build: Split out "private" sources variable that can be easily appended

Move the action muxing copy stuff in there.

js/ui/panel.js

@@ -3,6 +3,7 @@
 const Cairo = imports.cairo;
 const Clutter = imports.gi.Clutter;
 const Gio = imports.gi.Gio;
+const GLib = imports.gi.GLib;
 const Lang = imports.lang;
 const Mainloop = imports.mainloop;
 const Pango = imports.gi.Pango;
@@ -235,11 +236,15 @@ const AppMenuButton = new Lang.Class({
     Name: 'AppMenuButton',
     Extends: PanelMenu.Button,
 
-    _init: function() {
+    _init: function(menuManager) {
-        this.parent(0.0);
+        this.parent(0.0, true);
+
         this._startingApps = [];
 
+        this._menuManager = menuManager;
         this._targetApp = null;
+        this._appMenuNotifyId = 0;
+        this._actionGroupNotifyId = 0;
 
         let bin = new St.Bin({ name: 'appMenu' });
         this.actor.add_actor(bin);
@@ -264,10 +269,6 @@ const AppMenuButton = new Lang.Class({
 
         this._iconBottomClip = 0;
 
-        this._quitMenu = new PopupMenu.PopupMenuItem('');
-        this.menu.addMenuItem(this._quitMenu);
-        this._quitMenu.connect('activate', Lang.bind(this, this._onQuit));
-
         this._visible = !Main.overview.visible;
         if (!this._visible)
             this.actor.hide();
@@ -446,12 +447,6 @@ const AppMenuButton = new Lang.Class({
         }
     },
 
-    _onQuit: function() {
-        if (this._targetApp == null)
-            return;
-        this._targetApp.request_quit();
-    },
-
     _onAppStateChanged: function(appSys, app) {
         let state = app.state;
         if (state != Shell.AppState.STARTING) {
@@ -513,8 +508,10 @@ const AppMenuButton = new Lang.Class({
         }
 
         if (targetApp == this._targetApp) {
-            if (targetApp && targetApp.get_state() != Shell.AppState.STARTING)
+            if (targetApp && targetApp.get_state() != Shell.AppState.STARTING) {
                 this.stopAnimation();
+                this._maybeSetMenu();
+            }
             return;
         }
 
@@ -524,20 +521,53 @@ const AppMenuButton = new Lang.Class({
         this._iconBox.hide();
         this._label.setText('');
 
+        if (this._appMenuNotifyId)
+            this._targetApp.disconnect(this._appMenuNotifyId);
+        if (this._actionGroupNotifyId)
+            this._targetApp.disconnect(this._actionGroupNotifyId);
+        if (targetApp) {
+            this._appMenuNotifyId = targetApp.connect('notify::menu', Lang.bind(this, this._sync));
+            this._actionGroupNotifyId = targetApp.connect('notify::action-group', Lang.bind(this, this._sync));
+        }
+
         this._targetApp = targetApp;
         let icon = targetApp.get_faded_icon(2 * PANEL_ICON_SIZE);
 
         this._label.setText(targetApp.get_name());
-        // TODO - _quit() doesn't really work on apps in state STARTING yet
-        this._quitMenu.label.set_text(_("Quit %s").format(targetApp.get_name()));
 
         this._iconBox.set_child(icon);
         this._iconBox.show();
 
         if (targetApp.get_state() == Shell.AppState.STARTING)
             this.startAnimation();
+        else
+            this._maybeSetMenu();
 
         this.emit('changed');
+    },
+
+    _maybeSetMenu: function() {
+        let menu;
+
+        if (this._targetApp.action_group) {
+            if (this.menu instanceof PopupMenu.RemoteMenu &&
+                this.menu.actionGroup == this._targetApp.action_group)
+                return;
+
+            menu = new PopupMenu.RemoteMenu(this.actor, this._targetApp.menu, this._targetApp.action_group);
+        } else {
+            if (this.menu && !(this.menu instanceof PopupMenu.RemoteMenu))
+                return;
+
+            // fallback to older menu
+            menu = new PopupMenu.PopupMenu(this.actor, 0.0, St.Side.TOP, 0);
+            menu.addAction(_("Quit"), Lang.bind(this, function() {
+                this._targetApp.request_quit();
+            }));
+        }
+
+        this.setMenu(menu);
+        this._menuManager.addMenu(menu);
     }
 });
 
@@ -924,9 +954,8 @@ const Panel = new Lang.Class({
             // more cleanly with the rest of the panel
             this._menus.addMenu(this._activitiesButton.menu);
 
-            this._appMenu = new AppMenuButton();
+            this._appMenu = new AppMenuButton(this._menus);
             this._leftBox.add(this._appMenu.actor);
-            this._menus.addMenu(this._appMenu.menu);
         }
 
         /* center */

js/ui/panelMenu.js

@@ -96,22 +96,39 @@ const Button = new Lang.Class({
     Name: 'PanelMenuButton',
     Extends: ButtonBox,
 
-    _init: function(menuAlignment) {
+    _init: function(menuAlignment, dontCreateMenu) {
         this.parent({ reactive: true,
                       can_focus: true,
                       track_hover: true });
 
         this.actor.connect('button-press-event', Lang.bind(this, this._onButtonPress));
         this.actor.connect('key-press-event', Lang.bind(this, this._onSourceKeyPress));
-        this.menu = new PopupMenu.PopupMenu(this.actor, menuAlignment, St.Side.TOP);
+
+        if (dontCreateMenu)
+            this.menu = null;
+        else
+            this.setMenu(new PopupMenu.PopupMenu(this.actor, menuAlignment, St.Side.TOP, 0));
+    },
+
+    setMenu: function(menu) {
+        if (this.menu)
+            this.menu.destroy();
+
+        this.menu = menu;
+        if (this.menu) {
             this.menu.actor.add_style_class_name('panel-menu');
             this.menu.connect('open-state-changed', Lang.bind(this, this._onOpenStateChanged));
             this.menu.actor.connect('key-press-event', Lang.bind(this, this._onMenuKeyPress));
+
             Main.uiGroup.add_actor(this.menu.actor);
             this.menu.actor.hide();
+        }
     },
 
     _onButtonPress: function(actor, event) {
+        if (!this.menu)
+            return;
+
         if (!this.menu.isOpen) {
             // Setting the max-height won't do any good if the minimum height of the
             // menu is higher then the screen; it's useful if part of the menu is
@@ -125,6 +142,9 @@ const Button = new Lang.Class({
     },
 
     _onSourceKeyPress: function(actor, event) {
+        if (!this.menu)
+            return false;
+
         let symbol = event.get_key_symbol();
         if (symbol == Clutter.KEY_space || symbol == Clutter.KEY_Return) {
             this.menu.toggle();

js/ui/popupMenu.js

@@ -2,7 +2,9 @@
 
 const Cairo = imports.cairo;
 const Clutter = imports.gi.Clutter;
+const GLib = imports.gi.GLib;
 const Gtk = imports.gi.Gtk;
+const Gio = imports.gi.Gio;
 const Lang = imports.lang;
 const Shell = imports.gi.Shell;
 const Signals = imports.signals;
@@ -1692,6 +1694,246 @@ const PopupComboBoxMenuItem = new Lang.Class({
     }
 });
 
