[gedit] Move tab DND support to GeditNotebook

[Sébastien Wilmet <swilmet src gnome org>]

commit 7aee29ecc9efb49fbd16798245410cbd90f45256
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Thu Jun 25 13:39:25 2015 +0200

    Move tab DND support to GeditNotebook
    
    To remove the dependency on GeditNotebook in GeditView. A class should
    not be aware of who contains it. The purpose is to make GeditView more
    self-contained, so it can be reused more easily in other text editors.
    
    Instead of handling the DND in the object method handler of GeditView,
    we connect to the signal externally, which works fine too. And since the
    code is related to notebooks, it's more logical to have that code in
    GeditNotebook.

 gedit/gedit-notebook.c |   95 ++++++++++++++++++++++++++++++++++++++++++++++++
 gedit/gedit-view.c     |   57 +----------------------------
 2 files changed, 96 insertions(+), 56 deletions(-)
---
diff --git a/gedit/gedit-notebook.c b/gedit/gedit-notebook.c
index 16465ca..1022ed2 100644
--- a/gedit/gedit-notebook.c
+++ b/gedit/gedit-notebook.c
@@ -33,6 +33,11 @@
 
 #define GEDIT_NOTEBOOK_GROUP_NAME "GeditNotebookGroup"
 
+/* The DND targets defined in GeditView start at 100.
+ * Those defined in GtkSourceView start at 200.
+ */
+#define TARGET_TAB 150
+
 struct _GeditNotebookPrivate
 {
        /* History of focused pages. The first element contains the most recent
@@ -273,6 +278,66 @@ switch_to_last_focused_page (GeditNotebook *notebook,
        }
 }
 
+static GtkWidget *
+get_notebook_from_view (GtkWidget *view)
+{
+       GtkWidget *widget;
+
+       widget = view;
+
+       do
+       {
+               widget = gtk_widget_get_parent (widget);
+       }
+       while (!GEDIT_IS_NOTEBOOK (widget));
+
+       return widget;
+}
+
+static void
+drag_data_received_cb (GtkWidget        *widget,
+                      GdkDragContext   *context,
+                      gint              x,
+                      gint              y,
+                      GtkSelectionData *selection_data,
+                      guint             info,
+                      guint             timestamp)
+{
+       GtkWidget *notebook;
+       GtkWidget *new_notebook;
+       GtkWidget *page;
+
+       if (info != TARGET_TAB)
+       {
+               return;
+       }
+
+       notebook = gtk_drag_get_source_widget (context);
+
+       if (!GTK_IS_WIDGET (notebook))
+       {
+               return;
+       }
+
+       page = *(GtkWidget **) gtk_selection_data_get_data (selection_data);
+       g_return_if_fail (page != NULL);
+
+       /* We need to iterate and get the notebook of the target view
+        * because we can have several notebooks per window.
+        */
+       new_notebook = get_notebook_from_view (widget);
+
+       if (notebook != new_notebook)
+       {
+               gedit_notebook_move_tab (GEDIT_NOTEBOOK (notebook),
+                                        GEDIT_NOTEBOOK (new_notebook),
+                                        GEDIT_TAB (page),
+                                        0);
+       }
+
+       gtk_drag_finish (context, TRUE, TRUE, timestamp);
+}
+
 static void
 gedit_notebook_page_removed (GtkNotebook *notebook,
                              GtkWidget   *page,
@@ -300,6 +365,9 @@ gedit_notebook_page_added (GtkNotebook *notebook,
                            guint        page_num)
 {
        GtkWidget *tab_label;
+       GeditView *view;
+
+       g_return_if_fail (GEDIT_IS_TAB (page));
 
        tab_label = gtk_notebook_get_tab_label (notebook, page);
        g_return_if_fail (GEDIT_IS_TAB_LABEL (tab_label));
@@ -314,6 +382,12 @@ gedit_notebook_page_added (GtkNotebook *notebook,
                          "close-clicked",
                          G_CALLBACK (close_button_clicked_cb),
                          notebook);
+
+       view = gedit_tab_get_view (GEDIT_TAB (page));
+       g_signal_connect (view,
+                         "drag-data-received",
+                         G_CALLBACK (drag_data_received_cb),
+                         NULL);
 }
 
 static void
@@ -323,6 +397,7 @@ gedit_notebook_remove (GtkContainer *container,
        GtkNotebook *notebook = GTK_NOTEBOOK (container);
        GeditNotebookPrivate *priv = GEDIT_NOTEBOOK (container)->priv;
        GtkWidget *tab_label;
+       GeditView *view;
 
        g_return_if_fail (GEDIT_IS_TAB (widget));
 
@@ -336,6 +411,9 @@ gedit_notebook_remove (GtkContainer *container,
                                              G_CALLBACK (close_button_clicked_cb),
                                              notebook);
 
