/*

Copyright (c) 2009, Yahoo! Inc. All rights reserved.

Code licensed under the BSD License:

http://developer.yahoo.net/yui/license.txt

version: 3.0.0b1

build: 1163

*/

YUI.add('node-menunav', function(Y) {

/**

* <p>The MenuNav Node Plugin makes it easy to transform existing list-based 

* markup into traditional, drop down navigational menus that are both accessible 

* and easy to customize, and only require a small set of dependencies.</p>

* 

* 

* <p>To use the MenuNav Node Plugin, simply pass a reference to the plugin to a 

* Node instance's <code>plug</code> method.</p>

* 

* <p>

* <code>

* &#60;script type="text/javascript"&#62; <br>

* <br>

* 		//	Call the "use" method, passing in "node-menunav".  This will <br>

* 		//	load the script and CSS for the MenuNav Node Plugin and all of <br>

* 		//	the required dependencies. <br>

* <br>

* 		YUI().use("node-menunav", function(Y) { <br>

* <br>

* 			//	Use the "contentready" event to initialize the menu when <br>

* 			//	the subtree of element representing the root menu <br>

* 			//	(&#60;div id="menu-1"&#62;) is ready to be scripted. <br>

* <br>

* 			Y.on("contentready", function () { <br>

* <br>

* 				//	The scope of the callback will be a Node instance <br>

* 				//	representing the root menu (&#60;div id="menu-1"&#62;). <br>

* 				//	Therefore, since "this" represents a Node instance, it <br>

* 				//	is possible to just call "this.plug" passing in a <br>

*				//	reference to the MenuNav Node Plugin. <br>

* <br>

* 				this.plug(Y.Plugin.NodeMenuNav); <br>

* <br>

* 			}, "#menu-1"); <br>

* <br>		

* 		}); <br>

* <br>	

* 	&#60;/script&#62; <br>

* </code>

* </p>

*

* <p>The MenuNav Node Plugin has several configuration properties that can be 

* set via an object literal that is passed as a second argument to a Node 

* instance's <code>plug</code> method.

* </p>

*

* <p>

* <code>

* &#60;script type="text/javascript"&#62; <br>

* <br>

* 		//	Call the "use" method, passing in "node-menunav".  This will <br>

* 		//	load the script and CSS for the MenuNav Node Plugin and all of <br>

* 		//	the required dependencies. <br>

* <br>

* 		YUI().use("node-menunav", function(Y) { <br>

* <br>

* 			//	Use the "contentready" event to initialize the menu when <br>

* 			//	the subtree of element representing the root menu <br>

* 			//	(&#60;div id="menu-1"&#62;) is ready to be scripted. <br>

* <br>

* 			Y.on("contentready", function () { <br>

* <br>

* 				//	The scope of the callback will be a Node instance <br>

* 				//	representing the root menu (&#60;div id="menu-1"&#62;). <br>

* 				//	Therefore, since "this" represents a Node instance, it <br>

* 				//	is possible to just call "this.plug" passing in a <br>

*				//	reference to the MenuNav Node Plugin. <br>

* <br>

* 				this.plug(Y.Plugin.NodeMenuNav, { mouseOutHideDelay: 1000 });

