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       frame = gtk_frame_new ("Markup label");
       label = gtk_label_new (NULL);
@@ -1050,7 +1042,7 @@ static void create_labels (GtkWidget *widget)
       g_assert (gtk_label_get_mnemonic_keyval (GTK_LABEL (label)) == GDK_KEY_s);
 
       gtk_frame_set_child (GTK_FRAME (frame), label);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
     }
 
   if (!gtk_widget_get_visible (window))
@@ -1157,7 +1149,7 @@ create_rotated_text (GtkWidget *widget)
       content_area = gtk_dialog_get_content_area (GTK_DIALOG (window));
 
       drawing_area = gtk_drawing_area_new ();
-      gtk_container_add (GTK_CONTAINER (content_area), drawing_area);
+      gtk_box_append (GTK_BOX (content_area), drawing_area);
 
       tile_pixbuf = gdk_pixbuf_new_from_file ("marble.xpm", NULL);
 
@@ -1213,10 +1205,10 @@ create_pixbuf (GtkWidget *widget)
       gtk_window_set_child (GTK_WINDOW (window), box1);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_button_new ();
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       gdk_surface = gtk_native_get_surface (GTK_NATIVE (window));
 
@@ -1224,34 +1216,34 @@ create_pixbuf (GtkWidget *widget)
 
       label = gtk_label_new ("Pixbuf\ntest");
       box3 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (box3), pixbufwid);
-      gtk_container_add (GTK_CONTAINER (box3), label);
+      gtk_box_append (GTK_BOX (box3), pixbufwid);
+      gtk_box_append (GTK_BOX (box3), label);
       gtk_button_set_child (GTK_BUTTON (button), box3);
 
       button = gtk_button_new ();
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       pixbufwid = new_pixbuf ("test.xpm", gdk_surface);
 
       label = gtk_label_new ("Pixbuf\ntest");
       box3 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (box3), pixbufwid);
-      gtk_container_add (GTK_CONTAINER (box3), label);
+      gtk_box_append (GTK_BOX (box3), pixbufwid);
+      gtk_box_append (GTK_BOX (box3), label);
       gtk_button_set_child (GTK_BUTTON (button), box3);
 
       gtk_widget_set_sensitive (button, FALSE);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_button_new_with_label ("close");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       gtk_window_set_default_widget (GTK_WINDOW (window), button);
     }
 
@@ -1288,15 +1280,15 @@ create_tooltips (GtkWidget *widget)
       gtk_window_set_child (GTK_WINDOW (window), box1);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_toggle_button_new_with_label ("button1");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       gtk_widget_set_tooltip_text (button, "This is button 1");
 
       button = gtk_toggle_button_new_with_label ("button2");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       gtk_widget_set_tooltip_text (button,
         "This is button 2. This is also a really long tooltip which probably "
@@ -1304,7 +1296,7 @@ create_tooltips (GtkWidget *widget)
         "Hopefully the wrapping will work correctly.");
 
       toggle = gtk_toggle_button_new_with_label ("Override TipsQuery Label");
-      gtk_container_add (GTK_CONTAINER (box2), toggle);
+      gtk_box_append (GTK_BOX (box2), toggle);
 
       gtk_widget_set_tooltip_text (toggle, "Toggle TipsQuery view.");
 
@@ -1319,27 +1311,27 @@ create_tooltips (GtkWidget *widget)
        g_object_new (gtk_button_get_type (),
                        "label", "[?]",
                        NULL);
-      gtk_container_add (GTK_CONTAINER (box3), button);
+      gtk_box_append (GTK_BOX (box3), button);
       gtk_widget_set_tooltip_text (button, "Start the Tooltips Inspector");
 
       frame = g_object_new (gtk_frame_get_type (),
                              "label", "ToolTips Inspector",
                              "label_xalign", (double) 0.5,
                              NULL);
-      gtk_container_add (GTK_CONTAINER (box2), frame);
+      gtk_box_append (GTK_BOX (box2), frame);
       gtk_frame_set_child (GTK_FRAME (frame), box3);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_button_new_with_label ("close");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       gtk_window_set_default_widget (GTK_WINDOW (window), button);
 
       gtk_widget_set_tooltip_text (button, "Push this button to close window");
@@ -1360,10 +1352,10 @@ pack_image (GtkWidget *box,
             const gchar *text,
             GtkWidget *image)
 {
-  gtk_container_add (GTK_CONTAINER (box),
+  gtk_box_append (GTK_BOX (box),
                       gtk_label_new (text));
 
-  gtk_container_add (GTK_CONTAINER (box),
+  gtk_box_append (GTK_BOX (box),
                       image);
 }
 
@@ -1518,17 +1510,17 @@ create_listbox (GtkWidget *widget)
 
       scrolled = gtk_scrolled_window_new (NULL, NULL);
       gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled), GTK_POLICY_NEVER, 
GTK_POLICY_AUTOMATIC);
-      gtk_container_add (GTK_CONTAINER (hbox), scrolled);
+      gtk_box_append (GTK_BOX (hbox), scrolled);
 
       scrolled_box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
       gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolled), scrolled_box);
 
       label = gtk_label_new ("This is \na LABEL\nwith rows");
-      gtk_container_add (GTK_CONTAINER (scrolled_box), label);
+      gtk_box_append (GTK_BOX (scrolled_box), label);
 
       list = gtk_list_box_new();
       gtk_list_box_set_adjustment (GTK_LIST_BOX (list), gtk_scrolled_window_get_vadjustment 
(GTK_SCROLLED_WINDOW (scrolled)));
-      gtk_container_add (GTK_CONTAINER (scrolled_box), list);
+      gtk_box_append (GTK_BOX (scrolled_box), list);
 
       for (i = 0; i < 1000; i++)
         {
@@ -1540,30 +1532,30 @@ create_listbox (GtkWidget *widget)
         }
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox);
+      gtk_box_append (GTK_BOX (hbox), vbox);
 
       button = gtk_button_new_with_label ("sort");
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
       g_signal_connect (button, "clicked", G_CALLBACK (list_sort_clicked_cb), list);
 
       button = gtk_button_new_with_label ("filter odd");
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
       g_signal_connect (button, "clicked", G_CALLBACK (list_filter_odd_clicked_cb), list);
 
       button = gtk_button_new_with_label ("filter all");
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
       g_signal_connect (button, "clicked", G_CALLBACK (list_filter_all_clicked_cb), list);
 
       button = gtk_button_new_with_label ("unfilter");
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
       g_signal_connect (button, "clicked", G_CALLBACK (list_unfilter_clicked_cb), list);
 
       button = gtk_button_new_with_label ("add placeholder");
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
       g_signal_connect (button, "clicked", G_CALLBACK (add_placeholder_clicked_cb), list);
 
       button = gtk_button_new_with_label ("remove placeholder");
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
       g_signal_connect (button, "clicked", G_CALLBACK (remove_placeholder_clicked_cb), list);
     }
 
@@ -1631,33 +1623,33 @@ create_key_lookup (GtkWidget *widget)
       content_area = gtk_dialog_get_content_area (GTK_DIALOG (window));
 
       button = gtk_button_new_with_mnemonic ("Button 1 (_a)");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = gtk_button_new_with_mnemonic ("Button 2 (_A)");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = gtk_button_new_with_mnemonic ("Button 3 (_\321\204)");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = gtk_button_new_with_mnemonic ("Button 4 (_\320\244)");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = gtk_button_new_with_mnemonic ("Button 6 (_b)");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = accel_button_new ("Button 7", "<Alt><Shift>b");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = accel_button_new ("Button 8", "<Alt>d");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = accel_button_new ("Button 9", "<Alt>Cyrillic_ve");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = gtk_button_new_with_mnemonic ("Button 10 (_1)");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = gtk_button_new_with_mnemonic ("Button 11 (_!)");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = accel_button_new ("Button 12", "<Super>a");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = accel_button_new ("Button 13", "<Hyper>a");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = accel_button_new ("Button 14", "<Meta>a");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
       button = accel_button_new ("Button 15", "<Shift><Mod4>b");
-      gtk_container_add (GTK_CONTAINER (content_area), button);
+      gtk_box_append (GTK_BOX (content_area), button);
 
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
       g_signal_connect (window, "response", G_CALLBACK (gtk_window_destroy), NULL);
@@ -1758,12 +1750,12 @@ create_modal_window (GtkWidget *widget)
 
   /* Pack widgets */
   gtk_window_set_child (GTK_WINDOW (window), box1);
-  gtk_container_add (GTK_CONTAINER (box1), frame1);
+  gtk_box_append (GTK_BOX (box1), frame1);
   gtk_frame_set_child (GTK_FRAME (frame1), box2);
-  gtk_container_add (GTK_CONTAINER (box2), btnColor);
-  gtk_container_add (GTK_CONTAINER (box2), btnFile);
-  gtk_container_add (GTK_CONTAINER (box1), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
-  gtk_container_add (GTK_CONTAINER (box1), btnClose);
+  gtk_box_append (GTK_BOX (box2), btnColor);
+  gtk_box_append (GTK_BOX (box2), btnFile);
+  gtk_box_append (GTK_BOX (box1), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+  gtk_box_append (GTK_BOX (box1), btnClose);
 
   /* connect signals */
   g_signal_connect_swapped (btnClose, "clicked",
@@ -1848,7 +1840,7 @@ scrolled_windows_delete_cb (GtkWidget *widget,
                             GtkWidget *scrollwin)
 {
   g_object_ref (scrollwin);
-  gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (scrollwin)), scrollwin);
+  gtk_box_remove (GTK_BOX (gtk_widget_get_parent (scrollwin)), scrollwin);
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw_parent), scrollwin);
   g_object_unref (scrollwin);
 
@@ -1882,7 +1874,7 @@ scrolled_windows_remove (GtkWidget *dialog, gint response, GtkWidget *scrollwin)
   if (sw_parent)
     {
       g_object_ref (scrollwin);
-      gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (scrollwin)), scrollwin);
+      gtk_box_remove (GTK_BOX (gtk_widget_get_parent (scrollwin)), scrollwin);
       gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw_parent), scrollwin);
       g_object_unref (scrollwin);
 
@@ -1904,7 +1896,7 @@ scrolled_windows_remove (GtkWidget *dialog, gint response, GtkWidget *scrollwin)
       gtk_window_set_default_size (GTK_WINDOW (sw_float_parent), 200, 200);
       
       g_object_ref (scrollwin);
-      gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (scrollwin)), scrollwin);
+      gtk_box_remove (GTK_BOX (gtk_widget_get_parent (scrollwin)), scrollwin);
       gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw_float_parent), scrollwin);
       g_object_unref (scrollwin);
 
@@ -1948,7 +1940,7 @@ create_scrolled_windows (GtkWidget *widget)
       gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window),
                                      GTK_POLICY_AUTOMATIC,
                                      GTK_POLICY_AUTOMATIC);
-      gtk_container_add (GTK_CONTAINER (content_area), scrolled_window);
+      gtk_box_append (GTK_BOX (content_area), scrolled_window);
       gtk_widget_show (scrolled_window);
 
       grid = gtk_grid_new ();
@@ -2096,15 +2088,15 @@ create_entry (GtkWidget *widget)
 
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
-      gtk_container_add (GTK_CONTAINER (box2), hbox);
+      gtk_box_append (GTK_BOX (box2), hbox);
 
       entry = gtk_entry_new ();
       gtk_editable_set_text (GTK_EDITABLE (entry), "hello world 
\330\247\331\204\330\263\331\204\330\247\331\205 \330\271\331\204\331\212\331\203\331\205");
       gtk_editable_select_region (GTK_EDITABLE (entry), 0, 5);
-      gtk_container_add (GTK_CONTAINER (hbox), entry);
+      gtk_box_append (GTK_BOX (hbox), entry);
 
       cb = GTK_COMBO_BOX_TEXT (gtk_combo_box_text_new_with_entry ());
 
@@ -2123,41 +2115,41 @@ create_entry (GtkWidget *widget)
       cb_entry = gtk_button_get_child (GTK_BUTTON (cb));
       gtk_editable_set_text (GTK_EDITABLE (cb_entry), "hello world \n\n\n foo");
       gtk_editable_select_region (GTK_EDITABLE (cb_entry), 0, -1);
-      gtk_container_add (GTK_CONTAINER (box2), GTK_WIDGET (cb));
+      gtk_box_append (GTK_BOX (box2), GTK_WIDGET (cb));
 
       sensitive_check = gtk_check_button_new_with_label("Sensitive");
-      gtk_container_add (GTK_CONTAINER (box2), sensitive_check);
+      gtk_box_append (GTK_BOX (box2), sensitive_check);
       g_signal_connect (sensitive_check, "toggled",
                        G_CALLBACK (entry_toggle_sensitive), entry);
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (sensitive_check), TRUE);
 
       has_frame_check = gtk_check_button_new_with_label("Has Frame");
-      gtk_container_add (GTK_CONTAINER (box2), has_frame_check);
+      gtk_box_append (GTK_BOX (box2), has_frame_check);
       g_signal_connect (has_frame_check, "toggled",
                        G_CALLBACK (entry_toggle_frame), entry);
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (has_frame_check), TRUE);
 
       progress_check = gtk_check_button_new_with_label("Show Progress");
-      gtk_container_add (GTK_CONTAINER (box2), progress_check);
+      gtk_box_append (GTK_BOX (box2), progress_check);
       g_signal_connect (progress_check, "toggled",
                        G_CALLBACK (entry_toggle_progress), entry);
 
       progress_check = gtk_check_button_new_with_label("Pulse Progress");
-      gtk_container_add (GTK_CONTAINER (box2), progress_check);
+      gtk_box_append (GTK_BOX (box2), progress_check);
       g_signal_connect (progress_check, "toggled",
                        G_CALLBACK (entry_toggle_pulse), entry);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_button_new_with_label ("close");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       gtk_window_set_default_widget (GTK_WINDOW (window), button);
     }
 
@@ -2189,7 +2181,7 @@ create_expander (GtkWidget *widget)
 
       expander = gtk_expander_new ("The Hidden");
 
-      gtk_container_add (GTK_CONTAINER (box1), expander);
+      gtk_box_append (GTK_BOX (box1), expander);
 
       hidden = gtk_label_new ("Revealed!");
 
@@ -2260,7 +2252,7 @@ create_size_group_window (GdkDisplay   *display,
   content_area = gtk_dialog_get_content_area (GTK_DIALOG (window));
 
   grid = gtk_grid_new ();
-  gtk_container_add (GTK_CONTAINER (content_area), grid);
+  gtk_box_append (GTK_BOX (content_area), grid);
 
   gtk_grid_set_row_spacing (GTK_GRID (grid), 5);
   gtk_grid_set_column_spacing (GTK_GRID (grid), 5);
@@ -2321,17 +2313,17 @@ create_size_group_window (GdkDisplay   *display,
   g_object_unref (vgroup2);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
-  gtk_container_add (GTK_CONTAINER (content_area), hbox);
+  gtk_box_append (GTK_BOX (content_area), hbox);
 
   spin_button = gtk_spin_button_new_with_range (1, 100, 1);
   gtk_spin_button_set_value (GTK_SPIN_BUTTON (spin_button), SIZE_GROUP_INITIAL_SIZE);
-  gtk_container_add (GTK_CONTAINER (hbox), spin_button);
+  gtk_box_append (GTK_BOX (hbox), spin_button);
   g_signal_connect (spin_button, "value_changed",
                    G_CALLBACK (size_group_hsize_changed), main_button);
 
   spin_button = gtk_spin_button_new_with_range (1, 100, 1);
   gtk_spin_button_set_value (GTK_SPIN_BUTTON (spin_button), SIZE_GROUP_INITIAL_SIZE);
-  gtk_container_add (GTK_CONTAINER (hbox), spin_button);
+  gtk_box_append (GTK_BOX (hbox), spin_button);
   g_signal_connect (spin_button, "value_changed",
                    G_CALLBACK (size_group_vsize_changed), main_button);
 
@@ -2574,7 +2566,7 @@ create_spins (GtkWidget *widget)
       gtk_window_set_child (GTK_WINDOW (window), main_vbox);
 
       frame = gtk_frame_new ("Not accelerated");
-      gtk_container_add (GTK_CONTAINER (main_vbox), frame);
+      gtk_box_append (GTK_BOX (main_vbox), frame);
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
       gtk_frame_set_child (GTK_FRAME (frame), vbox);
@@ -2582,15 +2574,15 @@ create_spins (GtkWidget *widget)
       /* Time, month, hex spinners */
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox2);
+      gtk_box_append (GTK_BOX (hbox), vbox2);
 
       label = gtk_label_new ("Time :");
       gtk_widget_set_halign (label, GTK_ALIGN_START);
       gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox2), label);
+      gtk_box_append (GTK_BOX (vbox2), label);
 
       adjustment = gtk_adjustment_new (0, 0, 1410, 30, 60, 0);
       spinner = gtk_spin_button_new (adjustment, 0, 0);
@@ -2601,15 +2593,15 @@ create_spins (GtkWidget *widget)
                        NULL);
       gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spinner), TRUE);
       gtk_editable_set_width_chars (GTK_EDITABLE (spinner), 5);
-      gtk_container_add (GTK_CONTAINER (vbox2), spinner);
+      gtk_box_append (GTK_BOX (vbox2), spinner);
 
       vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox2);
+      gtk_box_append (GTK_BOX (hbox), vbox2);
 
       label = gtk_label_new ("Month :");
       gtk_widget_set_halign (label, GTK_ALIGN_START);
       gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox2), label);
+      gtk_box_append (GTK_BOX (vbox2), label);
 
       adjustment = gtk_adjustment_new (1.0, 1.0, 12.0, 1.0,
                                                  5.0, 0.0);
@@ -2626,15 +2618,15 @@ create_spins (GtkWidget *widget)
                        NULL);
       gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spinner), TRUE);
       gtk_editable_set_width_chars (GTK_EDITABLE (spinner), 9);
-      gtk_container_add (GTK_CONTAINER (vbox2), spinner);
+      gtk_box_append (GTK_BOX (vbox2), spinner);
 
       vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox2);
+      gtk_box_append (GTK_BOX (hbox), vbox2);
 
       label = gtk_label_new ("Hex :");
       gtk_widget_set_halign (label, GTK_ALIGN_START);
       gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox2), label);
+      gtk_box_append (GTK_BOX (vbox2), label);
 
       adjustment = gtk_adjustment_new (0, 0, 255, 1, 16, 0);
       spinner = gtk_spin_button_new (adjustment, 0, 0);
@@ -2649,87 +2641,87 @@ create_spins (GtkWidget *widget)
                        NULL);
       gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spinner), TRUE);
       gtk_editable_set_width_chars (GTK_EDITABLE (spinner), 4);
-      gtk_container_add (GTK_CONTAINER (vbox2), spinner);
+      gtk_box_append (GTK_BOX (vbox2), spinner);
 
       frame = gtk_frame_new ("Accelerated");
-      gtk_container_add (GTK_CONTAINER (main_vbox), frame);
+      gtk_box_append (GTK_BOX (main_vbox), frame);
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
       gtk_frame_set_child (GTK_FRAME (frame), vbox);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox2);
+      gtk_box_append (GTK_BOX (hbox), vbox2);
 
       label = gtk_label_new ("Value :");
       gtk_widget_set_halign (label, GTK_ALIGN_START);
       gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox2), label);
+      gtk_box_append (GTK_BOX (vbox2), label);
 
       adjustment = gtk_adjustment_new (0.0, -10000.0, 10000.0,
                                                  0.5, 100.0, 0.0);
       spinner1 = gtk_spin_button_new (adjustment, 1.0, 2);
       gtk_spin_button_set_wrap (GTK_SPIN_BUTTON (spinner1), TRUE);
-      gtk_container_add (GTK_CONTAINER (vbox2), spinner1);
+      gtk_box_append (GTK_BOX (vbox2), spinner1);
 
       vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-      gtk_container_add (GTK_CONTAINER (hbox), vbox2);
+      gtk_box_append (GTK_BOX (hbox), vbox2);
 
       label = gtk_label_new ("Digits :");
       gtk_widget_set_halign (label, GTK_ALIGN_START);
       gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox2), label);
+      gtk_box_append (GTK_BOX (vbox2), label);
 
       adjustment = gtk_adjustment_new (2, 1, 15, 1, 1, 0);
       spinner2 = gtk_spin_button_new (adjustment, 0.0, 0);
       g_signal_connect (adjustment, "value_changed",
                        G_CALLBACK (change_digits),
                        spinner2);
-      gtk_container_add (GTK_CONTAINER (vbox2), spinner2);
+      gtk_box_append (GTK_BOX (vbox2), spinner2);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       button = gtk_check_button_new_with_label ("Snap to 0.5-ticks");
       g_signal_connect (button, "clicked",
                        G_CALLBACK (toggle_snap),
                        spinner1);
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
 
       button = gtk_check_button_new_with_label ("Numeric only input mode");
       g_signal_connect (button, "clicked",
                        G_CALLBACK (toggle_numeric),
                        spinner1);
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
 
       val_label = gtk_label_new ("");
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       button = gtk_button_new_with_label ("Value as Int");
       g_object_set_data (G_OBJECT (button), "user_data", val_label);
       g_signal_connect (button, "clicked",
                        G_CALLBACK (get_value),
                        GINT_TO_POINTER (1));
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
       button = gtk_button_new_with_label ("Value as Float");
       g_object_set_data (G_OBJECT (button), "user_data", val_label);
       g_signal_connect (button, "clicked",
                        G_CALLBACK (get_value),
                        GINT_TO_POINTER (2));
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
-      gtk_container_add (GTK_CONTAINER (vbox), val_label);
+      gtk_box_append (GTK_BOX (vbox), val_label);
       gtk_label_set_text (GTK_LABEL (val_label), "0");
 
       frame = gtk_frame_new ("Using Convenience Constructor");
-      gtk_container_add (GTK_CONTAINER (main_vbox), frame);
+      gtk_box_append (GTK_BOX (main_vbox), frame);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
       gtk_frame_set_child (GTK_FRAME (frame), vbox);
@@ -2740,17 +2732,17 @@ create_spins (GtkWidget *widget)
       gtk_spin_button_set_value (GTK_SPIN_BUTTON (spinner), 0.0);
       g_signal_connect (spinner, "value_changed",
                        G_CALLBACK (get_spin_value), val_label);
-      gtk_container_add (GTK_CONTAINER (hbox), spinner);
-      gtk_container_add (GTK_CONTAINER (hbox), val_label);
+      gtk_box_append (GTK_BOX (hbox), spinner);
+      gtk_box_append (GTK_BOX (hbox), val_label);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (main_vbox), hbox);
+      gtk_box_append (GTK_BOX (main_vbox), hbox);
 
       button = gtk_button_new_with_label ("Close");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
     }
 
   if (!gtk_widget_get_visible (window))
@@ -2953,20 +2945,20 @@ set_cursor_from_name (GtkWidget *entry,
 
 static void
 change_cursor_theme (GtkWidget *widget,
-                    gpointer   data)
+                     gpointer   data)
 {
 #if defined(GDK_WINDOWING_X11) || defined (GDK_WINDOWING_WAYLAND)
   const gchar *theme;
   gint size;
-  GList *children;
   GdkDisplay *display;
+  GtkWidget *entry;
+  GtkWidget *spin;
 
