/*

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('queue-base', function(Y) {

/**

 * <p>The Queue module adds a common data structure for FIFO operations. In its

 * simplest form, it is little more than an array wrapper. Additional

 * submodules introduce more functionality such as promotion and removal of

 * queued items.</p>

 *

 * <p>An AsyncQueue class is provided in the queue-run submodule.  This class

 * affords a mechanism to do complex sequential and iterative callback

 * execution across configured timeouts.

 *

 * @module queue

 */

/**

 * A simple FIFO queue.  Items are added to the Queue with add(1..n items) and

 * removed using next().

 *

 * @module queue

 * @submodule queue-base

 * @class Queue

 * @param item* {MIXED} 0..n items to seed the queue

 */

function Queue() {

    this._init();

    this.add.apply(this, arguments);

}

Queue.prototype = {

    /**

     * Initialize the queue

     *

     * @method _init

     * @protected

     */

    _init : function () {

        /**

         * The collection of enqueued items

         *

         * @property _q

         * @type {Array}

         * @protected

         */

        this._q = [];

    },

    /**

     * Get the next item in the queue.

     *

     * @method next

     * @return {MIXED} the next item in the queue

     */

    next : function () {

        return this._q.shift();

    },

    /**

     * Add 0..n items to the end of the queue

     *

     * @method add

     * @param item* {MIXED} 0..n items

     */

    add : function () {

        Y.Array.each(Y.Array(arguments,0,true),function (fn) {

            this._q.push(fn);

        },this);

        return this;

    },

    /**

     * Returns the current number of queued items

     *

     * @method size

     * @return {Number}

     */

    size : function () {

        return this._q.length;

    }

};

Y.Queue = Queue;

}, '3.0.0b1' ,{requires:['widget','dd-constrain']});