[gtk/wip/chergert/textundo: 17/20] gtk-demo: add an undo demo for GtkEntry

[Christian Hergert <chergert src gnome org>]

commit a441e1cd5f9f5a9b4cd23e14486d71019d6b174f
Author: Christian Hergert <chergert redhat com>
Date:   Fri Nov 1 11:20:02 2019 -0700

    gtk-demo: add an undo demo for GtkEntry

 demos/gtk-demo/demo.gresource.xml |  1 +
 demos/gtk-demo/entry_undo.c       | 52 +++++++++++++++++++++++++++++++++++++++
 demos/gtk-demo/meson.build        |  1 +
 3 files changed, 54 insertions(+)
---
diff --git a/demos/gtk-demo/demo.gresource.xml b/demos/gtk-demo/demo.gresource.xml
index 625ecac18a..a299fe9101 100644
--- a/demos/gtk-demo/demo.gresource.xml
+++ b/demos/gtk-demo/demo.gresource.xml
@@ -169,6 +169,7 @@
     <file>editable_cells.c</file>
     <file>entry_buffer.c</file>
     <file>entry_completion.c</file>
+    <file>entry_undo.c</file>
     <file>expander.c</file>
     <file>filtermodel.c</file>
     <file>fishbowl.c</file>
diff --git a/demos/gtk-demo/entry_undo.c b/demos/gtk-demo/entry_undo.c
new file mode 100644
index 0000000000..e94aefd529
--- /dev/null
+++ b/demos/gtk-demo/entry_undo.c
@@ -0,0 +1,52 @@
+/* Entry/Entry Undo
+ *
+ * GtkEntry can provide basic Undo/Redo support using standard keyboard
+ * accelerators such as Primary+z to undo and Primary+Shift+z to redo.
+ * Additionally, Primary+y can be used to redo.
+ *
+ * Use gtk_entry_set_enable_undo() to enable undo/redo support.
+ */
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+GtkWidget *
+do_entry_undo (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+  GtkWidget *vbox;
+  GtkWidget *label;
+  GtkWidget *entry;
+
+  if (!window)
+    {
+      window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+      gtk_window_set_display (GTK_WINDOW (window),
+                              gtk_widget_get_display (do_widget));
+      gtk_window_set_title (GTK_WINDOW (window), "Entry Undo");
+      gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
+      g_signal_connect (window, "destroy",
+                        G_CALLBACK (gtk_widget_destroyed), &window);
+
+      vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 5);
+      g_object_set (vbox, "margin", 5, NULL);
+      gtk_container_add (GTK_CONTAINER (window), vbox);
+
+      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);
+
+      /* Create our entry */
+      entry = gtk_entry_new ();
+      gtk_editable_set_enable_undo (GTK_EDITABLE (entry), TRUE);
+      gtk_container_add (GTK_CONTAINER (vbox), entry);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_widget_show (window);
+  else
+    gtk_widget_destroy (window);
+
+  return window;
+}
diff --git a/demos/gtk-demo/meson.build b/demos/gtk-demo/meson.build
index c021f9f60a..a107d52b58 100644
--- a/demos/gtk-demo/meson.build
+++ b/demos/gtk-demo/meson.build
@@ -24,6 +24,7 @@ demos = files([
   'editable_cells.c',
   'entry_buffer.c',
   'entry_completion.c',
+  'entry_undo.c',
   'expander.c',
   'filtermodel.c',
   'fishbowl.c',