gecko/mobile/android/base/gfx/FlexibleGLSurfaceView.java

/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
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 *
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 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
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 * for the specific language governing rights and limitations under the
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 * The Original Code is Mozilla Android code.
 *
 * The Initial Developer of the Original Code is Mozilla Foundation.
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 * Contributor(s):
 *   Patrick Walton <pcwalton@mozilla.com>
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package org.mozilla.gecko.gfx;

import org.mozilla.gecko.GeckoApp;
import android.content.Context;
import android.graphics.PixelFormat;
import android.opengl.GLSurfaceView;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/*
 * This class extends SurfaceView and allows dynamically switching between two modes
 * of operation. In one mode, it is used like a GLSurfaceView, and has it's own GL
 * thread. In the other mode, it allows external code to perform GL composition, by
 * exposing the GL controller.
 *
 * In our case, we start off in the first mode because we are rendering the placeholder
 * image. This mode is initiated by a call to createGLThread(). Once Gecko comes up,
 * it invokes registerCxxCompositor() via a JNI call, which shuts down the GL thread and
 * returns the GL controller. The JNI code then takes the EGL surface from the GL
 * controller and allows the off-main thread compositor to deal with it directly.
 */
public class FlexibleGLSurfaceView extends SurfaceView implements SurfaceHolder.Callback {
    private static final String LOGTAG = "GeckoFlexibleGLSurfaceView";

    private GLSurfaceView.Renderer mRenderer;
    private GLThread mGLThread; // Protected by this class's monitor.
    private GLController mController;
    private Listener mListener;

    public FlexibleGLSurfaceView(Context context) {
        super(context);
        init();
    }

    public FlexibleGLSurfaceView(Context context, AttributeSet attributeSet) {
        super(context, attributeSet);
        init();
    }

    public void init() {
        SurfaceHolder holder = getHolder();
        holder.addCallback(this);
        holder.setFormat(PixelFormat.RGB_565);

        mController = new GLController(this);
    }

    public void setRenderer(GLSurfaceView.Renderer renderer) {
        mRenderer = renderer;
    }

    public GLSurfaceView.Renderer getRenderer() {
        return mRenderer;
    }

    public void setListener(Listener listener) {
        mListener = listener;
    }

    public synchronized void requestRender() {
        if (mGLThread != null) {
            mGLThread.renderFrame();
        }
        if (mListener != null) {
            mListener.renderRequested();
        }
    }

    /**
     * Creates a Java GL thread. After this is called, the FlexibleGLSurfaceView may be used just
     * like a GLSurfaceView. It is illegal to access the controller after this has been called.
     */
    public synchronized void createGLThread() {
        if (mGLThread != null) {
            throw new FlexibleGLSurfaceViewException("createGLThread() called with a GL thread " +
                                                     "already in place!");
        }

        mGLThread = new GLThread(mController);
        mGLThread.start();
        notifyAll();
    }

    /**
     * Destroys the Java GL thread. Returns a Thread that completes when the Java GL thread is
     * fully shut down.
     */
    public synchronized Thread destroyGLThread() {
        // Wait for the GL thread to be started.
        while (mGLThread == null) {
            try {
                wait();
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        }

        Thread glThread = mGLThread;
        mGLThread.shutdown();
        mGLThread = null;
        return glThread;
    }

    public synchronized void recreateSurface() {
        if (mGLThread == null) {
            throw new FlexibleGLSurfaceViewException("recreateSurface() called with no GL " +
                                                     "thread active!");
        }

        mGLThread.recreateSurface();
    }

    public synchronized GLController getGLController() {
        if (mGLThread != null) {
            throw new FlexibleGLSurfaceViewException("getGLController() called with a GL thread " +
                                                     "active; shut down the GL thread first!");
        }

        return mController;
    }

    /** Implementation of SurfaceHolder.Callback */
    public synchronized void surfaceChanged(SurfaceHolder holder, int format, int width,
                                            int height) {
        mController.sizeChanged(width, height);
        if (mGLThread != null) {
            mGLThread.surfaceChanged(width, height);
        }
        
        if (mListener != null) {
            mListener.surfaceChanged(width, height);
        }
    }

    /** Implementation of SurfaceHolder.Callback */
    public synchronized void surfaceCreated(SurfaceHolder holder) {
        mController.surfaceCreated();
        if (mGLThread != null) {
            mGLThread.surfaceCreated();
        }
    }

    /** Implementation of SurfaceHolder.Callback */
    public synchronized void surfaceDestroyed(SurfaceHolder holder) {
        mController.surfaceDestroyed();
        if (mGLThread != null) {
            mGLThread.surfaceDestroyed();
        }
        
        if (mListener != null) {
            mListener.compositionPauseRequested();
        }
    }

    /** This function is invoked by Gecko (compositor thread) via JNI; be careful when modifying signature. */
    public static GLController registerCxxCompositor() {
        try {
            FlexibleGLSurfaceView flexView = (FlexibleGLSurfaceView)GeckoApp.mAppContext.getLayerController().getView();
            try {
                flexView.destroyGLThread().join();
            } catch (InterruptedException e) {}
            return flexView.getGLController();
        } catch (Exception e) {
            Log.e(LOGTAG, "### Exception! " + e);
            return null;
        }
    }

    public interface Listener {
        void renderRequested();
        void compositionPauseRequested();
        void compositionResumeRequested();
        void surfaceChanged(int width, int height);
    }

    public static class FlexibleGLSurfaceViewException extends RuntimeException {
        public static final long serialVersionUID = 1L;

        FlexibleGLSurfaceViewException(String e) {
            super(e);
        }
    }
}