src/com/android/gallery3d/ui/SurfaceTextureScreenNail.java

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.gallery3d.ui;

import android.graphics.RectF;
import android.graphics.SurfaceTexture;
import android.opengl.GLES11Ext;
import android.util.Log;

import com.android.gallery3d.ui.GLCanvas;
import com.android.gallery3d.ui.ScreenNail;
import com.android.gallery3d.ui.ExtTexture;

public abstract class SurfaceTextureScreenNail implements ScreenNail,
        SurfaceTexture.OnFrameAvailableListener {
    private static final String TAG = "SurfaceTextureScreenNail";
    private ExtTexture mExtTexture;
    private SurfaceTexture mSurfaceTexture;
    private int mWidth, mHeight;
    private float[] mTransform = new float[16];
    private boolean mHasTexture = false;

    public SurfaceTextureScreenNail() {
    }

    public void acquireSurfaceTexture() {
        mExtTexture = new ExtTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES);
        mExtTexture.setSize(mWidth, mHeight);
        mSurfaceTexture = new SurfaceTexture(mExtTexture.getId());
        mSurfaceTexture.setOnFrameAvailableListener(this);
        synchronized (this) {
            mHasTexture = true;
        }
    }

    public SurfaceTexture getSurfaceTexture() {
        return mSurfaceTexture;
    }

    public void releaseSurfaceTexture() {
        synchronized (this) {
            mHasTexture = false;
        }
        mExtTexture.recycle();
        mExtTexture = null;
        mSurfaceTexture.release();
        mSurfaceTexture = null;
    }

    public void setSize(int width, int height) {
        mWidth = width;
        mHeight = height;
    }

    @Override
    public int getWidth() {
        return mWidth;
    }

    @Override
    public int getHeight() {
        return mHeight;
    }

    @Override
    public void draw(GLCanvas canvas, int x, int y, int width, int height) {
        synchronized (this) {
            if (!mHasTexture) return;
            mSurfaceTexture.updateTexImage();
            mSurfaceTexture.getTransformMatrix(mTransform);

            // Flip vertically.
            canvas.save(GLCanvas.SAVE_FLAG_MATRIX);
            int cx = x + width / 2;
            int cy = y + height / 2;
            canvas.translate(cx, cy);
            canvas.scale(1, -1, 1);
            canvas.translate(-cx, -cy);
            canvas.drawTexture(mExtTexture, mTransform, x, y, width, height);
            canvas.restore();
        }
    }

    @Override
    public void draw(GLCanvas canvas, RectF source, RectF dest) {
        throw new UnsupportedOperationException();
    }

    @Override
    abstract public void noDraw();

    @Override
    abstract public void recycle();

    @Override
    abstract public void onFrameAvailable(SurfaceTexture surfaceTexture);
}