var isString = Y.Lang.isString,
+
+ fireMouseEventForNode = function (node, relatedTarget, eventName, e, spec) {
+
+ if (!node.compareTo(relatedTarget) && !node.contains(relatedTarget)) {
+
+ e.container = e.currentTarget;
+ e.currentTarget = node;
+
+ Y.fire(eventName, e);
+
+ }
+
+ },
+
+
+ handleMouseEvent = function (e, eventName, spec) {
+
+ var relatedTarget = e.relatedTarget,
+ currentTarget = e.currentTarget,
+ target = e.target;
+
+ if (spec) {
+
+ currentTarget.queryAll(spec).some(function (v) {
+
+ var bReturnVal;
+
+ if (v.compareTo(target) || v.contains(target)) {
+ fireMouseEventForNode(v, relatedTarget, eventName, e, spec);
+ bReturnVal = true;
+ }
+
+ return bReturnVal;
+
+ });
+
+ }
+ else {
+ fireMouseEventForNode(currentTarget, relatedTarget, eventName, e);
+ }
+
+ },
+
+ sanitize = Y.cached(function (str) {
+
+ return str.replace(/[|,:]/g, "~");
+
+ }),
+
+ eventConfig = {
+
+ on: function(type, fn, el, spec) {
+
+ var sDOMEvent = (type === "mouseenter") ? "mouseover" : "mouseout",
+ sEventName = type + ":" + (isString(el) ? el : Y.stamp(el)) + sDOMEvent,
+ args = Y.Array(arguments, 0, true),
+ sSelector;
+
+ if (isString(spec)) {
+ sSelector = spec;
+ sEventName = sEventName + sanitize(sSelector);
+ }
+
+ if (!Y.getEvent(sEventName)) {
+
+ // Set up the listener on the container
+ Y.on(sDOMEvent, function (e) {
+
+ handleMouseEvent(e, sEventName, sSelector);
+
+ }, el);
+ }
+
+ args[0] = sEventName;
+
+
+ // Remove the element (and the spec--if defined) from the args
+
+ if (sSelector) {
+ args.splice(2, 2);
+ }
+ else {
+ args.splice(2, 1);
+ }
+
+
+ // Subscribe to the custom event for the delegation spec
+ return Y.on.apply(Y, args);
+
+ }
+
+ };
+
+/**
+ * Sets up a "mouseenter" listener—a listener that is called the first time
+ * the user's mouse enters the specified element(s). By passing a CSS selector
+ * as the fourth argument, can also be used to delegate a "mouseenter"
+ * event listener.
+ *
+ * @event mouseenter
+ * @param type {string} "mouseenter"
+ * @param fn {string} 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
+ */
+Y.Env.evt.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). By passing a CSS selector
+* as the fourth argument, can also be used to delegate a "mouseleave"
+* event listener.
+*
+* @event mouseleave
+* @param type {string} "mouseleave"
+* @param fn {string} 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
+ */
+Y.Env.evt.plugins.mouseleave = eventConfig;
+