+/**
+ * RemoteMenu:
+ *
+ * A PopupMenu that tracks a GMenuModel and shows its actions
+ * (exposed by GApplication/GActionGroup)
+ */
+const RemoteMenu = new Lang.Class({
+    Name: 'RemoteMenu',
+    Extends: PopupMenu,
+
+    _init: function(sourceActor, model, actionGroup) {
+        this.parent(sourceActor, 0.0, St.Side.TOP);
+
+        this.model = model;
+        this.actionGroup = actionGroup;
+
+        this._actions = { };
+        this._modelChanged(this.model, 0, 0, this.model.get_n_items(), this);
+
+        this._actionStateChangeId = this.actionGroup.connect('action-state-changed', Lang.bind(this, this._actionStateChanged));
+        this._actionEnableChangeId = this.actionGroup.connect('action-enabled-changed', Lang.bind(this, this._actionEnabledChanged));
+    },
+
+    destroy: function() {
+        if (this._actionStateChangeId) {
+            this.actionGroup.disconnect(this._actionStateChangeId);
+            this._actionStateChangeId = 0;
+        }
+
+        if (this._actionEnableChangeId) {
+            this.actionGroup.disconnect(this._actionEnableChangeId);
+            this._actionEnableChangeId = 0;
+        }
+
+        this.parent();
+    },
+
+    _createMenuItem: function(model, index) {
+        let section_link = model.get_item_link(index, Gio.MENU_LINK_SECTION);
+        if (section_link) {
+            let item = new PopupMenuSection();
+            this._modelChanged(section_link, 0, 0, section_link.get_n_items(), item);
+            return [item, true, ''];
+        }
+
+        // labels are not checked for existance, as they're required for all items
+        let label = model.get_item_attribute_value(index, Gio.MENU_ATTRIBUTE_LABEL, null).deep_unpack();
+        // remove all underscores that are not followed by another underscore
+        label = label.replace(/_([^_])/, '$1');
+        let submenu_link = model.get_item_link(index, Gio.MENU_LINK_SUBMENU);
+
+        if (submenu_link) {
+            let item = new PopupSubMenuMenuItem(label);
+            this._modelChanged(submenu_link, 0, 0, submenu_link.get_n_items(), item.menu);
+            return [item, false, ''];
+        }
+
+        let action_id = model.get_item_attribute_value(index, Gio.MENU_ATTRIBUTE_ACTION, null).deep_unpack();
+        if (!this.actionGroup.has_action(action_id)) {
+            // the action may not be there yet, wait for action-added
+            return [null, false, 'action-added'];
+        }
+
+        if (!this._actions[action_id])
+            this._actions[action_id] = { enabled: this.actionGroup.get_action_enabled(action_id),
+                                         state: this.actionGroup.get_action_state(action_id),
+                                         items: [ ],
+                                       };
+        let action = this._actions[action_id];
+        let item, target, destroyId, specificSignalId;
+
+        if (action.state) {
+            // Docs have get_state_hint(), except that the DBus protocol
+            // has no provision for it (so ShellApp does not implement it,
+            // and neither GApplication), and g_action_get_state_hint()
+            // always returns null
+            // Funny :)
+
+            switch (String.fromCharCode(action.state.classify())) {
+            case 'b':
+                item = new PopupSwitchMenuItem(label, action.state.get_boolean());
+                action.items.push(item);
+                specificSignalId = item.connect('toggled', Lang.bind(this, function(item) {
+                    this.actionGroup.activate_action(action_id, null);
+                }));
+                break;
+            case 's':
+                item = new PopupMenuItem(label);
+                item._remoteTarget = model.get_item_attribute_value(index, Gio.MENU_ATTRIBUTE_TARGET, null).deep_unpack();
+                action.items.push(item);
+                item.setShowDot(action.state.deep_unpack() == item._remoteTarget);
+                specificSignalId = item.connect('activate', Lang.bind(this, function(item) {
+                    this.actionGroup.activate_action(action_id, GLib.Variant.new_string(item._remoteTarget));
+                }));
+                break;
+            default:
+                log('Action "%s" has state of type %s, which is not supported'.format(action_id, action.state.get_type_string()));
+                return [null, false, 'action-state-changed'];
+            }
+        } else {
+            target = model.get_item_attribute_value(index, Gio.MENU_ATTRIBUTE_TARGET, null);
+            item = new PopupMenuItem(label);
+            action.items.push(item);
+            specificSignalId = item.connect('activate', Lang.bind(this, function() {
+                this.actionGroup.activate_action(action_id, target);
+            }));
+        }
+
+        item.actor.reactive = item.actor.can_focus = action.enabled;
+        if (action.enabled)
+            item.actor.remove_style_pseudo_class('insensitive');
+        else
+            item.actor.add_style_pseudo_class('insensitive');
+
+        destroyId = item.connect('destroy', Lang.bind(this, function() {
+            item.disconnect(destroyId);
+            item.disconnect(specificSignalId);
+
+            let pos = action.items.indexOf(item);
+            if (pos != -1)
+                action.items.splice(pos, 1);
+        }));
+
+        return [item, false, ''];
+    }, 
+
+    _modelChanged: function(model, position, removed, added, target) {
+        let j, k;
+        let j0, k0;
+
+        let currentItems = target._getMenuItems();
+
+        for (j0 = 0, k0 = 0; j0 < position; j0++, k0++) {
+            if (currentItems[k0] instanceof PopupSeparatorMenuItem)
+                k0++;
+        }
+
+        if (removed == -1) {
+            // special flag to indicate we should destroy everything
+            for (k = k0; k < currentItems.length; k++)
+                currentItems[k].destroy();
+        } else {
+            for (j = j0, k = k0; j < j0 + removed; j++, k++) {
+                currentItems[k].destroy();
+
+                if (currentItems[k] instanceof PopupSeparatorMenuItem)
+                    j--;
+            }
+        }
+
+        for (j = j0, k = k0; j < j0 + added; j++, k++) {
+            let [item, addSeparator, changeSignal] = this._createMenuItem(model, j);
+
+            if (item) {
+                // separators must be added in the parent to make autohiding work
+                if (addSeparator) {
+                    target.addMenuItem(new PopupSeparatorMenuItem(), k+1);
+                    k++;
+                }
+
+                target.addMenuItem(item, k);
+
+                if (addSeparator) {
+                    target.addMenuItem(new PopupSeparatorMenuItem(), k+1);
+                    k++;
+                }
+            } else if (changeSignal) {
+                let signalId = this.actionGroup.connect(changeSignal, Lang.bind(this, function() {
+                    this.actionGroup.disconnect(signalId);
+
+                    // force a full update
+                    this._modelChanged(model, 0, -1, model.get_n_items(), target);
+                }));
+            }
+        }
+
+        if (!model._changedId) {
+            model._changedId = model.connect('items-changed', Lang.bind(this, this._modelChanged, target));
+            model._destroyId = target.connect('destroy', function() {
+                if (model._changedId)
+                    model.disconnect(model._changedId);
+                if (model._destroyId)
+                    target.disconnect(model._destroyId);
+                model._changedId = 0;
+                model._destroyId = 0;
+            });
+        }
+
+        if (target instanceof PopupMenuSection) {
+            target.actor.visible = target.numMenuItems != 0;
+        } else {
+            let sourceItem = target.sourceActor._delegate;
+            if (sourceItem instanceof PopupSubMenuMenuItem)
+                sourceItem.actor.visible = target.numMenuItems != 0;
+        }
+    },
+
+    _actionStateChanged: function(actionGroup, action_id) {
+        let action = this._actions[action_id];
+        if (!action)
+            return;
+
+        action.state = actionGroup.get_action_state(action_id);
+        if (action.items.length) {
+            switch (String.fromCharCode(action.state.classify())) {
+            case 'b':
+                for (let i = 0; i < action.items.length; i++)
+                    action.items[i].setToggleState(action.state.get_boolean());
+                break;
+            case 'd':
+                for (let i = 0; i < action.items.length; i++)
+                    action.items[i].setValue(action.state.get_double());
+                break;
+            case 's':
+                for (let i = 0; i < action.items.length; i++)
+                    action.items[i].setShowDot(action.items[i]._remoteTarget == action.state.deep_unpack());
+            }
+        }
+    },
+
+    _actionEnabledChanged: function(actionGroup, action_id) {
+        let action = this._actions[action_id];
+        if (!action)
+            return;
+
+        action.enabled = actionGroup.get_action_enabled(action_id);
+        if (action.items.length) {
+            for (let i = 0; i < action.items.length; i++) {
+                let item = action.items[i];
+                item.actor.reactive = item.actor.can_focus = action.enabled;
+
+                if (action.enabled)
+                    item.actor.remove_style_pseudo_class('insensitive');
+                else
+                    item.actor.add_style_pseudo_class('insensitive');
+            }
+        }
+    }
+});
+
 /* Basic implementation of a menu manager.
  * Call addMenu to add menus
  */

src/Makefile.am

@@ -121,9 +121,18 @@ shell_public_headers_h =		\
 	shell-wm.h			\
 	shell-xfixes-cursor.h
 
+shell_private_sources = \
+	gactionmuxer.h			\
+	gactionmuxer.c			\
+	gactionobservable.h		\
+	gactionobservable.c		\
+	gactionobserver.h		\
+	gactionobserver.c
+
 libgnome_shell_la_SOURCES =		\
 	$(shell_built_sources)		\
 	$(shell_public_headers_h)	\
+	$(shell_private_sources)	\
 	shell-app-private.h		\
 	shell-app-system-private.h	\
 	shell-embedded-window-private.h	\
@@ -157,10 +166,12 @@ libgnome_shell_la_SOURCES =		\
 	shell-util.c			\
 	shell-window-tracker.c		\
 	shell-wm.c			\
-	shell-xfixes-cursor.c
+	shell-xfixes-cursor.c		\
+	$(NULL)
+
 
 libgnome_shell_la_gir_sources = \
-	$(filter-out %-private.h $(shell_recorder_non_gir_sources), $(shell_public_headers_h) $(libgnome_shell_la_SOURCES))
+	$(filter-out %-private.h $(shell_private_sources), $(shell_public_headers_h) $(libgnome_shell_la_SOURCES))
 
 gnome_shell_real_SOURCES =		\
 	main.c
@@ -175,12 +186,16 @@ shell_recorder_sources =        \
 	shell-recorder.h
 
