patch for #809 - add the addEventType() function to the OpenLayers.Events objects so that subclasses can safely add new event types without modifying their parents' constant values

git-svn-id: http://svn.openlayers.org/trunk/openlayers@3622 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Events.js

@@ -410,7 +410,7 @@ OpenLayers.Events.prototype = {
         // custom application event.
         if (this.eventTypes != null) {
             for (var i = 0; i < this.eventTypes.length; i++) {
-                this.listeners[ this.eventTypes[i] ] = new Array();
+                this.addEventType(this.eventTypes[i]);
             }
         }
         
@@ -437,6 +437,20 @@ OpenLayers.Events.prototype = {
         this.eventHandler = null;
     },
 
+    /**
+     * APIMethod: addEventType
+     * Add a new event type to this events object.
+     * If the event type has already been added, do nothing.
+     * 
+     * Parameters:
+     * eventName - {String}
+     */
+    addEventType: function(eventName) {
+        if (!this.listeners[eventName]) {
+            this.listeners[eventName] = new Array();
+        }
+    },
+
     /**
      * Method: attachToElement
      *
@@ -449,9 +463,7 @@ OpenLayers.Events.prototype = {
 
             // every browser event has a corresponding application event 
             // (whether it's listened for or not).
-            if (this.listeners[eventType] == null) {
+            this.addEventType(eventType);
-                this.listeners[eventType] = new Array();
-            }
             
             // use Prototype to register the event cross-browser
             OpenLayers.Event.observe(element, eventType, this.eventHandler);

tests/test_Events.html

@@ -304,6 +304,33 @@
         
     }
 
+    function test_06_Events_addEventType(t) {
+
+        t.plan( 6 );
+ 
+        var mapDiv = OpenLayers.Util.getElement('map');
+        var obj = {result: 0};
+        var eventTypes = ["doThingA", "doThingB"];
+
+        events = new OpenLayers.Events(obj, mapDiv, eventTypes);
+
+
+        t.eq( events.listeners["doThingA"].length, 0, "event type passed as passed as param to OpenLayers.Events constructor correctly set up" );
+        t.eq( events.listeners["doThingB"].length, 0, "event type passed as passed as param to OpenLayers.Events constructor correctly set up" );
+
+        var newEventType = "onFoo";
+        t.ok( events.listeners[newEventType] == null, "event type not yet registered has null entry in listeners array");
+
+        events.addEventType(newEventType);
+        t.eq( events.listeners[newEventType].length, 0, "event type passed to addEventType correctly set up" );
+        
+        var func = function () {};
+        events.register( "doThingA", obj, func );
+        t.eq( events.listeners["doThingA"].length, 1, "listener correctly registered" );
+
+        events.addEventType("doThingsA");
+        t.eq( events.listeners["doThingA"].length, 1, "event type passed to addEventType correctly does nothing if clashes with already defined event type" );
+    }
 
    
   // -->