initial import

1 files changed, 724 insertions, 0 deletions

diff --git a/module/main.c b/module/main.c
new file mode 100644
index 0000000..42ea332
--- /dev/null
+++ b/module/main.c
@@ -0,0 +1,724 @@
+/*
+ * Copyright 2012 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Ryan Lortie <desrt@desrt.ca>
+ *          William Hua <william.hua@canonical.com>
+ */
+
+#include <gtk/gtk.h>
+#include <gdk/gdkx.h>
+
+#include "../global.h"
+#include "../libtopmenu-client/topmenu-client.h"
+#include "../libtopmenu-client/topmenu-monitor.h"
+
+#include "menuitem-proxy.h"
+#include "appmenu.h"
+#include "data.h"
+
+static gboolean already_initialized = FALSE;
+
+static void (* pre_hijacked_window_realize)                          (GtkWidget      *widget);
+
+static void (* pre_hijacked_window_unrealize)                        (GtkWidget      *widget);
+
+#if GTK_MAJOR_VERSION == 3
+static void (* pre_hijacked_application_window_realize)              (GtkWidget      *widget);
+#endif
+
+static void (* pre_hijacked_menu_bar_realize)                        (GtkWidget      *widget);
+
+static void (* pre_hijacked_menu_bar_unrealize)                      (GtkWidget      *widget);
+
+static void (* pre_hijacked_widget_size_allocate)                    (GtkWidget      *widget,
+                                                                      GtkAllocation  *allocation);
+
+static void (* pre_hijacked_menu_bar_size_allocate)                  (GtkWidget      *widget,
+                                                                      GtkAllocation  *allocation);
+
+#if GTK_MAJOR_VERSION == 2
+static void (* pre_hijacked_menu_bar_size_request)                   (GtkWidget      *widget,
+                                                                      GtkRequisition *requisition);
+#elif GTK_MAJOR_VERSION == 3
+static void (* pre_hijacked_menu_bar_get_preferred_width)            (GtkWidget      *widget,
+                                                                      gint           *minimum_width,
+                                                                      gint           *natural_width);
+
+static void (* pre_hijacked_menu_bar_get_preferred_height)           (GtkWidget      *widget,
+                                                                      gint           *minimum_height,
+                                                                      gint           *natural_height);
+
+static void (* pre_hijacked_menu_bar_get_preferred_width_for_height) (GtkWidget      *widget,
+                                                                      gint            height,
+                                                                      gint           *minimum_width,
+                                                                      gint           *natural_width);
+
+static void (* pre_hijacked_menu_bar_get_preferred_height_for_width) (GtkWidget      *widget,
+                                                                      gint            width,
+                                                                      gint           *minimum_height,
+                                                                      gint           *natural_height);
+#endif
+
+static void
+handle_should_hide_menubar_updated (GObject    *object,
+                                    GParamSpec *pspec,
+                                    gpointer    user_data);
+
+static void
+count_container_items_helper (GtkWidget *widget, gpointer data)
+{
+	gint *count = data;
+	(*count)++;
+}
+
+static gint
+count_container_items (GtkContainer *container)
+{
+	gint count = 0;
+	gtk_container_foreach (container, count_container_items_helper, &count);
+	return count;
+}
+
+
+
+
+static gboolean
+topmenu_should_hide_menubar_on_window (GtkWindow *window)
+{
+	TopMenuMonitor *monitor = topmenu_monitor_get_instance ();
+
+	if (topmenu_is_window_blacklisted (window))
+		return FALSE;
+
+	return monitor->available;
+}
+
+static gboolean
+topmenu_should_hide_menubar (GtkWidget *widget)
+{
+	GtkWindow *window = GTK_WINDOW (gtk_widget_get_toplevel (widget));
+
+	g_return_val_if_fail (GTK_IS_MENU_SHELL (widget), FALSE);
+
+	return topmenu_should_hide_menubar_on_window (window);
+}
+
+static void
+topmenu_prepare_window (GtkWindow *window)
+{
+	WindowData *window_data;
+
+	g_return_if_fail (GTK_IS_WINDOW (window));
+	g_return_if_fail (gtk_widget_get_realized (GTK_WIDGET (window)));
+
+	window_data = topmenu_get_window_data (window);
+
+	if (window_data == NULL)
+		return; // Window is ignored
+
+	if (window_data->appmenubar != 0)
+		return; // Already prepared
+
+	window_data->appmenubar = TOPMENU_APP_MENU_BAR (topmenu_app_menu_bar_new ());
+	gtk_widget_show(GTK_WIDGET(window_data->appmenubar));
+
+	topmenu_app_menu_bar_set_app_menu (window_data->appmenubar,
+	                                   topmenu_appmenu_build(&window_data->appmenu));
+}
+
+static void
+topmenu_connect_window (GtkWindow *window)
+{
+	WindowData *window_data;
+
+	g_return_if_fail (GTK_IS_WINDOW (window));
+	g_return_if_fail (gtk_widget_get_realized (GTK_WIDGET (window)));
+
+	window_data = topmenu_get_window_data (window);
+
+	if (window_data == NULL)
+		return; // Window is ignored
+
+	if (window_data->monitor_connection_id != 0)
+		return; // Already connected
+
+	g_return_if_fail (window_data->menus != NULL); // Must contain one menu at least.