 # Custom element is an internal detail
-shell_recorder_non_gir_sources =  \
-	shell-recorder-src.c	  \
-	shell-recorder-src.h
 
 if BUILD_RECORDER
-libgnome_shell_la_SOURCES += $(shell_recorder_sources) $(shell_recorder_non_gir_sources)
+libgnome_shell_la_SOURCES += $(shell_recorder_sources)
+
+shell_recorder_private_sources =  \
+	shell-recorder-src.c	\
+	shell-recorder-src.h	\
+	$(NULL)
+
+shell_private_sources += $(shell_recorder_private_sources)
 
 noinst_PROGRAMS += test-recorder
 
@@ -188,7 +203,7 @@ test_recorder_CPPFLAGS = $(TEST_SHELL_RECORDER_CFLAGS)
 test_recorder_LDADD = $(TEST_SHELL_RECORDER_LIBS)
 
 test_recorder_SOURCES =     \
-	$(shell_recorder_sources) $(shell_recorder_non_gir_sources) \
+	$(shell_recorder_sources) $(shell_recorder_private_sources) \
 	test-recorder.c
 endif BUILD_RECORDER
 

src/gactionmuxer.c

@@ -0,0 +1,533 @@
+/*
+ * Copyright © 2011 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>
+ */
+
+#include "config.h"
+
+#include "gactionmuxer.h"
+
+#include "gactionobservable.h"
+#include "gactionobserver.h"
+
+#include <clutter/clutter.h>
+
+#include <string.h>
+
+/*
+ * SECTION:gactionmuxer
+ * @short_description: Aggregate and monitor several action groups
+ *
+ * #GActionMuxer is a #GActionGroup and #GActionObservable that is
+ * capable of containing other #GActionGroup instances.
+ *
+ * The typical use is aggregating all of the actions applicable to a
+ * particular context into a single action group, with namespacing.
+ *
+ * Consider the case of two action groups -- one containing actions
+ * applicable to an entire application (such as 'quit') and one
+ * containing actions applicable to a particular window in the
+ * application (such as 'fullscreen').
+ *
+ * In this case, each of these action groups could be added to a
+ * #GActionMuxer with the prefixes "app" and "win", respectively.  This
+ * would expose the actions as "app.quit" and "win.fullscreen" on the
+ * #GActionGroup interface presented by the #GActionMuxer.
+ *
+ * Activations and state change requests on the #GActionMuxer are wired
+ * through to the underlying action group in the expected way.
+ *
+ * This class is typically only used at the site of "consumption" of
+ * actions (eg: when displaying a menu that contains many actions on
+ * different objects).
+ */
+
+static void     g_action_muxer_group_iface_init         (GActionGroupInterface      *iface);
+static void     g_action_muxer_observable_iface_init    (GActionObservableInterface *iface);
+
+typedef GObjectClass GActionMuxerClass;
+
+struct _GActionMuxer
+{
+  GObject parent_instance;
+
+  GHashTable *actions;
+  GHashTable *groups;
+};
+
+G_DEFINE_TYPE_WITH_CODE (GActionMuxer, g_action_muxer, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (G_TYPE_ACTION_GROUP, g_action_muxer_group_iface_init)
+                         G_IMPLEMENT_INTERFACE (G_TYPE_ACTION_OBSERVABLE, g_action_muxer_observable_iface_init))
+
+typedef struct
+{
+  GActionMuxer *muxer;
+  GSList       *watchers;
+  gchar        *fullname;
+} Action;
+
+typedef struct
+{
+  GActionMuxer *muxer;
+  GActionGroup *group;
+  gchar        *prefix;
+  gulong        handler_ids[4];
+} Group;
+
+static gchar **
+g_action_muxer_list_actions (GActionGroup *action_group)
+{
+  GActionMuxer *muxer = G_ACTION_MUXER (action_group);
+
+  return (gchar **) muxer->groups;
+}
+
+static Group *
+g_action_muxer_find_group (GActionMuxer  *muxer,
+                              const gchar     **name)
+{
+  const gchar *dot;
+  gchar *prefix;
+  Group *group;
+
+  dot = strchr (*name, '.');
+
+  if (!dot)
+    return NULL;
+
+  prefix = g_strndup (*name, dot - *name);
+  group = g_hash_table_lookup (muxer->groups, prefix);
+  g_free (prefix);
+
+  *name = dot + 1;
+
+  return group;
+}
+
+static Action *
+g_action_muxer_lookup_action (GActionMuxer  *muxer,
+                              const gchar   *prefix,
+                              const gchar   *action_name,
+                              gchar        **fullname)
+{
+  Action *action;
+
+  *fullname = g_strconcat (prefix, ".", action_name, NULL);
+  action = g_hash_table_lookup (muxer->actions, *fullname);
+
+  return action;
+}
+
+static void
+g_action_muxer_action_enabled_changed (GActionGroup *action_group,
+                                       const gchar  *action_name,
+                                       gboolean      enabled,
+                                       gpointer      user_data)
+{
+  Group *group = user_data;
+  gchar *fullname;
+  Action *action;
+  GSList *node;
+
+  action = g_action_muxer_lookup_action (group->muxer, group->prefix, action_name, &fullname);
+  for (node = action ? action->watchers : NULL; node; node = node->next)
+    g_action_observer_action_enabled_changed (node->data, G_ACTION_OBSERVABLE (group->muxer), fullname, enabled);
+  g_action_group_action_enabled_changed (G_ACTION_GROUP (group->muxer), fullname, enabled);
+  g_free (fullname);
+}
+
+static void
+g_action_muxer_action_state_changed (GActionGroup *action_group,
+                                     const gchar  *action_name,
+                                     GVariant     *state,
+                                     gpointer      user_data)
+{
+  Group *group = user_data;
+  gchar *fullname;
+  Action *action;
+  GSList *node;
+
+  action = g_action_muxer_lookup_action (group->muxer, group->prefix, action_name, &fullname);
+  for (node = action ? action->watchers : NULL; node; node = node->next)
+    g_action_observer_action_state_changed (node->data, G_ACTION_OBSERVABLE (group->muxer), fullname, state);
+  g_action_group_action_state_changed (G_ACTION_GROUP (group->muxer), fullname, state);
+  g_free (fullname);
+}
+
+static void
+g_action_muxer_action_added (GActionGroup *action_group,
+                             const gchar  *action_name,
+                             gpointer      user_data)
+{
+  const GVariantType *parameter_type;
+  Group *group = user_data;
+  gboolean enabled;
+  GVariant *state;
+
+  if (g_action_group_query_action (group->group, action_name, &enabled, &parameter_type, NULL, NULL, &state))
+    {
+      gchar *fullname;
+      Action *action;
+      GSList *node;
+
+      action = g_action_muxer_lookup_action (group->muxer, group->prefix, action_name, &fullname);
+
+      for (node = action ? action->watchers : NULL; node; node = node->next)
+        g_action_observer_action_added (node->data,
+                                        G_ACTION_OBSERVABLE (group->muxer),
+                                        fullname, parameter_type, enabled, state);
+
+      g_action_group_action_added (G_ACTION_GROUP (group->muxer), fullname);
+
+      if (state)
+        g_variant_unref (state);
+
+      g_free (fullname);
+    }
+}
+
+static void
+g_action_muxer_action_removed (GActionGroup *action_group,
+                               const gchar  *action_name,
+                               gpointer      user_data)
+{
+  Group *group = user_data;
+  gchar *fullname;
+  Action *action;
+  GSList *node;
+
+  action = g_action_muxer_lookup_action (group->muxer, group->prefix, action_name, &fullname);
+  for (node = action ? action->watchers : NULL; node; node = node->next)
+    g_action_observer_action_removed (node->data, G_ACTION_OBSERVABLE (group->muxer), fullname);
+  g_action_group_action_removed (G_ACTION_GROUP (group->muxer), fullname);
+  g_free (fullname);
+}
+
+static gboolean
+g_action_muxer_query_action (GActionGroup        *action_group,
+                             const gchar         *action_name,
+                             gboolean            *enabled,
+                             const GVariantType **parameter_type,
+                             const GVariantType **state_type,
+                             GVariant           **state_hint,
+                             GVariant           **state)
+{
+  GActionMuxer *muxer = G_ACTION_MUXER (action_group);
+  Group *group;
+
+  group = g_action_muxer_find_group (muxer, &action_name);
+
+  if (!group)
+    return FALSE;
+
+  return g_action_group_query_action (group->group, action_name, enabled,
+                                      parameter_type, state_type, state_hint, state);
+}
+
+static GVariant *
+get_platform_data (void)
+{
+  gchar time[32];
+  GVariantBuilder *builder;
+  GVariant *result;
+
+  g_snprintf (time, 32, "_TIME%d", clutter_get_current_event_time ());
+
+  builder = g_variant_builder_new (G_VARIANT_TYPE ("a{sv}"));
+
+  g_variant_builder_add (builder, "{sv}", "desktop-startup-id",
+                         g_variant_new_string (time));
+
+  result = g_variant_builder_end (builder);
