From 786beccca5d3f6252a1aa331453dddfd4c2486fb Mon Sep 17 00:00:00 2001
From: Stefano Facchini <stefano.facchini@gmail.com>
Date: Tue, 21 Feb 2012 20:46:27 +0100
Subject: [PATCH] workspaceThumbnail: don't queue unnecessary relayouts

Relayouts are expensive and can make the UI laggy.
---
 js/ui/workspaceThumbnail.js | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/js/ui/workspaceThumbnail.js b/js/ui/workspaceThumbnail.js
index 52b2a747f..1d18e0291 100644
--- a/js/ui/workspaceThumbnail.js
+++ b/js/ui/workspaceThumbnail.js
@@ -598,6 +598,9 @@ const ThumbnailsBox = new Lang.Class({
     },
 
     _clearDragPlaceholder: function() {
+        if (this._dropPlaceholderPos == -1)
+            return;
+
         this._dropPlaceholderPos = -1;
         this.actor.queue_relayout();
     },
@@ -635,8 +638,10 @@ const ThumbnailsBox = new Lang.Class({
             }
         }
 
-        this._dropPlaceholderPos = workspace;
-        this.actor.queue_relayout();
+        if (this._dropPlaceholderPos != workspace) {
+            this._dropPlaceholderPos = workspace;
+            this.actor.queue_relayout();
+        }
 
         if (workspace == -1)
             return DND.DragMotionResult.CONTINUE;