[meld] meldwindow: Manually handle app menu for non-Gnome shells (bgo#725430)

[Kai Willadsen <kaiw src gnome org>]

commit c253e13d1a44bf76c82e04bb43aba7f12df85e85
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sun Mar 30 07:27:43 2014 +1000

    meldwindow: Manually handle app menu for non-Gnome shells (bgo#725430)
    
    Since we don't have a global application menu bar (due to limitations
    of GMenuModel, and having to totally redesign all of our menus and
    rewrite associated code because of GtkUIManager deprecation), this
    commit adds a fallback that manually recreates the application menu
    in a UIManager-compatible form, and inserts it into the appropriate
    (new) placeholder.

 data/ui/appmenu-fallback.xml |   12 ++++++++++++
 data/ui/meldapp-ui.xml       |    1 +
 meld/meldwindow.py           |   33 +++++++++++++++++++++++++++++++++
 3 files changed, 46 insertions(+), 0 deletions(-)
---
diff --git a/data/ui/appmenu-fallback.xml b/data/ui/appmenu-fallback.xml
new file mode 100644
index 0000000..17c6db4
--- /dev/null
+++ b/data/ui/appmenu-fallback.xml
@@ -0,0 +1,12 @@
+<ui>
+  <menubar name="Menubar">
+    <placeholder name="AppMenuPlaceholder">
+      <menu action="AppMenu">
+        <menuitem action="Preferences"/>
+        <menuitem action="Help"/>
+        <menuitem action="About"/>
+        <menuitem action="Quit"/>
+      </menu>
+    </placeholder>
+  </menubar>
+</ui>
diff --git a/data/ui/meldapp-ui.xml b/data/ui/meldapp-ui.xml
index 43e8041..3cde9bd 100644
--- a/data/ui/meldapp-ui.xml
+++ b/data/ui/meldapp-ui.xml
@@ -1,5 +1,6 @@
 <ui>
   <menubar name="Menubar">
+    <placeholder name="AppMenuPlaceholder" />
     <menu action="FileMenu">
       <menuitem action="New" />
       <menuitem action="Save" />
diff --git a/meld/meldwindow.py b/meld/meldwindow.py
index 6638c25..d4b64ce 100644
--- a/meld/meldwindow.py
+++ b/meld/meldwindow.py
@@ -149,6 +149,39 @@ class MeldWindow(gnomeglade.Component):
         self.ui = Gtk.UIManager()
         self.ui.insert_action_group(self.actiongroup, 0)
         self.ui.add_ui_from_file(ui_file)
+
+        # Manually handle shells that don't show an application menu
+        gtk_settings = Gtk.Settings.get_default()
+        if not gtk_settings.props.gtk_shell_shows_app_menu:
+            from meldapp import app
+
+            def make_app_action(name):
+                def app_action(*args):
+                    app.lookup_action(name).activate(None)
+                return app_action
+
+            app_actions = (
+                ("AppMenu", None, _("_Meld")),
+                ("Quit", Gtk.STOCK_QUIT, None, None, _("Quit the program"),
+                 make_app_action('quit')),
+                ("Preferences", Gtk.STOCK_PREFERENCES, _("Prefere_nces"), None,
+                 _("Configure the application"),
+                 make_app_action('preferences')),
+                ("Help", Gtk.STOCK_HELP, _("_Contents"), "F1",
+                 _("Open the Meld manual"), make_app_action('help')),
+                ("About", Gtk.STOCK_ABOUT, None, None,
+                 _("About this application"), make_app_action('about')),
+            )
+
+            app_actiongroup = Gtk.ActionGroup(name="AppActions")
+            app_actiongroup.set_translation_domain("meld")
+            app_actiongroup.add_actions(app_actions)
+            self.ui.insert_action_group(app_actiongroup, 0)
+
+            ui_file = gnomeglade.ui_file("appmenu-fallback.xml")
+            self.ui.add_ui_from_file(ui_file)
+            self.widget.set_show_menubar(False)
+
         self.tab_switch_actiongroup = None
         self.tab_switch_merge_id = None