+  g_variant_builder_unref (builder);
+
+  return result;
+}
+
+static void
+g_action_muxer_activate_action (GActionGroup *action_group,
+                                const gchar  *action_name,
+                                GVariant     *parameter)
+{
+  GActionMuxer *muxer = G_ACTION_MUXER (action_group);
+  Group *group;
+
+  group = g_action_muxer_find_group (muxer, &action_name);
+
+  if (group)
+    {
+      if (G_IS_REMOTE_ACTION_GROUP (group->group))
+        g_remote_action_group_activate_action_full (G_REMOTE_ACTION_GROUP (group->group),
+                                                    action_name,
+                                                    parameter,
+                                                    get_platform_data ());
+      else
+        g_action_group_activate_action (group->group, action_name, parameter);
+    }
+}
+
+static void
+g_action_muxer_change_action_state (GActionGroup *action_group,
+                                    const gchar  *action_name,
+                                    GVariant     *state)
+{
+  GActionMuxer *muxer = G_ACTION_MUXER (action_group);
+  Group *group;
+
+  group = g_action_muxer_find_group (muxer, &action_name);
+
+  if (group)
+    {
+      if (G_IS_REMOTE_ACTION_GROUP (group->group))
+        g_remote_action_group_change_action_state_full (G_REMOTE_ACTION_GROUP (group->group),
+                                                        action_name,
+                                                        state,
+                                                        get_platform_data ());
+      else
+        g_action_group_change_action_state (group->group, action_name, state);
+    }
+}
+
+static void
+g_action_muxer_unregister_internal (Action   *action,
+                                    gpointer  observer)
+{
+  GActionMuxer *muxer = action->muxer;
+  GSList **ptr;
+
+  for (ptr = &action->watchers; *ptr; ptr = &(*ptr)->next)
+    if ((*ptr)->data == observer)
+      {
+        *ptr = g_slist_remove (*ptr, observer);
+
+        if (action->watchers == NULL)
+          {
+            g_hash_table_remove (muxer->actions, action->fullname);
+            g_free (action->fullname);
+
+            g_slice_free (Action, action);
+
+            g_object_unref (muxer);
+          }
+
+        break;
+      }
+}
+
+static void
+g_action_muxer_weak_notify (gpointer  data,
+                            GObject  *where_the_object_was)
+{
+  Action *action = data;
+
+  g_action_muxer_unregister_internal (action, where_the_object_was);
+}
+
+static void
+g_action_muxer_register_observer (GActionObservable *observable,
+                                  const gchar       *name,
+                                  GActionObserver   *observer)
+{
+  GActionMuxer *muxer = G_ACTION_MUXER (observable);
+  Action *action;
+
+  action = g_hash_table_lookup (muxer->actions, name);
+
+  if (action == NULL)
+    {
+      action = g_slice_new (Action);
+      action->muxer = g_object_ref (muxer);
+      action->fullname = g_strdup (name);
+      action->watchers = NULL;
+
+      g_hash_table_insert (muxer->actions, action->fullname, action);
+    }
+
+  action->watchers = g_slist_prepend (action->watchers, observer);
+  g_object_weak_ref (G_OBJECT (observer), g_action_muxer_weak_notify, action);
+}
+
+static void
+g_action_muxer_unregister_observer (GActionObservable *observable,
+                                    const gchar       *name,
+                                    GActionObserver   *observer)
+{
+  GActionMuxer *muxer = G_ACTION_MUXER (observable);
+  Action *action;
+
+  action = g_hash_table_lookup (muxer->actions, name);
+  g_object_weak_unref (G_OBJECT (observer), g_action_muxer_weak_notify, action);
+  g_action_muxer_unregister_internal (action, observer);
+}
+
+static void
+g_action_muxer_free_group (gpointer data)
+{
+  Group *group = data;
+
+  g_object_unref (group->group);
+  g_free (group->prefix);
+
+  g_slice_free (Group, group);
+}
+
+static void
+g_action_muxer_finalize (GObject *object)
+{
+  GActionMuxer *muxer = G_ACTION_MUXER (object);
+
+  g_assert_cmpint (g_hash_table_size (muxer->actions), ==, 0);
+  g_hash_table_unref (muxer->actions);
+  g_hash_table_unref (muxer->groups);
+
+  G_OBJECT_CLASS (g_action_muxer_parent_class)
+    ->finalize (object);
+}
+
+static void
+g_action_muxer_init (GActionMuxer *muxer)
+{
+  muxer->actions = g_hash_table_new (g_str_hash, g_str_equal);
+  muxer->groups = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, g_action_muxer_free_group);
+}
+
+static void
+g_action_muxer_observable_iface_init (GActionObservableInterface *iface)
+{
+  iface->register_observer = g_action_muxer_register_observer;
+  iface->unregister_observer = g_action_muxer_unregister_observer;
+}
+
+static void
+g_action_muxer_group_iface_init (GActionGroupInterface *iface)
+{
+  iface->list_actions = g_action_muxer_list_actions;
+  iface->query_action = g_action_muxer_query_action;
+  iface->activate_action = g_action_muxer_activate_action;
+  iface->change_action_state = g_action_muxer_change_action_state;
+}
+
+static void
+g_action_muxer_class_init (GObjectClass *class)
+{
+  class->finalize = g_action_muxer_finalize;
+}
+
+/*
+ * g_action_muxer_insert:
+ * @muxer: a #GActionMuxer
+ * @prefix: the prefix string for the action group
+ * @action_group: a #GActionGroup
+ *
+ * Adds the actions in @action_group to the list of actions provided by
+ * @muxer.  @prefix is prefixed to each action name, such that for each
+ * action <varname>x</varname> in @action_group, there is an equivalent
+ * action @prefix<literal>.</literal><varname>x</varname> in @muxer.
+ *
+ * For example, if @prefix is "<literal>app</literal>" and @action_group
+ * contains an action called "<literal>quit</literal>", then @muxer will
+ * now contain an action called "<literal>app.quit</literal>".
+ *
+ * If any #GActionObservers are registered for actions in the group,
+ * "action_added" notifications will be emitted, as appropriate.
+ *
+ * @prefix must not contain a dot ('.').
+ */
+void
+g_action_muxer_insert (GActionMuxer *muxer,
+                       const gchar  *prefix,
+                       GActionGroup *action_group)
+{
+  gchar **actions;
+  Group *group;
+  gint i;
+
+  /* TODO: diff instead of ripout and replace */
+  g_action_muxer_remove (muxer, prefix);
+
+  group = g_slice_new (Group);
+  group->muxer = muxer;
+  group->group = g_object_ref (action_group);
+  group->prefix = g_strdup (prefix);
+
+  g_hash_table_insert (muxer->groups, group->prefix, group);
+
+  actions = g_action_group_list_actions (group->group);
+  for (i = 0; actions[i]; i++)
+    g_action_muxer_action_added (group->group, actions[i], group);
+  g_strfreev (actions);
+
+  group->handler_ids[0] = g_signal_connect (group->group, "action-added",
+                                            G_CALLBACK (g_action_muxer_action_added), group);
+  group->handler_ids[1] = g_signal_connect (group->group, "action-removed",
+                                            G_CALLBACK (g_action_muxer_action_removed), group);
+  group->handler_ids[2] = g_signal_connect (group->group, "action-enabled-changed",
+                                            G_CALLBACK (g_action_muxer_action_enabled_changed), group);
+  group->handler_ids[3] = g_signal_connect (group->group, "action-state-changed",
+                                            G_CALLBACK (g_action_muxer_action_state_changed), group);
+}
+
+/*
+ * g_action_muxer_remove:
+ * @muxer: a #GActionMuxer
+ * @prefix: the prefix of the action group to remove
+ *
+ * Removes a #GActionGroup from the #GActionMuxer.
+ *
+ * If any #GActionObservers are registered for actions in the group,
+ * "action_removed" notifications will be emitted, as appropriate.
+ */
+void
+g_action_muxer_remove (GActionMuxer *muxer,
+                       const gchar  *prefix)
+{
+  Group *group;
+
+  group = g_hash_table_lookup (muxer->groups, prefix);
+
+  if (group != NULL)
+    {
+      gchar **actions;
+      gint i;
+
+      g_hash_table_steal (muxer->groups, prefix);
+
+      actions = g_action_group_list_actions (group->group);
+      for (i = 0; actions[i]; i++)
+        g_action_muxer_action_removed (group->group, actions[i], group);
+      g_strfreev (actions);
+
+      /* 'for loop' or 'four loop'? */
+      for (i = 0; i < 4; i++)
+        g_signal_handler_disconnect (group->group, group->handler_ids[i]);
+
+      g_action_muxer_free_group (group);
+    }
+}
+
+/*
+ * g_action_muxer_new:
+ *
+ * Creates a new #GActionMuxer.
+ */
+GActionMuxer *
+g_action_muxer_new (void)
+{
+  return g_object_new (G_TYPE_ACTION_MUXER, NULL);
+}

