public class Activity01 extends Activity { 
  GameSurfaceView mGameSurfaceView; 
  @Override 
  public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    mGameSurfaceView = new GameSurfaceView(this); 
    setContentView(mGameSurfaceView); 
  } 
  @Override 
  public boolean onTouchEvent(MotionEvent event) { 
    if(event.getAction() == MotionEvent.ACTION_DOWN){ 
      mGameSurfaceView.x = event.getX(); 
      mGameSurfaceView.y = event.getY(); 
    } 
    return true; 
  } 
  @Override 
  public boolean onKeyDown(int keyCode, KeyEvent event) { 
    if(keyCode == KeyEvent.KEYCODE_BACK){ 
      this.finish(); 
    } 
    return true; 
  } 
}

public class GameSurfaceView extends SurfaceView implements SurfaceHolder.Callback, Runnable { 
  boolean mbLoop = false; 
  SurfaceHolder mSurfaceHolder = null; 
  int count = 0; 
  float x = 50, y = 50; 
  int screenWidth = 480, screenHeight = 800; 
  public GameSurfaceView(Context context) { 
    super(context); 
    mbLoop = true; 
    mSurfaceHolder = this.getHolder(); 
    mSurfaceHolder.addCallback(this); 
    this.setFocusable(true); 
  } 
  @Override 
  public void surfaceCreated(SurfaceHolder holder) { 
    new Thread(this).start();  // start paint thread 
  } 
  @Override 
  public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { 
    screenWidth = width;    // reset width when screen orientation is changed 
    screenHeight = height;   // reset height when screen orientation is changed 
  } 
  @Override 
  public void surfaceDestroyed(SurfaceHolder holder) { 
    mbLoop = false; 
  } 
  @Override 
  public void run() { 
    while (mbLoop) { 
      synchronized (mSurfaceHolder) { 
        onDraw(); 
      } 
      try { 
        Thread.sleep(200); 
      } catch (Exception e) { 
      } 
    } 
  } 
  public void onDraw() { 
    Canvas canvas = mSurfaceHolder.lockCanvas(); 
    if (mSurfaceHolder == null || canvas == null) { 
      return; 
    } 
    if (count < 100) { 
      count++; 
    } else { 
      count = 0; 
    } 
    Paint mPaint = new Paint(); 
    mPaint.setAntiAlias(true); 
    mPaint.setColor(Color.CYAN); 
    canvas.drawRect(0, 0, screenWidth, screenHeight, mPaint);  // repaint background color 
    switch (count % 4) { 
    case 0: 
      mPaint.setColor(Color.BLUE); 
      break; 
    case 1: 
      mPaint.setColor(Color.GREEN); 
      break; 
    case 2: 
      mPaint.setColor(Color.RED); 
      break; 
    case 3: 
      mPaint.setColor(Color.YELLOW); 
      break; 
    default: 
      mPaint.setColor(Color.WHITE); 
      break; 
    } 
    canvas.drawCircle(x, y, 50, mPaint); 
    mSurfaceHolder.unlockCanvasAndPost(canvas); 
  } 
}