Extend goog.events.Event for custom vector layer events

Vector events include features and extents.  In the case of feature change events, the extents array will include old and new extents for features with modified geometries.w

src/ol/layer/vectorlayer.js

@@ -1,8 +1,9 @@
 goog.provide('ol.layer.Vector');
-goog.provide('ol.layer.VectorLayerEventType');
+goog.provide('ol.layer.VectorEventType');
 
 goog.require('goog.array');
 goog.require('goog.asserts');
+goog.require('goog.events.Event');
 goog.require('goog.object');
 goog.require('ol.Feature');
 goog.require('ol.extent');
@@ -127,25 +128,6 @@ ol.layer.FeatureCache.prototype.remove = function(feature) {
 };
 
 
-/**
- * @enum {string}
- */
-ol.layer.VectorLayerEventType = {
-  ADD: 'add',
-  CHANGE: 'featurechange',
-  REMOVE: 'remove',
-  INTENTCHANGE: 'intentchange'
-};
-
-
-/**
- * @typedef {{extent: (ol.Extent|undefined),
- *            features: (Array.<ol.Feature>|undefined),
- *            type: ol.layer.VectorLayerEventType}}
- */
-ol.layer.VectorLayerEventObject;
-
-
 
 /**
  * @constructor
@@ -200,11 +182,8 @@ ol.layer.Vector.prototype.addFeatures = function(features) {
       ol.extent.extend(extent, geometry.getBounds());
     }
   }
-  this.dispatchEvent(/** @type {ol.layer.VectorLayerEventObject} */ ({
-    extent: extent,
-    features: features,
-    type: ol.layer.VectorLayerEventType.ADD
-  }));
+  this.dispatchEvent(new ol.layer.VectorEvent(ol.layer.VectorEventType.ADD,
+      features, [extent]));
 };
 
 
@@ -213,9 +192,8 @@ ol.layer.Vector.prototype.addFeatures = function(features) {
  */
 ol.layer.Vector.prototype.clear = function() {
   this.featureCache_.clear();
-  this.dispatchEvent(/** @type {ol.layer.VectorLayerEventObject} */ ({
-    type: ol.layer.VectorLayerEventType.CHANGE
-  }));
+  this.dispatchEvent(
+      new ol.layer.VectorEvent(ol.layer.VectorEventType.CHANGE, [], []));
 };
 
 
@@ -409,11 +387,8 @@ ol.layer.Vector.prototype.removeFeatures = function(features) {
       ol.extent.extend(extent, geometry.getBounds());
     }
   }
-  this.dispatchEvent(/** @type {ol.layer.VectorLayerEventObject} */ ({
-    extent: extent,
-    features: features,
-    type: ol.layer.VectorLayerEventType.REMOVE
-  }));
+  this.dispatchEvent(new ol.layer.VectorEvent(ol.layer.VectorEventType.REMOVE,
+      features, [extent]));
 };
 
 
@@ -437,11 +412,8 @@ ol.layer.Vector.prototype.setRenderIntent =
       ol.extent.extend(extent, geometry.getBounds());
     }
   }
-  this.dispatchEvent(/** @type {ol.layer.VectorLayerEventObject} */ ({
-    extent: extent,
-    features: features,
-    type: ol.layer.VectorLayerEventType.INTENTCHANGE
-  }));
+  this.dispatchEvent(new ol.layer.VectorEvent(
+      ol.layer.VectorEventType.INTENTCHANGE, features, [extent]));
 };
 
 
@@ -462,3 +434,40 @@ ol.layer.Vector.uidTransformFeatureInfo = function(features) {
       function(feature) { return goog.getUid(feature); });
   return uids.join(', ');
 };
+
+
+
+/**
+ * @constructor
+ * @extends {goog.events.Event}
+ * @param {string} type Event type.
+ * @param {Array.<ol.Feature>} features Features associated with the event.
+ * @param {Array.<ol.Extent>} extents Any extents associated with the event.
+ */
+ol.layer.VectorEvent = function(type, features, extents) {
+
+  goog.base(this, type);
+
+  /**
+   * @type {Array.<ol.Feature>}
+   */
+  this.features = features;
+
+  /**
+   * @type {Array.<ol.Extent>}
+   */
+  this.extents = extents;
+
+};
+goog.inherits(ol.layer.VectorEvent, goog.events.Event);
+
+
+/**
+ * @enum {string}
+ */
+ol.layer.VectorEventType = {
+  ADD: 'featureadd',
+  CHANGE: 'featurechange',
+  REMOVE: 'featureremove',
+  INTENTCHANGE: 'intentchange'
+};