[gedit/wip/tab-dnd] Move tab DND support to GeditNotebook

[Sébastien Wilmet <swilmet src gnome org>]

commit 48e714a0a6f89a0d147036937092290b134a00b5
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Thu Jun 25 13:39:25 2015 +0200

    Move tab DND support to GeditNotebook
    
    So GeditView doesn't depend on GeditNotebook. A class should not be
    aware of who contains it.
    
    It is more logical to implement the tab DND support (to drag and drop a
    tab to another notebook) in GeditNotebook.

 gedit/gedit-notebook.c |   84 ++++++++++++++++++++++++++++++++++++++++++++++++
 gedit/gedit-view.c     |   57 +--------------------------------
 2 files changed, 85 insertions(+), 56 deletions(-)
---
diff --git a/gedit/gedit-notebook.c b/gedit/gedit-notebook.c
index ec0deec..6189411 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 102
+
 struct _GeditNotebookPrivate
 {
        /* History of focused pages. The first element contains the most recent
@@ -460,6 +465,66 @@ gedit_notebook_init (GeditNotebook *notebook)
        gtk_container_set_border_width (GTK_CONTAINER (notebook), 0);
 }
 
+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);
+}
+
 /**
  * gedit_notebook_add_tab:
  * @notebook: a #GeditNotebook
@@ -476,6 +541,8 @@ 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));
@@ -500,6 +567,23 @@ gedit_notebook_add_tab (GeditNotebook *notebook,
                                 "tab-expand", TRUE,
                                 NULL);
 
+       /* Drag and drop support: move a tab to another notebook. */
+       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);
+       }
+
+       g_signal_connect (view,
+                         "drag-data-received",
+                         G_CALLBACK (drag_data_received_cb),
+                         NULL);
+
        /* 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;