[gnome-shell] overviewControls: Use a custom layout to catch all geometry changes

[Florian Müllner <fmuellner src gnome org>]

commit df09109d81f71c47a8d64086c052d4006d90be1e
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Sep 13 09:34:13 2013 +0200

    overviewControls: Use a custom layout to catch all geometry changes
    
    We currently update workspaces geometry when we are notified about
    allocation changes of the overview group; however as the geometry
    is based on stage coordinates, we miss notifications when the
    allocation relative to the parent is unchanged, which happens when
    the primary monitor's position changes but not its resolution.
    Use a custom layout manager to give us a signal that is emitted
    reliably.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=708009

 js/ui/overviewControls.js |   16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)
---
diff --git a/js/ui/overviewControls.js b/js/ui/overviewControls.js
index 12ab2aa..c16c4ac 100644
--- a/js/ui/overviewControls.js
+++ b/js/ui/overviewControls.js
@@ -504,6 +504,17 @@ const MessagesIndicator = new Lang.Class({
     }
 });
 
+const ControlsLayout = new Lang.Class({
+    Name: 'ControlsLayout',
+    Extends: Clutter.BinLayout,
+    Signals: { 'allocation-changed': { flags: GObject.SignalFlags.RUN_LAST } },
+
+    vfunc_allocate: function(container, box, flags) {
+        this.parent(container, box, flags);
+        this.emit('allocation-changed');
+    }
+});
+
 const ControlsManager = new Lang.Class({
     Name: 'ControlsManager',
 
@@ -524,7 +535,8 @@ const ControlsManager = new Lang.Class({
         this._indicator = new MessagesIndicator(this.viewSelector);
         this.indicatorActor = this._indicator.actor;
 
-        this.actor = new St.Widget({ layout_manager: new Clutter.BinLayout(),
+        let layout = new ControlsLayout();
+        this.actor = new St.Widget({ layout_manager: layout,
                                      reactive: true,
                                      x_expand: true, y_expand: true,
                                      clip_to_allocation: true });
@@ -539,7 +551,7 @@ const ControlsManager = new Lang.Class({
                                                    expand: true });
         this._group.add_actor(this._thumbnailsSlider.actor);
 
-        this._group.connect('notify::allocation', Lang.bind(this, this._updateWorkspacesGeometry));
+        layout.connect('allocation-changed', Lang.bind(this, this._updateWorkspacesGeometry));
 
         Main.overview.connect('showing', Lang.bind(this, this._updateSpacerVisibility));
         Main.overview.connect('item-drag-begin', Lang.bind(this,