* <br><br>

* 			}, "#menu-1"); <br>

* <br>		

* 		}); <br>

* <br>	

* 	&#60;/script&#62; <br>

* </code>

* </p>

* 

* @module node-menunav

*/

	//	Util shortcuts

var UA = Y.UA,

	later = Y.later,

	getClassName = Y.ClassNameManager.getClassName,

	//	Frequently used strings

	MENU = "menu",

	MENUITEM = "menuitem",

	HIDDEN = "hidden",

	PARENT_NODE = "parentNode",

	CHILDREN = "children",

	OFFSET_HEIGHT = "offsetHeight",

	OFFSET_WIDTH = "offsetWidth",

	PX = "px",

	ID = "id",

	PERIOD = ".",

	HANDLED_MOUSEOUT = "handledMouseOut",

	HANDLED_MOUSEOVER = "handledMouseOver",

	ACTIVE = "active",

	LABEL = "label",

	LOWERCASE_A = "a",

	MOUSEDOWN = "mousedown",

	KEYDOWN = "keydown",

	CLICK = "click",

	EMPTY_STRING = "",

	FIRST_OF_TYPE = "first-of-type",

	ROLE = "role",

	PRESENTATION = "presentation",

	DESCENDANTS = "descendants",

	UI = "UI",

	ACTIVE_DESCENDANT = "activeDescendant",

	USE_ARIA = "useARIA",

	ARIA_HIDDEN = "aria-hidden",

	CONTENT = "content",

	HOST = "host",

	ACTIVE_DESCENDANT_CHANGE = ACTIVE_DESCENDANT + "Change",

	STANDARD_QUERY = ">.yui-menu-content>ul>li>a",

	EXTENDED_QUERY = ">.yui-menu-content>ul>li>.yui-menu-label>a:first-child",

	//	Attribute keys

	AUTO_SUBMENU_DISPLAY = "autoSubmenuDisplay",

	MOUSEOUT_HIDE_DELAY = "mouseOutHideDelay",

	//	CSS class names

	CSS_MENU = getClassName(MENU),

	CSS_MENU_HIDDEN = getClassName(MENU, HIDDEN),

	CSS_MENU_HORIZONTAL = getClassName(MENU, "horizontal"),

	CSS_MENU_LABEL = getClassName(MENU, LABEL),

	CSS_MENU_LABEL_ACTIVE = getClassName(MENU, LABEL, ACTIVE),

	CSS_MENU_LABEL_MENUVISIBLE = getClassName(MENU, LABEL, (MENU + "visible")),

	CSS_MENUITEM = getClassName(MENUITEM),

	CSS_MENUITEM_ACTIVE = getClassName(MENUITEM, ACTIVE),

	//	CSS selectors

	MENU_SELECTOR = PERIOD + CSS_MENU,

	MENU_TOGGLE_SELECTOR = (PERIOD + getClassName(MENU, "toggle"));

//	Utility functions

var getPreviousSibling = function (node) {

	var oPrevious = node.previous(),

		oChildren;

	if (!oPrevious) {

		oChildren = node.get(PARENT_NODE).get(CHILDREN);

		oPrevious = oChildren.item(oChildren.size() - 1);

	}

	return oPrevious;

};

var getNextSibling = function (node) {

	var oNext = node.next();

	if (!oNext) {

		oNext = node.get(PARENT_NODE).get(CHILDREN).item(0);		

	}

	return oNext;

};

var isAnchor = function (node) {

	var bReturnVal = false;

	if (node) {

		bReturnVal = node.get("nodeName").toLowerCase() === LOWERCASE_A;

	}

	return bReturnVal;

};

var isMenuItem = function (node) {

	return node.hasClass(CSS_MENUITEM);

};

var isMenuLabel = function (node) {

	return node.hasClass(CSS_MENU_LABEL);

};

var isHorizontalMenu = function (menu) {

	return menu.hasClass(CSS_MENU_HORIZONTAL);

};

var hasVisibleSubmenu = function (menuLabel) {

	return menuLabel.hasClass(CSS_MENU_LABEL_MENUVISIBLE);

};

var getItemAnchor = function (node) {

	return isAnchor(node) ? node : node.query(LOWERCASE_A);

};

var getNodeWithClass = function (node, className, searchAncestors) {

	var oItem;

	if (node) {

		if (node.hasClass(className)) {

			oItem = node;

		}

		if (!oItem && searchAncestors) {

			oItem = node.ancestor((PERIOD + className));

		}

	}

	return oItem;

};

var getParentMenu = function (node) {

	return node.ancestor(MENU_SELECTOR);

};

var getMenu = function (node, searchAncestors) {

	return getNodeWithClass(node, CSS_MENU, searchAncestors);

};

var getMenuItem = function (node, searchAncestors) {

	var oItem;

	if (node) {

		oItem = getNodeWithClass(node, CSS_MENUITEM, searchAncestors);