-  children = gtk_container_get_children (GTK_CONTAINER (data));
-
-  theme = gtk_editable_get_text (GTK_EDITABLE (children->next->data));
-  size = (gint) gtk_spin_button_get_value (GTK_SPIN_BUTTON (children->next->next->data));
+  entry = gtk_widget_get_next_sibling (gtk_widget_get_first_child (GTK_WIDGET (data)));
+  spin = gtk_widget_get_next_sibling (entry);
 
-  g_list_free (children);
+  theme = gtk_editable_get_text (GTK_EDITABLE (entry));
+  size = (gint) gtk_spin_button_get_value (GTK_SPIN_BUTTON (spin));
 
   display = gtk_widget_get_display (widget);
 #ifdef GDK_WINDOWING_X11
@@ -3017,7 +3009,7 @@ create_cursors (GtkWidget *widget)
                            "homogeneous", FALSE,
                            "spacing", 5,
                            NULL);
-      gtk_container_add (GTK_CONTAINER (main_vbox), vbox);
+      gtk_box_append (GTK_BOX (main_vbox), vbox);
 
 #ifdef GDK_WINDOWING_X11
       if (GDK_IS_X11_DISPLAY (gtk_widget_get_display (vbox)))
@@ -3031,20 +3023,20 @@ create_cursors (GtkWidget *widget)
     if (cursor_demo)
         {
           hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
-          gtk_container_add (GTK_CONTAINER (vbox), hbox);
+          gtk_box_append (GTK_BOX (vbox), hbox);
 
           label = gtk_label_new ("Cursor Theme:");
           gtk_widget_set_halign (label, GTK_ALIGN_START);
           gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
-          gtk_container_add (GTK_CONTAINER (hbox), label);
+          gtk_box_append (GTK_BOX (hbox), label);
 
           entry = gtk_entry_new ();
           gtk_editable_set_text (GTK_EDITABLE (entry), "default");
-          gtk_container_add (GTK_CONTAINER (hbox), entry);
+          gtk_box_append (GTK_BOX (hbox), entry);
 
           size = gtk_spin_button_new_with_range (1.0, 128.0, 1.0);
           gtk_spin_button_set_value (GTK_SPIN_BUTTON (size), 24.0);
-          gtk_container_add (GTK_CONTAINER (hbox), size);
+          gtk_box_append (GTK_BOX (hbox), size);
 
           g_signal_connect (entry, "changed",
                             G_CALLBACK (change_cursor_theme), hbox);
@@ -3053,12 +3045,12 @@ create_cursors (GtkWidget *widget)
         }
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       label = gtk_label_new ("Cursor Name:");
       gtk_widget_set_halign (label, GTK_ALIGN_START);
       gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       entry = gtk_entry_new ();
       completion = gtk_entry_completion_new ();
@@ -3067,14 +3059,14 @@ create_cursors (GtkWidget *widget)
       gtk_entry_completion_set_text_column (completion, 0);
       gtk_entry_set_completion (GTK_ENTRY (entry), completion);
       g_object_unref (model);
-      gtk_container_add (GTK_CONTAINER (hbox), entry);
+      gtk_box_append (GTK_BOX (hbox), entry);
 
       frame =
        g_object_new (gtk_frame_get_type (),
                        "label_xalign", 0.5,
                        "label", "Cursor Area",
                        NULL);
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       darea = gtk_drawing_area_new ();
       gtk_drawing_area_set_content_width (GTK_DRAWING_AREA (darea), 80);
@@ -3092,16 +3084,16 @@ create_cursors (GtkWidget *widget)
 
 
       any = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (main_vbox), any);
+      gtk_box_append (GTK_BOX (main_vbox), any);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-      gtk_container_add (GTK_CONTAINER (main_vbox), hbox);
+      gtk_box_append (GTK_BOX (main_vbox), hbox);
 
       button = gtk_button_new_with_label ("Close");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
 
       gtk_widget_show (window);
 
@@ -3137,11 +3129,11 @@ create_color_selection (GtkWidget *widget)
       gtk_window_set_child (GTK_WINDOW (window), hbox);
       
       label = gtk_label_new ("Pick a color");
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       picker = gtk_color_button_new ();
       gtk_color_chooser_set_use_alpha (GTK_COLOR_CHOOSER (picker), TRUE);
-      gtk_container_add (GTK_CONTAINER (hbox), picker);
+      gtk_box_append (GTK_BOX (hbox), picker);
     }
 
   if (!gtk_widget_get_visible (window))
@@ -3163,6 +3155,7 @@ static void
 orientable_toggle_orientation (GtkOrientable *orientable)
 {
   GtkOrientation orientation;
+  GtkWidget *child;
 
   orientation = gtk_orientable_get_orientation (orientable);
   gtk_orientable_set_orientation (orientable,
@@ -3170,20 +3163,13 @@ orientable_toggle_orientation (GtkOrientable *orientable)
                                   GTK_ORIENTATION_VERTICAL :
                                   GTK_ORIENTATION_HORIZONTAL);
 
-  if (GTK_IS_CONTAINER (orientable))
-    {
-      GList *children;
-      GList *child;
-
-      children = gtk_container_get_children (GTK_CONTAINER (orientable));
-
-      for (child = children; child; child = child->next)
-        {
-          if (GTK_IS_ORIENTABLE (child->data))
-            orientable_toggle_orientation (child->data);
-        }
 
-      g_list_free (children);
+  for (child = gtk_widget_get_first_child (GTK_WIDGET (orientable));
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    {
+      if (GTK_IS_ORIENTABLE (child))
+        orientable_toggle_orientation (GTK_ORIENTABLE (child));
     }
 }
 
@@ -3200,15 +3186,16 @@ flipping_orientation_toggled_cb (GtkWidget *widget, gpointer data)
 
 static void
 set_direction_recurse (GtkWidget *widget,
-                      gpointer   data)
+                       gpointer   data)
 {
   GtkTextDirection *dir = data;
-  
+  GtkWidget *child;
+
   gtk_widget_set_direction (widget, *dir);
-  if (GTK_IS_CONTAINER (widget))
-    gtk_container_foreach (GTK_CONTAINER (widget),
-                          set_direction_recurse,
-                          data);
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    set_direction_recurse (child, data);
 }
 
 static GtkWidget *
@@ -3221,8 +3208,8 @@ create_forward_back (const char       *title,
   GtkWidget *forward_button = gtk_button_new_with_label ("Forward");
 
   gtk_frame_set_child (GTK_FRAME (frame), bbox);
-  gtk_container_add (GTK_CONTAINER (bbox), back_button);
-  gtk_container_add (GTK_CONTAINER (bbox), forward_button);
+  gtk_box_append (GTK_BOX (bbox), back_button);
+  gtk_box_append (GTK_BOX (bbox), forward_button);
 
   set_direction_recurse (frame, &text_dir);
 
@@ -3249,7 +3236,7 @@ create_flipping (GtkWidget *widget)
       gtk_window_set_title (GTK_WINDOW (window), "Bidirectional Flipping");
 
       check_button = gtk_check_button_new_with_label ("Right-to-left global direction");
-      gtk_container_add (GTK_CONTAINER (content_area), check_button);
+      gtk_box_append (GTK_BOX (content_area), check_button);
 
       if (gtk_widget_get_default_direction () == GTK_TEXT_DIR_RTL)
        gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check_button), TRUE);
@@ -3258,18 +3245,18 @@ create_flipping (GtkWidget *widget)
                        G_CALLBACK (flipping_toggled_cb), NULL);
 
       check_button = gtk_check_button_new_with_label ("Toggle orientation of all boxes");
-      gtk_container_add (GTK_CONTAINER (content_area), check_button);
+      gtk_box_append (GTK_BOX (content_area), check_button);
 
       g_signal_connect (check_button, "toggled",
                        G_CALLBACK (flipping_orientation_toggled_cb), NULL);
 
-      gtk_container_add (GTK_CONTAINER (content_area),
+      gtk_box_append (GTK_BOX (content_area),
                          create_forward_back ("Default", GTK_TEXT_DIR_NONE));
 
-      gtk_container_add (GTK_CONTAINER (content_area),
+      gtk_box_append (GTK_BOX (content_area),
                          create_forward_back ("Left-to-Right", GTK_TEXT_DIR_LTR));
 
-      gtk_container_add (GTK_CONTAINER (content_area),
+      gtk_box_append (GTK_BOX (content_area),
                          create_forward_back ("Right-to-Left", GTK_TEXT_DIR_RTL));
 
       gtk_dialog_add_button (GTK_DIALOG (window), "Close", GTK_RESPONSE_CLOSE);
@@ -3308,11 +3295,11 @@ create_font_selection (GtkWidget *widget)
       gtk_window_set_child (GTK_WINDOW (window), hbox);
       
       label = gtk_label_new ("Pick a font");
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       picker = gtk_font_button_new ();
       gtk_font_button_set_use_font (GTK_FONT_BUTTON (picker), TRUE);
-      gtk_container_add (GTK_CONTAINER (hbox), picker);
+      gtk_box_append (GTK_BOX (hbox), picker);
     }
   
   if (!gtk_widget_get_visible (window))
@@ -3331,24 +3318,25 @@ static void
 dialog_response_cb (GtkWidget *widget, gint response, gpointer unused)
 {
   GtkWidget *content_area;
-  GList *l, *children;
+  GtkWidget *child;
 
   if (response == GTK_RESPONSE_APPLY)
     {
       content_area = gtk_dialog_get_content_area (GTK_DIALOG (dialog_window));
-      children = gtk_container_get_children (GTK_CONTAINER (content_area));
 
-      for (l = children; l; l = l->next)
+      for (child = gtk_widget_get_first_child (content_area);
+           child != NULL;
+           child = gtk_widget_get_next_sibling (child))
         {
-          if (GTK_IS_LABEL (l->data))
+          if (GTK_IS_LABEL (child))
             {
-              gtk_container_remove (GTK_CONTAINER (content_area), l->data);
+              gtk_box_remove (GTK_BOX (content_area), child);
               break;
             }
         }
 
       /* no label removed, so add one */
-      if (l == NULL)
+      if (child == NULL)
         {
           GtkWidget *label;
 
@@ -3357,12 +3345,9 @@ dialog_response_cb (GtkWidget *widget, gint response, gpointer unused)
           gtk_widget_set_margin_end (label, 10);
           gtk_widget_set_margin_top (label, 10);
           gtk_widget_set_margin_bottom (label, 10);
-          gtk_container_add (GTK_CONTAINER (content_area),
-                              label);
+          gtk_box_append (GTK_BOX (content_area), label);
           gtk_widget_show (label);
         }
-
-      g_list_free (children);
     }
 }
 
@@ -3490,7 +3475,7 @@ create_display_screen (GtkWidget *widget)
   gtk_window_set_child (GTK_WINDOW (window), vbox);
   
   frame = gtk_frame_new ("Select display");
-  gtk_container_add (GTK_CONTAINER (vbox), frame);
+  gtk_box_append (GTK_BOX (vbox), frame);
   
   grid = gtk_grid_new ();
   gtk_grid_set_row_spacing (GTK_GRID (grid), 3);
@@ -3513,10 +3498,10 @@ create_display_screen (GtkWidget *widget)
   applyb = gtk_button_new_with_label ("_Apply");
   cancelb = gtk_button_new_with_label ("_Cancel");
   
-  gtk_container_add (GTK_CONTAINER (vbox), bbox);
+  gtk_box_append (GTK_BOX (vbox), bbox);
 
-  gtk_container_add (GTK_CONTAINER (bbox), applyb);
-  gtk_container_add (GTK_CONTAINER (bbox), cancelb);
+  gtk_box_append (GTK_BOX (bbox), applyb);
+  gtk_box_append (GTK_BOX (bbox), cancelb);
 
   scr_dpy_data = g_new0 (ScreenDisplaySelection, 1);
 
@@ -3573,7 +3558,7 @@ create_range_controls (GtkWidget *widget)
 
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
       gtk_widget_show (box2);
 
 
@@ -3583,11 +3568,11 @@ create_range_controls (GtkWidget *widget)
       gtk_widget_set_size_request (GTK_WIDGET (scale), 150, -1);
       gtk_scale_set_digits (GTK_SCALE (scale), 1);
       gtk_scale_set_draw_value (GTK_SCALE (scale), TRUE);
-      gtk_container_add (GTK_CONTAINER (box2), scale);
+      gtk_box_append (GTK_BOX (box2), scale);
       gtk_widget_show (scale);
 
       scrollbar = gtk_scrollbar_new (GTK_ORIENTATION_HORIZONTAL, GTK_ADJUSTMENT (adjustment));
-      gtk_container_add (GTK_CONTAINER (box2), scrollbar);
+      gtk_box_append (GTK_BOX (box2), scrollbar);
       gtk_widget_show (scrollbar);
 
       scale = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL, GTK_ADJUSTMENT (adjustment));
@@ -3596,7 +3581,7 @@ create_range_controls (GtkWidget *widget)
                         "format_value",
                         G_CALLBACK (reformat_value),
                         NULL);
-      gtk_container_add (GTK_CONTAINER (box2), scale);
+      gtk_box_append (GTK_BOX (box2), scale);
       gtk_widget_show (scale);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
@@ -3605,7 +3590,7 @@ create_range_controls (GtkWidget *widget)
       gtk_widget_set_size_request (scale, -1, 200);
       gtk_scale_set_digits (GTK_SCALE (scale), 2);
       gtk_scale_set_draw_value (GTK_SCALE (scale), TRUE);
-      gtk_container_add (GTK_CONTAINER (hbox), scale);
+      gtk_box_append (GTK_BOX (hbox), scale);
       gtk_widget_show (scale);
 
       scale = gtk_scale_new (GTK_ORIENTATION_VERTICAL, GTK_ADJUSTMENT (adjustment));
@@ -3613,7 +3598,7 @@ create_range_controls (GtkWidget *widget)
       gtk_scale_set_digits (GTK_SCALE (scale), 2);
       gtk_scale_set_draw_value (GTK_SCALE (scale), TRUE);
       gtk_range_set_inverted (GTK_RANGE (scale), TRUE);
-      gtk_container_add (GTK_CONTAINER (hbox), scale);
+      gtk_box_append (GTK_BOX (hbox), scale);
       gtk_widget_show (scale);
 
       scale = gtk_scale_new (GTK_ORIENTATION_VERTICAL, GTK_ADJUSTMENT (adjustment));
@@ -3622,20 +3607,20 @@ create_range_controls (GtkWidget *widget)
                         "format_value",
                         G_CALLBACK (reformat_value),
                         NULL);
-      gtk_container_add (GTK_CONTAINER (hbox), scale);
+      gtk_box_append (GTK_BOX (hbox), scale);
       gtk_widget_show (scale);
 
 
-      gtk_container_add (GTK_CONTAINER (box2), hbox);
+      gtk_box_append (GTK_BOX (box2), hbox);
       gtk_widget_show (hbox);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
       gtk_widget_show (separator);
 
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
       gtk_widget_show (box2);
 
 
@@ -3643,7 +3628,7 @@ create_range_controls (GtkWidget *widget)
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       gtk_window_set_default_widget (GTK_WINDOW (window), button);
       gtk_widget_show (button);
     }
@@ -3778,20 +3763,20 @@ create_pages (GtkNotebook *notebook, gint start, gint end)
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
       gtk_box_set_homogeneous (GTK_BOX (vbox), TRUE);
-      gtk_container_add (GTK_CONTAINER (child), vbox);
+      gtk_box_append (GTK_BOX (child), vbox);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
       gtk_box_set_homogeneous (GTK_BOX (hbox), TRUE);
-      gtk_container_add (GTK_CONTAINER (vbox), hbox);
+      gtk_box_append (GTK_BOX (vbox), hbox);
 
       button = gtk_check_button_new_with_label ("Fill Tab");
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
       gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
       g_signal_connect (button, "toggled",
                        G_CALLBACK (tab_fill), child);
 
       button = gtk_check_button_new_with_label ("Expand Tab");
-      gtk_container_add (GTK_CONTAINER (hbox), button);
+      gtk_box_append (GTK_BOX (hbox), button);
       g_signal_connect (button, "toggled",
                        G_CALLBACK (tab_expand), child);
 
@@ -3806,13 +3791,13 @@ create_pages (GtkNotebook *notebook, gint start, gint end)
       pixwid = gtk_image_new_from_pixbuf (book_closed);
       g_object_set_data (G_OBJECT (child), "tab_pixmap", pixwid);
 
-      gtk_container_add (GTK_CONTAINER (label_box), pixwid);
+      gtk_box_append (GTK_BOX (label_box), pixwid);
       gtk_widget_set_margin_start (pixwid, 3);
       gtk_widget_set_margin_end (pixwid, 3);
       gtk_widget_set_margin_bottom (pixwid, 1);
       gtk_widget_set_margin_top (pixwid, 1);
       label = gtk_label_new_with_mnemonic (accel_buffer);
-      gtk_container_add (GTK_CONTAINER (label_box), label);
+      gtk_box_append (GTK_BOX (label_box), label);
       gtk_widget_show (label_box);
 
 
@@ -3820,13 +3805,13 @@ create_pages (GtkNotebook *notebook, gint start, gint end)
       pixwid = gtk_image_new_from_pixbuf (book_closed);
       g_object_set_data (G_OBJECT (child), "menu_pixmap", pixwid);
 
-      gtk_container_add (GTK_CONTAINER (menu_box), pixwid);
+      gtk_box_append (GTK_BOX (menu_box), pixwid);
       gtk_widget_set_margin_start (pixwid, 3);
       gtk_widget_set_margin_end (pixwid, 3);
       gtk_widget_set_margin_bottom (pixwid, 1);
       gtk_widget_set_margin_top (pixwid, 1);
       label = gtk_label_new (buffer);
-      gtk_container_add (GTK_CONTAINER (menu_box), label);
+      gtk_box_append (GTK_BOX (menu_box), label);
       gtk_widget_show (menu_box);
 
       gtk_notebook_append_page_menu (notebook, child, label_box, menu_box);
@@ -3953,7 +3938,7 @@ create_notebook (GtkWidget *widget)
       g_signal_connect (sample_notebook, "switch_page",
                        G_CALLBACK (page_switch), NULL);
       gtk_notebook_set_tab_pos (GTK_NOTEBOOK (sample_notebook), GTK_POS_TOP);
-      gtk_container_add (GTK_CONTAINER (box1), sample_notebook);
+      gtk_box_append (GTK_BOX (box1), sample_notebook);
 
       gtk_widget_realize (sample_notebook);
 
@@ -3966,62 +3951,62 @@ create_notebook (GtkWidget *widget)
       create_pages (GTK_NOTEBOOK (sample_notebook), 1, 5);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_check_button_new_with_label ("popup menu");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       g_signal_connect (button, "clicked",
                        G_CALLBACK (notebook_popup),
                        sample_notebook);
 
       box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       label = gtk_label_new ("Notebook Style :");
-      gtk_container_add (GTK_CONTAINER (box2), label);
+      gtk_box_append (GTK_BOX (box2), label);
 
       omenu = build_option_menu (items, G_N_ELEMENTS (items), 0,
                                 notebook_type_changed,
                                 sample_notebook);
-      gtk_container_add (GTK_CONTAINER (box2), omenu);
+      gtk_box_append (GTK_BOX (box2), omenu);
 
       button = gtk_button_new_with_label ("Show all Pages");
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       g_signal_connect (button, "clicked",
                        G_CALLBACK (show_all_pages), sample_notebook);
 
       box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
       gtk_box_set_homogeneous (GTK_BOX (box2), TRUE);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
 
       button = gtk_button_new_with_label ("prev");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_notebook_prev_page),
                                sample_notebook);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_button_new_with_label ("next");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_notebook_next_page),
                                sample_notebook);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       button = gtk_button_new_with_label ("rotate");
       g_signal_connect (button, "clicked",
                        G_CALLBACK (rotate_notebook), sample_notebook);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
 
       button = gtk_button_new_with_label ("close");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (box1), button);
+      gtk_box_append (GTK_BOX (box1), button);
       gtk_window_set_default_widget (GTK_WINDOW (window), button);
     }
 
@@ -4140,7 +4125,7 @@ create_panes (GtkWidget *widget)
       gtk_window_set_child (GTK_WINDOW (window), vbox);
 
       vpaned = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
-      gtk_container_add (GTK_CONTAINER (vbox), vpaned);
+      gtk_box_append (GTK_BOX (vbox), vpaned);
 
       hpaned = gtk_paned_new (GTK_ORIENTATION_HORIZONTAL);
       gtk_paned_set_start_child (GTK_PANED (vpaned), hpaned);
@@ -4162,13 +4147,13 @@ create_panes (GtkWidget *widget)
 