+	g_return_if_fail (window_data->appmenubar != NULL); // Must be prepared
+
+	TopMenuMonitor *monitor = topmenu_monitor_get_instance();
+	window_data->monitor_connection_id = g_signal_connect(monitor, "notify::available",
+	                                                      G_CALLBACK (handle_should_hide_menubar_updated), window);
+
+	topmenu_client_connect_window_widget (gtk_widget_get_window (GTK_WIDGET (window)),
+	                                      GTK_WIDGET (window_data->appmenubar));
+}
+
+static void
+topmenu_disconnect_window (GtkWindow *window)
+{
+	WindowData *window_data;
+
+	g_return_if_fail (GTK_IS_WINDOW (window));
+
+	window_data = topmenu_get_window_data (window);
+
+	if (window_data == NULL)
+		return; // Already disconnected or ignored
+
+	if (window_data->monitor_connection_id == 0)
+		return; // Already disconnected
+
+	TopMenuMonitor *monitor = topmenu_monitor_get_instance();
+	g_signal_handler_disconnect(monitor, window_data->monitor_connection_id);
+	window_data->monitor_connection_id = 0;
+
+	if (window_data->appmenu.menu)
+		topmenu_appmenu_destroy(&window_data->appmenu);
+
+	if (window_data->appmenubar)
+	{
+		gtk_widget_destroy (GTK_WIDGET (window_data->appmenubar));
+		window_data->appmenubar = NULL;
+	}
+
+	if (gtk_widget_get_realized (GTK_WIDGET(window)))
+	{
+		topmenu_client_disconnect_window (gtk_widget_get_window (GTK_WIDGET (window)));
+	}
+}
+
+static gint
+compute_shell_position_in_appmenu (WindowData *window_data, GtkMenuShell *menu_shell)
+{
+	GSList *iter;
+	gint position = 1; // Skip app_menu_item
+
+	for (iter = window_data->menus; iter; iter = g_slist_next (iter))
+	{
+		if (iter->data == menu_shell) {
+			return position;
+		}
+
+		position += count_container_items (GTK_CONTAINER (iter->data));
+	}
+
+	return -1;
+}
+
+static void
+add_menu_item_to_appmenu (WindowData *window_data, GtkMenuItem *item, gint position)
+{
+	MenuItemData *item_data = topmenu_get_menu_item_data (item);
+	item_data->proxy = topmenu_create_proxy_menu_item (item);
+
+	gtk_menu_shell_insert (GTK_MENU_SHELL (window_data->appmenubar),
+	                       GTK_WIDGET (item_data->proxy), position);
+}
+
+static void
+remove_menu_item_from_appmenu (WindowData *window_data, GtkMenuItem *item)
+{
+	MenuItemData *item_data = topmenu_get_menu_item_data (item);
+
+	if (item_data->proxy) {
+		gtk_widget_destroy (GTK_WIDGET (item_data->proxy));
+		item_data->proxy = NULL;
+	}
+}
+
+static void
+handle_shell_insert (GtkMenuShell *menu_shell, GtkWidget *child, gint position, WindowData *window_data)
+{
+	GtkMenuItem *item = GTK_MENU_ITEM (child);
+	gint offset = compute_shell_position_in_appmenu (window_data, menu_shell);
+	g_return_if_fail (offset >= 0);
+
+	add_menu_item_to_appmenu (window_data, item, offset + position);
+}
+
+static void
+handle_shell_remove (GtkMenuShell *menu_shell, GtkWidget *widget, WindowData *window_data)
+{
+	GtkMenuItem *item = GTK_MENU_ITEM (widget);
+	remove_menu_item_from_appmenu (window_data, item);
+}
+
+typedef struct _AddShellCbData
+{
+	WindowData *window_data;
+	gint position;
+} AddShellCbData;
+
+static void
+add_shell_cb (GtkWidget *widget, gpointer user_data)
+{
+	AddShellCbData *data = user_data;
