Replace goog.events.Event/EventTarget system with our own

This also removes goog.events.listen, goog.events.unlisten,
goog.events.unlistenByKey and goog.events.BrowserEvent.

src/ol/events/eventtarget.js

@@ -0,0 +1,113 @@
+goog.provide('ol.events.EventTarget');
+
+goog.require('goog.Disposable');
+goog.require('ol.events');
+goog.require('ol.events.Event');
+
+/**
+ * @constructor
+ * @extends {goog.Disposable}
+ */
+ol.events.EventTarget = function() {
+
+  goog.base(this);
+
+  /**
+   * @private
+   * @type {!Object.<string, Array.<ol.events.ListenerFunctionType>>}
+   */
+  this.listeners_ = {};
+
+};
+goog.inherits(ol.events.EventTarget, goog.Disposable);
+
+
+/**
+ * @param {ol.events.EventType|string} type Type.
+ * @param {ol.events.ListenerFunctionType} listener Listener.
+ * @param {boolean=} opt_capture Call listener before already registered
+ *     listeners. Default is false.
+ */
+ol.events.EventTarget.prototype.addEventListener = function(type, listener, opt_capture) {
+  var listeners = this.listeners_[type];
+  if (!listeners) {
+    listeners = this.listeners_[type] = [];
+  }
+  if (listeners.indexOf(listener) === -1) {
+    if (opt_capture) {
+      listeners.push(listener);
+    } else {
+      listeners.unshift(listener);
+    }
+  }
+};
+
+
+/**
+ * @param {{type: (ol.events.EventType|string),
+ *     target: (EventTarget|ol.events.EventTarget|undefined)}|ol.events.Event|
+ *     ol.events.EventType|string} event Event or event type.
+ * @return {boolean|undefined} `false` if anyone called preventDefault on the
+ *     event object or if any of the listeners returned false.
+ */
+ol.events.EventTarget.prototype.dispatchEvent = function(event) {
+  var evt = goog.isString(event) ? new ol.events.Event(event) : event;
+  var type = evt.type;
+  evt.target = this;
+  var listeners = this.listeners_[type];
+  if (listeners) {
+    for (var i = listeners.length - 1; i >= 0; --i) {
+      if (listeners[i].call(this, evt) === false || evt.propagationStopped) {
+        return false;
+      }
+    }
+  }
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.events.EventTarget.prototype.disposeInternal = function() {
+  ol.events.unlistenAll(this);
+  goog.base(this, 'disposeInternal');
+};
+
+
+/**
+ * @param {ol.events.EventType|string} type Type.
+ * @return {Array.<ol.events.ListenerFunctionType>} Listeners.
+ */
+ol.events.EventTarget.prototype.getListeners = function(type) {
+  return this.listeners_[type];
+};
+
+
+/**
+ * @param {(ol.events.EventType|string)=} opt_type Type. If not provided,
+ *     `true` will be returned if this EventTarget has any listeners.
+ * @return {boolean} Has listeners.
+ */
+ol.events.EventTarget.prototype.hasListener = function(opt_type) {
+  return opt_type ?
+      opt_type in this.listeners_ :
+      Object.keys(this.listeners_).length > 0;
+};
+
+
+/**
+ * @param {ol.events.EventType|string} type Type.
+ * @param {ol.events.ListenerFunctionType} listener Listener.
+ * @param {boolean=} opt_capture Call listener before already registered
+ *     listeners. Default is false.
+ */
+ol.events.EventTarget.prototype.removeEventListener = function(type, listener, opt_capture) {
+  var listeners = this.listeners_[type];
+  if (listeners) {
+    var index = listeners.indexOf(listener);
+    listeners.splice(index, 1);
+    if (listeners.length === 0) {
+      delete this.listeners_[type];
+    }
+  }
+};