       /* Now create toggle buttons to control sizing */
 
-      gtk_container_add (GTK_CONTAINER (vbox),
+      gtk_box_append (GTK_BOX (vbox),
                          create_pane_options (GTK_PANED (hpaned),
                                               "Horizontal",
                                               "Left",
                                               "Right"));
 
-      gtk_container_add (GTK_CONTAINER (vbox),
+      gtk_box_append (GTK_BOX (vbox),
                          create_pane_options (GTK_PANED (vpaned),
                                               "Vertical",
                                               "Top",
@@ -4228,13 +4213,13 @@ paned_keyboard_window1 (GtkWidget *widget)
   gtk_frame_set_child (GTK_FRAME (frame1), vbox1);
 
   button7 = gtk_button_new_with_label ("button7");
-  gtk_container_add (GTK_CONTAINER (vbox1), button7);
+  gtk_box_append (GTK_BOX (vbox1), button7);
 
   button8 = gtk_button_new_with_label ("button8");
-  gtk_container_add (GTK_CONTAINER (vbox1), button8);
+  gtk_box_append (GTK_BOX (vbox1), button8);
 
   button9 = gtk_button_new_with_label ("button9");
-  gtk_container_add (GTK_CONTAINER (vbox1), button9);
+  gtk_box_append (GTK_BOX (vbox1), button9);
 
   vpaned1 = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
   gtk_paned_set_end_child (GTK_PANED (hpaned1), vpaned1);
@@ -4253,10 +4238,10 @@ paned_keyboard_window1 (GtkWidget *widget)
   gtk_frame_set_child (GTK_FRAME (frame5), hbox1);
 
   button5 = gtk_button_new_with_label ("button5");
-  gtk_container_add (GTK_CONTAINER (hbox1), button5);
+  gtk_box_append (GTK_BOX (hbox1), button5);
 
   button6 = gtk_button_new_with_label ("button6");
-  gtk_container_add (GTK_CONTAINER (hbox1), button6);
+  gtk_box_append (GTK_BOX (hbox1), button6);
 
   frame3 = gtk_frame_new (NULL);
   gtk_paned_set_end_child (GTK_PANED (vpaned1), frame3);
@@ -4322,7 +4307,7 @@ paned_keyboard_window2 (GtkWidget *widget)
   gtk_paned_set_shrink_end_child (GTK_PANED (hpaned2), TRUE);
 
   vpaned2 = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
-  gtk_container_add (GTK_CONTAINER (hbox2), vpaned2);
+  gtk_box_append (GTK_BOX (hbox2), vpaned2);
 
   frame7 = gtk_frame_new (NULL);
   gtk_paned_set_start_child (GTK_PANED (vpaned2), frame7);
@@ -4341,7 +4326,7 @@ paned_keyboard_window2 (GtkWidget *widget)
   gtk_frame_set_child (GTK_FRAME (frame8), button11);
 
   button10 = gtk_button_new_with_label ("button10");
-  gtk_container_add (GTK_CONTAINER (hbox2), button10);
+  gtk_box_append (GTK_BOX (hbox2), button10);
 
   return window2;
 }
@@ -4376,10 +4361,10 @@ paned_keyboard_window3 (GtkWidget *widget)
   gtk_window_set_child (GTK_WINDOW (window3), vbox2);
 
   label1 = gtk_label_new ("Three panes nested inside each other");
-  gtk_container_add (GTK_CONTAINER (vbox2), label1);
+  gtk_box_append (GTK_BOX (vbox2), label1);
 
   hpaned3 = gtk_paned_new (GTK_ORIENTATION_HORIZONTAL);
-  gtk_container_add (GTK_CONTAINER (vbox2), hpaned3);
+  gtk_box_append (GTK_BOX (vbox2), hpaned3);
 
   frame9 = gtk_frame_new (NULL);
   gtk_paned_set_start_child (GTK_PANED (hpaned3), frame9);
@@ -4458,11 +4443,11 @@ paned_keyboard_window4 (GtkWidget *widget)
   gtk_window_set_child (GTK_WINDOW (window4), vbox3);
 
   label2 = gtk_label_new ("Widget tree:\n\nhpaned \n - vpaned\n - hbox\n    - vpaned\n    - vpaned\n    - 
vpaned\n");
-  gtk_container_add (GTK_CONTAINER (vbox3), label2);
+  gtk_box_append (GTK_BOX (vbox3), label2);
   gtk_label_set_justify (GTK_LABEL (label2), GTK_JUSTIFY_LEFT);
 
   hpaned6 = gtk_paned_new (GTK_ORIENTATION_HORIZONTAL);
-  gtk_container_add (GTK_CONTAINER (vbox3), hpaned6);
+  gtk_box_append (GTK_BOX (vbox3), hpaned6);
 
   vpaned3 = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
   gtk_paned_set_start_child (GTK_PANED (hpaned6), vpaned3);
@@ -4485,7 +4470,7 @@ paned_keyboard_window4 (GtkWidget *widget)
   gtk_paned_set_shrink_end_child (GTK_PANED (hpaned6), TRUE);
 
   vpaned4 = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
-  gtk_container_add (GTK_CONTAINER (hbox3), vpaned4);
+  gtk_box_append (GTK_BOX (hbox3), vpaned4);
 
   button21 = gtk_button_new_with_label ("button21");
   gtk_paned_set_start_child (GTK_PANED (vpaned4), button21);
@@ -4498,7 +4483,7 @@ paned_keyboard_window4 (GtkWidget *widget)
   gtk_paned_set_shrink_end_child (GTK_PANED (vpaned4), TRUE);
 
   vpaned5 = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
-  gtk_container_add (GTK_CONTAINER (hbox3), vpaned5);
+  gtk_box_append (GTK_BOX (hbox3), vpaned5);
 
   button23 = gtk_button_new_with_label ("button23");
   gtk_paned_set_start_child (GTK_PANED (vpaned5), button23);
@@ -4511,7 +4496,7 @@ paned_keyboard_window4 (GtkWidget *widget)
   gtk_paned_set_shrink_end_child (GTK_PANED (vpaned5), TRUE);
 
   vpaned6 = gtk_paned_new (GTK_ORIENTATION_VERTICAL);
-  gtk_container_add (GTK_CONTAINER (hbox3), vpaned6);
+  gtk_box_append (GTK_BOX (hbox3), vpaned6);
 
   button25 = gtk_button_new_with_label ("button25");
   gtk_paned_set_start_child (GTK_PANED (vpaned6), button25);
@@ -4632,17 +4617,17 @@ create_wmhints (GtkWidget *widget)
 
       label = gtk_label_new ("Try iconizing me!");
       gtk_widget_set_size_request (label, 150, 50);
-      gtk_container_add (GTK_CONTAINER (box1), label);
+      gtk_box_append (GTK_BOX (box1), label);
       gtk_widget_show (label);
 
 
       separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-      gtk_container_add (GTK_CONTAINER (box1), separator);
+      gtk_box_append (GTK_BOX (box1), separator);
       gtk_widget_show (separator);
 
 
       box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-      gtk_container_add (GTK_CONTAINER (box1), box2);
+      gtk_box_append (GTK_BOX (box1), box2);
       gtk_widget_show (box2);
 
 
@@ -4652,7 +4637,7 @@ create_wmhints (GtkWidget *widget)
                                G_CALLBACK (gtk_window_destroy),
                                window);
 
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
       gtk_window_set_default_widget (GTK_WINDOW (window), button);
       gtk_widget_show (button);
     }
@@ -4715,7 +4700,7 @@ tracking_label (GtkWidget *window)
 
   label = gtk_label_new ("<no window state events received>");
   gtk_label_set_wrap (GTK_LABEL (label), TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
 
   g_object_set_data (G_OBJECT (label), "title", (gpointer)gtk_window_get_title (GTK_WINDOW (window)));
   g_signal_connect (gtk_native_get_surface (GTK_NATIVE (window)), "notify::state",
@@ -4728,7 +4713,7 @@ tracking_label (GtkWidget *window)
                           G_CALLBACK (gtk_window_unminimize),
                            window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   button = gtk_button_new_with_label ("Minimize");
   g_signal_connect_object (button,
@@ -4736,7 +4721,7 @@ tracking_label (GtkWidget *window)
                           G_CALLBACK (gtk_window_minimize),
                            window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   button = gtk_button_new_with_label ("Fullscreen");
   g_signal_connect_object (button,
@@ -4744,7 +4729,7 @@ tracking_label (GtkWidget *window)
                           G_CALLBACK (gtk_window_fullscreen),
                            window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   button = gtk_button_new_with_label ("Unfullscreen");
   g_signal_connect_object (button,
@@ -4752,7 +4737,7 @@ tracking_label (GtkWidget *window)
                           G_CALLBACK (gtk_window_unfullscreen),
                            window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   button = gtk_button_new_with_label ("Present");
   g_signal_connect_object (button,
@@ -4760,7 +4745,7 @@ tracking_label (GtkWidget *window)
                           G_CALLBACK (gtk_window_present),
                            window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   button = gtk_button_new_with_label ("Show");
   g_signal_connect_object (button,
@@ -4768,7 +4753,7 @@ tracking_label (GtkWidget *window)
                           G_CALLBACK (gtk_widget_show),
                            window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   gtk_widget_show (hbox);
 
@@ -4789,7 +4774,7 @@ get_state_controls (GtkWidget *window)
                           G_CALLBACK (gtk_window_maximize),
                           window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Unmaximize");
   g_signal_connect_object (button,
@@ -4797,7 +4782,7 @@ get_state_controls (GtkWidget *window)
                           G_CALLBACK (gtk_window_unmaximize),
                           window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Minimize");
   g_signal_connect_object (button,
@@ -4805,7 +4790,7 @@ get_state_controls (GtkWidget *window)
                           G_CALLBACK (gtk_window_minimize),
                           window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Fullscreen");
   g_signal_connect_object (button,
@@ -4813,7 +4798,7 @@ get_state_controls (GtkWidget *window)
                           G_CALLBACK (gtk_window_fullscreen),
                            window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Unfullscreen");
   g_signal_connect_object (button,
@@ -4821,7 +4806,7 @@ get_state_controls (GtkWidget *window)
                            G_CALLBACK (gtk_window_unfullscreen),
                           window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Hide (withdraw)");
   g_signal_connect_object (button,
@@ -4829,7 +4814,7 @@ get_state_controls (GtkWidget *window)
                           G_CALLBACK (gtk_widget_hide),
                           window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   gtk_widget_show (vbox);
 
@@ -4870,7 +4855,7 @@ create_surface_states (GtkWidget *widget)
       gtk_window_minimize (GTK_WINDOW (iconified));
       gtk_window_set_title (GTK_WINDOW (iconified), "Minimized initially");
       controls = get_state_controls (iconified);
-      gtk_container_add (GTK_CONTAINER (iconified), controls);
+      gtk_box_append (GTK_BOX (iconified), controls);
       
       normal = gtk_window_new ();
 
@@ -4884,16 +4869,16 @@ create_surface_states (GtkWidget *widget)
       
       gtk_window_set_title (GTK_WINDOW (normal), "Unminimized initially");
       controls = get_state_controls (normal);
-      gtk_container_add (GTK_CONTAINER (normal), controls);
+      gtk_box_append (GTK_BOX (normal), controls);
       
       gtk_widget_realize (iconified);
       gtk_widget_realize (normal);
 
       label = tracking_label (iconified);
-      gtk_container_add (GTK_CONTAINER (box1), label);
+      gtk_box_append (GTK_BOX (box1), label);
 
       label = tracking_label (normal);
-      gtk_container_add (GTK_CONTAINER (box1), label);
+      gtk_box_append (GTK_BOX (box1), label);
 
       gtk_widget_show (iconified);
       gtk_widget_show (normal);
@@ -5014,22 +4999,22 @@ window_controls (GtkWidget *window)
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
 
-  gtk_container_add (GTK_CONTAINER (control_window), vbox);
+  gtk_box_append (GTK_BOX (control_window), vbox);
 
   label = gtk_label_new ("<no size>");
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   adjustment = gtk_adjustment_new (10.0, -2000.0, 2000.0, 1.0, 5.0, 0.0);
   spin = gtk_spin_button_new (adjustment, 0, 0);
 
-  gtk_container_add (GTK_CONTAINER (vbox), spin);
+  gtk_box_append (GTK_BOX (vbox), spin);
 
   g_object_set_data (G_OBJECT (control_window), "spin1", spin);
 
   adjustment = gtk_adjustment_new (10.0, -2000.0, 2000.0, 1.0, 5.0, 0.0);
   spin = gtk_spin_button_new (adjustment, 0, 0);
 
-  gtk_container_add (GTK_CONTAINER (vbox), spin);
+  gtk_box_append (GTK_BOX (vbox), spin);
 
   g_object_set_data (G_OBJECT (control_window), "spin2", spin);
 
@@ -5039,42 +5024,42 @@ window_controls (GtkWidget *window)
                           G_CALLBACK (gtk_widget_queue_resize),
                           window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Resize");
   g_signal_connect (button,
                    "clicked",
                    G_CALLBACK (set_size_callback),
                    control_window);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Set default size");
   g_signal_connect (button,
                    "clicked",
                    G_CALLBACK (set_default_size_callback),
                    control_window);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Unset default size");
   g_signal_connect (button,
                    "clicked",
                    G_CALLBACK (unset_default_size_callback),
                     control_window);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Set size request");
   g_signal_connect (button,
                    "clicked",
                    G_CALLBACK (set_size_request_callback),
                    control_window);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_label ("Unset size request");
   g_signal_connect (button,
                    "clicked",
                    G_CALLBACK (unset_size_request_callback),
                     control_window);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_check_button_new_with_label ("Allow resize");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
@@ -5082,7 +5067,7 @@ window_controls (GtkWidget *window)
                    "toggled",
                    G_CALLBACK (resizable_callback),
                     control_window);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_mnemonic ("_Show");
   g_signal_connect_object (button,
@@ -5090,7 +5075,7 @@ window_controls (GtkWidget *window)
                           G_CALLBACK (gtk_widget_show),
                           window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   button = gtk_button_new_with_mnemonic ("_Hide");
   g_signal_connect_object (button,
@@ -5098,7 +5083,7 @@ window_controls (GtkWidget *window)
                           G_CALLBACK (gtk_widget_hide),
                            window,
                           G_CONNECT_SWAPPED);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   gtk_widget_show (vbox);
 
@@ -5120,7 +5105,7 @@ create_window_sizing (GtkWidget *widget)
                              gtk_widget_get_display (widget));
       label = gtk_label_new (NULL);
       gtk_label_set_markup (GTK_LABEL (label), "<span foreground=\"purple\"><big>Window being 
resized</big></span>\nBlah blah blah blah\nblah blah blah\nblah blah blah blah blah");
-      gtk_container_add (GTK_CONTAINER (target_window), label);
+      gtk_box_append (GTK_BOX (target_window), label);
       gtk_widget_show (label);
 
       g_object_add_weak_pointer (G_OBJECT (target_window), (gpointer *)&target_window);
@@ -5331,10 +5316,10 @@ create_progress_bar (GtkWidget *widget)
       gtk_window_set_title (GTK_WINDOW (pdata->window), "GtkProgressBar");
 
       vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
-      gtk_container_add (GTK_CONTAINER (content_area), vbox);
+      gtk_box_append (GTK_BOX (content_area), vbox);
 
       frame = gtk_frame_new ("Progress");
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
       gtk_frame_set_child (GTK_FRAME (frame), vbox2);
@@ -5344,19 +5329,19 @@ create_progress_bar (GtkWidget *widget)
                                       PANGO_ELLIPSIZE_MIDDLE);
       gtk_widget_set_halign (pdata->pbar, GTK_ALIGN_CENTER);
       gtk_widget_set_valign (pdata->pbar, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox2), pdata->pbar);
+      gtk_box_append (GTK_BOX (vbox2), pdata->pbar);
 
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
       gtk_widget_set_halign (hbox, GTK_ALIGN_CENTER);
       gtk_widget_set_valign (hbox, GTK_ALIGN_CENTER);
-      gtk_container_add (GTK_CONTAINER (vbox2), hbox);
+      gtk_box_append (GTK_BOX (vbox2), hbox);
       label = gtk_label_new ("Label updated by user :");
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
       pdata->label = gtk_label_new ("");
-      gtk_container_add (GTK_CONTAINER (hbox), pdata->label);
+      gtk_box_append (GTK_BOX (hbox), pdata->label);
 
       frame = gtk_frame_new ("Options");
-      gtk_container_add (GTK_CONTAINER (vbox), frame);
+      gtk_box_append (GTK_BOX (vbox), frame);
 
       vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
       gtk_frame_set_child (GTK_FRAME (frame), vbox2);
@@ -5364,7 +5349,7 @@ create_progress_bar (GtkWidget *widget)
       grid = gtk_grid_new ();
       gtk_grid_set_row_spacing (GTK_GRID (grid), 10);
       gtk_grid_set_column_spacing (GTK_GRID (grid), 10);
-      gtk_container_add (GTK_CONTAINER (vbox2), grid);
+      gtk_box_append (GTK_BOX (vbox2), grid);
 
       label = gtk_label_new ("Orientation :");
       gtk_grid_attach (GTK_GRID (grid), label, 0, 0, 1, 1);
@@ -5393,14 +5378,14 @@ create_progress_bar (GtkWidget *widget)
       gtk_grid_attach (GTK_GRID (grid), hbox, 1, 2, 1, 1);
 
       label = gtk_label_new ("Text: ");
-      gtk_container_add (GTK_CONTAINER (hbox), label);
+      gtk_box_append (GTK_BOX (hbox), label);
 
       pdata->entry = gtk_entry_new ();
       gtk_widget_set_hexpand (pdata->entry, TRUE);
       g_signal_connect (pdata->entry, "changed",
                        G_CALLBACK (entry_changed),
                        pdata);
-      gtk_container_add (GTK_CONTAINER (hbox), pdata->entry);
+      gtk_box_append (GTK_BOX (hbox), pdata->entry);
       gtk_widget_set_size_request (pdata->entry, 100, -1);
 
       label = gtk_label_new ("Ellipsize text :");
@@ -5509,14 +5494,14 @@ create_timeout_test (GtkWidget *widget)
       gtk_widget_set_margin_end (label, 10);
       gtk_widget_set_margin_top (label, 10);
       gtk_widget_set_margin_bottom (label, 10);
-      gtk_container_add (GTK_CONTAINER (content_area), label);
+      gtk_box_append (GTK_BOX (content_area), label);
       gtk_widget_show (label);
 
       button = gtk_button_new_with_label ("close");
       g_signal_connect_swapped (button, "clicked",
                                G_CALLBACK (gtk_window_destroy),
                                window);
-      gtk_container_add (GTK_CONTAINER (action_area), button);
+      gtk_box_append (GTK_BOX (action_area), button);
       gtk_window_set_default_widget (GTK_WINDOW (window), button);
       gtk_widget_show (button);
 
@@ -5524,14 +5509,14 @@ create_timeout_test (GtkWidget *widget)
       g_signal_connect (button, "clicked",
                        G_CALLBACK(start_timeout_test),
                        label);
-      gtk_container_add (GTK_CONTAINER (action_area), button);
+      gtk_box_append (GTK_BOX (action_area), button);
       gtk_widget_show (button);
 
       button = gtk_button_new_with_label ("stop");
       g_signal_connect (button, "clicked",
                        G_CALLBACK (stop_timeout_test),
                        NULL);
-      gtk_container_add (GTK_CONTAINER (action_area), button);
+      gtk_box_append (GTK_BOX (action_area), button);
       gtk_widget_show (button);
     }
 
@@ -5819,7 +5804,7 @@ create_native_dialogs (GtkWidget *widget)
       gtk_window_set_child (GTK_WINDOW (window), box);
 
       label = gtk_label_new ("");
-      gtk_container_add (GTK_CONTAINER (box), label);
+      gtk_box_append (GTK_BOX (box), label);
 
       combo = gtk_combo_box_text_new ();
 
@@ -5832,7 +5817,7 @@ create_native_dialogs (GtkWidget *widget)
       g_signal_connect (combo, "changed",
                         G_CALLBACK (native_action_changed), native);
       gtk_combo_box_set_active (GTK_COMBO_BOX (combo), GTK_FILE_CHOOSER_ACTION_OPEN);
-      gtk_container_add (GTK_CONTAINER (box), combo);
+      gtk_box_append (GTK_BOX (box), combo);
 
       combo = gtk_combo_box_text_new ();
 
@@ -5843,24 +5828,24 @@ create_native_dialogs (GtkWidget *widget)
       g_signal_connect (combo, "changed",
                         G_CALLBACK (native_filter_changed), native);
       gtk_combo_box_set_active (GTK_COMBO_BOX (combo), 0);
-      gtk_container_add (GTK_CONTAINER (box), combo);
+      gtk_box_append (GTK_BOX (box), combo);
 
       check_button = gtk_check_button_new_with_label ("Modal");
       g_signal_connect (check_button, "toggled",
                         G_CALLBACK (native_modal_toggle), native);
-      gtk_container_add (GTK_CONTAINER (box), check_button);
+      gtk_box_append (GTK_BOX (box), check_button);
 
       check_button = gtk_check_button_new_with_label ("Multiple select");
       g_signal_connect (check_button, "toggled",
                         G_CALLBACK (native_multi_select_toggle), native);
-      gtk_container_add (GTK_CONTAINER (box), check_button);
+      gtk_box_append (GTK_BOX (box), check_button);
 
       show_button = gtk_button_new_with_label ("Show");
       hide_button = gtk_button_new_with_label ("Hide");
       gtk_widget_set_sensitive (hide_button, FALSE);
 
-      gtk_container_add (GTK_CONTAINER (box), show_button);
-      gtk_container_add (GTK_CONTAINER (box), hide_button);
+      gtk_box_append (GTK_BOX (box), show_button);
+      gtk_box_append (GTK_BOX (box), hide_button);
 
