/*!
 * jQuery UI Focusable @VERSION
 * http://jqueryui.com
 *
 * Copyright jQuery Foundation and other contributors
 * Released under the MIT license.
 * http://jquery.org/license
 */

//>>label: focusable
//>>group: Core
//>>description: Selects elements which can be focused.
//>>docs: http://api.jqueryui.com/focusable-selector/

( function( factory ) {
	if ( typeof define === "function" && define.amd ) {

		// AMD. Register as an anonymous module.
		define( [ "jquery", "./version" ], factory );
	} else {

		// Browser globals
		factory( jQuery );
	}
} ( function( $ ) {

// selectors
$.ui.focusable = function( element, hasTabindex ) {
	var map, mapName, img,
		nodeName = element.nodeName.toLowerCase();
	if ( "area" === nodeName ) {
		map = element.parentNode;
		mapName = map.name;
		if ( !element.href || !mapName || map.nodeName.toLowerCase() !== "map" ) {
			return false;
		}
		img = $( "img[usemap='#" + mapName + "']" )[ 0 ];
		return !!img && visible( img );
	}
	return ( /^(input|select|textarea|button|object)$/.test( nodeName ) ?
		!element.disabled :
		"a" === nodeName ?
			element.href || hasTabindex :
			hasTabindex ) &&
		// the element and all of its ancestors must be visible
		visible( element );
};

function visible( element ) {
	return $.expr.filters.visible( element ) &&
		!$( element ).parents().addBack().filter( function() {
			return $.css( this, "visibility" ) === "hidden";
		} ).length;
}

$.extend( $.expr[ ":" ], {
	focusable: function( element ) {
		return $.ui.focusable( element, $.attr( element, "tabindex" ) != null );
	}
} );

return $.ui.focusable;

} ) );