Introduce GtkMenuTracker

GtkMenuTracker folds a nested structure of sections in a GMenuModel into
a single linear menu, which it expresses to its user by means of 'insert
item at position' and 'remove item at position' callbacks.

The logic for where to insert separators and how to handle action
namespaces is contained within the tracker, removing the need to have
this logic duplicated in the 3 or 4 places that consume GMenuModel.

In comparison with the previous code, the tracker no longer completely
destroys and rebuilds menus every time a single change occurs.  As a
result, the new gtkmenu testcase now runs in approximately 3 seconds
instead of ~60 before.

https://bugzilla.gnome.org/show_bug.cgi?id=696468

1 files changed, 51 insertions, 0 deletions

diff --git a/gtk/gtkmenutracker.h b/gtk/gtkmenutracker.h
new file mode 100644
index 0000000000..51810a104c
--- /dev/null
+++ b/gtk/gtkmenutracker.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright © 2013 Canonical Limited
+ *
+ * This library 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; either
+ * version 2 of the licence, or (at your option) any later version.
+ *
+ * This library 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 library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Ryan Lortie <desrt@desrt.ca>
+ */
+
+#ifndef __GTK_MENU_TRACKER_H__
+#define __GTK_MENU_TRACKER_H__
+
+#include <gio/gio.h>
+
+typedef struct _GtkMenuTracker GtkMenuTracker;
+
+typedef void         (* GtkMenuTrackerInsertFunc)       (gint                      position,
+                                                         GMenuModel               *model,
+                                                         gint                      item_index,
+                                                         const gchar              *action_namespace,
+                                                         gboolean                  is_separator,
+                                                         gpointer                  user_data);
+
+typedef void         (* GtkMenuTrackerRemoveFunc)       (gint                      position,
+                                                         gpointer                  user_data);
+
+
+G_GNUC_INTERNAL
+GtkMenuTracker *        gtk_menu_tracker_new            (GMenuModel               *model,
+                                                         gboolean                  with_separators,
+                                                         const gchar              *action_namespace,
+                                                         GtkMenuTrackerInsertFunc  insert_func,
+                                                         GtkMenuTrackerRemoveFunc  remove_func,
+                                                         gpointer                  user_data);
+
+G_GNUC_INTERNAL
+void                    gtk_menu_tracker_free           (GtkMenuTracker           *tracker);
+
+#endif /* __GTK_MENU_TRACKER_H__ */