       /* connect signals */
       g_signal_connect (native, "response",
@@ -5987,7 +5972,7 @@ create_main_window (void)
             gtk_get_minor_version ());
 
   label = gtk_label_new (buffer);
-  gtk_container_add (GTK_CONTAINER (box1), label);
+  gtk_box_append (GTK_BOX (box1), label);
   gtk_widget_set_name (label, "testgtk-version-label");
 
   scrolled_window = gtk_scrolled_window_new (NULL, NULL);
@@ -5995,7 +5980,7 @@ create_main_window (void)
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window),
                                  GTK_POLICY_NEVER, 
                                   GTK_POLICY_AUTOMATIC);
-  gtk_container_add (GTK_CONTAINER (box1), scrolled_window);
+  gtk_box_append (GTK_BOX (box1), scrolled_window);
 
   box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolled_window), box2);
@@ -6012,20 +5997,20 @@ create_main_window (void)
                          NULL);
       else
         gtk_widget_set_sensitive (button, FALSE);
-      gtk_container_add (GTK_CONTAINER (box2), button);
+      gtk_box_append (GTK_BOX (box2), button);
     }
 
   separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-  gtk_container_add (GTK_CONTAINER (box1), separator);
+  gtk_box_append (GTK_BOX (box1), separator);
 
   box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
-  gtk_container_add (GTK_CONTAINER (box1), box2);
+  gtk_box_append (GTK_BOX (box1), box2);
 
   button = gtk_button_new_with_mnemonic ("_Close");
   g_signal_connect (button, "clicked",
                    G_CALLBACK (do_exit),
                    window);
-  gtk_container_add (GTK_CONTAINER (box2), button);
+  gtk_box_append (GTK_BOX (box2), button);
   gtk_window_set_default_widget (GTK_WINDOW (window), button);
 
   gtk_widget_show (window);
diff --git a/tests/testheaderbar.c b/tests/testheaderbar.c
index 1c1e7bd34b..ea59bf066e 100644
--- a/tests/testheaderbar.c
+++ b/tests/testheaderbar.c
@@ -85,11 +85,11 @@ change_header (GtkButton *button, gpointer data)
       gtk_widget_set_margin_top (header, 10);
       gtk_widget_set_margin_bottom (header, 10);
       label = gtk_label_new ("Label");
-      gtk_container_add (GTK_CONTAINER (header), label);
+      gtk_box_append (GTK_BOX (header), label);
       widget = gtk_level_bar_new ();
       gtk_level_bar_set_value (GTK_LEVEL_BAR (widget), 0.4);
       gtk_widget_set_hexpand (widget, TRUE);
-      gtk_container_add (GTK_CONTAINER (header), widget);
+      gtk_box_append (GTK_BOX (header), widget);
     }
   else
     {
@@ -144,7 +144,7 @@ main (int argc, char *argv[])
   content = gtk_image_new_from_icon_name ("start-here-symbolic");
   gtk_image_set_pixel_size (GTK_IMAGE (content), 512);
 
-  gtk_container_add (GTK_CONTAINER (box), content);
+  gtk_box_append (GTK_BOX (box), content);
 
   footer = gtk_action_bar_new ();
   gtk_action_bar_set_center_widget (GTK_ACTION_BAR (footer), gtk_check_button_new_with_label ("Middle"));
@@ -154,7 +154,7 @@ main (int argc, char *argv[])
   button = gtk_button_new_with_label ("Fullscreen");
   gtk_action_bar_pack_end (GTK_ACTION_BAR (footer), button);
   g_signal_connect (button, "clicked", G_CALLBACK (toggle_fullscreen), window);
-  gtk_container_add (GTK_CONTAINER (box), footer);
+  gtk_box_append (GTK_BOX (box), footer);
   gtk_widget_show (window);
 
   while (!done)
diff --git a/tests/testheightforwidth.c b/tests/testheightforwidth.c
index 41c62f24b6..8da01ba878 100644
--- a/tests/testheightforwidth.c
+++ b/tests/testheightforwidth.c
@@ -827,7 +827,7 @@ create_window (void)
       g_signal_connect (button, "clicked",
                         G_CALLBACK (test_clicked), &interfaces[i]);
 
-      gtk_container_add (GTK_CONTAINER (vbox), button);
+      gtk_box_append (GTK_BOX (vbox), button);
     }
 
   return window;
diff --git a/tests/testhover.c b/tests/testhover.c
index daf4c1cb07..e493155eef 100644
--- a/tests/testhover.c
+++ b/tests/testhover.c
@@ -85,8 +85,8 @@ enter1_cb (GtkEventController *controller)
 {
   GtkWidget *box = gtk_event_controller_get_widget (controller);
 
-  gtk_container_remove (GTK_CONTAINER (box), gtk_widget_get_first_child (box));
-  gtk_container_add (GTK_CONTAINER (box), gtk_label_new ("HOVER!"));
+  gtk_box_remove (GTK_BOX (box), gtk_widget_get_first_child (box));
+  gtk_box_append (GTK_BOX (box), gtk_label_new ("HOVER!"));
 }
 
 static void
@@ -94,8 +94,8 @@ leave1_cb (GtkEventController *controller)
 {
   GtkWidget *box = gtk_event_controller_get_widget (controller);
 
-  gtk_container_remove (GTK_CONTAINER (box), gtk_widget_get_first_child (box));
-  gtk_container_add (GTK_CONTAINER (box), gtk_image_new_from_icon_name ("start-here"));
+  gtk_box_remove (GTK_BOX (box), gtk_widget_get_first_child (box));
+  gtk_box_append (GTK_BOX (box), gtk_image_new_from_icon_name ("start-here"));
 }
 
 static void
@@ -115,7 +115,7 @@ test1 (void)
   g_signal_connect (controller, "leave", G_CALLBACK (leave1_cb), NULL);
   gtk_widget_add_controller (box, controller);
 
-  gtk_container_add (GTK_CONTAINER (box), gtk_image_new_from_icon_name ("start-here"));
+  gtk_box_append (GTK_BOX (box), gtk_image_new_from_icon_name ("start-here"));
 
   gtk_widget_show (win);
 
@@ -159,8 +159,8 @@ test2 (void)
   g_signal_connect (controller, "leave", G_CALLBACK (leave2_cb), NULL);
   gtk_widget_add_controller (box, controller);
 
-  gtk_container_add (GTK_CONTAINER (box), gtk_image_new_from_icon_name ("start-here"));
-  gtk_container_add (GTK_CONTAINER (box), gtk_label_new ("HOVER!"));
+  gtk_box_append (GTK_BOX (box), gtk_image_new_from_icon_name ("start-here"));
+  gtk_box_append (GTK_BOX (box), gtk_label_new ("HOVER!"));
   gtk_widget_hide (gtk_widget_get_last_child (box));
 
   gtk_widget_show (win);
diff --git a/tests/testiconview-keynav.c b/tests/testiconview-keynav.c
index 5c4dcdbac5..000304dc5d 100644
--- a/tests/testiconview-keynav.c
+++ b/tests/testiconview-keynav.c
@@ -254,10 +254,10 @@ main (int argc, char *argv[])
   g_signal_connect (views.view1, "notify::has-focus", G_CALLBACK (focus_changed), &views);
   g_signal_connect (views.view2, "notify::has-focus", G_CALLBACK (focus_changed), &views);
 
-  gtk_container_add (GTK_CONTAINER (vbox), views.header1);
-  gtk_container_add (GTK_CONTAINER (vbox), views.view1);
-  gtk_container_add (GTK_CONTAINER (vbox), views.header2);
-  gtk_container_add (GTK_CONTAINER (vbox), views.view2);
+  gtk_box_append (GTK_BOX (vbox), views.header1);
+  gtk_box_append (GTK_BOX (vbox), views.view1);
+  gtk_box_append (GTK_BOX (vbox), views.header2);
+  gtk_box_append (GTK_BOX (vbox), views.view2);
 
   gtk_widget_show (window);
 
diff --git a/tests/testiconview.c b/tests/testiconview.c
index 73018aa580..f56fe3f597 100644
--- a/tests/testiconview.c
+++ b/tests/testiconview.c
@@ -349,7 +349,7 @@ do_popup_menu (GtkWidget   *icon_list,
   g_object_set_data_full (G_OBJECT (menu), "item-path", data, (GDestroyNotify)free_item_data);
 
   item = gtk_button_new_with_label ("Activate");
-  gtk_container_add (GTK_CONTAINER (menu), item);
+  gtk_box_append (GTK_BOX (menu), item);
   g_signal_connect (item, "clicked", G_CALLBACK (item_cb), data);
 
   gtk_popover_popup (GTK_POPOVER (menu));
@@ -421,7 +421,7 @@ main (gint argc, gchar **argv)
 
   paned = gtk_paned_new (GTK_ORIENTATION_HORIZONTAL);
   gtk_widget_set_vexpand (paned, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), paned);
+  gtk_box_append (GTK_BOX (vbox), paned);
 
   icon_list = gtk_icon_view_new ();
   gtk_icon_view_set_selection_mode (GTK_ICON_VIEW (icon_list), GTK_SELECTION_MULTIPLE);
@@ -537,43 +537,43 @@ main (gint argc, gchar **argv)
 
   bbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_set_halign (bbox, GTK_ALIGN_START);
-  gtk_container_add (GTK_CONTAINER (vbox), bbox);
+  gtk_box_append (GTK_BOX (vbox), bbox);
 
   button = gtk_button_new_with_label ("Add some");
   g_signal_connect (button, "clicked", G_CALLBACK (add_some), icon_list);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   button = gtk_button_new_with_label ("Add many");
   g_signal_connect (button, "clicked", G_CALLBACK (add_many), icon_list);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   button = gtk_button_new_with_label ("Add large");
   g_signal_connect (button, "clicked", G_CALLBACK (add_large), icon_list);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   button = gtk_button_new_with_label ("Remove selected");
   g_signal_connect (button, "clicked", G_CALLBACK (foreach_selected_remove), icon_list);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   button = gtk_button_new_with_label ("Swap");
   g_signal_connect (button, "clicked", G_CALLBACK (swap_rows), icon_list);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   bbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_set_halign (bbox, GTK_ALIGN_START);
-  gtk_container_add (GTK_CONTAINER (vbox), bbox);
+  gtk_box_append (GTK_BOX (vbox), bbox);
 
   button = gtk_button_new_with_label ("Select all");
   g_signal_connect (button, "clicked", G_CALLBACK (select_all), icon_list);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   button = gtk_button_new_with_label ("Unselect all");
   g_signal_connect (button, "clicked", G_CALLBACK (unselect_all), icon_list);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   button = gtk_button_new_with_label ("Select nonexisting");
   g_signal_connect (button, "clicked", G_CALLBACK (select_nonexisting), icon_list);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   icon_list = gtk_icon_view_new ();
 
diff --git a/tests/testinfobar.c b/tests/testinfobar.c
index ee7ab749fb..a49403d1ff 100644
--- a/tests/testinfobar.c
+++ b/tests/testinfobar.c
@@ -43,21 +43,21 @@ on_activate (GApplication *application,
   g_object_bind_property (widget, "active",
                           info_bar, "visible",
                           G_BINDING_SYNC_CREATE | G_BINDING_BIDIRECTIONAL);
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
 
   widget = gtk_toggle_button_new_with_label ("Toggle :revealed");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), TRUE);
   g_object_bind_property (widget, "active",
                           info_bar, "revealed",
                           G_BINDING_SYNC_CREATE | G_BINDING_BIDIRECTIONAL);
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
 
   widget = gtk_toggle_button_new_with_label ("Toggle :show-close-button");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), TRUE);
   g_object_bind_property (widget, "active",
                           info_bar, "show-close-button",
                           G_BINDING_SYNC_CREATE | G_BINDING_BIDIRECTIONAL);
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
 
   widget = gtk_combo_box_text_new ();
   gtk_combo_box_text_append (GTK_COMBO_BOX_TEXT (widget),
@@ -74,9 +74,9 @@ on_activate (GApplication *application,
   g_object_bind_property (widget, "active",
                           info_bar, "message-type",
                           G_BINDING_SYNC_CREATE | G_BINDING_BIDIRECTIONAL);
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
 
-  gtk_container_add (GTK_CONTAINER (box), info_bar);
+  gtk_box_append (GTK_BOX (box), info_bar);
 
   widget = gtk_button_new_with_label ("Un-reveal");
   gtk_info_bar_add_action_widget (GTK_INFO_BAR (info_bar), widget,
diff --git a/tests/testinhibitshortcuts.c b/tests/testinhibitshortcuts.c
index abdf232569..967a3f0ed5 100644
--- a/tests/testinhibitshortcuts.c
+++ b/tests/testinhibitshortcuts.c
@@ -85,11 +85,11 @@ main (int argc, char *argv[])
   text_view = gtk_text_view_new ();
   gtk_widget_set_hexpand (text_view, TRUE);
   gtk_widget_set_vexpand (text_view, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), text_view);
+  gtk_box_append (GTK_BOX (vbox), text_view);
 
   button = gtk_check_button_new_with_label ("Inhibit system keyboard shorcuts");
 
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (G_OBJECT (button), "toggled",
                     G_CALLBACK (on_button_toggle), surface);
 
diff --git a/tests/testlevelbar.c b/tests/testlevelbar.c
index e9fd02df91..5a79ec66ef 100644
--- a/tests/testlevelbar.c
+++ b/tests/testlevelbar.c
@@ -98,12 +98,12 @@ main (int argc, char *argv[])
   gtk_widget_set_margin_bottom (box, 20);
   bar = create_level_bar ();
   gtk_window_set_child (GTK_WINDOW (window), box);
-  gtk_container_add (GTK_CONTAINER (box), bar);
+  gtk_box_append (GTK_BOX (box), bar);
   box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (box), box2);
-  gtk_container_add (GTK_CONTAINER (box2), gtk_label_new ("Discrete"));
+  gtk_box_append (GTK_BOX (box), box2);
+  gtk_box_append (GTK_BOX (box2), gtk_label_new ("Discrete"));
   sw = gtk_switch_new ();
-  gtk_container_add (GTK_CONTAINER (box2), sw);
+  gtk_box_append (GTK_BOX (box2), sw);
   g_signal_connect (sw, "notify::active", G_CALLBACK (toggle), bar);
 
   gtk_widget_show (window);
diff --git a/tests/testlist.c b/tests/testlist.c
index 6fe9566342..a78b23fc2c 100644
--- a/tests/testlist.c
+++ b/tests/testlist.c
@@ -64,7 +64,6 @@ static void
 update_header_cb (Row *row, Row *before, gpointer data)
 {
   GtkWidget *hbox, *l, *b;
-  GList *children;
 
   if (before == NULL ||
       (row->label != NULL &&
@@ -75,9 +74,9 @@ update_header_cb (Row *row, Row *before, gpointer data)
         {
           hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
           l = gtk_label_new ("Header");
-          gtk_container_add (GTK_CONTAINER (hbox), l);
+          gtk_box_append (GTK_BOX (hbox), l);
           b = gtk_button_new_with_label ("button");
-          gtk_container_add (GTK_CONTAINER (hbox), b);
+          gtk_box_append (GTK_BOX (hbox), b);
           gtk_widget_show (l);
           gtk_widget_show (b);
           gtk_list_box_row_set_header (GTK_LIST_BOX_ROW (row), hbox);
@@ -85,9 +84,7 @@ update_header_cb (Row *row, Row *before, gpointer data)
 
       hbox = gtk_list_box_row_get_header(GTK_LIST_BOX_ROW (row));
 
-      children = gtk_container_get_children (GTK_CONTAINER (hbox));
-      l = children->data;
-      g_list_free (children);
+      l = gtk_widget_get_first_child (hbox);
       gtk_label_set_text (GTK_LABEL (l), g_strdup_printf ("Header %d", row->sort_id));
     }
   else
@@ -271,7 +268,7 @@ main (int argc, char *argv[])
   list = gtk_list_box_new ();
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
 
   combo = gtk_combo_box_text_new ();
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo),
@@ -281,17 +278,17 @@ main (int argc, char *argv[])
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo),
                                   "GTK_SELECTION_BROWSE");
   g_signal_connect (combo, "changed", G_CALLBACK (selection_mode_changed), list);
-  gtk_container_add (GTK_CONTAINER (vbox), combo);
+  gtk_box_append (GTK_BOX (vbox), combo);
   gtk_combo_box_set_active (GTK_COMBO_BOX (combo), gtk_list_box_get_selection_mode (GTK_LIST_BOX (list)));
   check = gtk_check_button_new_with_label ("single click mode");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check), gtk_list_box_get_activate_on_single_click 
(GTK_LIST_BOX (list)));
   g_signal_connect (check, "toggled", G_CALLBACK (single_click_clicked), list);
-  gtk_container_add (GTK_CONTAINER (vbox), check);
+  gtk_box_append (GTK_BOX (vbox), check);
 
   scrolled = gtk_scrolled_window_new (NULL, NULL);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled), GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolled), list);
-  gtk_container_add (GTK_CONTAINER (hbox), scrolled);
+  gtk_box_append (GTK_BOX (hbox), scrolled);
 
   g_signal_connect (list, "row-activated", G_CALLBACK (row_activated_cb), NULL);
   g_signal_connect (list, "row-selected", G_CALLBACK (row_selected_cb), NULL);
@@ -309,14 +306,14 @@ main (int argc, char *argv[])
   row_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   row_hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   l = gtk_label_new ("da box for da man");
-  gtk_container_add (GTK_CONTAINER (row_hbox), l);
+  gtk_box_append (GTK_BOX (row_hbox), l);
   check = gtk_check_button_new ();
-  gtk_container_add (GTK_CONTAINER (row_hbox), check);
+  gtk_box_append (GTK_BOX (row_hbox), check);
   button = gtk_button_new_with_label ("ya!");
-  gtk_container_add (GTK_CONTAINER (row_hbox), button);
-  gtk_container_add (GTK_CONTAINER (row_vbox), row_hbox);
+  gtk_box_append (GTK_BOX (row_hbox), button);
+  gtk_box_append (GTK_BOX (row_vbox), row_hbox);
   check = gtk_check_button_new ();
-  gtk_container_add (GTK_CONTAINER (row_vbox), check);
+  gtk_box_append (GTK_BOX (row_vbox), check);
   gtk_list_box_row_set_child (GTK_LIST_BOX_ROW (row), row_vbox);
   gtk_list_box_insert (GTK_LIST_BOX (list), row, -1);
 
@@ -328,42 +325,42 @@ main (int argc, char *argv[])
   gtk_list_box_insert (GTK_LIST_BOX (list), row, -1);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
 
   button = gtk_button_new_with_label ("sort");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (sort_clicked_cb), list);
 
   button = gtk_button_new_with_label ("reverse");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (reverse_sort_clicked_cb), list);
 
   button = gtk_button_new_with_label ("change");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (change_clicked_cb), row3);
 
   button = gtk_button_new_with_label ("filter");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (filter_clicked_cb), list);
 
   button = gtk_button_new_with_label ("unfilter");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (unfilter_clicked_cb), list);
 
   button = gtk_button_new_with_label ("add");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (add_clicked_cb), list);
 
   button = gtk_button_new_with_label ("separate");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (separate_clicked_cb), list);
 
   button = gtk_button_new_with_label ("unseparate");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (unseparate_clicked_cb), list);
 
   button = gtk_button_new_with_label ("visibility");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked", G_CALLBACK (visibility_clicked_cb), row3);
 
   gtk_widget_show (window);
diff --git a/tests/testlist2.c b/tests/testlist2.c
index f44a2be23a..85303b319f 100644
--- a/tests/testlist2.c
+++ b/tests/testlist2.c
@@ -21,10 +21,10 @@ remove_this_row (GtkButton *button, GtkWidget *child)
   gtk_revealer_set_reveal_child (GTK_REVEALER (revealer), TRUE);
   gtk_widget_show (revealer);
   g_object_ref (child);
-  gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (child)), child);
+  gtk_box_remove (GTK_BOX (gtk_widget_get_parent (child)), child);
   gtk_revealer_set_child (GTK_REVEALER (revealer), child);
   g_object_unref (child);
-  gtk_container_add (GTK_CONTAINER (row), revealer);
+  gtk_box_append (GTK_BOX (row), revealer);
   g_signal_connect (revealer, "notify::child-revealed",
                     G_CALLBACK (row_unrevealed), NULL);
   gtk_revealer_set_reveal_child (GTK_REVEALER (revealer), FALSE);
@@ -41,8 +41,9 @@ row_revealed (GObject *revealer, GParamSpec *pspec, gpointer data)
   child = gtk_revealer_get_child (GTK_REVEALER (revealer));
   g_object_ref (child);
   gtk_revealer_set_child (GTK_REVEALER (revealer), NULL);
+
   gtk_widget_unparent (GTK_WIDGET (revealer));
-  gtk_container_add (GTK_CONTAINER (row), child);
+  gtk_box_append (GTK_BOX (row), child);
   g_object_unref (child);
 }
 
@@ -80,16 +81,16 @@ create_row (const gchar *text)
 
   row = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
   label = gtk_label_new (text);
-  gtk_container_add (GTK_CONTAINER (row), label);
+  gtk_box_append (GTK_BOX (row), label);
   button = gtk_button_new_with_label ("x");
   gtk_widget_set_hexpand (button, TRUE);
   gtk_widget_set_halign (button, GTK_ALIGN_END);
   gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (row), button);
+  gtk_box_append (GTK_BOX (row), button);
   g_signal_connect (button, "clicked", G_CALLBACK (remove_this_row), row);
   button = gtk_button_new_with_label ("+");
   gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (row), button);
+  gtk_box_append (GTK_BOX (row), button);
   g_signal_connect (button, "clicked", G_CALLBACK (add_row_below), row);
 
   return row;
diff --git a/tests/testlist3.c b/tests/testlist3.c
index b067a5b42c..e3940a2c46 100644
--- a/tests/testlist3.c
+++ b/tests/testlist3.c
@@ -49,7 +49,7 @@ drag_drop (GtkDropTarget *dest,
     return FALSE;
 
   g_object_ref (source);
-  gtk_container_remove (GTK_CONTAINER (gtk_widget_get_parent (source)), source);
+  gtk_box_remove (GTK_BOX (gtk_widget_get_parent (source)), source);
   gtk_list_box_insert (GTK_LIST_BOX (gtk_widget_get_parent (target)), source, pos);
   g_object_unref (source);
 
