/**
+ * Adds support for mouseenter/mouseleave events
+ * @module event
+ * @submodule event-mouseenter
+ */
+var Event = Y.Event,
+ Lang = Y.Lang,
+
+ plugins = Y.Env.evt.plugins,
+
+ listeners = {},
+
+ eventConfig = {
+
+ on: function(type, fn, el) {
+
+ var args = Y.Array(arguments, 0, true),
+ element = el,
+ availHandle;
+
+
+ if (Lang.isString(el)) {
+
+ // Need to use Y.all because if el is a string it could be a
+ // selector that returns a NodeList
+
+ element = Y.all(el);
+
+ if (element.size() === 0) { // Not found, check using onAvailable
+
+ availHandle = Event.onAvailable(el, function() {
+
+ availHandle.handle = Y.on.apply(Y, args);
+
+ }, Event, true, false);
+
+ return availHandle;
+
+ }
+
+ }
+
+
+ var sDOMEvent = (type === "mouseenter") ? "mouseover" : "mouseout",
+
+ // The name of the custom event
+ sEventName = type + ":" + Y.stamp(element) + sDOMEvent,
+
+ listener = listeners[sEventName],
+
+ domEventHandle,
+
+ ceHandle,
+
+ nListeners;
+
+
+ // Bind an actual DOM event listener that will call the
+ // the custom event
+ if (!listener) {
+
+ domEventHandle = Y.on(sDOMEvent, Y.rbind(Event._fireMouseEnter, Y, sEventName), element);
+
+ // Hook into the _delete method for the Custom Event wrapper of this
+ // DOM Event in order to clean up the 'listeners' map and unsubscribe
+ // the associated Custom Event listeners fired by this DOM event
+ // listener if/when the user calls "purgeElement" OR removes all
+ // listeners of the Custom Event.
+
+ Y.after(function (sub) {
+
+ if (domEventHandle.sub == sub) {
+
+ // Delete this event from the map of known mouseenter
+ // and mouseleave listeners
+ delete listeners[sEventName];
+
+ Y.log("DOM event listener associated with the " + sEventName + " Custom Event removed. Removing all " + sEventName + " listeners.", "info", "Event");
+
+ // Unsubscribe all listeners of the Custom Event fired
+ // by this DOM event.
+ Y.detachAll(sEventName);
+
+ }
+
+ }, domEventHandle.evt, "_delete");
+
+
+ listener = {};
+ listener.handle = domEventHandle;
+
+ listeners[sEventName] = listener;
+
+ }
+
+ nListeners = listener.count;
+
+ listener.count = nListeners ? (nListeners + 1) : 1;
+
+ args[0] = sEventName;
+
+ // Remove the element from the args
+ args.splice(2, 1);
+
+ // Subscribe to the custom event
+ ceHandle = Y.on.apply(Y, args);
+
+ // Hook into the detach method of the handle in order to clean up the
+ // 'listeners' map and remove the associated DOM event handler
+ // responsible for firing this Custom Event if all listener for this
+ // event have been removed.
+
+ Y.after(function () {
+
+ listener.count = (listener.count - 1);
+
+ if (listener.count === 0) {
+ Y.log("No more listeners for the " + sEventName + " Custom Event. Removing its associated DOM event listener.", "info", "Event");
+ listener.handle.detach();
+ }
+
+ }, ceHandle, "detach");
+
+
+ return ceHandle;
+
+ }
+
+ };
+
+
+Event._fireMouseEnter = function (e, eventName) {
+
+ var relatedTarget = e.relatedTarget,
+ currentTarget = e.currentTarget;
+
+ if (currentTarget !== relatedTarget &&
+ !currentTarget.contains(relatedTarget)) {
+
+ Y.publish(eventName, {
+ contextFn: function() {
+ return currentTarget;
+ }
+ });
+
+ Y.fire(eventName, e);
+
+ }
+
+};
+
+
+/**
+ * Sets up a "mouseenter" listener—a listener that is called the first time
+ * the user's mouse enters the specified element(s).
+ *
+ * @event mouseenter
+ * @param type {string} "mouseenter"
+ * @param fn {function} The method the event invokes.
+ * @param el {string|node} The element(s) to assign the listener to.
+ * @param spec {string} Optional. String representing a selector that must
+ * match the target of the event in order for the listener to be called.
+ * @return {EventHandle} the detach handle
+ * @for YUI
+ */
+plugins.mouseenter = eventConfig;
+
+/**
+* Sets up a "mouseleave" listener—a listener that is called the first time
+* the user's mouse leaves the specified element(s).
+*
+* @event mouseleave
+* @param type {string} "mouseleave"
+* @param fn {function} The method the event invokes.
+* @param el {string|node} The element(s) to assign the listener to.
+* @param spec {string} Optional. String representing a selector that must
+* match the target of the event in order for the listener to be called.
+* @return {EventHandle} the detach handle
+* @for YUI
+ */
+plugins.mouseleave = eventConfig;
+