+	GtkMenuItem *item = GTK_MENU_ITEM (widget);
+	add_menu_item_to_appmenu (data->window_data, item, data->position);
+
+	data->position++;
+}
+
+static void
+add_shell_to_appmenu (WindowData *window_data, GtkMenuShell *menu_shell)
+{
+	AddShellCbData data;
+	data.window_data = window_data;
+	data.position = compute_shell_position_in_appmenu (window_data, menu_shell);
+
+	g_warn_if_fail (data.position >= 0);
+
+	gtk_container_foreach (GTK_CONTAINER (menu_shell),
+	                       add_shell_cb, &data);
+
+	topmenu_appmenu_scan_for_items (&window_data->appmenu, menu_shell);
+
+	g_signal_connect (menu_shell, "insert",
+	                  G_CALLBACK (handle_shell_insert), window_data);
+	g_signal_connect (menu_shell, "remove",
+	                  G_CALLBACK (handle_shell_remove), window_data);
+}
+
+static void
+remove_shell_cb (GtkWidget *widget, gpointer user_data)
+{
+	WindowData *window_data = user_data;
+	GtkMenuItem *item = GTK_MENU_ITEM (widget);
+	remove_menu_item_from_appmenu (window_data, item);
+}
+
+static void
+remove_shell_from_appmenu (WindowData *window_data, GtkMenuShell *menu_shell)
+{
+	gtk_container_foreach (GTK_CONTAINER (menu_shell),
+	                       remove_shell_cb, window_data);
+
+	g_signal_handlers_disconnect_by_data (menu_shell, window_data);
+}
+
+static void
+topmenu_disconnect_menu_shell (GtkWindow    *window,
+                               GtkMenuShell *menu_shell)
+{
+	WindowData *window_data;
+	MenuShellData *menu_shell_data;
+
+	g_return_if_fail (GTK_IS_WINDOW (window));
+	g_return_if_fail (GTK_IS_MENU_SHELL (menu_shell));
+
+	menu_shell_data = topmenu_get_menu_shell_data (menu_shell);
+
+	g_warn_if_fail (window == menu_shell_data->window);
+
+	window_data = topmenu_get_window_data (menu_shell_data->window);
+
+	if (window_data != NULL)
+	{
+		GSList *iter;
+
+		for (iter = window_data->menus; iter != NULL; iter = g_slist_next (iter))
+			if (GTK_MENU_SHELL(iter->data) == menu_shell)
+				break;
+
+		if (iter != NULL)
+		{
+			GtkMenuShell *menu_shell = GTK_MENU_SHELL(iter->data);
+
+			remove_shell_from_appmenu (window_data, menu_shell);
+
+			window_data->menus = g_slist_delete_link (window_data->menus, iter);
+		}
+	}
+
+	menu_shell_data->window = NULL;
+}
+
+static void
+topmenu_connect_menu_shell (GtkWindow    *window,
+                            GtkMenuShell *menu_shell)
+{
+	MenuShellData *menu_shell_data;
+
+	g_return_if_fail (GTK_IS_WINDOW (window));
+	g_return_if_fail (GTK_IS_MENU_SHELL (menu_shell));
+
+	menu_shell_data = topmenu_get_menu_shell_data (menu_shell);
+
+	if (window != menu_shell_data->window)
+	{
+		WindowData *window_data;
+
+		if (menu_shell_data->window != NULL)
+			topmenu_disconnect_menu_shell (menu_shell_data->window, menu_shell);
+
+		window_data = topmenu_get_window_data (window);
+
+		if (window_data != NULL)
+		{
+			GSList *iter;
+
+			for (iter = window_data->menus; iter != NULL; iter = g_slist_next (iter))
+				if (GTK_MENU_SHELL(iter->data) == menu_shell)
+					break;
+
+			if (iter == NULL)
+			{
+				topmenu_prepare_window (window);
+
+				window_data->menus = g_slist_append (window_data->menus, menu_shell);
+
+				add_shell_to_appmenu (window_data, menu_shell);
