[gnome-shell/wip/fmuellner/fix-osd-warnings] osdWindow: Disconnect signals on destroy

[Florian Müllner <fmuellner src gnome org>]

commit d2e022a07902369504364db94918277b1b664ae0
Author: Florian Müllner <fmuellner gnome org>
Date:   Sun Sep 23 03:06:21 2018 +0200

    osdWindow: Disconnect signals on destroy
    
    Since we started to show OSD windows on all monitors, OSD windows are
    destroyed when the corresponding monitor is disconnected. We shouldn't
    leave any signal handlers around in that case - they prevent the object
    from being garbage collected, and trigger warnings for accessing proper-
    ties of invalidated GObjects.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/issues/602

 js/ui/osdWindow.js | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)
---
diff --git a/js/ui/osdWindow.js b/js/ui/osdWindow.js
index 9021c22d2..a61cf5e12 100644
--- a/js/ui/osdWindow.js
+++ b/js/ui/osdWindow.js
@@ -118,15 +118,30 @@ var OsdWindow = new Lang.Class({
         this._hideTimeoutId = 0;
         this._reset();
 
-        Main.layoutManager.connect('monitors-changed',
-                                   this._relayout.bind(this));
+        this.actor.connect('destroy', this._onDestroy.bind(this));
+
+        this._monitorsChangedId =
+            Main.layoutManager.connect('monitors-changed',
+                                       this._relayout.bind(this));
         let themeContext = St.ThemeContext.get_for_stage(global.stage);
-        themeContext.connect('notify::scale-factor',
-                             this._relayout.bind(this));
+        this._scaleChangedId =
+            themeContext.connect('notify::scale-factor',
+                                 this._relayout.bind(this));
         this._relayout();
         Main.uiGroup.add_child(this.actor);
     },
 
+    _onDestroy() {
+        if (this._monitorsChangedId)
+            Main.layoutManager.disconnect(this._monitorsChangedId);
+        this._monitorsChangedId = 0;
+
+        let themeContext = St.ThemeContext.get_for_stage(global.stage);
+        if (this._scaleChangedId)
+            themeContext.disconnect(this._scaleChangedId);
+        this._scaleChangedId = 0;
+    },
+
     setIcon(icon) {
         this._icon.gicon = icon;
     },