src/com/android/musicvis/vis1/Visualization1.java

/*
 * Copyright (C) 2009 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.musicvis.vis1;

import com.android.musicvis.AudioCapture;

import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.media.MediaPlayer;
import android.os.Handler;
import android.os.SystemClock;
import android.service.wallpaper.WallpaperService;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;

import java.util.Arrays;

public class Visualization1 extends WallpaperService {

    private final Handler mHandler = new Handler();

    @Override
    public void onCreate() {
        super.onCreate();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }

    @Override
    public Engine onCreateEngine() {
        return new CubeEngine();
    }

    class CubeEngine extends Engine {

        private final Paint mPaint = new Paint();
        private float mOffset;
        private float mTouchX = -1;
        private float mTouchY = -1;
        private long mStartTime;
        private int mWidth;
        private float mCenterX;
        private float mCenterY;
        private AudioCapture mAudioCapture;
        private int [] mVizData = new int[1024];

        private final Runnable mDrawCube = new Runnable() {
            public void run() {
                drawFrame();
            }
        };
        private boolean mVisible;

        CubeEngine() {
        }

        @Override
        public void onCreate(SurfaceHolder surfaceHolder) {
            super.onCreate(surfaceHolder);

            final Paint paint = mPaint;
            paint.setColor(0xffffffff);
            paint.setAntiAlias(true);
            paint.setStrokeWidth(2);
            paint.setStrokeCap(Paint.Cap.ROUND);
            paint.setStyle(Paint.Style.STROKE);

            mStartTime = SystemClock.elapsedRealtime();
        }

        @Override
        public void onDestroy() {
            super.onDestroy();
            mHandler.removeCallbacks(mDrawCube);
            if (mAudioCapture != null) {
                mAudioCapture.stop();
                mAudioCapture.release();
                mAudioCapture = null;
            }
        }

        @Override
        public void onVisibilityChanged(boolean visible) {
            mVisible = visible;
            if (visible) {
                if (mAudioCapture == null) {
                    mAudioCapture = new AudioCapture(AudioCapture.TYPE_PCM, 1024);
                }
                mAudioCapture.start();
                drawFrame();
            } else {
                mHandler.removeCallbacks(mDrawCube);
                if (mAudioCapture != null) {
                    mAudioCapture.stop();
                    mAudioCapture.release();
                    mAudioCapture = null;
                }
            }
        }

        @Override
        public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            super.onSurfaceChanged(holder, format, width, height);
            mWidth = width;
            mCenterX = width/2.0f;
            mCenterY = height/2.0f;
            drawFrame();
        }

        @Override
        public void onSurfaceCreated(SurfaceHolder holder) {
            super.onSurfaceCreated(holder);
        }

        @Override
        public void onSurfaceDestroyed(SurfaceHolder holder) {
            super.onSurfaceDestroyed(holder);
            mVisible = false;
            mHandler.removeCallbacks(mDrawCube);
        }

        @Override
        public void onOffsetsChanged(float xOffset, float yOffset,
                float xStep, float yStep, int xPixels, int yPixels) {
            mOffset = xOffset;
            drawFrame();
        }

        @Override
        public void onTouchEvent(MotionEvent event) {
            // touch events don't actually work for wallpapers, but if they did,
            // we'd be using them to draw a circle around the touch point
            if (event.getAction() == MotionEvent.ACTION_MOVE) {
                mTouchX = event.getX();
                mTouchY = event.getY();
            } else {
                mTouchX = -1;
                mTouchY = -1;
            }
            super.onTouchEvent(event);
        }

        void drawFrame() {
            final SurfaceHolder holder = getSurfaceHolder();
            final Rect frame = holder.getSurfaceFrame();
            final int width = frame.width();
            final int height = frame.height();

            Canvas c = null;
            try {
                c = holder.lockCanvas();
                if (c != null) {
                    // draw something
                    drawCube(c);
                    drawTouchPoint(c);
                }
            } finally {
                if (c != null) holder.unlockCanvasAndPost(c);
            }

            mHandler.removeCallbacks(mDrawCube);
            if (mVisible) {
                mHandler.postDelayed(mDrawCube, 1000 / 25);
            }
        }

        void drawCube(Canvas c) {
            c.save();
            c.drawColor(0xff000000);

            if (mAudioCapture != null) {
                mVizData = mAudioCapture.getFormattedData(1, 1);
            } else {
                Arrays.fill(mVizData, (int)0);
            }

            for (int i = 0; i < mWidth; i++) {
                c.drawPoint(i, mCenterY + mVizData[i], mPaint);
            }
            c.restore();
        }

        void drawTouchPoint(Canvas c) {
            if (mTouchX >=0 && mTouchY >= 0) {
                c.drawCircle(mTouchX, mTouchY, 50, mPaint);
            }
        }

    }
}