+
+				topmenu_connect_window (window); // Does nothing if already connected
+			}
+		}
+
+		menu_shell_data->window = window;
+	}
+}
+
+static void
+handle_should_hide_menubar_updated (GObject    *object,
+                                    GParamSpec *pspec,
+                                    gpointer    user_data)
+{
+	g_return_if_fail (GTK_IS_WINDOW (user_data));
+
+	GtkWindow *window = GTK_WINDOW (user_data);
+	WindowData *window_data = topmenu_get_window_data (window);
+	GSList *iter;
+
+	for (iter = window_data->menus; iter != NULL; iter = g_slist_next (iter))
+	{
+		gtk_widget_queue_resize (GTK_WIDGET (iter->data));
+	}
+}
+
+static void
+hijacked_window_realize (GtkWidget *widget)
+{
+	g_return_if_fail (GTK_IS_WINDOW (widget));
+
+	if (pre_hijacked_window_realize != NULL)
+		(* pre_hijacked_window_realize) (widget);
+
+#if GTK_MAJOR_VERSION == 3
+	if (!GTK_IS_APPLICATION_WINDOW (widget))
+#endif
+		topmenu_get_window_data (GTK_WINDOW (widget));
+}
+
+static void
+hijacked_window_unrealize (GtkWidget *widget)
+{
+	g_return_if_fail (GTK_IS_WINDOW (widget));
+
+	if (pre_hijacked_window_unrealize != NULL)
+		(* pre_hijacked_window_unrealize) (widget);
+
+	topmenu_disconnect_window (GTK_WINDOW (widget));
+	topmenu_remove_window_data (GTK_WINDOW (widget));
+}
+
+#if GTK_MAJOR_VERSION == 3
+static void
+hijacked_application_window_realize (GtkWidget *widget)
+{
+	g_return_if_fail (GTK_IS_APPLICATION_WINDOW (widget));
+
+	if (pre_hijacked_application_window_realize != NULL)
+		(* pre_hijacked_application_window_realize) (widget);
+
+	gtk_window_get_window_data (GTK_WINDOW (widget));
+}
+#endif
+
+static void
+hijacked_menu_bar_realize (GtkWidget *widget)
+{
+	GtkWidget *window;
+
+	g_return_if_fail (GTK_IS_MENU_BAR (widget));
+
+	if (pre_hijacked_menu_bar_realize != NULL)
+		(* pre_hijacked_menu_bar_realize) (widget);
+
+	window = gtk_widget_get_toplevel (widget);
+
+	if (GTK_IS_WINDOW (window))
+		topmenu_connect_menu_shell (GTK_WINDOW (window), GTK_MENU_SHELL (widget));
+}
+
+static void
+hijacked_menu_bar_unrealize (GtkWidget *widget)
+{
+	MenuShellData *menu_shell_data;
+
+	g_return_if_fail (GTK_IS_MENU_BAR (widget));
+
+	if (pre_hijacked_menu_bar_unrealize != NULL)
+		(* pre_hijacked_menu_bar_unrealize) (widget);
+
+	menu_shell_data = topmenu_get_menu_shell_data (GTK_MENU_SHELL (widget));
+
+	if (menu_shell_data->window != NULL)
+		topmenu_disconnect_menu_shell (menu_shell_data->window, GTK_MENU_SHELL (widget));
+}
+
+static void
+hijacked_menu_bar_size_allocate (GtkWidget     *widget,
+                                 GtkAllocation *allocation)
+{
+	GtkAllocation zero = { 0, 0, 0, 0 };
+	GdkWindow *window;
+
+	g_return_if_fail (GTK_IS_MENU_BAR (widget));
+
+	if (topmenu_should_hide_menubar (widget))
+	{
+		/*
+	   * We manually assign an empty allocation to the menu bar to
+	   * prevent the container from attempting to draw it at all.
+	   */
+		if (pre_hijacked_widget_size_allocate != NULL)
+			(* pre_hijacked_widget_size_allocate) (widget, &zero);
+
+		/*
+	   * Then we move the GdkWindow belonging to the menu bar outside of
+	   * the clipping rectangle of the parent window so that we can't
+	   * see it.
