[gnome-shell] dateMenu: Use AppSettingsMonitor for world clocks

[Florian Müllner <fmuellner src gnome org>]

commit 0353ebde5dd8ae408cc246330db793664e8029ba
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Feb 23 22:54:32 2017 +0100

    dateMenu: Use AppSettingsMonitor for world clocks
    
    When gnome-clocks is installed, there is currently a race between the
    GSettings schema being added to the database and the world clocks
    session trying to use it. The prize if we win that race is an abort
    in GIO, so use the newly added AppSettingsMonitor skip the race
    altogether.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=766410

 js/ui/dateMenu.js |   38 ++++++++++----------------------------
 1 files changed, 10 insertions(+), 28 deletions(-)
---
diff --git a/js/ui/dateMenu.js b/js/ui/dateMenu.js
index 36c7950..eab55b4 100644
--- a/js/ui/dateMenu.js
+++ b/js/ui/dateMenu.js
@@ -87,9 +87,7 @@ const WorldClocksSection = new Lang.Class({
 
     _init: function() {
         this._clock = new GnomeDesktop.WallClock();
-        this._settings = null;
         this._clockNotifyId = 0;
-        this._changedId = 0;
 
         this._locations = [];
 
@@ -98,8 +96,7 @@ const WorldClocksSection = new Lang.Class({
                                      can_focus: true });
         this.actor.connect('clicked', Lang.bind(this,
             function() {
-                let app = this._getClockApp();
-                app.activate();
+                this._clockAppMon.activateApp();
 
                 Main.overview.hide();
                 Main.panel.closeCalendar();
@@ -112,40 +109,25 @@ const WorldClocksSection = new Lang.Class({
 
         this.actor.child = this._grid;
 
-        Shell.AppSystem.get_default().connect('installed-changed',
-                                              Lang.bind(this, this._sync));
+        this._clockAppMon = new Util.AppSettingsMonitor('org.gnome.clocks.desktop',
+                                                        'org.gnome.clocks');
+        this._clockAppMon.connect('available-changed',
+                                  Lang.bind(this, this._sync));
+        this._clockAppMon.watchSetting('world-clocks',
+                                       Lang.bind(this, this._clocksChanged));
         this._sync();
     },
 
-    _getClockApp: function() {
-        return Shell.AppSystem.get_default().lookup_app('org.gnome.clocks.desktop');
-    },
-
     _sync: function() {
-        this.actor.visible = (this._getClockApp() != null);
-
-        if (this.actor.visible) {
-            if (!this._settings) {
-                this._settings = new Gio.Settings({ schema_id: 'org.gnome.clocks' });
-                this._changedId =
-                    this._settings.connect('changed::world-clocks',
-                                           Lang.bind(this, this._clocksChanged));
-                this._clocksChanged();
-            }
-        } else {
-            if (this._settings)
-                this._settings.disconnect(this._changedId);
-            this._settings = null;
-            this._changedId = 0;
-        }
+        this.actor.visible = this._clockAppMon.available;
     },
 
-    _clocksChanged: function() {
+    _clocksChanged: function(settings) {
         this._grid.destroy_all_children();
         this._locations = [];
 
         let world = GWeather.Location.get_world();
-        let clocks = this._settings.get_value('world-clocks').deep_unpack();
+        let clocks = settings.get_value('world-clocks').deep_unpack();
         for (let i = 0; i < clocks.length; i++) {
             let l = world.deserialize(clocks[i].location);
             this._locations.push({ location: l });