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

diff --git a/js/ui/osdWindow.js b/js/ui/osdWindow.js
index fb6587be0136c65ab70db0db24735c86a83cfe65..d7077a063c3717df3fa9859055c93770e37fd7d0 100644 (file)
--- 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;
     },