src/gactionmuxer.h

@@ -0,0 +1,53 @@
+/*
+ * Copyright © 2011 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 __G_ACTION_MUXER_H__
+#define __G_ACTION_MUXER_H__
+
+#include <gio/gio.h>
+
+G_BEGIN_DECLS
+
+#define G_TYPE_ACTION_MUXER                                 (g_action_muxer_get_type ())
+#define G_ACTION_MUXER(inst)                                (G_TYPE_CHECK_INSTANCE_CAST ((inst),                     \
+                                                             G_TYPE_ACTION_MUXER, GActionMuxer))
+#define G_IS_ACTION_MUXER(inst)                             (G_TYPE_CHECK_INSTANCE_TYPE ((inst),                     \
+                                                             G_TYPE_ACTION_MUXER))
+
+typedef struct _GActionMuxer                                GActionMuxer;
+
+G_GNUC_INTERNAL
+GType                   g_action_muxer_get_type                         (void);
+G_GNUC_INTERNAL
+GActionMuxer *          g_action_muxer_new                              (void);
+
+G_GNUC_INTERNAL
+void                    g_action_muxer_insert                           (GActionMuxer *muxer,
+                                                                         const gchar  *prefix,
+                                                                         GActionGroup *group);
+
+G_GNUC_INTERNAL
+void                    g_action_muxer_remove                           (GActionMuxer *muxer,
+                                                                         const gchar  *prefix);
+
+G_END_DECLS
+
+#endif /* __G_ACTION_MUXER_H__ */

src/gactionobservable.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright © 2011 Canonical Limited
+ *
+ * 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; 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.
+ *
+ * Authors: Ryan Lortie <desrt@desrt.ca>
+ */
+
+#include "config.h"
+
+#include "gactionobservable.h"
+
+G_DEFINE_INTERFACE (GActionObservable, g_action_observable, G_TYPE_OBJECT)
+
+/*
+ * SECTION:gactionobserable
+ * @short_description: an interface implemented by objects that report
+ *                     changes to actions
+ */
+
+void
+g_action_observable_default_init (GActionObservableInterface *iface)
+{
+}
+
+/*
+ * g_action_observable_register_observer:
+ * @observable: a #GActionObservable
+ * @action_name: the name of the action
+ * @observer: the #GActionObserver to which the events will be reported
+ *
+ * Registers @observer as being interested in changes to @action_name on
+ * @observable.
+ */
+void
+g_action_observable_register_observer (GActionObservable *observable,
+                                       const gchar       *action_name,
+                                       GActionObserver   *observer)
+{
+  g_return_if_fail (G_IS_ACTION_OBSERVABLE (observable));
+
+  G_ACTION_OBSERVABLE_GET_IFACE (observable)
+    ->register_observer (observable, action_name, observer);
+}
+
+/*
+ * g_action_observable_unregister_observer:
+ * @observable: a #GActionObservable
+ * @action_name: the name of the action
+ * @observer: the #GActionObserver to which the events will be reported
+ *
+ * Removes the registration of @observer as being interested in changes
+ * to @action_name on @observable.
+ *
+ * If the observer was registered multiple times, it must be
+ * unregistered an equal number of times.
+ */
+void
+g_action_observable_unregister_observer (GActionObservable *observable,
+                                         const gchar       *action_name,
+                                         GActionObserver   *observer)
+{
+  g_return_if_fail (G_IS_ACTION_OBSERVABLE (observable));
+
+  G_ACTION_OBSERVABLE_GET_IFACE (observable)
+    ->unregister_observer (observable, action_name, observer);
+}

src/gactionobservable.h

@@ -0,0 +1,64 @@
+/*
+ * Copyright © 2011 Canonical Limited
+ *
+ * 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; 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.
+ *
+ * Authors: Ryan Lortie <desrt@desrt.ca>
+ */
+
+#ifndef __G_ACTION_OBSERVABLE_H__
+#define __G_ACTION_OBSERVABLE_H__
+
+#include "gactionobserver.h"
+
+G_BEGIN_DECLS
+
+#define G_TYPE_ACTION_OBSERVABLE                            (g_action_observable_get_type ())
+#define G_ACTION_OBSERVABLE(inst)                           (G_TYPE_CHECK_INSTANCE_CAST ((inst),                     \
+                                                             G_TYPE_ACTION_OBSERVABLE, GActionObservable))
+#define G_IS_ACTION_OBSERVABLE(inst)                        (G_TYPE_CHECK_INSTANCE_TYPE ((inst),                     \
+                                                             G_TYPE_ACTION_OBSERVABLE))
+#define G_ACTION_OBSERVABLE_GET_IFACE(inst)                 (G_TYPE_INSTANCE_GET_INTERFACE ((inst),                  \
+                                                             G_TYPE_ACTION_OBSERVABLE, GActionObservableInterface))
+
+typedef struct _GActionObservableInterface                  GActionObservableInterface;
+
+struct _GActionObservableInterface
+{
+  GTypeInterface g_iface;
+
+  void (* register_observer)   (GActionObservable *observable,
+                                const gchar       *action_name,
+                                GActionObserver   *observer);
+  void (* unregister_observer) (GActionObservable *observable,
+                                const gchar       *action_name,
+                                GActionObserver   *observer);
+};
+
+G_GNUC_INTERNAL
+GType                   g_action_observable_get_type                    (void);
+G_GNUC_INTERNAL
+void                    g_action_observable_register_observer           (GActionObservable  *observable,
+                                                                         const gchar        *action_name,
+                                                                         GActionObserver    *observer);
+G_GNUC_INTERNAL
+void                    g_action_observable_unregister_observer         (GActionObservable  *observable,
+                                                                         const gchar        *action_name,
+                                                                         GActionObserver    *observer);
+
+G_END_DECLS
+
+#endif /* __G_ACTION_OBSERVABLE_H__ */

