Store a reference to the bound mouse cache clearer so we can unregister it as a listener later. This solves an issue with slider events on the PanZoomBar. r=crschmidt (pullup #2054)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@9401 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Events.js

@@ -435,6 +435,14 @@ OpenLayers.Events = OpenLayers.Class({
     */
     includeXY: false,      
 
+    /**
+     * Method: clearMouseListener
+     * A version of <clearMouseCache> that is bound to this instance so that
+     *     it can be used with <OpenLayers.Event.observe> and
+     *     <OpenLayers.Event.stopObserving>.
+     */
+    clearMouseListener: null,
+
     /**
      * Constructor: OpenLayers.Events
      * Construct an OpenLayers.Events object.
@@ -458,6 +466,11 @@ OpenLayers.Events = OpenLayers.Class({
         this.eventHandler = OpenLayers.Function.bindAsEventListener(
             this.handleBrowserEvent, this
         );
+        
+        // to be used with observe and stopObserving
+        this.clearMouseListener = OpenLayers.Function.bind(
+            this.clearMouseCache, this
+        );
 
         // if eventTypes is specified, create a listeners list for each 
         // custom application event.
@@ -481,6 +494,11 @@ OpenLayers.Events = OpenLayers.Class({
     destroy: function () {
         if (this.element) {
             OpenLayers.Event.stopObservingElement(this.element);
+            if(this.element.hasScrollEvent) {
+                OpenLayers.Event.stopObserving(
+                    window, "scroll", this.clearMouseListener
+                );
+            }
         }
         this.element = null;
 
@@ -773,8 +791,7 @@ OpenLayers.Events = OpenLayers.Class({
         if (!this.includeXY) {
             this.clearMouseCache();
         } else if (!this.element.hasScrollEvent) {
-            OpenLayers.Event.observe(window, 'scroll', 
-                OpenLayers.Function.bind(this.clearMouseCache, this)); 
+            OpenLayers.Event.observe(window, "scroll", this.clearMouseListener);
             this.element.hasScrollEvent = true;
         }