Improving the PanZoomBar behavior so that when you click on the bar after dragging to the top, the map doesn't re-zoom on mouse up. r=me (closes #1861)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@10025 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/PanZoomBar.js

@@ -65,6 +65,18 @@ OpenLayers.Control.PanZoomBar = OpenLayers.Class(OpenLayers.Control.PanZoom, {
      */
     forceFixedZoomLevel: false,
 
+    /**
+     * Property: mouseDragStart
+     * {<OpenLayers.Pixel>}
+     */
+    mouseDragStart: null,
+
+    /**
+     * Property: zoomStart
+     * {<OpenLayers.Pixel>}
+     */
+    zoomStart: null,
+
     /**
      * Constructor: OpenLayers.Control.PanZoomBar
      */ 
@@ -85,6 +97,9 @@ OpenLayers.Control.PanZoomBar = OpenLayers.Class(OpenLayers.Control.PanZoom, {
         });
 
         OpenLayers.Control.PanZoom.prototype.destroy.apply(this, arguments);
+
+        delete this.mouseDragStart;
+        delete this.zoomStart;
     },
     
     /**
@@ -342,7 +357,7 @@ OpenLayers.Control.PanZoomBar = OpenLayers.Class(OpenLayers.Control.PanZoom, {
         if (!OpenLayers.Event.isLeftClick(evt)) {
             return;
         }
-        if (this.zoomStart) {
+        if (this.mouseDragStart) {
             this.div.style.cursor="";
             this.map.events.un({
                 "mouseup": this.passEventToSlider,
@@ -359,7 +374,6 @@ OpenLayers.Control.PanZoomBar = OpenLayers.Class(OpenLayers.Control.PanZoom, {
                 zoomLevel += Math.round(deltaY/this.zoomStopHeight);
             }
             this.map.zoomTo(zoomLevel);
-            this.moveZoomBar();
             this.mouseDragStart = null;
             OpenLayers.Event.stop(evt);
         }