src/gactionobserver.c

@@ -0,0 +1,161 @@
+/*
+ * Copyright © 2011 Canonical Limited
+ *
+ * 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; 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.
+ *
+ * Authors: Ryan Lortie <desrt@desrt.ca>
+ */
+
+#include "config.h"
+
+#include "gactionobserver.h"
+
+G_DEFINE_INTERFACE (GActionObserver, g_action_observer, G_TYPE_OBJECT)
+
+/**
+ * SECTION:gactionobserver
+ * @short_description: an interface implemented by objects that are
+ *                     interested in monitoring actions for changes
+ *
+ * GActionObserver is a simple interface allowing objects that wish to
+ * be notified of changes to actions to be notified of those changes.
+ *
+ * It is also possible to monitor changes to action groups using
+ * #GObject signals, but there are a number of reasons that this
+ * approach could become problematic:
+ *
+ *  - there are four separate signals that must be manually connected
+ *    and disconnected
+ *
+ *  - when a large number of different observers wish to monitor a
+ *    (usually disjoint) set of actions within the same action group,
+ *    there is only one way to avoid having all notifications delivered
+ *    to all observers: signal detail.  In order to use signal detail,
+ *    each action name must be quarked, which is not always practical.
+ *
+ *  - even if quarking is acceptable, #GObject signal details are
+ *    implemented by scanning a linked list, so there is no real
+ *    decrease in complexity
+ */
+
+void
+g_action_observer_default_init (GActionObserverInterface *class)
+{
+}
+
+/*
+ * g_action_observer_action_added:
+ * @observer: a #GActionObserver
+ * @observable: the source of the event
+ * @action_name: the name of the action
+ * @enabled: %TRUE if the action is now enabled
+ * @parameter_type: the parameter type for action invocations, or %NULL
+ *                  if no parameter is required
+ * @state: the current state of the action, or %NULL if the action is
+ *         stateless
+ *
+ * This function is called when an action that the observer is
+ * registered to receive events for is added.
+ *
+ * This function should only be called by objects with which the
+ * observer has explicitly registered itself to receive events.
+ */
+void
+g_action_observer_action_added (GActionObserver    *observer,
+                                GActionObservable  *observable,
+                                const gchar        *action_name,
+                                const GVariantType *parameter_type,
+                                gboolean            enabled,
+                                GVariant           *state)
+{
+  g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
+
+  G_ACTION_OBSERVER_GET_IFACE (observer)
+    ->action_added (observer, observable, action_name, parameter_type, enabled, state);
+}
+
+/*
+ * g_action_observer_action_enabled_changed:
+ * @observer: a #GActionObserver
+ * @observable: the source of the event
+ * @action_name: the name of the action
+ * @enabled: %TRUE if the action is now enabled
+ *
+ * This function is called when an action that the observer is
+ * registered to receive events for becomes enabled or disabled.
+ *
+ * This function should only be called by objects with which the
+ * observer has explicitly registered itself to receive events.
+ */
+void
+g_action_observer_action_enabled_changed (GActionObserver   *observer,
+                                          GActionObservable *observable,
+                                          const gchar       *action_name,
+                                          gboolean           enabled)
+{
+  g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
+
+  G_ACTION_OBSERVER_GET_IFACE (observer)
+    ->action_enabled_changed (observer, observable, action_name, enabled);
+}
+
+/*
+ * g_action_observer_action_state_changed:
+ * @observer: a #GActionObserver
+ * @observable: the source of the event
+ * @action_name: the name of the action
+ * @state: the new state of the action
+ *
+ * This function is called when an action that the observer is
+ * registered to receive events for changes its state.
+ *
+ * This function should only be called by objects with which the
+ * observer has explicitly registered itself to receive events.
+ */
+void
+g_action_observer_action_state_changed (GActionObserver   *observer,
+                                        GActionObservable *observable,
+                                        const gchar       *action_name,
+                                        GVariant          *state)
+{
+  g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
+
+  G_ACTION_OBSERVER_GET_IFACE (observer)
+    ->action_state_changed (observer, observable, action_name, state);
+}
+
+/*
+ * g_action_observer_action_removed:
+ * @observer: a #GActionObserver
+ * @observable: the source of the event
+ * @action_name: the name of the action
+ *
+ * This function is called when an action that the observer is
+ * registered to receive events for is removed.
+ *
+ * This function should only be called by objects with which the
+ * observer has explicitly registered itself to receive events.
+ */
+void
+g_action_observer_action_removed (GActionObserver   *observer,
+                                  GActionObservable *observable,
+                                  const gchar       *action_name)
+{
+  g_return_if_fail (G_IS_ACTION_OBSERVER (observer));
+
+  G_ACTION_OBSERVER_GET_IFACE (observer)
+    ->action_removed (observer, observable, action_name);
+}

src/gactionobserver.h

@@ -0,0 +1,90 @@
+/*
+ * Copyright © 2011 Canonical Limited
+ *
+ * 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; 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.
+ *
+ * Authors: Ryan Lortie <desrt@desrt.ca>
+ */
+
+#ifndef __G_ACTION_OBSERVER_H__
+#define __G_ACTION_OBSERVER_H__
+
+#include <gio/gio.h>
+
+G_BEGIN_DECLS
+
+#define G_TYPE_ACTION_OBSERVER                              (g_action_observer_get_type ())
+#define G_ACTION_OBSERVER(inst)                             (G_TYPE_CHECK_INSTANCE_CAST ((inst),                     \
+                                                             G_TYPE_ACTION_OBSERVER, GActionObserver))
+#define G_IS_ACTION_OBSERVER(inst)                          (G_TYPE_CHECK_INSTANCE_TYPE ((inst),                     \
+                                                             G_TYPE_ACTION_OBSERVER))
+#define G_ACTION_OBSERVER_GET_IFACE(inst)                   (G_TYPE_INSTANCE_GET_INTERFACE ((inst),                  \
+                                                             G_TYPE_ACTION_OBSERVER, GActionObserverInterface))
+
+typedef struct _GActionObserverInterface                    GActionObserverInterface;
+typedef struct _GActionObservable                           GActionObservable;
+typedef struct _GActionObserver                             GActionObserver;
+
+struct _GActionObserverInterface
+{
+  GTypeInterface g_iface;
+
+  void (* action_added)           (GActionObserver    *observer,
+                                   GActionObservable  *observable,
+                                   const gchar        *action_name,
+                                   const GVariantType *parameter_type,
+                                   gboolean            enabled,
+                                   GVariant           *state);
+  void (* action_enabled_changed) (GActionObserver    *observer,
+                                   GActionObservable  *observable,
+                                   const gchar        *action_name,
+                                   gboolean            enabled);
+  void (* action_state_changed)   (GActionObserver    *observer,
+                                   GActionObservable  *observable,
+                                   const gchar        *action_name,
+                                   GVariant           *state);
+  void (* action_removed)         (GActionObserver    *observer,
+                                   GActionObservable  *observable,
+                                   const gchar        *action_name);
+};
+
+G_GNUC_INTERNAL
+GType                   g_action_observer_get_type                      (void);
+G_GNUC_INTERNAL
+void                    g_action_observer_action_added                  (GActionObserver    *observer,
+                                                                         GActionObservable  *observable,
+                                                                         const gchar        *action_name,
+                                                                         const GVariantType *parameter_type,
+                                                                         gboolean            enabled,
+                                                                         GVariant           *state);
+G_GNUC_INTERNAL
+void                    g_action_observer_action_enabled_changed        (GActionObserver    *observer,
+                                                                         GActionObservable  *observable,
+                                                                         const gchar        *action_name,
+                                                                         gboolean            enabled);
+G_GNUC_INTERNAL
+void                    g_action_observer_action_state_changed          (GActionObserver    *observer,
+                                                                         GActionObservable  *observable,
+                                                                         const gchar        *action_name,
+                                                                         GVariant           *state);
+G_GNUC_INTERNAL
+void                    g_action_observer_action_removed                (GActionObserver    *observer,
+                                                                         GActionObservable  *observable,
+                                                                         const gchar        *action_name);
+
+G_END_DECLS
+
+#endif /* __G_ACTION_OBSERVER_H__ */

src/shell-app.c

@@ -15,6 +15,7 @@
 #include "shell-app-system-private.h"
 #include "shell-window-tracker-private.h"
 #include "st.h"
+#include "gactionmuxer.h"
 
 typedef enum {
   MATCH_NONE,
@@ -37,6 +38,15 @@ typedef struct {
 
   /* Whether or not we need to resort the windows; this is done on demand */
   gboolean window_sort_stale : 1;
+
+  /* See GApplication documentation */
+  gint              name_watcher_id;
+  gchar            *dbus_name;
+  GDBusProxy       *app_proxy;
+  GActionGroup     *remote_actions;
+  GMenuModel       *remote_menu;
+  GActionMuxer     *muxer;
+  GCancellable     *dbus_cancellable;
 } ShellAppRunningState;
 
 /**
@@ -72,11 +82,13 @@ struct _ShellApp
   char *casefolded_exec;
 };
 
-G_DEFINE_TYPE (ShellApp, shell_app, G_TYPE_OBJECT);
-
 enum {
   PROP_0,
-  PROP_STATE
+  PROP_STATE,
+  PROP_ID,
+  PROP_DBUS_ID,
+  PROP_ACTION_GROUP,
+  PROP_MENU
 };
 
 enum {
@@ -88,6 +100,15 @@ static guint shell_app_signals[LAST_SIGNAL] = { 0 };
 
 static void create_running_state (ShellApp *app);
 static void unref_running_state (ShellAppRunningState *state);
+static void on_dbus_name_appeared (GDBusConnection *bus,
+                                   const gchar     *name,
+                                   const gchar     *name_owner,
+                                   gpointer         user_data);
+static void on_dbus_name_disappeared (GDBusConnection *bus,
+                                      const gchar     *name,
+                                      gpointer         user_data);
+
+G_DEFINE_TYPE (ShellApp, shell_app, G_TYPE_OBJECT)
 
 static void
 shell_app_get_property (GObject    *gobject,
@@ -102,6 +123,20 @@ shell_app_get_property (GObject    *gobject,
     case PROP_STATE:
       g_value_set_enum (value, app->state);
       break;
+    case PROP_ID:
+      g_value_set_string (value, shell_app_get_id (app));
+      break;
+    case PROP_DBUS_ID:
+      g_value_set_string (value, shell_app_get_dbus_id (app));
+      break;
+    case PROP_ACTION_GROUP:
+      if (app->running_state)
+        g_value_set_object (value, app->running_state->muxer);
+      break;
+    case PROP_MENU:
+      if (app->running_state)
+        g_value_set_object (value, app->running_state->remote_menu);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
       break;
@@ -151,6 +186,15 @@ window_backed_app_get_icon (ShellApp *app,
   return actor;
 }
 
