* added an UpdateControl so you can easily enqueue tasks into jme's update loop

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@7832 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/core/com/jme3/scene/control/UpdateControl.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2009-2010 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.jme3.scene.control;
+
+import com.jme3.app.AppTask;
+import com.jme3.renderer.RenderManager;
+import com.jme3.renderer.ViewPort;
+import com.jme3.scene.Spatial;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.Future;
+
+/**
+ * Allows for enqueueing tasks onto the update loop / rendering thread.
+ * 
+ * Usage:
+ * mySpatial.addControl(new UpdateControl()); // add it once
+ * mySpatial.getControl(UpdateControl.class).enqueue(new Callable() {
+ *        public Object call() throws Exception {
+ *            // do stuff here
+ *            return null;
+ *        }
+ *    });
+ * 
+ * @author Brent Owens
+ */
+public class UpdateControl extends AbstractControl {
+
+    private final ConcurrentLinkedQueue<AppTask<?>> taskQueue = new ConcurrentLinkedQueue<AppTask<?>>();
+
+    /**
+     * Enqueues a task/callable object to execute in the jME3
+     * rendering thread.
+     */
+    public <V> Future<V> enqueue(Callable<V> callable) {
+        AppTask<V> task = new AppTask<V>(callable);
+        taskQueue.add(task);
+        return task;
+    }
+    
+    @Override
+    protected void controlUpdate(float tpf) {
+        AppTask<?> task = taskQueue.poll();
+        toploop: do {
+            if (task == null) break;
+            while (task.isCancelled()) {
+                task = taskQueue.poll();
+                if (task == null) break toploop;
+            }
+            task.invoke();
+        } while (((task = taskQueue.poll()) != null));
+    }
+
+    @Override
+    protected void controlRender(RenderManager rm, ViewPort vp) {
+        
+    }
+
+    public Control cloneForSpatial(Spatial newSpatial) {
+        UpdateControl control = new UpdateControl(); 
+        control.setSpatial(newSpatial);
+        control.setEnabled(isEnabled());
+        control.taskQueue.addAll(taskQueue);
+        return control;
+    }
+    
+}