panel: Consider visibility changes for solid style

We currently assume that window state changes are accompanied by an
allocation change (triggered for example by the minimize animation).
However this misses the case where a window actor is simply hidden
without any transition, as is the case with the 'show-desktop' action
for instance, so start tracking plain visibility changes as well.

https://bugzilla.gnome.org/show_bug.cgi?id=783975

diff --git a/js/ui/panel.js b/js/ui/panel.js
index 83fda0ea848395cb201afed6889a994c759bdff0..52c89d79cd2ebe7ded3fa9014ba2edfcefb15e05 100644 (file)
--- a/js/ui/panel.js
+++ b/js/ui/panel.js
@@ -823,12 +823,17 @@ const Panel = new Lang.Class({
     },
 
     _onWindowActorAdded: function(container, metaWindowActor) {
-        let signalId = metaWindowActor.connect('allocation-changed', Lang.bind(this, this._updateSolidStyle));
-        this._trackedWindows.set(metaWindowActor, signalId);
+        let signalIds = [];
+        ['allocation-changed', 'notify::visible'].forEach(s => {
+            signalIds.push(metaWindowActor.connect(s, Lang.bind(this, this._updateSolidStyle)));
+        });
+        this._trackedWindows.set(metaWindowActor, signalIds);
     },
 
     _onWindowActorRemoved: function(container, metaWindowActor) {
-        metaWindowActor.disconnect(this._trackedWindows.get(metaWindowActor));
+        this._trackedWindows.get(metaWindowActor).forEach(id => {
+            metaWindowActor.disconnect(id);
+        });
         this._trackedWindows.delete(metaWindowActor);
         this._updateSolidStyle();
     },