+const char *
+shell_app_get_dbus_id (ShellApp *app)
+{
+  if (app->running_state)
+    return app->running_state->dbus_name;
+  else
+    return NULL;
+}
+
 /**
  * shell_app_create_icon_texture:
  *
@@ -513,6 +557,31 @@ shell_app_activate_window (ShellApp     *app,
     }
 }
 
+
+void
+shell_app_update_window_actions (ShellApp *app, MetaWindow *window)
+{
+  const char *object_path;
+
+  object_path = meta_window_get_dbus_object_path (window);
+  if (object_path != NULL)
+    {
+      GActionGroup *actions;
+
+      actions = g_object_get_data (G_OBJECT (window), "actions");
+      if (actions == NULL)
+        {
+          actions = G_ACTION_GROUP (g_dbus_action_group_get (g_dbus_proxy_get_connection (app->running_state->app_proxy),
+                                                             meta_window_get_dbus_unique_name (window),
+                                                             object_path));
+          g_object_set_data_full (G_OBJECT (window), "actions", actions, g_object_unref);
+        }
+
+      g_action_muxer_insert (app->running_state->muxer, "win", actions);
+      g_object_notify (G_OBJECT (app), "action-group");
+    }
+}
+
 /**
  * shell_app_activate:
  * @app: a #ShellApp
@@ -903,6 +972,34 @@ shell_app_on_ws_switch (MetaScreen         *screen,
   g_signal_emit (app, shell_app_signals[WINDOWS_CHANGED], 0);
 }
 
+static void
+on_dbus_application_id_changed (MetaWindow   *window,
+                                GParamSpec   *pspec,
+                                gpointer      user_data)
+{
+  const char *appid;
+  ShellApp *app = SHELL_APP (user_data);
+
+  /* Ignore changes in the appid after it's set, shouldn't happen */
+  if (app->running_state->dbus_name != NULL)
+    return;
+
+  appid = meta_window_get_dbus_application_id (window);
+
+  if (!appid)
+    return;
+
+  g_assert (app->running_state != NULL);
+  app->running_state->dbus_name = g_strdup (appid);
+  app->running_state->name_watcher_id = g_bus_watch_name (G_BUS_TYPE_SESSION,
+                                                          appid,
+                                                          G_BUS_NAME_WATCHER_FLAGS_NONE,
+                                                          on_dbus_name_appeared,
+                                                          on_dbus_name_disappeared,
+                                                          g_object_ref (app),
+                                                          g_object_unref);
+}
+
 void
 _shell_app_add_window (ShellApp        *app,
                        MetaWindow      *window)
@@ -923,6 +1020,9 @@ _shell_app_add_window (ShellApp        *app,
   if (app->state != SHELL_APP_STATE_STARTING)
     shell_app_state_transition (app, SHELL_APP_STATE_RUNNING);
 
+  g_signal_connect (window, "notify::dbus-application-id", G_CALLBACK(on_dbus_application_id_changed), app);
+  on_dbus_application_id_changed (window, NULL, app);
+
   g_object_thaw_notify (G_OBJECT (app));
 
   g_signal_emit (app, shell_app_signals[WINDOWS_CHANGED], 0);
@@ -939,6 +1039,7 @@ _shell_app_remove_window (ShellApp   *app,
 
   g_signal_handlers_disconnect_by_func (window, G_CALLBACK(shell_app_on_unmanaged), app);
   g_signal_handlers_disconnect_by_func (window, G_CALLBACK(shell_app_on_user_time_changed), app);
+  g_signal_handlers_disconnect_by_func (window, G_CALLBACK(on_dbus_application_id_changed), app);
   g_object_unref (window);
   app->running_state->windows = g_slist_remove (app->running_state->windows, window);
 
@@ -948,6 +1049,134 @@ _shell_app_remove_window (ShellApp   *app,
   g_signal_emit (app, shell_app_signals[WINDOWS_CHANGED], 0);
 }
 
+static void
+on_dbus_proxy_gotten (GObject      *initable,
+                      GAsyncResult *result,
+                      gpointer      user_data)
+{
+  ShellApp *self = SHELL_APP (user_data);
+  ShellAppRunningState *state = self->running_state;
+  GError *error = NULL;
+  GVariant *menu_property;
+
+  state->app_proxy = g_dbus_proxy_new_finish (result,
+                                              &error);
+
+  if (error)
+    {
+      if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED) &&
+          !g_error_matches (error, G_DBUS_ERROR, G_DBUS_ERROR_UNKNOWN_METHOD))
+        {
+          g_warning ("Unexpected error while creating application proxy: %s", error->message);
+        }
+
+      g_clear_error (&error);
+      g_clear_object (&state->dbus_cancellable);
+
+      if (state->name_watcher_id)
+        {
+          g_bus_unwatch_name (state->name_watcher_id);
+          state->name_watcher_id = 0;
+        }
+
+      g_free (state->dbus_name);
+      state->dbus_name = NULL;
+
+      g_object_unref (self);
+      return;
+    }
+
+  /* on to the second step, the primary action group */
+
+  state->remote_actions = (GActionGroup*)g_dbus_action_group_get (
+                           g_dbus_proxy_get_connection (state->app_proxy),
+                           g_dbus_proxy_get_name (state->app_proxy),
+                           g_dbus_proxy_get_object_path (state->app_proxy));
+  state->muxer = g_action_muxer_new ();
+  g_action_muxer_insert (state->muxer, "app", state->remote_actions);
+  g_strfreev (g_action_group_list_actions (state->remote_actions));
+
+  g_object_notify (G_OBJECT (self), "action-group");
+
+  menu_property = g_dbus_proxy_get_cached_property (state->app_proxy, "AppMenu");
+
+  if (menu_property && g_variant_n_children (menu_property) > 0)
+    {
+      const gchar *object_path;
+
+      g_variant_get_child (menu_property, 0, "&o", &object_path);
+
+      state->remote_menu = G_MENU_MODEL (g_dbus_menu_model_get (g_dbus_proxy_get_connection (state->app_proxy),
+                                                                state->dbus_name,
+                                                                object_path));
+
+      g_object_notify (G_OBJECT (self), "menu");
+    }
+}
+
+static void
+on_dbus_name_appeared (GDBusConnection *bus,
+                       const gchar     *name,
+                       const gchar     *name_owner,
+                       gpointer         user_data)
+{
+  ShellApp *self = SHELL_APP (user_data);
+  ShellAppRunningState *state = self->running_state;
+  char *object_path;
+
+  g_assert (state != NULL);
+
+  object_path = g_strconcat ("/", name, NULL);
+  g_strdelimit (object_path, ".", '/');
+
+  if (!state->dbus_cancellable)
+    state->dbus_cancellable = g_cancellable_new ();
+
+  /* first step: the application proxy */
+
+  g_dbus_proxy_new (bus,
+                    G_DBUS_PROXY_FLAGS_NONE,
+                    NULL, /* interface info */
+                    name_owner,
+                    object_path,
+                    "org.gtk.Application",
+                    state->dbus_cancellable,
+                    on_dbus_proxy_gotten,
+                    g_object_ref (self));
+
+  g_object_notify (G_OBJECT (self), "dbus-id");
+
+  g_free (object_path);
+}
+
+static void
+on_dbus_name_disappeared (GDBusConnection *bus,
+                          const gchar     *name,
+                          gpointer         user_data)
+{
+  ShellApp *self = SHELL_APP (user_data);
+  ShellAppRunningState *state = self->running_state;
+
+  g_assert (state != NULL);
+
+  if (state->dbus_cancellable)
+    {
+      g_cancellable_cancel (state->dbus_cancellable);
+      g_clear_object (&state->dbus_cancellable);
+    }
+
+  g_clear_object (&state->app_proxy);
+  g_clear_object (&state->remote_actions);
+  g_clear_object (&state->remote_menu);
+  g_clear_object (&state->muxer);
+
+  g_free (state->dbus_name);
+  state->dbus_name = NULL;
+
+  g_bus_unwatch_name (state->name_watcher_id);
+  state->name_watcher_id = 0;
+}
+
 /**
  * shell_app_get_pids:
  * @app: a #ShellApp
@@ -1167,13 +1396,30 @@ unref_running_state (ShellAppRunningState *state)
 {
   MetaScreen *screen;
 
