Merge pull request #193 from fredj/event-listeners

New eventListeners APIProperty for OpenLayers.Tile. r=elemoine

lib/OpenLayers/Tile.js

@@ -38,6 +38,30 @@ OpenLayers.Tile = OpenLayers.Class({
      */
     events: null,
 
+    /**
+     * APIProperty: eventListeners
+     * {Object} If set as an option at construction, the eventListeners
+     *     object will be registered with <OpenLayers.Events.on>.  Object
+     *     structure must be a listeners object as shown in the example for
+     *     the events.on method.
+     *
+     * This options can be set in the ``tileOptions`` option from
+     * <OpenLayers.Layer.Grid>. For example, to be notified of the
+     * ``loadend`` event of each tiles:
+     * (code)
+     * new OpenLayers.Layer.OSM('osm', 'http://tile.openstreetmap.org/${z}/${x}/${y}.png', {
+     *     tileOptions: {
+     *         eventListeners: {
+     *             'loadend': function(evt) {
+     *                 // do something on loadend
+     *             }
+     *         }
+     *     }
+     * });
+     * (end)
+     */
+    eventListeners: null,
+
     /**
      * Property: id 
      * {String} null
@@ -109,10 +133,13 @@ OpenLayers.Tile = OpenLayers.Class({
 
         //give the tile a unique id based on its BBOX.
         this.id = OpenLayers.Util.createUniqueID("Tile_");
-        
-        this.events = new OpenLayers.Events(this);
 
         OpenLayers.Util.extend(this, options);
+
+        this.events = new OpenLayers.Events(this);
+        if (this.eventListeners instanceof Object) {
+            this.events.on(this.eventListeners);
+        }
     },
 
     /**
@@ -139,7 +166,11 @@ OpenLayers.Tile = OpenLayers.Class({
         this.size = null;
         this.position = null;
         
+        if (this.eventListeners) {
+            this.events.un(this.eventListeners);
+        }
         this.events.destroy();
+        this.eventListeners = null;
         this.events = null;
     },
     

tests/Tile.html

@@ -22,7 +22,7 @@
 
     
     function test_Tile_constructor (t) {
-        t.plan( 12 );
+        t.plan( 13 );
      
         setUp();
         
@@ -33,7 +33,11 @@
         var url = "bobob";
         var size = new OpenLayers.Size(5,6);
         
-        tile = new OpenLayers.Tile(layer, position, bounds, url, size);
+        tile = new OpenLayers.Tile(layer, position, bounds, url, size, {
+            eventListeners: {
+                loadstart: OpenLayers.Function.False
+            }
+        });
 
         t.ok(tile instanceof OpenLayers.Tile, "new OpenLayers.Tile returns Tile object");
         t.ok(tile.layer === layer, "tile.layer set correctly");
@@ -48,7 +52,9 @@
         t.ok(tile.id != null, "tile is given an id");
         t.ok(OpenLayers.String.startsWith(tile.id, "Tile_"),
              "tile's id starts correctly");
-        t.ok(tile.events != null, "tile's events intitialized");
+        t.ok(tile.events != null, "tile's events initialized");
+        t.ok(tile.events.listeners.loadstart.length == 1, 
+             "tile's events initialized from eventListeners option");
         
         tearDown();