@@ -70,8 +70,8 @@ create_row (const gchar *text)
   label = gtk_label_new (text);
   gtk_list_box_row_set_child (GTK_LIST_BOX_ROW (row), box);
   gtk_widget_set_hexpand (label, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), label);
-  gtk_container_add (GTK_CONTAINER (box), image);
+  gtk_box_append (GTK_BOX (box), label);
+  gtk_box_append (GTK_BOX (box), image);
 
   source = gtk_drag_source_new ();
   gtk_drag_source_set_actions (source, GDK_ACTION_MOVE);
@@ -145,7 +145,7 @@ main (int argc, char *argv[])
   gtk_widget_set_margin_end (vbox, 12);
   gtk_widget_set_margin_top (vbox, 12);
   gtk_widget_set_margin_bottom (vbox, 12);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
 
   list = gtk_list_box_new ();
   gtk_list_box_set_selection_mode (GTK_LIST_BOX (list), GTK_SELECTION_NONE);
@@ -157,14 +157,14 @@ main (int argc, char *argv[])
   sw = gtk_scrolled_window_new (NULL, NULL);
   gtk_widget_set_hexpand (sw, TRUE);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw), GTK_POLICY_NEVER, GTK_POLICY_ALWAYS);
-  gtk_container_add (GTK_CONTAINER (hbox), sw);
+  gtk_box_append (GTK_BOX (hbox), sw);
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), list);
 
   button = gtk_check_button_new_with_label ("Activate on single click");
   g_object_bind_property (list, "activate-on-single-click",
                           button, "active",
                           G_BINDING_BIDIRECTIONAL | G_BINDING_SYNC_CREATE);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   combo = gtk_combo_box_text_new ();
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo), "None");
@@ -172,7 +172,7 @@ main (int argc, char *argv[])
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo), "Browse");
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo), "Multiple");
   g_signal_connect (combo, "changed", G_CALLBACK (selection_mode_changed), list);
-  gtk_container_add (GTK_CONTAINER (vbox), combo);
+  gtk_box_append (GTK_BOX (vbox), combo);
   gtk_combo_box_set_active (GTK_COMBO_BOX (combo), gtk_list_box_get_selection_mode (GTK_LIST_BOX (list)));
 
   for (i = 0; i < 20; i++)
diff --git a/tests/testlist4.c b/tests/testlist4.c
index d820d58b52..bae109f989 100644
--- a/tests/testlist4.c
+++ b/tests/testlist4.c
@@ -79,7 +79,7 @@ create_row (const gchar *text)
   row_content = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
 
   label = gtk_label_new (text);
-  gtk_container_add (GTK_CONTAINER (row_content), label);
+  gtk_box_append (GTK_BOX (row_content), label);
 
   return row_content;
 }
diff --git a/tests/testlockbutton.c b/tests/testlockbutton.c
index da37f6c897..9832bb53cf 100644
--- a/tests/testlockbutton.c
+++ b/tests/testlockbutton.c
@@ -230,15 +230,15 @@ main (int argc, char *argv[])
   gtk_window_set_child (GTK_WINDOW (window), box);
 
   allowed_button = gtk_check_button_new_with_label ("Allowed");
-  gtk_container_add (GTK_CONTAINER (box), allowed_button);
+  gtk_box_append (GTK_BOX (box), allowed_button);
   can_acquire_button = gtk_check_button_new_with_label ("Can acquire");
-  gtk_container_add (GTK_CONTAINER (box), can_acquire_button);
+  gtk_box_append (GTK_BOX (box), can_acquire_button);
   can_release_button = gtk_check_button_new_with_label ("Can release");
-  gtk_container_add (GTK_CONTAINER (box), can_release_button);
+  gtk_box_append (GTK_BOX (box), can_release_button);
   success_button = gtk_check_button_new_with_label ("Will succeed");
-  gtk_container_add (GTK_CONTAINER (box), success_button);
+  gtk_box_append (GTK_BOX (box), success_button);
   update = gtk_button_new_with_label ("Update");
-  gtk_container_add (GTK_CONTAINER (box), update);
+  gtk_box_append (GTK_BOX (box), update);
   g_signal_connect (permission, "notify",
                     G_CALLBACK (permission_changed), NULL);
 
@@ -254,12 +254,12 @@ main (int argc, char *argv[])
   gtk_window_set_resizable (GTK_WINDOW (dialog), FALSE);
 
   content = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
-  gtk_container_add (GTK_CONTAINER (content), gtk_check_button_new_with_label ("Control 1"));
-  gtk_container_add (GTK_CONTAINER (content), gtk_check_button_new_with_label ("Control 2"));
+  gtk_box_append (GTK_BOX (content), gtk_check_button_new_with_label ("Control 1"));
+  gtk_box_append (GTK_BOX (content), gtk_check_button_new_with_label ("Control 2"));
   gtk_widget_set_sensitive (content, FALSE);
 
-  gtk_container_add (GTK_CONTAINER (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), content);
-  gtk_container_add (GTK_CONTAINER (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), button);
+  gtk_box_append (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), content);
+  gtk_box_append (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))), button);
 
   gtk_widget_show (window);
   gtk_widget_show (dialog);
diff --git a/tests/testlogout.c b/tests/testlogout.c
index 8aa3d1a5cc..e975fe69ec 100644
--- a/tests/testlogout.c
+++ b/tests/testlogout.c
@@ -92,7 +92,7 @@ activate (GtkApplication *app,
   gtk_grid_set_row_spacing (GTK_GRID (grid), 6);
   gtk_grid_set_column_spacing (GTK_GRID (grid), 6);
 
-  gtk_container_add (GTK_CONTAINER (box), grid);
+  gtk_box_append (GTK_BOX (box), grid);
 
   label = gtk_label_new ("Inhibitor");
   gtk_grid_attach (GTK_GRID (grid), label, 0, 0, 1, 1);
@@ -121,7 +121,7 @@ activate (GtkApplication *app,
   gtk_grid_attach (GTK_GRID (grid), button, 2, 6, 1, 1);
 
   separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
-  gtk_container_add (GTK_CONTAINER (box), separator);
+  gtk_box_append (GTK_BOX (box), separator);
 
   grid = gtk_grid_new ();
   gtk_grid_set_row_spacing (GTK_GRID (grid), 6);
diff --git a/tests/testmodelbutton.c b/tests/testmodelbutton.c
index 523de0db26..3bf057648b 100644
--- a/tests/testmodelbutton.c
+++ b/tests/testmodelbutton.c
@@ -52,7 +52,7 @@ on_application_activate (GApplication *gapplication,
                                "text", "It’s-a-me! ModelButton",
                                "icon", gicon,
                                NULL);
-  gtk_container_add (GTK_CONTAINER (box), model_button);
+  gtk_box_append (GTK_BOX (box), model_button);
 
   g_object_unref (gicon);
 
@@ -67,16 +67,16 @@ on_application_activate (GApplication *gapplication,
   g_object_bind_property (widget, "active",
                           model_button, "role",
                           G_BINDING_SYNC_CREATE | G_BINDING_BIDIRECTIONAL);
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
 
   widget = gtk_toggle_button_new_with_label (":iconic");
   g_object_bind_property (widget, "active",
                           model_button, "iconic",
                           G_BINDING_SYNC_CREATE | G_BINDING_BIDIRECTIONAL);
-  gtk_container_add (GTK_CONTAINER (box), widget);
+  gtk_box_append (GTK_BOX (box), widget);
 
   widget = gtk_window_new ();
-  gtk_container_add (GTK_CONTAINER (widget), box);
+  gtk_box_append (GTK_BOX (widget), box);
   gtk_widget_show (widget);
   gtk_application_add_window (GTK_APPLICATION (application), GTK_WINDOW (widget));
 }
diff --git a/tests/testnotebookdnd.c b/tests/testnotebookdnd.c
index b55028299b..dc6c6b2b15 100644
--- a/tests/testnotebookdnd.c
+++ b/tests/testnotebookdnd.c
@@ -96,7 +96,7 @@ remove_in_idle (gpointer data)
 
   tab_label = gtk_notebook_get_tab_label (GTK_NOTEBOOK (parent), child);
   g_print ("Removing tab: %s\n", gtk_label_get_text (GTK_LABEL (tab_label)));
-  gtk_container_remove (GTK_CONTAINER (parent), child);
+  gtk_box_remove (GTK_BOX (parent), child);
 
   return G_SOURCE_REMOVE;
 }
@@ -202,13 +202,13 @@ create_notebook_non_dragable_content (const char      **labels,
       /* Use GtkListBox since it bubbles up motion notify event, which can
        * experience more issues than GtkBox. */
       page = gtk_list_box_new ();
-      gtk_container_add (GTK_CONTAINER (page), button);
+      gtk_box_append (GTK_BOX (page), button);
 
       button = gtk_button_new_with_label ("row 2");
-      gtk_container_add (GTK_CONTAINER (page), button);
+      gtk_box_append (GTK_BOX (page), button);
 
       button = gtk_button_new_with_label ("third row");
-      gtk_container_add (GTK_CONTAINER (page), button);
+      gtk_box_append (GTK_BOX (page), button);
 
       title = gtk_label_new (*labels);
 
diff --git a/tests/testorientable.c b/tests/testorientable.c
index 0ffa5b184c..6354d158c7 100644
--- a/tests/testorientable.c
+++ b/tests/testorientable.c
@@ -74,11 +74,11 @@ main (int argc, char **argv)
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
   orientables = g_list_prepend (orientables, box);
   gtk_grid_attach (GTK_GRID (grid), box, 0, 1, 1, 1);
-  gtk_container_add (GTK_CONTAINER (box),
+  gtk_box_append (GTK_BOX (box),
                   gtk_button_new_with_label ("GtkBox 1"));
-  gtk_container_add (GTK_CONTAINER (box),
+  gtk_box_append (GTK_BOX (box),
                   gtk_button_new_with_label ("GtkBox 2"));
-  gtk_container_add (GTK_CONTAINER (box),
+  gtk_box_append (GTK_BOX (box),
                   gtk_button_new_with_label ("GtkBox 3"));
 
   /* GtkSeparator */
diff --git a/tests/testoutsetshadowdrawing.c b/tests/testoutsetshadowdrawing.c
index 49ee0d12f9..9056ed855c 100644
--- a/tests/testoutsetshadowdrawing.c
+++ b/tests/testoutsetshadowdrawing.c
@@ -116,52 +116,52 @@ main (int argc, char **argv)
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "one");
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "two");
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "three");
   gtk_widget_set_opacity (w, 0.7);
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "four");
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "five");
-  gtk_container_add (GTK_CONTAINER (top), w);
+  gtk_box_append (GTK_BOX (top), w);
 
   /* Bottom */
   w = gtk_button_new ();
   gtk_widget_set_valign (w, GTK_ALIGN_CENTER);
   gtk_widget_add_css_class (w, "b1");
-  gtk_container_add (GTK_CONTAINER (bottom), w);
+  gtk_box_append (GTK_BOX (bottom), w);
 
   /*w = gtk_button_new ();*/
   /*gtk_widget_set_valign (w, GTK_ALIGN_CENTER);*/
   /*gtk_widget_add_css_class (w, "b2");*/
-  /*gtk_container_add (GTK_CONTAINER (bottom), w);*/
+  /*gtk_box_append (GTK_BOX (bottom), w);*/
 
   /*w = gtk_button_new ();*/
   /*gtk_widget_set_valign (w, GTK_ALIGN_CENTER);*/
   /*gtk_widget_add_css_class (w, "b3");*/
-  /*gtk_container_add (GTK_CONTAINER (bottom), w);*/
+  /*gtk_box_append (GTK_BOX (bottom), w);*/
 
   /*w = gtk_button_new ();*/
   /*gtk_widget_set_valign (w, GTK_ALIGN_CENTER);*/
   /*gtk_widget_add_css_class (w, "b4");*/
-  /*gtk_container_add (GTK_CONTAINER (bottom), w);*/
+  /*gtk_box_append (GTK_BOX (bottom), w);*/
 
-  gtk_container_add (GTK_CONTAINER (box), top);
-  gtk_container_add (GTK_CONTAINER (box), bottom);
+  gtk_box_append (GTK_BOX (box), top);
+  gtk_box_append (GTK_BOX (box), bottom);
   gtk_window_set_child (GTK_WINDOW (window), box);
   g_signal_connect (window, "destroy", G_CALLBACK (quit_cb), &done);
   gtk_widget_show (window);
diff --git a/tests/testoverlay.c b/tests/testoverlay.c
index 565adf549c..f8d6065e13 100644
--- a/tests/testoverlay.c
+++ b/tests/testoverlay.c
@@ -442,7 +442,7 @@ test_stacking (void)
 
   check2 = gtk_check_button_new_with_label ("Show overlay");
   g_object_bind_property (child, "visible", check2, "active", G_BINDING_BIDIRECTIONAL);
-  gtk_container_add (GTK_CONTAINER (main_child), label);
+  gtk_box_append (GTK_BOX (main_child), label);
   gtk_overlay_set_child (GTK_OVERLAY (overlay), main_child);
   gtk_overlay_add_overlay (GTK_OVERLAY (overlay), child);
   gtk_grid_attach (GTK_GRID (grid), overlay, 1, 0, 1, 3);
@@ -497,12 +497,12 @@ test_input_stacking (void)
                         "But the entry does");
   gtk_widget_set_margin_top (label, 8);
   gtk_widget_set_margin_bottom (label, 8);
-  gtk_container_add (GTK_CONTAINER (vbox), label);
+  gtk_box_append (GTK_BOX (vbox), label);
 
   entry = gtk_entry_new ();
   gtk_widget_set_margin_top (entry, 8);
   gtk_widget_set_margin_bottom (entry, 8);
-  gtk_container_add (GTK_CONTAINER (vbox), entry);
+  gtk_box_append (GTK_BOX (vbox), entry);
 
 
   gtk_window_set_child (GTK_WINDOW (win), overlay);
diff --git a/tests/testoverlaystyleclass.c b/tests/testoverlaystyleclass.c
index e0de538221..c77e2a94f5 100644
--- a/tests/testoverlaystyleclass.c
+++ b/tests/testoverlaystyleclass.c
@@ -66,7 +66,7 @@ main (int argc, char *argv[])
   label = gtk_label_new ("Main child");
   gtk_widget_set_halign (label, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (main_child), label);
+  gtk_box_append (GTK_BOX (main_child), label);
 
   child = gtk_label_new (NULL);
   str = g_strdup_printf ("%p", child);
diff --git a/tests/testpixbuf-scale.c b/tests/testpixbuf-scale.c
index eef877a2c1..2a67078858 100644
--- a/tests/testpixbuf-scale.c
+++ b/tests/testpixbuf-scale.c
@@ -120,13 +120,13 @@ main(int argc, char **argv)
                           NULL);
 
         gtk_widget_set_halign (combo_box, GTK_ALIGN_START);
-       gtk_container_add (GTK_CONTAINER (vbox), combo_box);
+       gtk_box_append (GTK_BOX (vbox), combo_box);
 
        hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
-       gtk_container_add (GTK_CONTAINER (vbox), hbox);
+       gtk_box_append (GTK_BOX (vbox), hbox);
 
        label = gtk_label_new ("Overall Alpha:");
-       gtk_container_add (GTK_CONTAINER (hbox), label);
+       gtk_box_append (GTK_BOX (hbox), label);
 
        adjustment = gtk_adjustment_new (overall_alpha, 0, 255, 1, 10, 0);
        g_signal_connect (adjustment, "value_changed",
@@ -135,7 +135,7 @@ main(int argc, char **argv)
        hscale = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL, adjustment);
        gtk_scale_set_digits (GTK_SCALE (hscale), 0);
         gtk_widget_set_hexpand (hscale, TRUE);
-       gtk_container_add (GTK_CONTAINER (hbox), hscale);
+       gtk_box_append (GTK_BOX (hbox), hscale);
 
        /* Compute the size without the drawing area, so we know how big to make the default size */
         gtk_widget_get_preferred_size ( (vbox),
@@ -143,7 +143,7 @@ main(int argc, char **argv)
 
        darea = gtk_drawing_area_new ();
         gtk_widget_set_hexpand (darea, TRUE);
-       gtk_container_add (GTK_CONTAINER (vbox), darea);
+       gtk_box_append (GTK_BOX (vbox), darea);
 
         gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (darea), draw_func, NULL, NULL);
 
diff --git a/tests/testpopover.c b/tests/testpopover.c
index be9a38fe19..6f62ca9f01 100644
--- a/tests/testpopover.c
+++ b/tests/testpopover.c
@@ -106,11 +106,11 @@ main (int argc, char *argv[])
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
   button = gtk_menu_button_new ();
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
   button1 = gtk_menu_button_new ();
-  gtk_container_add (GTK_CONTAINER (box), button1);
+  gtk_box_append (GTK_BOX (box), button1);
   button2 = gtk_menu_button_new ();
-  gtk_container_add (GTK_CONTAINER (box), button2);
+  gtk_box_append (GTK_BOX (box), button2);
 
   gtk_menu_button_set_menu_model (GTK_MENU_BUTTON (button), model);
   popover = GTK_WIDGET (gtk_menu_button_get_popover (GTK_MENU_BUTTON (button)));
diff --git a/tests/testrevealer2.c b/tests/testrevealer2.c
index 577254ff61..d058451a39 100644
--- a/tests/testrevealer2.c
+++ b/tests/testrevealer2.c
@@ -39,7 +39,7 @@ on_activate (GApplication *app,
       revealer = gtk_revealer_new ();
       gtk_revealer_set_transition_type (GTK_REVEALER (revealer),
                                         GTK_REVEALER_TRANSITION_TYPE_SLIDE_LEFT);
-      gtk_container_add (GTK_CONTAINER (hbox), revealer);
+      gtk_box_append (GTK_BOX (hbox), revealer);
 
       sidebar = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
       gtk_widget_set_size_request (sidebar, 150, -1);
@@ -53,7 +53,7 @@ on_activate (GApplication *app,
                          "halign", GTK_ALIGN_CENTER,
                          "valign", GTK_ALIGN_CENTER,
                          NULL);
-      gtk_container_add (GTK_CONTAINER (hbox), img);
+      gtk_box_append (GTK_BOX (hbox), img);
 
       g_object_bind_property (sidebar_toggle, "active",
                               revealer, "reveal-child",
diff --git a/tests/testscale.c b/tests/testscale.c
index 797f77d8da..86e9b47da2 100644
--- a/tests/testscale.c
+++ b/tests/testscale.c
@@ -135,7 +135,7 @@ int main (int argc, char *argv[])
   flipbox = box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
   gtk_widget_set_hexpand (flipbox, TRUE);
   gtk_widget_set_vexpand (flipbox, TRUE);
-  gtk_container_add (GTK_CONTAINER (box1), box);
+  gtk_box_append (GTK_BOX (box1), box);
   gtk_window_set_child (GTK_WINDOW (window), box1);
 
   frame = gtk_frame_new ("No marks");
@@ -143,7 +143,7 @@ int main (int argc, char *argv[])
   scales = g_slist_prepend (scales, scale);
   gtk_scale_set_draw_value (GTK_SCALE (scale), FALSE);
   gtk_frame_set_child (GTK_FRAME (frame), scale);
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
 
   frame = gtk_frame_new ("With fill level");
   scale = gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0, 100, 1);
@@ -152,7 +152,7 @@ int main (int argc, char *argv[])
   gtk_range_set_show_fill_level (GTK_RANGE (scale), TRUE);
   gtk_range_set_fill_level (GTK_RANGE (scale), 50);
   gtk_frame_set_child (GTK_FRAME (frame), scale);
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
 
   frame = gtk_frame_new ("Simple marks");
   extra_scale = scale = gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0, 100, 1);
@@ -162,7 +162,7 @@ int main (int argc, char *argv[])
   gtk_scale_add_mark (GTK_SCALE (scale), marks[1], GTK_POS_BOTTOM, NULL);
   gtk_scale_add_mark (GTK_SCALE (scale), marks[2], GTK_POS_BOTTOM, NULL);
   gtk_frame_set_child (GTK_FRAME (frame), scale);
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
 
   frame = gtk_frame_new ("Simple marks up");
   scale = gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0, 100, 1);
@@ -172,7 +172,7 @@ int main (int argc, char *argv[])
   gtk_scale_add_mark (GTK_SCALE (scale), marks[1], GTK_POS_TOP, NULL);
   gtk_scale_add_mark (GTK_SCALE (scale), marks[2], GTK_POS_TOP, NULL);
   gtk_frame_set_child (GTK_FRAME (frame), scale);
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
 
   frame = gtk_frame_new ("Labeled marks");
   box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
@@ -184,7 +184,7 @@ int main (int argc, char *argv[])
   gtk_scale_add_mark (GTK_SCALE (scale), marks[1], GTK_POS_BOTTOM, labels[1]);
   gtk_scale_add_mark (GTK_SCALE (scale), marks[2], GTK_POS_BOTTOM, labels[2]);
   gtk_frame_set_child (GTK_FRAME (frame), scale);
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
 
   frame = gtk_frame_new ("Some labels");
   scale = gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0, 100, 1);
@@ -194,7 +194,7 @@ int main (int argc, char *argv[])
   gtk_scale_add_mark (GTK_SCALE (scale), marks[1], GTK_POS_TOP, NULL);
   gtk_scale_add_mark (GTK_SCALE (scale), marks[2], GTK_POS_TOP, labels[2]);
   gtk_frame_set_child (GTK_FRAME (frame), scale);
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
 