+       view = gedit_tab_get_view (GEDIT_TAB (widget));
+       g_signal_handlers_disconnect_by_func (view, drag_data_received_cb, NULL);
+
        /* This is where GtkNotebook will remove the page. By doing so, it
         * will also switch to a new page, messing up our focus list. So we
         * set a flag here to ignore the switch temporarily.
@@ -479,6 +557,8 @@ gedit_notebook_add_tab (GeditNotebook *notebook,
                        gboolean       jump_to)
 {
        GtkWidget *tab_label;
+       GeditView *view;
+       GtkTargetList *target_list;
 
        g_return_if_fail (GEDIT_IS_NOTEBOOK (notebook));
        g_return_if_fail (GEDIT_IS_TAB (tab));
@@ -503,6 +583,21 @@ gedit_notebook_add_tab (GeditNotebook *notebook,
                                 "tab-expand", TRUE,
                                 NULL);
 
+       /* Drag and drop support: move a tab to another notebook, with the drop
+        * zone in the GeditView. The drop zone in the tab labels is already
+        * implemented by GtkNotebook.
+        */
+       view = gedit_tab_get_view (tab);
+       target_list = gtk_drag_dest_get_target_list (GTK_WIDGET (view));
+
+       if (target_list != NULL)
+       {
+               gtk_target_list_add (target_list,
+                                    gdk_atom_intern_static_string ("GTK_NOTEBOOK_TAB"),
+                                    GTK_TARGET_SAME_APP,
+                                    TARGET_TAB);
+       }
+
        /* The signal handler may have reordered the tabs */
        position = gtk_notebook_page_num (GTK_NOTEBOOK (notebook),
                                          GTK_WIDGET (tab));
diff --git a/gedit/gedit-view.c b/gedit/gedit-view.c
index 9ba45da..b4dc063 100644
--- a/gedit/gedit-view.c
+++ b/gedit/gedit-view.c
@@ -33,15 +33,13 @@
 #include "gedit-settings.h"
 #include "gedit-app.h"
 #include "gedit-app-private.h"
-#include "gedit-notebook.h"
 
 #define GEDIT_VIEW_SCROLL_MARGIN 0.02
 
 enum
 {
        TARGET_URI_LIST = 100,
-       TARGET_XDNDDIRECTSAVE,
-       TARGET_TAB
+       TARGET_XDNDDIRECTSAVE
 };
 
 struct _GeditViewPrivate
@@ -142,10 +140,6 @@ gedit_view_init (GeditView *view)
                                     0,
                                     TARGET_XDNDDIRECTSAVE);
                gtk_target_list_add_uri_targets (target_list, TARGET_URI_LIST);
-               gtk_target_list_add (target_list,
-                                    gdk_atom_intern_static_string ("GTK_NOTEBOOK_TAB"),
-                                    GTK_TARGET_SAME_APP,
-                                    TARGET_TAB);
        }
 
        view->priv->extensions =
@@ -333,22 +327,6 @@ gedit_view_drag_motion (GtkWidget      *widget,
        return drop_zone;
 }
 
-static GtkWidget *
-get_notebook_from_view (GtkWidget *view)
-{
-       GtkWidget *widget;
-
-       widget = view;
-
-       do
-       {
-               widget = gtk_widget_get_parent (widget);
-       }
-       while (!GEDIT_IS_NOTEBOOK (widget));
-
-       return widget;
-}
-
 static void
 gedit_view_drag_data_received (GtkWidget        *widget,
                               GdkDragContext   *context,
@@ -378,39 +356,6 @@ gedit_view_drag_data_received (GtkWidget        *widget,
                        break;
 
                }
-               case TARGET_TAB:
-               {
-                       GtkWidget *notebook;
-                       GtkWidget *new_notebook;
-                       GtkWidget *page;
-
-                       notebook = gtk_drag_get_source_widget (context);
-
-                       if (!GTK_IS_WIDGET (notebook))
-                       {
-                               return;
-                       }
-
-                       page = *(GtkWidget **) gtk_selection_data_get_data (selection_data);
-                       g_return_if_fail (page != NULL);
-
-                       /* We need to iterate and get the notebook of the target view
-                        * because we can have several notebooks per window.
-                        */
-                       new_notebook = get_notebook_from_view (widget);
-
-                       if (notebook != new_notebook)
-                       {
-                               gedit_notebook_move_tab (GEDIT_NOTEBOOK (notebook),
-                                                        GEDIT_NOTEBOOK (new_notebook),
-                                                        GEDIT_TAB (page),
-                                                        0);
-                       }
-
-                       gtk_drag_finish (context, TRUE, TRUE, timestamp);
-
-                       break;
-               }
                case TARGET_XDNDDIRECTSAVE:
                {
                        GeditView *view;