+	   */
+		window = gtk_widget_get_window (widget);
+
+		if (window != NULL)
+			gdk_window_move_resize (window, -1, -1, 1, 1);
+	}
+	else if (pre_hijacked_menu_bar_size_allocate != NULL)
+		(* pre_hijacked_menu_bar_size_allocate) (widget, allocation);
+}
+
+#if GTK_MAJOR_VERSION == 2
+static void
+hijacked_menu_bar_size_request (GtkWidget      *widget,
+                                GtkRequisition *requisition)
+{
+	g_return_if_fail (GTK_IS_MENU_BAR (widget));
+
+	if (pre_hijacked_menu_bar_size_request != NULL)
+		(* pre_hijacked_menu_bar_size_request) (widget, requisition);
+
+	if (topmenu_should_hide_menubar(widget))
+	{
+		requisition->width = 0;
+		requisition->height = 0;
+	}
+}
+#elif GTK_MAJOR_VERSION == 3
+static void
+hijacked_menu_bar_get_preferred_width (GtkWidget *widget,
+                                       gint      *minimum_width,
+                                       gint      *natural_width)
+{
+	g_return_if_fail (GTK_IS_MENU_BAR (widget));
+
+	if (pre_hijacked_menu_bar_get_preferred_width != NULL)
+		(* pre_hijacked_menu_bar_get_preferred_width) (widget, minimum_width, natural_width);
+
+	if (gtk_widget_shell_shows_menubar (widget))
+	{
+		*minimum_width = 0;
+		*natural_width = 0;
+	}
+}
+
+static void
+hijacked_menu_bar_get_preferred_height (GtkWidget *widget,
+                                        gint      *minimum_height,
+                                        gint      *natural_height)
+{
+	g_return_if_fail (GTK_IS_MENU_BAR (widget));
+
+	if (pre_hijacked_menu_bar_get_preferred_height != NULL)
+		(* pre_hijacked_menu_bar_get_preferred_height) (widget, minimum_height, natural_height);
+
+	if (gtk_widget_shell_shows_menubar (widget))
+	{
+		*minimum_height = 0;
+		*natural_height = 0;
+	}
+}
+
+static void
+hijacked_menu_bar_get_preferred_width_for_height (GtkWidget *widget,
+                                                  gint       height,
+                                                  gint      *minimum_width,
+                                                  gint      *natural_width)
+{
+	g_return_if_fail (GTK_IS_MENU_BAR (widget));
+
+	if (pre_hijacked_menu_bar_get_preferred_width_for_height != NULL)
+		(* pre_hijacked_menu_bar_get_preferred_width_for_height) (widget, height, minimum_width, natural_width);
+
+	if (gtk_widget_shell_shows_menubar (widget))
+	{
+		*minimum_width = 0;
+		*natural_width = 0;
+	}
+}
+
+static void
+hijacked_menu_bar_get_preferred_height_for_width (GtkWidget *widget,
+                                                  gint       width,
+                                                  gint      *minimum_height,
+                                                  gint      *natural_height)
+{
+	g_return_if_fail (GTK_IS_MENU_BAR (widget));
+
+	if (pre_hijacked_menu_bar_get_preferred_height_for_width != NULL)
+		(* pre_hijacked_menu_bar_get_preferred_height_for_width) (widget, width, minimum_height, natural_height);
+
+	if (gtk_widget_shell_shows_menubar (widget))
+	{
+		*minimum_height = 0;
+		*natural_height = 0;
+	}
+}
+#endif
+
+static void
+hijack_window_class_vtable (GType type)
+{
+	GtkWidgetClass *widget_class = g_type_class_ref (type);
+	GType *children;
+	guint n;
+	guint i;
+
+	if (widget_class->realize == pre_hijacked_window_realize)
+		widget_class->realize = hijacked_window_realize;
+
+#if GTK_MAJOR_VERSION == 3
+	if (widget_class->realize == pre_hijacked_application_window_realize)
+		widget_class->realize = hijacked_application_window_realize;
+#endif
+
+	if (widget_class->unrealize == pre_hijacked_window_unrealize)
+		widget_class->unrealize = hijacked_window_unrealize;
+
+	children = g_type_children (type, &n);
+
+	for (i = 0; i < n; i++)
+		hijack_window_class_vtable (children[i]);
+
+	g_free (children);
+}
+
+static void
+hijack_menu_bar_class_vtable (GType type)
