Refactored event handling to allow unregistration of event listeners.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@570 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Events.js

@@ -56,10 +56,24 @@ OpenLayers.Events.prototype = {
     * @param {Function} func
     */
     register: function (type, obj, func) {
+        if (func == null) {
+            obj = this.object;
+            func = obj;
+        }
         var listeners = this.listeners[type];
-        listeners.push( func.bindAsEventListener(obj) );
+        listeners.push( {obj: obj, func: func} );
     },
     
+    unregister: function (type, obj, func) {
+        var listeners = this.listeners[type];
+        for (var i = 0; i < listeners.length; i++) {
+            if (listeners[i].obj == obj && listeners[i].type == type) {
+                listeners.splice(i, 1);
+                break;
+            }
+        }
+    },
+
     remove: function(type) {
         this.listeners[type].pop();
     },
@@ -100,7 +114,8 @@ OpenLayers.Events.prototype = {
         var listeners = this.listeners[type];
         for (var i = 0; i < listeners.length; i++) {
             var callback = listeners[i];
-            callback(evt);
+            var continueChain = callback.func.call(callback.obj, evt);
+            if (continueChain != null && !continueChain) break;
         }
     }
 };