   frame = gtk_frame_new ("Above and below");
   scale = gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0, 100, 1);
@@ -205,7 +205,7 @@ int main (int argc, char *argv[])
   gtk_scale_add_mark (GTK_SCALE (scale), bath_marks[2], GTK_POS_BOTTOM, bath_labels[2]);
   gtk_scale_add_mark (GTK_SCALE (scale), bath_marks[3], GTK_POS_TOP, bath_labels[3]);
   gtk_frame_set_child (GTK_FRAME (frame), scale);
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
 
   frame = gtk_frame_new ("Positions");
   scale = gtk_scale_new_with_range (GTK_ORIENTATION_HORIZONTAL, 0, 100, 1);
@@ -216,28 +216,28 @@ int main (int argc, char *argv[])
   gtk_scale_add_mark (GTK_SCALE (scale), pos_marks[2], GTK_POS_TOP, pos_labels[2]);
   gtk_scale_add_mark (GTK_SCALE (scale), pos_marks[3], GTK_POS_BOTTOM, pos_labels[3]);
   gtk_frame_set_child (GTK_FRAME (frame), scale);
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
 
   box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
-  gtk_container_add (GTK_CONTAINER (box1), box2);
+  gtk_box_append (GTK_BOX (box1), box2);
   button = gtk_button_new_with_label ("Flip");
   g_signal_connect (button, "clicked", G_CALLBACK (flip), NULL);
-  gtk_container_add (GTK_CONTAINER (box2), button);
+  gtk_box_append (GTK_BOX (box2), button);
 
   button = gtk_button_new_with_label ("Invert");
   g_signal_connect (button, "clicked", G_CALLBACK (invert), NULL);
-  gtk_container_add (GTK_CONTAINER (box2), button);
+  gtk_box_append (GTK_BOX (box2), button);
 
   button = gtk_toggle_button_new_with_label ("Trough");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), TRUE);
   g_signal_connect (button, "toggled", G_CALLBACK (trough), NULL);
-  gtk_container_add (GTK_CONTAINER (box2), button);
+  gtk_box_append (GTK_BOX (box2), button);
   gtk_widget_show (window);
 
   button = gtk_toggle_button_new_with_label ("Extra");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button), FALSE);
   g_signal_connect (button, "toggled", G_CALLBACK (extra), NULL);
-  gtk_container_add (GTK_CONTAINER (box2), button);
+  gtk_box_append (GTK_BOX (box2), button);
   gtk_widget_show (window);
 
   while (!done)
diff --git a/tests/testscrolledge.c b/tests/testscrolledge.c
index 150d6fa936..1e1c45c065 100644
--- a/tests/testscrolledge.c
+++ b/tests/testscrolledge.c
@@ -114,8 +114,8 @@ main (int argc, char *argv[])
   gtk_widget_set_margin_bottom (popup, 40);
   label = gtk_label_new ("Getting more rows...");
   spinner = gtk_spinner_new ();
-  gtk_container_add (GTK_CONTAINER (popup), label);
-  gtk_container_add (GTK_CONTAINER (popup), spinner);
+  gtk_box_append (GTK_BOX (popup), label);
+  gtk_box_append (GTK_BOX (popup), spinner);
 
   gtk_overlay_add_overlay (GTK_OVERLAY (overlay), popup);
   gtk_widget_hide (popup);
diff --git a/tests/testscrolledwindow.c b/tests/testscrolledwindow.c
index 24844ce91c..ceb4b742c7 100644
--- a/tests/testscrolledwindow.c
+++ b/tests/testscrolledwindow.c
@@ -86,11 +86,11 @@ scrollable_policy (void)
   gtk_widget_show (vbox);
   gtk_widget_show (hbox);
   gtk_window_set_child (GTK_WINDOW (window), hbox);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox);
+  gtk_box_append (GTK_BOX (hbox), vbox);
 
   frame = gtk_frame_new ("Scrolled Window");
   gtk_widget_set_hexpand (frame, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), frame);
+  gtk_box_append (GTK_BOX (hbox), frame);
 
   swindow = gtk_scrolled_window_new (NULL, NULL);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (swindow),
@@ -124,7 +124,7 @@ scrollable_policy (void)
   gtk_widget_show (cntl);
   gtk_widget_show (expander);
   gtk_expander_set_child (GTK_EXPANDER (expander), cntl);
-  gtk_container_add (GTK_CONTAINER (vbox), expander);
+  gtk_box_append (GTK_BOX (vbox), expander);
 
   /* Add Horizontal policy control here */
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 2);
@@ -132,7 +132,7 @@ scrollable_policy (void)
 
   widget = gtk_label_new ("hscroll-policy");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   widget = gtk_combo_box_text_new ();
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (widget), "Minimum");
@@ -140,8 +140,8 @@ scrollable_policy (void)
   gtk_combo_box_set_active (GTK_COMBO_BOX (widget), 0);
   gtk_widget_set_hexpand (widget, TRUE);
 
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (cntl), hbox);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (cntl), hbox);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (horizontal_policy_changed), viewport);
@@ -152,7 +152,7 @@ scrollable_policy (void)
 
   widget = gtk_label_new ("vscroll-policy");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   widget = gtk_combo_box_text_new ();
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (widget), "Minimum");
@@ -160,8 +160,8 @@ scrollable_policy (void)
   gtk_combo_box_set_active (GTK_COMBO_BOX (widget), 0);
   gtk_widget_set_hexpand (widget, TRUE);
 
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (cntl), hbox);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (cntl), hbox);
 
   g_signal_connect (G_OBJECT (widget), "changed",
                     G_CALLBACK (vertical_policy_changed), viewport);
@@ -171,12 +171,12 @@ scrollable_policy (void)
 
   widget = gtk_label_new ("min-content-width");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   widget = gtk_spin_button_new_with_range (100.0, 1000.0, 10.0);
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (cntl), hbox);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (cntl), hbox);
   gtk_widget_show (widget);
   gtk_widget_show (hbox);
 
@@ -187,12 +187,12 @@ scrollable_policy (void)
 
   widget = gtk_label_new ("min-content-height");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   widget = gtk_spin_button_new_with_range (100.0, 1000.0, 10.0);
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (cntl), hbox);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (cntl), hbox);
   gtk_widget_show (widget);
   gtk_widget_show (hbox);
 
@@ -202,7 +202,7 @@ scrollable_policy (void)
   /* Add Kinetic scrolling control here */
   widget = gtk_check_button_new_with_label ("Kinetic scrolling");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (cntl), widget);
+  gtk_box_append (GTK_BOX (cntl), widget);
   g_signal_connect (G_OBJECT (widget), "toggled",
                     G_CALLBACK (kinetic_scrolling_changed), swindow);
 
@@ -214,7 +214,7 @@ scrollable_policy (void)
   widget = gtk_menu_button_new ();
   gtk_menu_button_set_popover (GTK_MENU_BUTTON (widget), popover);
   gtk_menu_button_set_label (GTK_MENU_BUTTON (widget), "Popover");
-  gtk_container_add (GTK_CONTAINER (cntl), widget);
+  gtk_box_append (GTK_BOX (cntl), widget);
 
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
   gtk_popover_set_child (GTK_POPOVER (popover), vbox);
@@ -224,7 +224,7 @@ scrollable_policy (void)
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (swindow),
                                   GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
 
-    gtk_container_add (GTK_CONTAINER (vbox), swindow);
+    gtk_box_append (GTK_BOX (vbox), swindow);
 
   /* Listbox */
   listbox = gtk_list_box_new ();
@@ -236,11 +236,11 @@ scrollable_policy (void)
 
   widget = gtk_label_new ("min-content-width");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   widget = gtk_spin_button_new_with_range (0.0, 150.0, 10.0);
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   g_object_bind_property (gtk_spin_button_get_adjustment (GTK_SPIN_BUTTON (widget)),
                           "value",
@@ -250,13 +250,13 @@ scrollable_policy (void)
 
   widget = gtk_label_new ("min-content-height");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
 
   widget = gtk_spin_button_new_with_range (0.0, 150.0, 10.0);
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   g_object_bind_property (gtk_spin_button_get_adjustment (GTK_SPIN_BUTTON (widget)),
                           "value",
@@ -269,11 +269,11 @@ scrollable_policy (void)
 
   widget = gtk_label_new ("max-content-width");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   widget = gtk_spin_button_new_with_range (250.0, 1000.0, 10.0);
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   g_object_bind_property (gtk_spin_button_get_adjustment (GTK_SPIN_BUTTON (widget)),
                           "value",
@@ -283,12 +283,12 @@ scrollable_policy (void)
 
   widget = gtk_label_new ("max-content-height");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   widget = gtk_spin_button_new_with_range (250.0, 1000.0, 10.0);
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   g_object_bind_property (gtk_spin_button_get_adjustment (GTK_SPIN_BUTTON (widget)),
                           "value",
@@ -301,15 +301,15 @@ scrollable_policy (void)
 
   widget = gtk_button_new_with_label ("Remove");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
+  gtk_box_append (GTK_BOX (hbox), widget);
 
   g_signal_connect (widget, "clicked",
                     G_CALLBACK (remove_row), listbox);
 
   widget = gtk_button_new_with_label ("Add");
   gtk_widget_set_hexpand (widget, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), widget);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (hbox), widget);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   g_signal_connect (widget, "clicked",
                     G_CALLBACK (add_row), listbox);
diff --git a/tests/testselectionmode.c b/tests/testselectionmode.c
index 7875d44d10..e7f87f11aa 100644
--- a/tests/testselectionmode.c
+++ b/tests/testselectionmode.c
@@ -30,15 +30,15 @@ selectable_row_init (SelectableRow *row)
   gtk_widget_show (row->box);
   gtk_widget_show (row->check);
 
-  gtk_container_add (GTK_CONTAINER (row), row->box);
-  gtk_container_add (GTK_CONTAINER (row->box), row->revealer);
-  gtk_container_add (GTK_CONTAINER (row->revealer), row->check);
+  gtk_box_append (GTK_BOX (row), row->box);
+  gtk_box_append (GTK_BOX (row->box), row->revealer);
+  gtk_box_append (GTK_BOX (row->revealer), row->check);
 }
 
 static void
 selectable_row_add (SelectableRow *row, GtkWidget *child)
 {
-  gtk_container_add (GTK_CONTAINER (row->box), child);
+  gtk_box_append (GTK_BOX (row->box), child);
 }
 
 static void
diff --git a/tests/testsensitive.c b/tests/testsensitive.c
index 7f8b0be77e..88eccfb1b5 100644
--- a/tests/testsensitive.c
+++ b/tests/testsensitive.c
@@ -65,15 +65,15 @@ int main (int argc, char *argv[])
   gtk_window_set_child (GTK_WINDOW (window), box);
 
   w = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 15);
-  gtk_container_add (GTK_CONTAINER (box), w);
-  gtk_container_add (GTK_CONTAINER (w), gtk_entry_new ());
+  gtk_box_append (GTK_BOX (box), w);
+  gtk_box_append (GTK_BOX (w), gtk_entry_new ());
   bu = gtk_button_new_with_label ("Bu");
-  gtk_container_add (GTK_CONTAINER (w), bu);
+  gtk_box_append (GTK_BOX (w), bu);
   c = gtk_switch_new ();
   gtk_switch_set_active (GTK_SWITCH (c), TRUE);
   gtk_widget_set_halign (c, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (c, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (box), c);
+  gtk_box_append (GTK_BOX (box), c);
   g_signal_connect (bu, "clicked", G_CALLBACK (set_insensitive), w);
   g_signal_connect (bu, "state-flags-changed", G_CALLBACK (state_flags_changed), NULL);
 
diff --git a/tests/testsounds.c b/tests/testsounds.c
index 3a62f69fae..31c65fa31c 100644
--- a/tests/testsounds.c
+++ b/tests/testsounds.c
@@ -53,11 +53,11 @@ int main (int argc, char *argv[])
 
   button = gtk_button_new_with_label ("Α");
   g_signal_connect (button, "clicked", G_CALLBACK (enter), NULL);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   button = gtk_button_new_with_label ("Ω");
   g_signal_connect (button, "clicked", G_CALLBACK (leave), NULL);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   gtk_window_present (GTK_WINDOW (window));
 
diff --git a/tests/testspinbutton.c b/tests/testspinbutton.c
index ca1ff40b67..ef8f2db648 100644
--- a/tests/testspinbutton.c
+++ b/tests/testspinbutton.c
@@ -48,7 +48,7 @@ prepare_window_for_orientation (GtkOrientation orientation)
   gtk_window_set_child (GTK_WINDOW (window), mainbox);
 
   wrap_button = gtk_toggle_button_new_with_label ("Wrap");
-  gtk_container_add (GTK_CONTAINER (mainbox), wrap_button);
+  gtk_box_append (GTK_BOX (mainbox), wrap_button);
 
   for (max = 9; max <= 999999999; max = max * 10 + 9)
     {
@@ -65,8 +65,8 @@ prepare_window_for_orientation (GtkOrientation orientation)
       g_object_bind_property (wrap_button, "active", spin, "wrap", G_BINDING_SYNC_CREATE);
 
       GtkWidget *hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
-      gtk_container_add (GTK_CONTAINER (hbox), spin);
-      gtk_container_add (GTK_CONTAINER (mainbox), hbox);
+      gtk_box_append (GTK_BOX (hbox), spin);
+      gtk_box_append (GTK_BOX (mainbox), hbox);
     }
 
   gtk_widget_show (window);
diff --git a/tests/teststack.c b/tests/teststack.c
index bfbf069959..b2274b5d09 100644
--- a/tests/teststack.c
+++ b/tests/teststack.c
@@ -129,7 +129,7 @@ main (gint argc,
   gtk_window_set_child (GTK_WINDOW (window), box);
 
   switcher = gtk_stack_switcher_new ();
-  gtk_container_add (GTK_CONTAINER (box), switcher);
+  gtk_box_append (GTK_BOX (box), switcher);
 
   stack = gtk_stack_new ();
 
@@ -143,11 +143,11 @@ main (gint argc,
   sidebar = gtk_stack_sidebar_new ();
   gtk_stack_sidebar_set_stack (GTK_STACK_SIDEBAR (sidebar), GTK_STACK (stack));
   layout = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (layout), sidebar);
+  gtk_box_append (GTK_BOX (layout), sidebar);
   gtk_widget_set_hexpand (stack, TRUE);
-  gtk_container_add (GTK_CONTAINER (layout), stack);
+  gtk_box_append (GTK_BOX (layout), stack);
 
-  gtk_container_add (GTK_CONTAINER (box), layout);
+  gtk_box_append (GTK_BOX (box), layout);
 
   gtk_stack_switcher_set_stack (GTK_STACK_SWITCHER (switcher), GTK_STACK (stack));
 
@@ -188,47 +188,47 @@ main (gint argc,
   gtk_stack_add_titled (GTK_STACK (stack), w3, "3", "3");
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (box), hbox);
+  gtk_box_append (GTK_BOX (box), hbox);
 
   button = gtk_button_new_with_label ("1");
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   g_signal_connect (button, "clicked", (GCallback) set_visible_child, w1);
 
   button = gtk_button_new_with_label ("2");
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   g_signal_connect (button, "clicked", (GCallback) set_visible_child, w2);
 
   button = gtk_button_new_with_label ("3");
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   g_signal_connect (button, "clicked", (GCallback) set_visible_child, w3);
 
   button = gtk_button_new_with_label ("1");
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   g_signal_connect (button, "clicked", (GCallback) set_visible_child_name, (gpointer) "1");
 
   button = gtk_button_new_with_label ("2");
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   g_signal_connect (button, "clicked", (GCallback) set_visible_child_name, (gpointer) "2");
 
   button = gtk_button_new_with_label ("3");
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   g_signal_connect (button, "clicked", (GCallback) set_visible_child_name, (gpointer) "3");
 
   button = gtk_check_button_new ();
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button),
                                gtk_stack_get_hhomogeneous (GTK_STACK (stack)));
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   g_signal_connect (button, "clicked", (GCallback) toggle_hhomogeneous, NULL);
 
   button = gtk_check_button_new_with_label ("homogeneous");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (button),
                                gtk_stack_get_vhomogeneous (GTK_STACK (stack)));
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   g_signal_connect (button, "clicked", (GCallback) toggle_vhomogeneous, NULL);
 
   button = gtk_toggle_button_new_with_label ("Add icon");
   g_signal_connect (button, "toggled", (GCallback) toggle_icon_name, NULL);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   combo = gtk_combo_box_text_new ();
   class = g_type_class_ref (GTK_TYPE_STACK_TRANSITION_TYPE);
@@ -236,21 +236,21 @@ main (gint argc,
     gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo), class->values[i].value_nick);
   g_type_class_unref (class);
 
-  gtk_container_add (GTK_CONTAINER (hbox), combo);
+  gtk_box_append (GTK_BOX (hbox), combo);
   g_signal_connect (combo, "changed", (GCallback) toggle_transitions, NULL);
   gtk_combo_box_set_active (GTK_COMBO_BOX (combo), 0);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (box), hbox);
+  gtk_box_append (GTK_BOX (box), hbox);
 
   button = gtk_button_new_with_label ("<");
   g_signal_connect (button, "clicked", (GCallback) on_back_button_clicked, stack);
   g_signal_connect (stack, "notify::visible-child-name",
                     (GCallback)update_back_button_sensitivity, button);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   button = gtk_button_new_with_label (">");
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   g_signal_connect (button, "clicked", (GCallback) on_forward_button_clicked, stack);
   g_signal_connect (stack, "notify::visible-child-name",
                     (GCallback)update_forward_button_sensitivity, button);
diff --git a/tests/testswitch.c b/tests/testswitch.c
index 0a3644ab6b..015700d1f4 100644
--- a/tests/testswitch.c
+++ b/tests/testswitch.c
@@ -26,12 +26,12 @@ make_switch (gboolean is_on,
 
   sw = gtk_switch_new ();
   gtk_switch_set_active (GTK_SWITCH (sw), is_on);
-  gtk_container_add (GTK_CONTAINER (hbox), sw);
+  gtk_box_append (GTK_BOX (hbox), sw);
   gtk_widget_set_sensitive (sw, is_sensitive);
 
   label = gtk_label_new (is_on ? "Enabled" : "Disabled");
   gtk_widget_set_hexpand (label, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
 
   g_object_bind_property_full (sw, "active",
                                label, "label",
@@ -116,18 +116,18 @@ make_delayed_switch (gboolean is_on,
 
   sw = gtk_switch_new ();
   gtk_switch_set_active (GTK_SWITCH (sw), is_on);
-  gtk_container_add (GTK_CONTAINER (hbox), sw);
+  gtk_box_append (GTK_BOX (hbox), sw);
   gtk_widget_set_sensitive (sw, is_sensitive);
 
   g_signal_connect (sw, "state-set", G_CALLBACK (set_state), NULL);
 
   spinner = gtk_spinner_new ();
-  gtk_container_add (GTK_CONTAINER (hbox), spinner);
+  gtk_box_append (GTK_BOX (hbox), spinner);
   gtk_widget_set_opacity (spinner, 0.0);
 
   label = gtk_label_new (is_on ? "Enabled" : "Disabled");
   gtk_widget_set_hexpand (label, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), label);
+  gtk_box_append (GTK_BOX (hbox), label);
 
   g_object_bind_property_full (sw, "active",
                                label, "label",
@@ -137,7 +137,7 @@ make_delayed_switch (gboolean is_on,
                                NULL, NULL);
 
   check = gtk_check_button_new ();
-  gtk_container_add (GTK_CONTAINER (hbox), check);
+  gtk_box_append (GTK_BOX (hbox), check);
   g_object_bind_property (sw, "state",
                           check, "active",
                           G_BINDING_BIDIRECTIONAL | G_BINDING_SYNC_CREATE);
@@ -176,19 +176,19 @@ int main (int argc, char *argv[])
   gtk_window_set_child (GTK_WINDOW (window), vbox);
 
   hbox = make_switch (FALSE, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   hbox = make_switch (TRUE, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   hbox = make_switch (FALSE, FALSE);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   hbox = make_switch (TRUE, FALSE);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   hbox = make_delayed_switch (FALSE, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   while (!done)
     g_main_context_iteration (NULL, TRUE);
diff --git a/tests/testtextview2.c b/tests/testtextview2.c
index b7a2af89c3..9d4b6c9c54 100644
--- a/tests/testtextview2.c
+++ b/tests/testtextview2.c
@@ -200,7 +200,7 @@ main (int argc, char *argv[])
   gtk_widget_set_hexpand (sw, TRUE);
   gtk_widget_set_vexpand (sw, TRUE);
   gtk_window_set_child (GTK_WINDOW (window), box);
-  gtk_container_add (GTK_CONTAINER (box), sw);
+  gtk_box_append (GTK_BOX (box), sw);
 
   tv = gtk_text_view_new ();
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), tv);
@@ -214,33 +214,33 @@ main (int argc, char *argv[])
 
   box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
   g_object_set (box, "margin-start", 10, "margin-end", 10, NULL);
-  gtk_container_add (GTK_CONTAINER (box), box2);
+  gtk_box_append (GTK_BOX (box), box2);
 
   the_mark = gtk_text_mark_new ("my mark", TRUE);
   box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
-  gtk_container_add (GTK_CONTAINER (box), box2);
+  gtk_box_append (GTK_BOX (box), box2);
   mark_check = gtk_check_button_new_with_label ("Mark");
   g_signal_connect (mark_check, "notify::active", G_CALLBACK (update_mark_exists), NULL);
-  gtk_container_add (GTK_CONTAINER (box2), mark_check);
+  gtk_box_append (GTK_BOX (box2), mark_check);
   mark_visible = gtk_check_button_new_with_label ("Visible");
   g_signal_connect (mark_visible, "notify::active", G_CALLBACK (update_mark_visible), NULL);
-  gtk_container_add (GTK_CONTAINER (box2), mark_visible);
-  gtk_container_add (GTK_CONTAINER (box2), gtk_label_new ("Position:"));
+  gtk_box_append (GTK_BOX (box2), mark_visible);
+  gtk_box_append (GTK_BOX (box2), gtk_label_new ("Position:"));
   position_spin = gtk_spin_button_new_with_range (0, len, 1);  
   g_signal_connect (position_spin, "value-changed", G_CALLBACK (update_mark_position), NULL);
-  gtk_container_add (GTK_CONTAINER (box2), position_spin);
+  gtk_box_append (GTK_BOX (box2), position_spin);
 