+{
+	GtkWidgetClass *widget_class = g_type_class_ref (type);
+	GType *children;
+	guint n;
+	guint i;
+
+	/* This fixes lp:1113008. */
+	widget_class->hierarchy_changed = NULL;
+
+	if (widget_class->realize == pre_hijacked_menu_bar_realize)
+		widget_class->realize = hijacked_menu_bar_realize;
+
+	if (widget_class->unrealize == pre_hijacked_menu_bar_unrealize)
+		widget_class->unrealize = hijacked_menu_bar_unrealize;
+
+	if (widget_class->size_allocate == pre_hijacked_menu_bar_size_allocate)
+		widget_class->size_allocate = hijacked_menu_bar_size_allocate;
+
+#if GTK_MAJOR_VERSION == 2
+	if (widget_class->size_request == pre_hijacked_menu_bar_size_request)
+		widget_class->size_request = hijacked_menu_bar_size_request;
+#elif GTK_MAJOR_VERSION == 3
+	if (widget_class->get_preferred_width == pre_hijacked_menu_bar_get_preferred_width)
+		widget_class->get_preferred_width = hijacked_menu_bar_get_preferred_width;
+
+	if (widget_class->get_preferred_height == pre_hijacked_menu_bar_get_preferred_height)
+		widget_class->get_preferred_height = hijacked_menu_bar_get_preferred_height;
+
+	if (widget_class->get_preferred_width_for_height == pre_hijacked_menu_bar_get_preferred_width_for_height)
+		widget_class->get_preferred_width_for_height = hijacked_menu_bar_get_preferred_width_for_height;
+
+	if (widget_class->get_preferred_height_for_width == pre_hijacked_menu_bar_get_preferred_height_for_width)
+		widget_class->get_preferred_height_for_width = hijacked_menu_bar_get_preferred_height_for_width;
+#endif
+
+	children = g_type_children (type, &n);
+
+	for (i = 0; i < n; i++)
+		hijack_menu_bar_class_vtable (children[i]);
+
+	g_free (children);
+}
+
+G_MODULE_EXPORT
+void gtk_module_init(void)
+{
+	if (!topmenu_is_blacklisted())
+	{
+		GtkWidgetClass *widget_class;
+
+		/* gtk_module_init may be called more than once in a resident module */
+		g_return_if_fail(!already_initialized);
+		already_initialized = TRUE;
+
+		/* store the base GtkWidget size_allocate vfunc */
+		widget_class = g_type_class_ref (GTK_TYPE_WIDGET);
+		pre_hijacked_widget_size_allocate = widget_class->size_allocate;
+
+#if GTK_MAJOR_VERSION == 3
+		/* store the base GtkApplicationWindow realize vfunc */
+		widget_class = g_type_class_ref (GTK_TYPE_APPLICATION_WINDOW);
+		pre_hijacked_application_window_realize = widget_class->realize;
+#endif
+
+		/* intercept window realize vcalls on GtkWindow */
+		widget_class = g_type_class_ref (GTK_TYPE_WINDOW);
+		pre_hijacked_window_realize = widget_class->realize;
+		pre_hijacked_window_unrealize = widget_class->unrealize;
+		hijack_window_class_vtable (GTK_TYPE_WINDOW);
+
+		/* intercept size request and allocate vcalls on GtkMenuBar (for hiding) */
+		widget_class = g_type_class_ref (GTK_TYPE_MENU_BAR);
+		pre_hijacked_menu_bar_realize = widget_class->realize;
+		pre_hijacked_menu_bar_unrealize = widget_class->unrealize;
+		pre_hijacked_menu_bar_size_allocate = widget_class->size_allocate;
+#if GTK_MAJOR_VERSION == 2
+		pre_hijacked_menu_bar_size_request = widget_class->size_request;
+#elif GTK_MAJOR_VERSION == 3
+		pre_hijacked_menu_bar_get_preferred_width = widget_class->get_preferred_width;
+		pre_hijacked_menu_bar_get_preferred_height = widget_class->get_preferred_height;
+		pre_hijacked_menu_bar_get_preferred_width_for_height = widget_class->get_preferred_width_for_height;
+		pre_hijacked_menu_bar_get_preferred_height_for_width = widget_class->get_preferred_height_for_width;
+#endif
+		hijack_menu_bar_class_vtable (GTK_TYPE_MENU_BAR);
+	}
+}
+
+G_MODULE_EXPORT
+const gchar * g_module_check_init(GModule *module)
+{
+	/* It is hard to unhijack Gtk's vtables, specially if some other module
+	 * has decided to also hijack them.
+	 * Thus, we just prevent unloading of this module. */
+	g_module_make_resident(module);
+	return NULL;
+}