	}

	return oItem;

};

var getMenuLabel = function (node, searchAncestors) {

	var oItem;

	if (node) {

		if (searchAncestors) {

			oItem = getNodeWithClass(node, CSS_MENU_LABEL, searchAncestors);

		}

		else {

			oItem = getNodeWithClass(node, CSS_MENU_LABEL) || 

				node.query((PERIOD + CSS_MENU_LABEL));

		}

	}

	return oItem;

};

var getItem = function (node, searchAncestors) {

	var oItem;

	if (node) {

		oItem = getMenuItem(node, searchAncestors) || 

			getMenuLabel(node, searchAncestors);

	}

	return oItem;	

};

var getFirstItem = function (menu) {

	return getItem(menu.query("li"));

};

var getActiveClass = function (node) {

	return isMenuItem(node) ? CSS_MENUITEM_ACTIVE : CSS_MENU_LABEL_ACTIVE;

};

var handleMouseOverForNode = function (node, target) {

	return node && !node[HANDLED_MOUSEOVER] && 

		(node === target || node.contains(target));

};

var handleMouseOutForNode = function (node, relatedTarget) {

	return node && !node[HANDLED_MOUSEOUT] && 

		(node !== relatedTarget && !node.contains(relatedTarget));

};

/**

* The NodeMenuNav class is a plugin for a Node instance.  The class is used via  

* the <a href="Node.html#method_plug"><code>plug</code></a> method of Node and 

* should not be instantiated directly.

* @namespace plugin

* @class NodeMenuNav

*/

var NodeMenuNav = function () {

	NodeMenuNav.superclass.constructor.apply(this, arguments);

};

NodeMenuNav.NAME = "nodeMenuNav";

NodeMenuNav.NS = "menuNav";

/** 

* @property NodeMenuNav.SHIM_TEMPLATE_TITLE

* @description String representing the value for the <code>title</code> 

* attribute for the shim used to prevent <code>&#60;select&#62;</code> elements 

* from poking through menus in IE 6.

* @default "Menu Stacking Shim"

* @type String

*/

NodeMenuNav.SHIM_TEMPLATE_TITLE = "Menu Stacking Shim";

/** 

* @property NodeMenuNav.SHIM_TEMPLATE

* @description String representing the HTML used to create the 

* <code>&#60;iframe&#62;</code> shim used to prevent 

* <code>&#60;select&#62;</code> elements from poking through menus in IE 6.

* @default "<iframe frameborder="0" tabindex="-1" 

* class="yui-shim" title="Menu Stacking Shim" 

* src="javascript:false;"></iframe>"

* @type String

*/

//	<iframe> shim notes:

//

//	1) Need to set the "frameBorder" property to 0 to suppress the default 

//	<iframe> border in IE.  (Setting the CSS "border" property alone doesn't  

//	suppress it.) 

//

//	2) The "src" attribute of the <iframe> is set to "javascript:false;" so 

//	that it won't load a page inside it, preventing the secure/nonsecure 

//	warning in IE when using HTTPS.

//

//	3) Since the role of the <iframe> shim is completely presentational, its 

//	"tabindex" attribute is set to "-1" and its title attribute is set to 

//	"Menu Stacking Shim".  Both strategies help users of screen readers to 

//	avoid mistakenly interacting with the <iframe> shim.

NodeMenuNav.SHIM_TEMPLATE = '<iframe frameborder="0" tabindex="-1" class="' + 

							getClassName("shim") + 

							'" title="' + NodeMenuNav.SHIM_TEMPLATE_TITLE + 

							'" src="javascript:false;"></iframe>';

NodeMenuNav.ATTRS = {

	/**

	* Boolean indicating if use of the WAI-ARIA Roles and States should be 

	* enabled for the menu.

	*

	* @attribute useARIA

	* @readOnly

	* @writeOnce	

	* @default true

	* @type boolean

	*/

	useARIA: {

		value: true,

		writeOnce: true,

		lazyAdd: false,