dateMenu: Stop accessing app settings directly

Clocks has exactly the same issue as Weather: Its integration currently
relies on accessing its settings directly, which isn't possible when
the app is sandboxed.

Fix this the same way we did for Weather, by adding our own setting
and syncing it with the app via a custom D-Bus interface.

https://gitlab.gnome.org/GNOME/gnome-shell/issues/1158

data/dbus-interfaces/org.gnome.Shell.ClocksIntegration.xml

@@ -0,0 +1,15 @@
+<node>
+
+  <!--
+      org.gnome.Shell.ClocksIntegration:
+      @short_description: Clocks integration interface
+
+      The interface used for exporting location settings to GNOME Shell's
+      world clocks integration.
+  -->
+  <interface name="org.gnome.Shell.ClocksIntegration">
+
+  <property name="Locations" type="av" access="read"/>
+
+  </interface>
+</node>

data/gnome-shell-dbus-interfaces.gresource.xml

@@ -40,6 +40,7 @@
     <file preprocess="xml-stripblanks">org.gnome.SettingsDaemon.Wacom.xml</file>
     <file preprocess="xml-stripblanks">org.gnome.Shell.AudioDeviceSelection.xml</file>
     <file preprocess="xml-stripblanks">org.gnome.Shell.CalendarServer.xml</file>
+    <file preprocess="xml-stripblanks">org.gnome.Shell.ClocksIntegration.xml</file>
     <file preprocess="xml-stripblanks">org.gnome.Shell.Extensions.xml</file>
     <file preprocess="xml-stripblanks">org.gnome.Shell.Introspect.xml</file>
     <file preprocess="xml-stripblanks">org.gnome.Shell.HotplugSniffer.xml</file>

data/org.gnome.shell.gschema.xml.in

@@ -228,6 +228,17 @@
     </key>
   </schema>
 
+  <schema id="org.gnome.shell.world-clocks" path="/org/gnome/shell/world-clocks/"
+          gettext-domain="@GETTEXT_PACKAGE@">
+    <key name="locations" type="av">
+      <summary>Locations</summary>
+      <description>
+        The locations to show in world clocks
+      </description>
+      <default>[]</default>
+    </key>
+  </schema>
+
   <schema id="org.gnome.shell.weather" path="/org/gnome/shell/weather/"
           gettext-domain="@GETTEXT_PACKAGE@">
     <key name="automatic-location" type="b">

js/ui/dateMenu.js

@@ -1,7 +1,7 @@
 // -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
 /* exported DateMenuButton */
 
-const { Clutter, GLib, GnomeDesktop,
+const { Clutter, Gio, GLib, GnomeDesktop,
         GObject, GWeather, Shell, St } = imports.gi;
 
 const Util = imports.misc.util;
@@ -11,8 +11,13 @@ const Calendar = imports.ui.calendar;
 const Weather = imports.misc.weather;
 const System = imports.system;
 
+const { loadInterfaceXML } = imports.misc.fileUtils;
+
 const MAX_FORECASTS = 5;
 
+const ClocksIntegrationIface = loadInterfaceXML('org.gnome.Shell.ClocksIntegration');
+const ClocksProxy = Gio.DBusProxy.makeProxyWrapper(ClocksIntegrationIface);
+
 function _isToday(date) {
     let now = new Date();
     return now.getYear() == date.getYear() &&
@@ -83,7 +88,8 @@ var WorldClocksSection = class WorldClocksSection {
                                      x_fill: true,
                                      can_focus: true });
         this.actor.connect('clicked', () => {
-            this._clockAppMon.activateApp();
+            if (this._clocksApp)
+                this._clocksApp.activate();
 
             Main.overview.hide();
             Main.panel.closeCalendar();
@@ -96,29 +102,40 @@ var WorldClocksSection = class WorldClocksSection {
 
         this.actor.child = this._grid;
 
-        this._clockAppMon = new Util.AppSettingsMonitor('org.gnome.clocks.desktop',
+        this._clocksApp = null;
-                                                        'org.gnome.clocks');
+        this._clocksProxy = new ClocksProxy(
-        this._clockAppMon.connect('available-changed',
+            Gio.DBus.session,
-                                  this._sync.bind(this));
+            'org.gnome.clocks',
-        this._clockAppMon.watchSetting('world-clocks',
+            '/org/gnome/clocks',
-                                       this._clocksChanged.bind(this));
+            this._onProxyReady.bind(this),
+            null /* cancellable */,
+            Gio.DBusProxyFlags.DO_NOT_AUTO_START | Gio.DBusProxyFlags.GET_INVALIDATED_PROPERTIES);
+
+        this._settings = new Gio.Settings({
+            schema_id: 'org.gnome.shell.world-clocks'
+        });
+        this._settings.connect('changed', this._clocksChanged.bind(this));
+        this._clocksChanged();
+
+        this._appSystem = Shell.AppSystem.get_default();
+        this._appSystem.connect('installed-changed',
+            this._sync.bind(this));
         this._sync();
     }
 
     _sync() {
-        this.actor.visible = this._clockAppMon.available;
+        this._clocksApp = this._appSystem.lookup_app('org.gnome.clocks.desktop');
+        this.actor.visible = this._clocksApp != null;
     }
 
-    _clocksChanged(settings) {
+    _clocksChanged() {
         this._grid.destroy_all_children();
         this._locations = [];
 
         let world = GWeather.Location.get_world();
-        let clocks = settings.get_value('world-clocks').deep_unpack();
+        let clocks = this._settings.get_value('locations').deep_unpack();
         for (let i = 0; i < clocks.length; i++) {
-            if (!clocks[i].location)
+            let l = world.deserialize(clocks[i]);
-                continue;
-            let l = world.deserialize(clocks[i].location);
             if (l && l.get_timezone() != null)
                 this._locations.push({ location: l });
         }
@@ -197,6 +214,25 @@ var WorldClocksSection = class WorldClocksSection {
             l.actor.text = Util.formatTime(now, { timeOnly: true });
         }
     }
+
+    _onProxyReady(proxy, error) {
+        if (error) {
+            log(`Failed to create GNOME Clocks proxy: ${error}`);
+            return;
+        }
+
+        this._clocksProxy.connect('g-properties-changed',
+            this._onClocksPropertiesChanged.bind(this));
+        this._onClocksPropertiesChanged();
+    }
+
+    _onClocksPropertiesChanged() {
+        if (this._clocksProxy.g_name_owner == null)
+            return;
+
+        this._settings.set_value('locations',
+            new GLib.Variant('av', this._clocksProxy.Locations));
+    }
 };
 
 var WeatherSection = class WeatherSection {