[gnome-shell/wip/sass] shellDBus: Emit a PropertyChanged for OverviewActive

[Jakub Steiner <jimmac src gnome org>]

commit 303b7f20f531a9dd38ee9ba9927fec44c04537a0
Author: Colin Walters <walters verbum org>
Date:   Sat Jul 13 14:58:36 2013 -0400

    shellDBus: Emit a PropertyChanged for OverviewActive
    
    I was going to add another DBus property to signal when the shell was
    done loading and was idle, and while implementing that I noticed we
    aren't emitting PropertyChanged for, well, any property.  Let's fix
    OverviewActive.
    
    It's unfortunate it's so tedious to correctly implement a DBus
    property =/
    
    https://bugzilla.gnome.org/show_bug.cgi?id=704163

 js/ui/shellDBus.js |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/shellDBus.js b/js/ui/shellDBus.js
index 4ef03c1..45a2054 100644
--- a/js/ui/shellDBus.js
+++ b/js/ui/shellDBus.js
@@ -90,6 +90,12 @@ const GnomeShell = new Lang.Class({
             function(display, action, deviceid, timestamp) {
                 this._emitAcceleratorActivated(action, deviceid, timestamp);
             }));
+
+        this._cachedOverviewVisible = false;
+        Main.overview.connect('showing',
+                              Lang.bind(this, this._checkOverviewVisibleChanged));
+        Main.overview.connect('hidden',
+                              Lang.bind(this, this._checkOverviewVisibleChanged));
     },
 
     /**
@@ -235,8 +241,15 @@ const GnomeShell = new Lang.Class({
 
     Mode: global.session_mode,
 
+    _checkOverviewVisibleChanged: function() {
+        if (Main.overview.visible !== this._cachedOverviewVisible) {
+            this._cachedOverviewVisible = Main.overview.visible;
+            this._dbusImpl.emit_property_changed('OverviewActive', new GLib.Variant('b', 
this._cachedOverviewVisible));
+        }
+    },
+
     get OverviewActive() {
-        return Main.overview.visible;
+        return this._cachedOverviewVisible;
     },
 
     set OverviewActive(visible) {