GtkWindow: change muxer setup with application

Previously, GtkWindow would add the "app" action group to its own
toplevel muxer.

Change the setup so that GtkApplication creates the toplevel muxer and
adds itself to it as "app".  Use this muxer as the parent muxer of any
GtkWindow associated with the application.

This saves a small amount of memory and will allow for accels to be
propagated from the application through to all of the windows.

gtk/gtkapplication.c

@@ -143,6 +143,7 @@ struct _GtkApplicationPrivate
   GMenuModel      *menubar;
 
   gboolean register_session;
+  GtkActionMuxer  *muxer;
 
 #ifdef GDK_WINDOWING_X11
   guint next_id;
@@ -396,19 +397,24 @@ gtk_application_focus_in_event_cb (GtkWindow      *window,
 }
 
 static void
-gtk_application_startup (GApplication *application)
+gtk_application_startup (GApplication *g_application)
 {
+  GtkApplication *application = GTK_APPLICATION (g_application);
+
   G_APPLICATION_CLASS (gtk_application_parent_class)
-    ->startup (application);
+    ->startup (g_application);
+
+  application->priv->muxer = gtk_action_muxer_new ();
+  gtk_action_muxer_insert (application->priv->muxer, "app", G_ACTION_GROUP (application));
 
   gtk_init (0, 0);
 
 #ifdef GDK_WINDOWING_X11
-  gtk_application_startup_x11 (GTK_APPLICATION (application));
+  gtk_application_startup_x11 (application);
 #endif
 
 #ifdef GDK_WINDOWING_QUARTZ
-  gtk_application_startup_quartz (GTK_APPLICATION (application));
+  gtk_application_startup_quartz (application);
 #endif
 }
 
@@ -1688,3 +1694,16 @@ gtk_application_is_inhibited (GtkApplication             *application,
 }
 
 #endif
+
+GtkActionMuxer *
+gtk_application_get_parent_muxer_for_window (GtkWindow *window)
+{
+  GtkApplication *application;
+
+  application = gtk_window_get_application (window);
+
+  if (!application)
+    return NULL;
+
+  return application->priv->muxer;
+}

gtk/gtkapplicationprivate.h

@@ -23,6 +23,8 @@
 
 #include "gtkapplicationwindow.h"
 
+#include "gtkactionmuxer.h"
+
 G_GNUC_INTERNAL
 gboolean                gtk_application_window_publish                  (GtkApplicationWindow *window,
                                                                          GDBusConnection      *session,
@@ -40,4 +42,7 @@ const gchar *           gtk_application_get_app_menu_object_path        (GtkAppl
 G_GNUC_INTERNAL
 const gchar *           gtk_application_get_menubar_object_path         (GtkApplication       *application);
 
+G_GNUC_INTERNAL
+GtkActionMuxer *        gtk_application_get_parent_muxer_for_window     (GtkWindow                *window);
+
 #endif /* __GTK_APPLICATION_PRIVATE_H__ */

gtk/gtkwidget.c

@@ -64,6 +64,7 @@
 #include "gtkplug.h"
 #include "gtktypebuiltins.h"
 #include "a11y/gtkwidgetaccessible.h"
+#include "gtkapplicationprivate.h"
 
 /* for the use of round() */
 #include "fallback-c89.c"
@@ -15457,18 +15458,26 @@ _gtk_widget_set_style (GtkWidget *widget,
 void
 _gtk_widget_update_parent_muxer (GtkWidget *widget)
 {
-  GtkWidget *parent;
   GtkActionMuxer *parent_muxer;
 
   if (widget->priv->muxer == NULL)
     return;
 
-  if (GTK_IS_MENU (widget))
-    parent = gtk_menu_get_attach_widget (GTK_MENU (widget));
+  if (GTK_IS_WINDOW (widget))
+    {
+      parent_muxer = gtk_application_get_parent_muxer_for_window (GTK_WINDOW (widget));
+    }
   else
-    parent = gtk_widget_get_parent (widget);
+    {
+      GtkWidget *parent;
 
-  parent_muxer = parent ? _gtk_widget_get_action_muxer (parent) : NULL;
+      if (GTK_IS_MENU (widget))
+        parent = gtk_menu_get_attach_widget (GTK_MENU (widget));
+      else
+        parent = gtk_widget_get_parent (widget);
+
+      parent_muxer = parent ? _gtk_widget_get_action_muxer (parent) : NULL;
+    }
 
   gtk_action_muxer_set_parent (widget->priv->muxer, parent_muxer);
 }

gtk/gtkwindow.c

@@ -2958,8 +2958,7 @@ gtk_window_set_application (GtkWindow      *window,
           gtk_application_add_window (priv->application, window);
         }
 
-      /* don't use a normal cast: application may be NULL */
-      gtk_widget_insert_action_group (GTK_WIDGET (window), "app", (GActionGroup *) application);
+      _gtk_widget_update_parent_muxer (GTK_WIDGET (window));
 
       g_object_notify (G_OBJECT (window), "application");
     }