   box2 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 10);
   g_object_set (box, "margin-start", 10, "margin-end", 10, NULL);
-  gtk_container_add (GTK_CONTAINER (box), box2);
+  gtk_box_append (GTK_BOX (box), box2);
 
   button = gtk_toggle_button_new_with_label ("Random marks");
   g_signal_connect (button, "notify::active", G_CALLBACK (toggle_marks), NULL);
-  gtk_container_add (GTK_CONTAINER (box2), button);
+  gtk_box_append (GTK_BOX (box2), button);
 
   button = gtk_toggle_button_new_with_label ("Wandering cursor");
   g_signal_connect (button, "notify::active", G_CALLBACK (toggle_cursor), NULL);
-  gtk_container_add (GTK_CONTAINER (box2), button);
+  gtk_box_append (GTK_BOX (box2), button);
 
   gtk_widget_show (window);
 
diff --git a/tests/testtoolbar2.c b/tests/testtoolbar2.c
index 50698713d8..82343293f9 100644
--- a/tests/testtoolbar2.c
+++ b/tests/testtoolbar2.c
@@ -16,10 +16,10 @@ int main (int argc, char *argv[])
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
   gtk_window_set_child (GTK_WINDOW (window), box);
   frame = gtk_frame_new (NULL);
-  gtk_container_add (GTK_CONTAINER (box), frame);
+  gtk_box_append (GTK_BOX (box), frame);
   view = gtk_text_view_new ();
   gtk_widget_set_vexpand (view, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), view);
+  gtk_box_append (GTK_BOX (box), view);
   box3 = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_set_margin_start (box3, 10);
   gtk_widget_set_margin_end (box3, 10);
@@ -28,11 +28,11 @@ int main (int argc, char *argv[])
 
   gtk_widget_add_css_class (box3, GTK_STYLE_CLASS_LINKED);
   button = gtk_button_new_from_icon_name ("document-new-symbolic");
-  gtk_container_add (GTK_CONTAINER (box3), button);
+  gtk_box_append (GTK_BOX (box3), button);
   button = gtk_button_new_from_icon_name ("document-open-symbolic");
-  gtk_container_add (GTK_CONTAINER (box3), button);
+  gtk_box_append (GTK_BOX (box3), button);
   button = gtk_button_new_from_icon_name ("document-save-symbolic");
-  gtk_container_add (GTK_CONTAINER (box3), button);
+  gtk_box_append (GTK_BOX (box3), button);
 
   gtk_frame_set_child (GTK_FRAME (frame), box3);
   
diff --git a/tests/testtooltips.c b/tests/testtooltips.c
index f4b384f6dc..10d4ca4083 100644
--- a/tests/testtooltips.c
+++ b/tests/testtooltips.c
@@ -309,13 +309,13 @@ main (int argc, char *argv[])
   gtk_widget_set_margin_top (tooltip, 20);
   gtk_widget_set_margin_bottom (tooltip, 20);
   gtk_widget_set_halign (tooltip, GTK_ALIGN_CENTER);
-  gtk_container_add (GTK_CONTAINER (box), tooltip);
+  gtk_box_append (GTK_BOX (box), tooltip);
 
 
   /* A check button using the tooltip-markup property */
   button = gtk_check_button_new_with_label ("This one uses the tooltip-markup property");
   gtk_widget_set_tooltip_text (button, "Hello, I am a static tooltip.");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   text = gtk_widget_get_tooltip_text (button);
   markup = gtk_widget_get_tooltip_markup (button);
@@ -328,13 +328,13 @@ main (int argc, char *argv[])
   g_object_set (button, "has-tooltip", TRUE, NULL);
   g_signal_connect (button, "query-tooltip",
                    G_CALLBACK (query_tooltip_cb), NULL);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   /* A label */
   button = gtk_label_new ("I am just a label");
   gtk_label_set_selectable (GTK_LABEL (button), FALSE);
   gtk_widget_set_tooltip_text (button, "Label & and tooltip");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   text = gtk_widget_get_tooltip_text (button);
   markup = gtk_widget_get_tooltip_markup (button);
@@ -346,7 +346,7 @@ main (int argc, char *argv[])
   button = gtk_label_new ("I am a selectable label");
   gtk_label_set_selectable (GTK_LABEL (button), TRUE);
   gtk_widget_set_tooltip_markup (button, "<b>Another</b> Label tooltip");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   text = gtk_widget_get_tooltip_text (button);
   markup = gtk_widget_get_tooltip_markup (button);
@@ -358,7 +358,7 @@ main (int argc, char *argv[])
   button = gtk_button_new_with_label ("This one is insensitive");
   gtk_widget_set_sensitive (button, FALSE);
   g_object_set (button, "tooltip-text", "Insensitive!", NULL);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   /* Testcases from Kris without a tree view don't exist. */
   tree_view = gtk_tree_view_new_with_model (create_model ());
@@ -381,7 +381,7 @@ main (int argc, char *argv[])
   gtk_tree_view_column_set_clickable (column, TRUE);
   g_object_set (gtk_tree_view_column_get_button (column), "tooltip-text", "Header", NULL);
 
-  gtk_container_add (GTK_CONTAINER (box), tree_view);
+  gtk_box_append (GTK_BOX (box), tree_view);
 
   /* And a text view for Matthias */
   buffer = gtk_text_buffer_new (NULL);
@@ -405,7 +405,7 @@ main (int argc, char *argv[])
   g_signal_connect (text_view, "query-tooltip",
                    G_CALLBACK (query_tooltip_text_view_cb), tag);
 
-  gtk_container_add (GTK_CONTAINER (box), text_view);
+  gtk_box_append (GTK_BOX (box), text_view);
 
   /* Drawing area */
   drawing_area = gtk_drawing_area_new ();
@@ -416,12 +416,12 @@ main (int argc, char *argv[])
   g_object_set (drawing_area, "has-tooltip", TRUE, NULL);
   g_signal_connect (drawing_area, "query-tooltip",
                    G_CALLBACK (query_tooltip_drawing_area_cb), NULL);
-  gtk_container_add (GTK_CONTAINER (box), drawing_area);
+  gtk_box_append (GTK_BOX (box), drawing_area);
 
   button = gtk_menu_button_new ();
   gtk_widget_set_halign (button, GTK_ALIGN_CENTER);
   gtk_menu_button_set_label (GTK_MENU_BUTTON (button), "Custom tooltip I");
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
   popover = gtk_popover_new ();
   gtk_menu_button_set_popover (GTK_MENU_BUTTON (button), popover);
   box2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
@@ -429,23 +429,23 @@ main (int argc, char *argv[])
 
   button = gtk_label_new ("Hidden here");
   custom = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
-  gtk_container_add (GTK_CONTAINER (custom), gtk_label_new ("See, custom"));
-  gtk_container_add (GTK_CONTAINER (custom), g_object_new (GTK_TYPE_SPINNER, "spinning", TRUE, NULL));
+  gtk_box_append (GTK_BOX (custom), gtk_label_new ("See, custom"));
+  gtk_box_append (GTK_BOX (custom), g_object_new (GTK_TYPE_SPINNER, "spinning", TRUE, NULL));
   g_object_ref_sink (custom);
   g_object_set (button, "has-tooltip", TRUE, NULL);
-  gtk_container_add (GTK_CONTAINER (box2), button);
+  gtk_box_append (GTK_BOX (box2), button);
   g_signal_connect (button, "query-tooltip",
                    G_CALLBACK (query_tooltip_label_cb), custom);
 
   button = gtk_label_new ("Custom tooltip II");
   custom = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 5);
-  gtk_container_add (GTK_CONTAINER (custom), gtk_label_new ("See, custom too"));
-  gtk_container_add (GTK_CONTAINER (custom), g_object_new (GTK_TYPE_SPINNER, "spinning", TRUE, NULL));
+  gtk_box_append (GTK_BOX (custom), gtk_label_new ("See, custom too"));
+  gtk_box_append (GTK_BOX (custom), g_object_new (GTK_TYPE_SPINNER, "spinning", TRUE, NULL));
   g_object_ref_sink (custom);
   g_object_set (button, "has-tooltip", TRUE, NULL);
   g_signal_connect (button, "query-tooltip",
                    G_CALLBACK (query_tooltip_label_cb), custom);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   /* Done! */
   gtk_widget_show (window);
diff --git a/tests/testtreecolumns.c b/tests/testtreecolumns.c
index f7bafa571b..3612a9269d 100644
--- a/tests/testtreecolumns.c
+++ b/tests/testtreecolumns.c
@@ -783,7 +783,7 @@ main (int argc, char *argv[])
   gtk_window_set_child (GTK_WINDOW (window), vbox);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   /* Left Pane */
   cell = gtk_cell_renderer_text_new ();
@@ -800,50 +800,50 @@ main (int argc, char *argv[])
   gtk_tree_view_append_column (GTK_TREE_VIEW (left_tree_view), column);
 
   gtk_tree_view_column_set_cell_data_func (column, cell, get_visible, NULL, NULL);
-  gtk_container_add (GTK_CONTAINER (hbox), swindow);
+  gtk_box_append (GTK_BOX (hbox), swindow);
 
   /* Middle Pane */
   vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox2);
+  gtk_box_append (GTK_BOX (hbox), vbox2);
 
   bbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (vbox2), bbox);
+  gtk_box_append (GTK_BOX (vbox2), bbox);
 
   button = gtk_button_new_with_mnemonic ("<< (_Q)");
   gtk_widget_set_sensitive (button, FALSE);
   g_signal_connect (button, "clicked", G_CALLBACK (add_left_clicked), top_right_tree_view);
   g_signal_connect (gtk_tree_view_get_selection (GTK_TREE_VIEW (top_right_tree_view)),
                     "changed", G_CALLBACK (selection_changed), button);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   button = gtk_button_new_with_mnemonic (">> (_W)");
   gtk_widget_set_sensitive (button, FALSE);
   g_signal_connect (button, "clicked", G_CALLBACK (add_right_clicked), top_right_tree_view);
   g_signal_connect (gtk_tree_view_get_selection (GTK_TREE_VIEW (left_tree_view)),
                     "changed", G_CALLBACK (selection_changed), button);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   bbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (vbox2), bbox);
+  gtk_box_append (GTK_BOX (vbox2), bbox);
 
   button = gtk_button_new_with_mnemonic ("<< (_E)");
   gtk_widget_set_sensitive (button, FALSE);
   g_signal_connect (button, "clicked", G_CALLBACK (add_left_clicked), bottom_right_tree_view);
   g_signal_connect (gtk_tree_view_get_selection (GTK_TREE_VIEW (bottom_right_tree_view)),
                     "changed", G_CALLBACK (selection_changed), button);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
   button = gtk_button_new_with_mnemonic (">> (_R)");
   gtk_widget_set_sensitive (button, FALSE);
   g_signal_connect (button, "clicked", G_CALLBACK (add_right_clicked), bottom_right_tree_view);
   g_signal_connect (gtk_tree_view_get_selection (GTK_TREE_VIEW (left_tree_view)),
                     "changed", G_CALLBACK (selection_changed), button);
-  gtk_container_add (GTK_CONTAINER (bbox), button);
+  gtk_box_append (GTK_BOX (bbox), button);
 
 
   /* Right Pane */
   vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-  gtk_container_add (GTK_CONTAINER (hbox), vbox2);
+  gtk_box_append (GTK_BOX (hbox), vbox2);
 
   swindow = gtk_scrolled_window_new (NULL, NULL);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (swindow), GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
@@ -858,7 +858,7 @@ main (int argc, char *argv[])
   gtk_tree_view_append_column (GTK_TREE_VIEW (top_right_tree_view), column);
 
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (swindow), top_right_tree_view);
-  gtk_container_add (GTK_CONTAINER (vbox2), swindow);
+  gtk_box_append (GTK_BOX (vbox2), swindow);
 
   swindow = gtk_scrolled_window_new (NULL, NULL);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (swindow), GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
@@ -872,7 +872,7 @@ main (int argc, char *argv[])
   gtk_tree_view_column_set_cell_data_func (column, cell, get_visible, NULL, NULL);
   gtk_tree_view_append_column (GTK_TREE_VIEW (bottom_right_tree_view), column);
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (swindow), bottom_right_tree_view);
-  gtk_container_add (GTK_CONTAINER (vbox2), swindow);
+  gtk_box_append (GTK_BOX (vbox2), swindow);
 
 
   /* Drag and Drop */
@@ -902,13 +902,13 @@ main (int argc, char *argv[])
                                        GDK_ACTION_MOVE);
   gdk_content_formats_unref (targets);
 
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
+  gtk_box_append (GTK_BOX (vbox), gtk_separator_new (GTK_ORIENTATION_HORIZONTAL));
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
   button = gtk_button_new_with_mnemonic ("_Add new Column");
   g_signal_connect (button, "clicked", G_CALLBACK (add_clicked), left_tree_model);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
 
   gtk_widget_show (window);
 
diff --git a/tests/testtreecolumnsizing.c b/tests/testtreecolumnsizing.c
index a9709aae47..71a03a5016 100644
--- a/tests/testtreecolumnsizing.c
+++ b/tests/testtreecolumnsizing.c
@@ -202,7 +202,7 @@ main (int argc, char **argv)
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo_box), BORDER_EXPAND);
   gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo_box), ALL_EXPAND);
 
-  gtk_container_add (GTK_CONTAINER (vbox), combo_box);
+  gtk_box_append (GTK_BOX (vbox), combo_box);
 
   /* Scrolled window and tree view */
   sw = gtk_scrolled_window_new (NULL, NULL);
@@ -210,7 +210,7 @@ main (int argc, char **argv)
                                   GTK_POLICY_AUTOMATIC,
                                   GTK_POLICY_AUTOMATIC);
   gtk_widget_set_vexpand (sw, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), sw);
+  gtk_box_append (GTK_BOX (vbox), sw);
 
   tree_view = gtk_tree_view_new_with_model (create_model ());
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), tree_view);
@@ -233,7 +233,7 @@ main (int argc, char **argv)
   button = gtk_toggle_button_new_with_label ("Toggle long content row");
   g_signal_connect (button, "toggled",
                     G_CALLBACK (toggle_long_content_row), tree_view);
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   /* Set up option menu callback and default item */
   g_signal_connect (combo_box, "changed",
diff --git a/tests/testtreednd.c b/tests/testtreednd.c
index 76483dd6b4..736b071c9a 100644
--- a/tests/testtreednd.c
+++ b/tests/testtreednd.c
@@ -123,8 +123,8 @@ main (int argc, char *argv[])
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_window_set_child (GTK_WINDOW (window), box);
-  gtk_container_add (GTK_CONTAINER (box), get_dragsource ());
-  gtk_container_add (GTK_CONTAINER (box), get_droptarget ());
+  gtk_box_append (GTK_BOX (box), get_dragsource ());
+  gtk_box_append (GTK_BOX (box), get_droptarget ());
 
   gtk_widget_show (window);
 
diff --git a/tests/testtreeedit.c b/tests/testtreeedit.c
index fb8b4825de..0ed30af13b 100644
--- a/tests/testtreeedit.c
+++ b/tests/testtreeedit.c
@@ -210,7 +210,7 @@ create_control (GtkWidget *box, gint number, gint cntl, CallbackData *data)
 
   checkbutton = gtk_check_button_new_with_label (name);
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (checkbutton), cntl == CNTL_FIXED);
-  gtk_container_add (GTK_CONTAINER (box), checkbutton);
+  gtk_box_append (GTK_BOX (box), checkbutton);
 
   g_signal_connect (G_OBJECT (checkbutton), "toggled", callback, data);
   g_free (name);
@@ -259,7 +259,7 @@ main (gint argc, gchar **argv)
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window),
                                  GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
   gtk_widget_set_vexpand (scrolled_window, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), scrolled_window);
+  gtk_box_append (GTK_BOX (vbox), scrolled_window);
 
   tree_model = create_model ();
   tree_view = gtk_tree_view_new_with_model (tree_model);
@@ -364,11 +364,11 @@ main (gint argc, gchar **argv)
                               800, 250);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   /* Alignment controls */
   cntl_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 2);
-  gtk_container_add (GTK_CONTAINER (hbox), cntl_vbox);
+  gtk_box_append (GTK_BOX (hbox), cntl_vbox);
 
   create_control (cntl_vbox, 1, CNTL_ALIGN, &callback[0]);
   create_control (cntl_vbox, 2, CNTL_ALIGN, &callback[1]);
@@ -377,7 +377,7 @@ main (gint argc, gchar **argv)
 
   /* Expand controls */
   cntl_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 2);
-  gtk_container_add (GTK_CONTAINER (hbox), cntl_vbox);
+  gtk_box_append (GTK_BOX (hbox), cntl_vbox);
 
   create_control (cntl_vbox, 1, CNTL_EXPAND, &callback[0]);
   create_control (cntl_vbox, 2, CNTL_EXPAND, &callback[1]);
@@ -386,7 +386,7 @@ main (gint argc, gchar **argv)
 
   /* Fixed controls */
   cntl_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 2);
-  gtk_container_add (GTK_CONTAINER (hbox), cntl_vbox);
+  gtk_box_append (GTK_BOX (hbox), cntl_vbox);
 
   create_control (cntl_vbox, 1, CNTL_FIXED, &callback[0]);
   create_control (cntl_vbox, 2, CNTL_FIXED, &callback[1]);
diff --git a/tests/testtreeflow.c b/tests/testtreeflow.c
index 10a5894d74..8088e9aaef 100644
--- a/tests/testtreeflow.c
+++ b/tests/testtreeflow.c
@@ -148,14 +148,14 @@ main (int argc, char *argv[])
   gtk_window_set_title (GTK_WINDOW (window), "Reflow test");
   g_signal_connect (window, "destroy", G_CALLBACK (quit_cb), &done);
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new ("Incremental Reflow Test"));
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new ("Incremental Reflow Test"));
   gtk_window_set_child (GTK_WINDOW (window), vbox);
   scrolled_window = gtk_scrolled_window_new (NULL, NULL);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window),
                                  GTK_POLICY_AUTOMATIC,
                                  GTK_POLICY_AUTOMATIC);
   gtk_widget_set_vexpand (scrolled_window, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), scrolled_window);
+  gtk_box_append (GTK_BOX (vbox), scrolled_window);
 
   initialize_model ();
   tree_view = gtk_tree_view_new_with_model (model);
@@ -171,9 +171,9 @@ main (int argc, char *argv[])
                                               NULL);
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolled_window), tree_view);
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
   button = gtk_button_new_with_mnemonic ("<b>_Futz!!</b>");
-  gtk_container_add (GTK_CONTAINER (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), button);
   gtk_label_set_use_markup (GTK_LABEL (gtk_button_get_child (GTK_BUTTON (button))), TRUE);
   g_signal_connect (button, "clicked", G_CALLBACK (futz), NULL);
   g_signal_connect (button, "realize", G_CALLBACK (gtk_widget_grab_focus), NULL);
diff --git a/tests/testtreefocus.c b/tests/testtreefocus.c
index 4c4928b9b3..cc071f1a1a 100644
--- a/tests/testtreefocus.c
+++ b/tests/testtreefocus.c
@@ -364,14 +364,14 @@ main (int argc, char *argv[])
   gtk_window_set_title (GTK_WINDOW (window), "Card planning sheet");
   g_signal_connect (window, "destroy", G_CALLBACK (quit_cb), &done);
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new ("Jonathan's Holiday Card Planning Sheet"));
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new ("Jonathan's Holiday Card Planning Sheet"));
   gtk_window_set_child (GTK_WINDOW (window), vbox);
 
   scrolled_window = gtk_scrolled_window_new (NULL, NULL);
   gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (scrolled_window), TRUE);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window), GTK_POLICY_AUTOMATIC, 
GTK_POLICY_AUTOMATIC);
   gtk_widget_set_vexpand (scrolled_window, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), scrolled_window);
+  gtk_box_append (GTK_BOX (vbox), scrolled_window);
 
   model = make_model ();
   tree_view = gtk_tree_view_new_with_model (model);
@@ -479,14 +479,14 @@ main (int argc, char *argv[])
   gtk_window_set_title (GTK_WINDOW (window), "Model");
   g_signal_connect (window, "destroy", G_CALLBACK (quit_cb), &done);
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new ("The model revealed"));
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new ("The model revealed"));
   gtk_window_set_child (GTK_WINDOW (window), vbox);
 
   scrolled_window = gtk_scrolled_window_new (NULL, NULL);
   gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (scrolled_window), TRUE);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window), GTK_POLICY_AUTOMATIC, 
GTK_POLICY_AUTOMATIC);
   gtk_widget_set_vexpand (scrolled_window, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), scrolled_window);
+  gtk_box_append (GTK_BOX (vbox), scrolled_window);
 
 
   tree_view = gtk_tree_view_new_with_model (model);
diff --git a/tests/testtreelistmodel.c b/tests/testtreelistmodel.c
index b267fded4c..35e22c1432 100644
--- a/tests/testtreelistmodel.c
+++ b/tests/testtreelistmodel.c
@@ -175,14 +175,14 @@ create_widget_for_model (gpointer item,
   gtk_widget_set_vexpand (row, TRUE);
 
