1/*
2 * Copyright (c) 2009-2010 jMonkeyEngine
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 * * Redistributions of source code must retain the above copyright
10 *   notice, this list of conditions and the following disclaimer.
11 *
12 * * Redistributions in binary form must reproduce the above copyright
13 *   notice, this list of conditions and the following disclaimer in the
14 *   documentation and/or other materials provided with the distribution.
15 *
16 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
17 *   may be used to endorse or promote products derived from this software
18 *   without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
24 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32package com.jme3.scene.control;
33
34import com.jme3.app.AppTask;
35import com.jme3.renderer.RenderManager;
36import com.jme3.renderer.ViewPort;
37import com.jme3.scene.Spatial;
38import java.util.concurrent.Callable;
39import java.util.concurrent.ConcurrentLinkedQueue;
40import java.util.concurrent.Future;
41
42/**
43 * Allows for enqueueing tasks onto the update loop / rendering thread.
44 *
45 * Usage:
46 * mySpatial.addControl(new UpdateControl()); // add it once
47 * mySpatial.getControl(UpdateControl.class).enqueue(new Callable() {
48 *        public Object call() throws Exception {
49 *            // do stuff here
50 *            return null;
51 *        }
52 *    });
53 *
54 * @author Brent Owens
55 */
56public class UpdateControl extends AbstractControl {
57
58    private final ConcurrentLinkedQueue<AppTask<?>> taskQueue = new ConcurrentLinkedQueue<AppTask<?>>();
59
60    /**
61     * Enqueues a task/callable object to execute in the jME3
62     * rendering thread.
63     */
64    public <V> Future<V> enqueue(Callable<V> callable) {
65        AppTask<V> task = new AppTask<V>(callable);
66        taskQueue.add(task);
67        return task;
68    }
69
70    @Override
71    protected void controlUpdate(float tpf) {
72        AppTask<?> task = taskQueue.poll();
73        toploop: do {
74            if (task == null) break;
75            while (task.isCancelled()) {
76                task = taskQueue.poll();
77                if (task == null) break toploop;
78            }
79            task.invoke();
80        } while (((task = taskQueue.poll()) != null));
81    }
82
83    @Override
84    protected void controlRender(RenderManager rm, ViewPort vp) {
85
86    }
87
88    public Control cloneForSpatial(Spatial newSpatial) {
89        UpdateControl control = new UpdateControl();
90        control.setSpatial(newSpatial);
91        control.setEnabled(isEnabled());
92        control.taskQueue.addAll(taskQueue);
93        return control;
94    }
95
96}
97