dnd: Cancel the animation on drag actor destruction

If the drag actor is destroyed before the animation
callback is called, the callback is never called and
we're sticked with dnd grabing the events after we
dropped the target.

https://bugzilla.gnome.org/show_bug.cgi?id=757676

diff --git a/js/ui/dnd.js b/js/ui/dnd.js
index c7140a1c2468a74217b5b8b78c3eca5cbf4b76ff..e749dd9a8121da0b0685d7b7ec47d40145d5dd93 100644 (file)
--- a/js/ui/dnd.js
+++ b/js/ui/dnd.js
@@ -571,20 +571,13 @@ const _Draggable = new Lang.Class({
             return;
         }
 
-        this._animationInProgress = true;
-        // No target, so snap back
-        Tweener.addTween(this._dragActor,
-                         { x: snapBackX,
-                           y: snapBackY,
-                           scale_x: snapBackScale,
-                           scale_y: snapBackScale,
-                           opacity: this._dragOrigOpacity,
-                           time: SNAP_BACK_ANIMATION_TIME,
-                           transition: 'easeOutQuad',
-                           onComplete: this._onAnimationComplete,
-                           onCompleteScope: this,
-                           onCompleteParams: [this._dragActor, eventTime]
-                         });
+        this._animateDragEnd(eventTime,
+                             { x: snapBackX,
+                               y: snapBackY,
+                               scale_x: snapBackScale,
+                               scale_y: snapBackScale,
+                               time: SNAP_BACK_ANIMATION_TIME,
+                             });
     },
 
     _restoreDragActor: function(eventTime) {
@@ -596,18 +589,44 @@ const _Draggable = new Lang.Class({
         this._dragActor.set_scale(restoreScale, restoreScale);
         this._dragActor.opacity = 0;
 
+        this._animateDragEnd(eventTime,
+                             { time: REVERT_ANIMATION_TIME });
+    },
+
+    _animateDragEnd: function (eventTime, params) {
         this._animationInProgress = true;
-        Tweener.addTween(this._dragActor,
-                         { opacity: this._dragOrigOpacity,
-                           time: REVERT_ANIMATION_TIME,
-                           transition: 'easeOutQuad',
-                           onComplete: this._onAnimationComplete,
-                           onCompleteScope: this,
-                           onCompleteParams: [this._dragActor, eventTime]
-                         });
+
+        // finish animation if the actor gets destroyed
+        // during it
+        this._dragActorDestroyId =
+            this._dragActor.connect('destroy',
+                                    Lang.bind(this, this._finishAnimation));
+
+        params['opacity']          = this._dragOrigOpacity;
+        params['transition']       = 'easeOutQuad';
+        params['onComplete']       = this._onAnimationComplete;
+        params['onCompleteScope']  = this;
+        params['onCompleteParams'] = [this._dragActor, eventTime];
+
+        // start the animation
+        Tweener.addTween(this._dragActor, params)
+    },
+
+    _finishAnimation : function () {
+        if (!this._animationInProgress)
+            return
+
+        this._animationInProgress = false;
+        if (!this._buttonDown)
+            this._dragComplete();
+
+        global.screen.set_cursor(Meta.Cursor.DEFAULT);
     },
 
     _onAnimationComplete : function (dragActor, eventTime) {
+        dragActor.disconnect(this._dragActorDestroyId);
+        this._dragActorDestroyId = 0;
+
         if (this._dragOrigParent) {
             Main.uiGroup.remove_child(this._dragActor);
             this._dragOrigParent.add_actor(this._dragActor);
@@ -616,12 +635,9 @@ const _Draggable = new Lang.Class({
         } else {
             dragActor.destroy();
         }
-        global.screen.set_cursor(Meta.Cursor.DEFAULT);
-        this.emit('drag-end', eventTime, false);
 
-        this._animationInProgress = false;
-        if (!this._buttonDown)
-            this._dragComplete();
+        this.emit('drag-end', eventTime, false);
+        this._finishAnimation();
     },
 
     _dragComplete: function() {