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
-  gtk_container_add (GTK_CONTAINER (row), box);
+  gtk_box_append (GTK_BOX (row), box);
 
   depth = gtk_tree_list_row_get_depth (item);
   if (depth > 0)
     {
       child = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
       gtk_widget_set_size_request (child, 16 * depth, 0);
-      gtk_container_add (GTK_CONTAINER (box), child);
+      gtk_box_append (GTK_BOX (box), child);
     }
 
   if (gtk_tree_list_row_is_expandable (item))
@@ -195,16 +195,16 @@ create_widget_for_model (gpointer item,
       gtk_button_set_has_frame (GTK_BUTTON (title), FALSE);
       g_object_bind_property (item, "expanded", title, "active", G_BINDING_BIDIRECTIONAL | 
G_BINDING_SYNC_CREATE);
       g_object_set_data_full (G_OBJECT (title), "make-sure-its-not-unreffed", g_object_ref (item), 
g_object_unref);
-      gtk_container_add (GTK_CONTAINER (child), title);
+      gtk_box_append (GTK_BOX (child), title);
 
       arrow = g_object_new (GTK_TYPE_SPINNER, "css-name", "arrow", NULL);
-      gtk_container_add (GTK_CONTAINER (title), arrow);
+      gtk_box_append (GTK_BOX (title), arrow);
     }
   else
     {
       child = gtk_image_new (); /* empty whatever */
     }
-  gtk_container_add (GTK_CONTAINER (box), child);
+  gtk_box_append (GTK_BOX (box), child);
 
   info = gtk_tree_list_row_get_item (item);
 
@@ -212,14 +212,14 @@ create_widget_for_model (gpointer item,
   if (icon)
     {
       child = gtk_image_new_from_gicon (icon);
-      gtk_container_add (GTK_CONTAINER (box), child);
+      gtk_box_append (GTK_BOX (box), child);
     }
 
   file = g_object_get_data (G_OBJECT (info), "file");
   child = gtk_label_new (g_file_get_basename (file));
   g_object_unref (info);
 
-  gtk_container_add (GTK_CONTAINER (box), child);
+  gtk_box_append (GTK_BOX (box), child);
 
   return row;
 }
@@ -330,15 +330,15 @@ main (int argc, char *argv[])
   gtk_window_set_child (GTK_WINDOW (win), vbox);
 
   search_entry = gtk_search_entry_new ();
-  gtk_container_add (GTK_CONTAINER (vbox), search_entry);
+  gtk_box_append (GTK_BOX (vbox), search_entry);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_search_entry_set_key_capture_widget (GTK_SEARCH_ENTRY (search_entry), hbox);
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
+  gtk_box_append (GTK_BOX (vbox), hbox);
 
   listbox = gtk_list_box_new ();
   gtk_widget_set_hexpand (listbox, TRUE);
-  gtk_container_add (GTK_CONTAINER (hbox), listbox);
+  gtk_box_append (GTK_BOX (hbox), listbox);
 
   if (argc > 1)
     root = g_file_new_for_commandline_arg (argv[1]);
@@ -372,14 +372,14 @@ main (int argc, char *argv[])
   g_signal_connect (filter, "items-changed", G_CALLBACK (update_adjustment), adjustment);
 
   scrollbar = gtk_scrollbar_new (GTK_ORIENTATION_VERTICAL, adjustment);
-  gtk_container_add (GTK_CONTAINER (hbox), scrollbar);
+  gtk_box_append (GTK_BOX (hbox), scrollbar);
 
   statusbar = gtk_statusbar_new ();
   gtk_widget_add_tick_callback (statusbar, (GtkTickCallback) update_statusbar, NULL, NULL);
   g_object_set_data (G_OBJECT (statusbar), "model", filter);
   g_signal_connect_swapped (filter, "items-changed", G_CALLBACK (update_statusbar), statusbar);
   update_statusbar (GTK_STATUSBAR (statusbar));
-  gtk_container_add (GTK_CONTAINER (vbox), statusbar);
+  gtk_box_append (GTK_BOX (vbox), statusbar);
 
   g_object_unref (tree);
   g_object_unref (filter);
diff --git a/tests/testtreesort.c b/tests/testtreesort.c
index dbb6ad52df..c4d29c8ed8 100644
--- a/tests/testtreesort.c
+++ b/tests/testtreesort.c
@@ -122,20 +122,20 @@ main (int argc, char *argv[])
   gtk_window_set_title (GTK_WINDOW (window), "Words, words, words - Window 1");
   g_signal_connect (window, "destroy", G_CALLBACK (quit_cb), &done);
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-  gtk_container_add (GTK_CONTAINER (vbox), gtk_label_new ("Jonathan and Kristian's list of cool words. (And 
Anders' cool list of numbers) \n\nThis is just a GtkTreeStore"));
+  gtk_box_append (GTK_BOX (vbox), gtk_label_new ("Jonathan and Kristian's list of cool words. (And Anders' 
cool list of numbers) \n\nThis is just a GtkTreeStore"));
   gtk_window_set_child (GTK_WINDOW (window), vbox);
 
   entry = gtk_entry_new ();
-  gtk_container_add (GTK_CONTAINER (vbox), entry);
+  gtk_box_append (GTK_BOX (vbox), entry);
 
   button = gtk_button_new_with_label ("Switch search method");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
 
   scrolled_window = gtk_scrolled_window_new (NULL, NULL);
   gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (scrolled_window), TRUE);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window), GTK_POLICY_AUTOMATIC, 
GTK_POLICY_AUTOMATIC);
   gtk_widget_set_vexpand (scrolled_window, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), scrolled_window);
+  gtk_box_append (GTK_BOX (vbox), scrolled_window);
 
   model = gtk_tree_store_new (NUM_COLUMNS, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING, 
G_TYPE_INT);
 
@@ -250,7 +250,7 @@ main (int argc, char *argv[])
                            "Words, words, words - window 2");
       g_signal_connect (window2, "destroy", G_CALLBACK (quit_cb), &done);
       vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-      gtk_container_add (GTK_CONTAINER (vbox2), 
+      gtk_box_append (GTK_BOX (vbox2), 
                          gtk_label_new ("Jonathan and Kristian's list of words.\n\nA GtkTreeModelSort 
wrapping the GtkTreeStore of window 1"));
       gtk_window_set_child (GTK_WINDOW (window2), vbox2);
       
@@ -260,7 +260,7 @@ main (int argc, char *argv[])
                                      GTK_POLICY_AUTOMATIC,
                                      GTK_POLICY_AUTOMATIC);
       gtk_widget_set_vexpand (scrolled_window2, TRUE);
-      gtk_container_add (GTK_CONTAINER (vbox2), scrolled_window2);
+      gtk_box_append (GTK_BOX (vbox2), scrolled_window2);
 
 
       tree_view2 = gtk_tree_view_new_with_model (smodel);
@@ -317,7 +317,7 @@ main (int argc, char *argv[])
                            "Words, words, words - Window 3");
       g_signal_connect (window3, "destroy", G_CALLBACK (quit_cb), &done);
       vbox3 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
-      gtk_container_add (GTK_CONTAINER (vbox3), 
+      gtk_box_append (GTK_BOX (vbox3), 
                          gtk_label_new ("Jonathan and Kristian's list of words.\n\nA GtkTreeModelSort 
wrapping the GtkTreeModelSort of window 2"));
       gtk_window_set_child (GTK_WINDOW (window3), vbox3);
       
@@ -327,7 +327,7 @@ main (int argc, char *argv[])
                                      GTK_POLICY_AUTOMATIC,
                                      GTK_POLICY_AUTOMATIC);
       gtk_widget_set_vexpand (scrolled_window3, TRUE);
-      gtk_container_add (GTK_CONTAINER (vbox3), scrolled_window3);
+      gtk_box_append (GTK_BOX (vbox3), scrolled_window3);
 
 
       tree_view3 = gtk_tree_view_new_with_model (ssmodel);
diff --git a/tests/testtreeview.c b/tests/testtreeview.c
index a5648c6be9..27adee9c74 100644
--- a/tests/testtreeview.c
+++ b/tests/testtreeview.c
@@ -724,7 +724,7 @@ main (int    argc,
   for (i = 0; i < MODEL_LAST; i++)
       gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo_box), model_names[i]);
 
-  gtk_container_add (GTK_CONTAINER (box), combo_box);
+  gtk_box_append (GTK_BOX (box), combo_box);
   g_signal_connect (combo_box,
                     "changed",
                     G_CALLBACK (model_selected),
@@ -736,7 +736,7 @@ main (int    argc,
   for (i = 0; i < COLUMNS_LAST; i++)
       gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT (combo_box), column_type_names[i]);
 
-  gtk_container_add (GTK_CONTAINER (box), combo_box);
+  gtk_box_append (GTK_BOX (box), combo_box);
 
   set_columns_type (GTK_TREE_VIEW (tv), COLUMNS_LOTS);
   gtk_combo_box_set_active (GTK_COMBO_BOX (combo_box), COLUMNS_LOTS);
@@ -753,7 +753,7 @@ main (int    argc,
                                   GTK_POLICY_AUTOMATIC,
                                   GTK_POLICY_AUTOMATIC);
   
-  gtk_container_add (GTK_CONTAINER (box), sw);
+  gtk_box_append (GTK_BOX (box), sw);
   
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), tv);
   
diff --git a/tests/testvolumebutton.c b/tests/testvolumebutton.c
index d79ec34aa9..00fc4bfe36 100644
--- a/tests/testvolumebutton.c
+++ b/tests/testvolumebutton.c
@@ -96,12 +96,12 @@ main (int    argc,
                     NULL);
 
   gtk_window_set_child (GTK_WINDOW (window), vbox);
-  gtk_container_add (GTK_CONTAINER (vbox), box);
-  gtk_container_add (GTK_CONTAINER (box), button);
-  gtk_container_add (GTK_CONTAINER (box), button2);
+  gtk_box_append (GTK_BOX (vbox), box);
+  gtk_box_append (GTK_BOX (box), button);
+  gtk_box_append (GTK_BOX (box), button2);
 
   button3 = gtk_button_new_with_label ("Toggle orientation");
-  gtk_container_add (GTK_CONTAINER (box), button3);
+  gtk_box_append (GTK_BOX (box), button3);
 
   g_signal_connect (G_OBJECT (button3), "clicked",
                     G_CALLBACK (toggle_orientation),
diff --git a/tests/testwidgettransforms.c b/tests/testwidgettransforms.c
index 3dc684d74c..aead504f9b 100644
--- a/tests/testwidgettransforms.c
+++ b/tests/testwidgettransforms.c
@@ -321,7 +321,7 @@ main (int argc, char **argv)
   gtk_button_set_label (GTK_BUTTON (toggle_button), "Picking");
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (toggle_button), do_picking);
   g_signal_connect (toggle_button, "toggled", G_CALLBACK (toggled_cb), NULL);
-  gtk_container_add (GTK_CONTAINER (titlebar), toggle_button);
+  gtk_box_append (GTK_BOX (titlebar), toggle_button);
 
   test_widget = gtk_button_new ();
   gtk_widget_set_size_request (test_widget, TEST_WIDGET_MIN_SIZE, TEST_WIDGET_MIN_SIZE);
@@ -333,14 +333,14 @@ main (int argc, char **argv)
   gtk_widget_set_halign (test_child, GTK_ALIGN_CENTER);
   gtk_widget_set_valign (test_child, GTK_ALIGN_CENTER);
   gtk_widget_set_size_request (test_child, TEST_WIDGET_MIN_SIZE / 2, TEST_WIDGET_MIN_SIZE / 2);
-  gtk_container_add (GTK_CONTAINER (test_widget), test_child);
+  gtk_box_append (GTK_BOX (test_widget), test_child);
 
 
   gtk_transform_tester_set_test_widget (GTK_TRANSFORM_TESTER (transform_tester), test_widget);
 
   gtk_widget_set_vexpand (transform_tester, TRUE);
-  gtk_container_add (GTK_CONTAINER (box), transform_tester);
-  gtk_container_add (GTK_CONTAINER (box), matrix_chooser);
+  gtk_box_append (GTK_BOX (box), transform_tester);
+  gtk_box_append (GTK_BOX (box), matrix_chooser);
   gtk_window_set_child (GTK_WINDOW (window), box);
 
   gtk_window_set_default_size ((GtkWindow *)window, 200, 200);
diff --git a/tests/testwindowsize.c b/tests/testwindowsize.c
index 6d05ddae19..772667a8ae 100644
--- a/tests/testwindowsize.c
+++ b/tests/testwindowsize.c
@@ -56,7 +56,7 @@ show_dialog (void)
   gtk_window_set_resizable (GTK_WINDOW (dialog), resizable);
 
 
-  gtk_container_add (GTK_CONTAINER (gtk_dialog_get_content_area (GTK_DIALOG (dialog))),
+  gtk_box_append (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))),
                       label);
   gtk_widget_show (label);
 
diff --git a/tests/treestoretest.c b/tests/treestoretest.c
index bd61bbdbfe..efb2444cee 100644
--- a/tests/treestoretest.c
+++ b/tests/treestoretest.c
@@ -344,7 +344,7 @@ make_window (gint view_type)
   /* Put them together */
   gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolled_window), tree_view);
   gtk_widget_set_vexpand (scrolled_window, TRUE);
-  gtk_container_add (GTK_CONTAINER (vbox), scrolled_window);
+  gtk_box_append (GTK_BOX (vbox), scrolled_window);
   gtk_window_set_child (GTK_WINDOW (window), vbox);
   gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window),
                                  GTK_POLICY_AUTOMATIC,
@@ -353,7 +353,7 @@ make_window (gint view_type)
 
   /* buttons */
   button = gtk_button_new_with_label ("gtk_tree_store_remove");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (selection, "changed",
                     G_CALLBACK (selection_changed),
                     button);
@@ -365,9 +365,9 @@ make_window (gint view_type)
   button = gtk_button_new_with_label ("gtk_tree_store_insert");
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
   entry = gtk_entry_new ();
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
-  gtk_container_add (GTK_CONTAINER (hbox), entry);
+  gtk_box_append (GTK_BOX (vbox), hbox);
+  gtk_box_append (GTK_BOX (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), entry);
   g_object_set_data (G_OBJECT (button), "user_data", entry);
   g_signal_connect (button, "clicked",
                     G_CALLBACK (iter_insert),
@@ -376,9 +376,9 @@ make_window (gint view_type)
   button = gtk_button_new_with_label ("gtk_tree_store_set");
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
   entry = gtk_entry_new ();
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
-  gtk_container_add (GTK_CONTAINER (hbox), entry);
+  gtk_box_append (GTK_BOX (vbox), hbox);
+  gtk_box_append (GTK_BOX (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), entry);
   g_object_set_data (G_OBJECT (button), "user_data", entry);
   g_signal_connect (button, "clicked",
                    G_CALLBACK (iter_change),
@@ -387,16 +387,16 @@ make_window (gint view_type)
   button = gtk_button_new_with_label ("gtk_tree_store_insert_with_values");
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 8);
   entry = gtk_entry_new ();
-  gtk_container_add (GTK_CONTAINER (vbox), hbox);
-  gtk_container_add (GTK_CONTAINER (hbox), button);
-  gtk_container_add (GTK_CONTAINER (hbox), entry);
+  gtk_box_append (GTK_BOX (vbox), hbox);
+  gtk_box_append (GTK_BOX (hbox), button);
+  gtk_box_append (GTK_BOX (hbox), entry);
   g_object_set_data (G_OBJECT (button), "user_data", entry);
   g_signal_connect (button, "clicked",
                    G_CALLBACK (iter_insert_with_values),
                    tree_view);
 
   button = gtk_button_new_with_label ("gtk_tree_store_insert_before");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked",
                     G_CALLBACK (iter_insert_before),
                     tree_view);
@@ -406,7 +406,7 @@ make_window (gint view_type)
   gtk_widget_set_sensitive (button, FALSE);
 
   button = gtk_button_new_with_label ("gtk_tree_store_insert_after");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked",
                     G_CALLBACK (iter_insert_after),
                     tree_view);
@@ -416,13 +416,13 @@ make_window (gint view_type)
   gtk_widget_set_sensitive (button, FALSE);
 
   button = gtk_button_new_with_label ("gtk_tree_store_prepend");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked",
                     G_CALLBACK (iter_prepend),
                     tree_view);
 
   button = gtk_button_new_with_label ("gtk_tree_store_append");
-  gtk_container_add (GTK_CONTAINER (vbox), button);
+  gtk_box_append (GTK_BOX (vbox), button);
   g_signal_connect (button, "clicked",
                     G_CALLBACK (iter_append),
                     tree_view);
diff --git a/testsuite/a11y/children.c b/testsuite/a11y/children.c
index f5c7d588a2..f024e8f5fa 100644
--- a/testsuite/a11y/children.c
+++ b/testsuite/a11y/children.c
@@ -98,7 +98,7 @@ remove_child (STATE *state,
         child = gtk_widget_get_parent (child);
     }
 
-  gtk_container_remove (GTK_CONTAINER (state->widget), child);
+  gtk_box_remove (GTK_BOX (state->widget), child);
 }
 
 static void
@@ -170,7 +170,7 @@ test_add_remove (GtkWidget *widget)
           child_accessible = gtk_widget_get_accessible (state.child[i]);
           g_signal_connect (child_accessible, "notify::accessible-parent",
                             G_CALLBACK (parent_notify), &(parent_data[i]));
-          gtk_container_add (GTK_CONTAINER (widget), state.child[i]);
+          gtk_box_append (GTK_BOX (widget), state.child[i]);
         }
       else
         child_accessible = atk_object_ref_accessible_child (accessible, i);
diff --git a/testsuite/gtk/action.c b/testsuite/gtk/action.c
index c0f5265395..db7fa27c70 100644
--- a/testsuite/gtk/action.c
+++ b/testsuite/gtk/action.c
@@ -59,7 +59,7 @@ test_action (void)
   button = gtk_button_new ();
 
   gtk_window_set_child (GTK_WINDOW (window), box);
-  gtk_container_add (GTK_CONTAINER (box), button);
+  gtk_box_append (GTK_BOX (box), button);
 
   win_actions = g_simple_action_group_new ();
   g_action_map_add_action_entries (G_ACTION_MAP (win_actions),
@@ -160,7 +160,7 @@ test_text (void)
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   text = gtk_text_new ();
 
-  gtk_container_add (GTK_CONTAINER (box), text);
+  gtk_box_append (GTK_BOX (box), text);
 
   clipboard_actions = g_simple_action_group_new ();
   g_action_map_add_action_entries (G_ACTION_MAP (clipboard_actions),
diff --git a/testsuite/gtk/gestures.c b/testsuite/gtk/gestures.c
index 1a98400309..b9ab90b3e8 100644
--- a/testsuite/gtk/gestures.c
+++ b/testsuite/gtk/gestures.c
@@ -424,8 +424,8 @@ test_phases (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -476,8 +476,8 @@ test_mixed (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -535,8 +535,8 @@ test_early_exit (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -590,8 +590,8 @@ test_claim_capture (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -637,8 +637,8 @@ test_claim_target (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -684,8 +684,8 @@ test_claim_bubble (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -738,8 +738,8 @@ test_early_claim_capture (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -795,8 +795,8 @@ test_late_claim_capture (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -854,8 +854,8 @@ test_group (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -905,8 +905,8 @@ test_gestures_outside_grab (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -965,8 +965,8 @@ test_gestures_inside_grab (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -1025,8 +1025,8 @@ test_multitouch_on_single (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -1076,8 +1076,8 @@ test_multitouch_activation (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
@@ -1152,8 +1152,8 @@ test_multitouch_interaction (void)
   gtk_widget_set_vexpand (C, TRUE);
   gtk_widget_set_name (C, "C");
 
-  gtk_container_add (GTK_CONTAINER (A), B);
-  gtk_container_add (GTK_CONTAINER (B), C);
+  gtk_box_append (GTK_BOX (A), B);
+  gtk_box_append (GTK_BOX (B), C);
 
   gtk_widget_show (A);
 
diff --git a/testsuite/gtk/propertylookuplistmodel.c b/testsuite/gtk/propertylookuplistmodel.c
index a79d07cfe2..b151e15a62 100644
--- a/testsuite/gtk/propertylookuplistmodel.c
+++ b/testsuite/gtk/propertylookuplistmodel.c
@@ -115,7 +115,7 @@ create_widget_tree (void)
   gtk_window_set_child (GTK_WINDOW (window), box);
 
   grid = gtk_grid_new ();
-  gtk_container_add (GTK_CONTAINER (box), grid);
+  gtk_box_append (GTK_BOX (box), grid);
 
   label = gtk_label_new ("Hello World");
   gtk_grid_attach (GTK_GRID (grid), label, 0, 0, 1, 1);
@@ -218,7 +218,7 @@ test_change_property (void)
   assert_model (model, "GtkLabel");
   assert_changes (model, "1-3");
 
-  gtk_container_add (GTK_CONTAINER (grandparent), widget);
+  gtk_box_append (GTK_BOX (grandparent), widget);
   assert_model (model, "GtkLabel GtkBox GtkWindow");
   assert_changes (model, "1+2");
 
diff --git a/testsuite/gtk/widgetorder.c b/testsuite/gtk/widgetorder.c
index c0ffafaeac..0603f2ad98 100644
--- a/testsuite/gtk/widgetorder.c
+++ b/testsuite/gtk/widgetorder.c
@@ -6,7 +6,7 @@ simple (void)
   GtkWidget *box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   GtkWidget *l = gtk_label_new ("");
 
-  gtk_container_add (GTK_CONTAINER (box), l);
+  gtk_box_append (GTK_BOX (box), l);
 
   g_assert (gtk_widget_get_parent (l) == box);
   g_assert (gtk_widget_get_prev_sibling (l) == NULL);
@@ -25,8 +25,8 @@ two (void)
   GtkWidget *l1 = gtk_label_new ("");
   GtkWidget *l2 = gtk_label_new ("");
 
-  gtk_container_add (GTK_CONTAINER (box), l1);
-  gtk_container_add (GTK_CONTAINER (box), l2);
+  gtk_box_append (GTK_BOX (box), l1);
+  gtk_box_append (GTK_BOX (box), l2);
 
   g_assert (gtk_widget_get_parent (l1) == box);
   g_assert (gtk_widget_get_prev_sibling (l1) == NULL);



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