Box Handler missing start callback, r=pgiraud (closes #3324)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@12051 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Handler/Box.js

@@ -43,12 +43,16 @@ OpenLayers.Handler.Box = OpenLayers.Class(OpenLayers.Handler, {
      *
      * Parameters:
      * control - {<OpenLayers.Control>} 
-     * callbacks - {Object} An object with a "done" property whose value is a
-     *     callback to be called when the box drag operation is finished.  
-     *     The callback should expect to recieve a single argument, the box 
+     * callbacks - {Object} An object with a properties whose values are
+     *     functions.  Various callbacks described below.
+     * options - {Object} 
+     *
+     * Named callbacks:
+     * start - Called when the box drag operation starts.
+     * done - Called when the box drag operation is finished.
+     *     The callback should expect to receive a single argument, the box 
      *     bounds or a pixel. If the box dragging didn't span more than a 5 
      *     pixel distance, a pixel will be returned instead of a bounds object.
-     * options - {Object} 
      */
     initialize: function(control, callbacks, options) {
         OpenLayers.Handler.prototype.initialize.apply(this, arguments);
@@ -89,9 +93,10 @@ OpenLayers.Handler.Box = OpenLayers.Class(OpenLayers.Handler, {
     * Method: startBox
     *
     * Parameters:
-    * evt - {Event} 
+    * xy - {<OpenLayers.Pixel>}
     */
     startBox: function (xy) {
+        this.callback("start", []);
         this.zoomBox = OpenLayers.Util.createDiv('zoomBox',
              new OpenLayers.Pixel(-9999, -9999));
         this.zoomBox.className = this.boxDivClassName;