scrolling with mousewheel triggers zooming.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@1215 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/MouseDefaults.js

@@ -19,6 +19,14 @@ OpenLayers.Control.MouseDefaults.prototype =
      */
     initialize: function() {
         OpenLayers.Control.prototype.initialize.apply(this, arguments);
+
+        //register mousewheel events specifically on the window and document
+        Event.observe(window, "DOMMouseScroll", 
+                      this.onWheelEvent.bindAsEventListener(this));
+        Event.observe(window, "mousewheel", 
+                      this.onWheelEvent.bindAsEventListener(this));
+        Event.observe(document, "mousewheel", 
+                      this.onWheelEvent.bindAsEventListener(this));
     },
 
     /**
@@ -148,6 +156,54 @@ OpenLayers.Control.MouseDefaults.prototype =
                 this.defaultMouseUp(evt);
         }
     },
+
+
+    /** User spun scroll wheel up
+     * 
+     */
+    defaultWheelUp: function()  {
+        this.map.zoomIn();
+    },
+
+    /** User spun scroll wheel down
+     * 
+     */
+    defaultWheelDown: function()  {
+        this.map.zoomOut();
+    },
+
+
+/**
+ *  Mouse ScrollWheel code thanks to http://adomas.org/javascript-mouse-wheel/
+ */
+
+
+    /** Catch the wheel event and handle it xbrowserly
+     * 
+     * @param {Event} e
+     */
+    onWheelEvent: function(e){
+        var delta = 0;
+        if (!e) {
+            e = window.event;
+        }
+        if (e.wheelDelta) {
+            delta = e.wheelDelta/120; 
+            if (window.opera) {
+                delta = -delta;
+            }
+        } else if (e.detail) {
+            delta = -e.detail / 3;
+        }
+        if (delta) {
+            if (delta < 0) {
+               this.map.zoomOut();
+            } else {
+               this.map.zoomIn();
+            }
+        }
+    },
+    
     
     /** @final @type String */
     CLASS_NAME: "OpenLayers.Control.MouseDefaults"