root/as3/Thread/trunk/samples/flickrsphere/src/org/libspark/flickrsphere/threads/flickr/PhotoImageQueue.as

/*
 * Flickr Sphere (Sample of the ActionScript Thread Library)
 * 
 * Licensed under the MIT License
 * 
 * Copyright (c) 2008 BeInteractive! (www.be-interactive.org) and
 *                    Spark project  (www.libspark.org)
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 * 
 */
package org.libspark.flickrsphere.threads.flickr
{
        import flash.display.Loader;
        import org.libspark.thread.IMonitor;
        import org.libspark.thread.Monitor;
        
        /**
         * PhotoImageQueue クラスは、ロードした写真イメージをストックするためのキューです.
         */
        public class PhotoImageQueue
        {
                public function PhotoImageQueue()
                {
                        _queue = [];
                        _monitor = new Monitor();
                }
                
                private var _queue:Array;
                private var _monitor:IMonitor;
                
                /**
                 * キューが空であれば true、そうでなければ false を返します.
                 */
                public function get isEmpty():Boolean
                {
                        return _queue.length == 0;
                }
                
                /**
                 * キューに指定されたイメージを追加します.
                 * 
                 * @param       image   追加するイメージ
                 */
                public function offer(image:Loader):void
                {
                        // キューに追加
                        _queue.push(image);
                        // checkPoll でイメージを取得可能になるまで待機しているスレッドを起こす
                        _monitor.notifyAll();
                }
                
                /**
                 * キューからイメージを取得可能かどうかをチェックし、可能でなければ取得可能になるまでスレッドを待機させます.
                 * 
                 * @return      スレッドが待機する場合に true、そうでなければ false
                 */
                public function checkPoll():Boolean
                {
                        // キューが空であれば
                        if (isEmpty) {
                                // スレッドを待機させる
                                _monitor.wait();
                                return true;
                        }
                        return false;
                }
                
                /**
                 * キューからイメージを取得します.
                 * 
                 * @return      イメージ
                 */
                public function poll():Loader
                {
                        // キューから取得
                        return _queue.shift();
                }
        }
}