+  g_assert (state->refcount > 0);
+
   state->refcount--;
   if (state->refcount > 0)
     return;
 
   screen = shell_global_get_screen (shell_global_get ());
-
   g_signal_handler_disconnect (screen, state->workspace_switch_id);
+
+  if (state->dbus_cancellable)
+    {
+      g_cancellable_cancel (state->dbus_cancellable);
+      g_object_unref (state->dbus_cancellable);
+    }
+
+  g_clear_object (&state->app_proxy);
+  g_clear_object (&state->remote_actions);
+  g_clear_object (&state->remote_menu);
+  g_clear_object (&state->muxer);
+  g_free (state->dbus_name);
+
+  if (state->name_watcher_id)
+    g_bus_unwatch_name (state->name_watcher_id);
+
   g_slice_free (ShellAppRunningState, state);
 }
 
@@ -1349,6 +1595,9 @@ shell_app_dispose (GObject *object)
       while (app->running_state->windows)
         _shell_app_remove_window (app, app->running_state->windows->data);
     }
+  /* We should have been transitioned when we removed all of our windows */
+  g_assert (app->state == SHELL_APP_STATE_STOPPED);
+  g_assert (app->running_state == NULL);
 
   G_OBJECT_CLASS(shell_app_parent_class)->dispose (object);
 }
@@ -1399,4 +1648,60 @@ shell_app_class_init(ShellAppClass *klass)
                                                       SHELL_TYPE_APP_STATE,
                                                       SHELL_APP_STATE_STOPPED,
                                                       G_PARAM_READABLE));
+
+  /**
+   * ShellApp:id:
+   *
+   * The id of this application (a desktop filename, or a special string
+   * like window:0xabcd1234)
+   */
+  g_object_class_install_property (gobject_class,
+                                   PROP_ID,
+                                   g_param_spec_string ("id",
+                                                        "Application id",
+                                                        "The desktop file id of this ShellApp",
+                                                        NULL,
+                                                        G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+
+  /**
+   * ShellApp:dbus-id:
+   *
+   * The DBus well-known name of the application, if one can be associated
+   * to this ShellApp (it means that the application is using GApplication)
+   */
+  g_object_class_install_property (gobject_class,
+                                   PROP_DBUS_ID,
+                                   g_param_spec_string ("dbus-id",
+                                                        "Application DBus Id",
+                                                        "The DBus well-known name of the application",
+                                                        NULL,
+                                                        G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+
+  /**
+   * ShellApp:action-group:
+   *
+   * The #GDBusActionGroup associated with this ShellApp, if any. See the
+   * documentation of #GApplication and #GActionGroup for details.
+   */
+  g_object_class_install_property (gobject_class,
+                                   PROP_ACTION_GROUP,
+                                   g_param_spec_object ("action-group",
+                                                        "Application Action Group",
+                                                        "The action group exported by the remote application",
+                                                        G_TYPE_ACTION_GROUP,
+                                                        G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+  /**
+   * ShellApp:menu:
+   *
+   * The #GMenuProxy associated with this ShellApp, if any. See the
+   * documentation of #GMenuModel for details.
+   */
+  g_object_class_install_property (gobject_class,
+                                   PROP_MENU,
+                                   g_param_spec_object ("menu",
+                                                        "Application Menu",
+                                                        "The primary menu exported by the remote application",
+                                                        G_TYPE_MENU_MODEL,
+                                                        G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+
 }

src/shell-app.h

@@ -13,6 +13,7 @@ G_BEGIN_DECLS
 typedef struct _ShellApp ShellApp;
 typedef struct _ShellAppClass ShellAppClass;
 typedef struct _ShellAppPrivate ShellAppPrivate;
+typedef struct _ShellAppAction ShellAppAction;
 
 #define SHELL_TYPE_APP              (shell_app_get_type ())
 #define SHELL_APP(object)           (G_TYPE_CHECK_INSTANCE_CAST ((object), SHELL_TYPE_APP, ShellApp))
@@ -36,9 +37,12 @@ typedef enum {
 GType shell_app_get_type (void) G_GNUC_CONST;
 
 const char *shell_app_get_id (ShellApp *app);
+
 GMenuTreeEntry *shell_app_get_tree_entry (ShellApp *app);
 GDesktopAppInfo *shell_app_get_app_info (ShellApp *app);
 
+const char *shell_app_get_dbus_id (ShellApp *app);
+
 ClutterActor *shell_app_create_icon_texture (ShellApp *app, int size);
 ClutterActor *shell_app_get_faded_icon (ShellApp *app, int size);
 const char *shell_app_get_name (ShellApp *app);
@@ -79,6 +83,8 @@ int shell_app_compare_by_name (ShellApp *app, ShellApp *other);
 
 int shell_app_compare (ShellApp *app, ShellApp *other);
 
+void shell_app_update_window_actions (ShellApp *app, MetaWindow *window);
+
 G_END_DECLS
 
 #endif /* __SHELL_APP_H__ */

src/shell-window-tracker.c

@@ -413,6 +413,9 @@ update_focus_app (ShellWindowTracker *self)
   new_focus_win = meta_display_get_focus_window (shell_global_get_display (shell_global_get ()));
   new_focus_app = new_focus_win ? shell_window_tracker_get_window_app (self, new_focus_win) : NULL;
 
+  if (new_focus_app)
+    shell_app_update_window_actions (new_focus_app, new_focus_win);
+
   set_focus_app (self, new_focus_app);
 }
 

src/test-gapplication.js

@@ -0,0 +1,104 @@
+#!/usr/bin/env gjs
+
+const Gdk = imports.gi.Gdk;
+const Gio = imports.gi.Gio;
+const GLib = imports.gi.GLib;
+const Gtk = imports.gi.Gtk;
+
+function do_action(action, parameter) {
+    print ("Action '" + action.name + "' invoked");
+}
+
+function do_action_param(action, parameter) {
+    print ("Action '" + action.name + "' invoked with parameter " + parameter.print(true));
+}
+
+function do_action_toggle(action) {
+    action.set_state(GLib.Variant.new('b', !action.state.deep_unpack()));
+    print ("Toggled");
+}
+
+function do_action_state_change(action) {
+    print ("Action '" + action.name + "' has now state " + action.state.print(true));
+}
+
+function main() {
+    Gtk.init(null, null);
+
+    let app = new Gtk.Application({ application_id: 'org.gnome.Shell.GtkApplicationTest' });
+    app.connect('activate', function() {
+	print ("Activated");
+    });
+
+    let action = new Gio.SimpleAction({ name: 'one' });
+    action.connect('activate', do_action);
+    app.add_action(action);
+
+    let action = new Gio.SimpleAction({ name: 'two' });
+    action.connect('activate', do_action);
+    app.add_action(action);
+
+    let action = new Gio.SimpleAction({ name: 'toggle', state: GLib.Variant.new('b', false) });
+    action.connect('activate', do_action_toggle);
+    action.connect('notify::state', do_action_state_change);
+    app.add_action(action);
+
+    let action = new Gio.SimpleAction({ name: 'disable', enabled: false });
+    action.set_enabled(false);
+    action.connect('activate', do_action);
+    app.add_action(action);
+
+    let action = new Gio.SimpleAction({ name: 'parameter-int', parameter_type: GLib.VariantType.new('u') });
+    action.connect('activate', do_action_param);
+    app.add_action(action);
+
+    let action = new Gio.SimpleAction({ name: 'parameter-string', parameter_type: GLib.VariantType.new('s') });
+    action.connect('activate', do_action_param);
+    app.add_action(action);
+
+    let menu = new Gio.Menu();
+    menu.append('An action', 'app.one');
+
+    let section = new Gio.Menu();
+    section.append('Another action', 'app.two');
+    section.append('Same as above', 'app.two');
+    menu.append_section(null, section);
+
+    // another section, to check separators
+    section = new Gio.Menu();
+    section.append('Checkbox', 'app.toggle');
+    section.append('Disabled', 'app.disable');
+    menu.append_section(null, section);
+
+    // empty sections or submenus should be invisible
+    menu.append_section('Empty section', new Gio.Menu());
+    menu.append_submenu('Empty submenu', new Gio.Menu());
+
+    let submenu = new Gio.Menu();
+    submenu.append('Open c:\\', 'app.parameter-string::c:\\');
+    submenu.append('Open /home', 'app.parameter-string::/home');
+    menu.append_submenu('Recent files', submenu);
+
+    let item = Gio.MenuItem.new('Say 42', null);
+    item.set_action_and_target_value('app.parameter-int', GLib.Variant.new('u', 42));
+    menu.append_item(item);
+
+    let item = Gio.MenuItem.new('Say 43', null);
+    item.set_action_and_target_value('app.parameter-int', GLib.Variant.new('u', 43));
+    menu.append_item(item);
+
+    app.set_app_menu(menu);
+
+    let window = null;
+
+    app.connect_after('startup', function(app) {
+	window = new Gtk.ApplicationWindow({ title: "Test Application", application: app });
+    });
+    app.connect('activate', function(app) {
+	window.present();
+    });
+
+    app.run(null);
+}
+
+main();