Android手势左右滑动效果

public class MyRelativeLayout extends RelativeLayout implements GestureDetector.OnGestureListener{
  private float mPosX, mPosY, mCurPosX, mCurPosY;
  private static final int FLING_MIN_DISTANCE = 20;// 移动最小距离
  private static final int FLING_MIN_VELOCITY = 200;// 移动最大速度
  //构建手势探测器 
  GestureDetector mygesture = new GestureDetector(this);
  public MyRelativeLayout(Context context){
    super(context)
  }

  public MyRelativeLayout(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    // TODO Auto-generated constructor stub
  }

  public MyRelativeLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
    // TODO Auto-generated constructor stub
  }
    @Override
  public boolean onTouchEvent(MotionEvent arg0) {
    // TODO Auto-generated method stub
    return mDetector.onTouchEvent(arg0);

  }

  @Override
  public boolean onSingleTapUp(MotionEvent e) {
    // TODO Auto-generated method stub
    return false;
  }

  @Override
  public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
              float distanceY) {
    // TODO Auto-generated method stub
    return false;
  }

  @Override
  public boolean onDown(MotionEvent e) {
    // TODO Auto-generated method stub
    return false;
  }


  @Override
  public void onShowPress(MotionEvent e) {
    // TODO Auto-generated method stub

  }

   @Override
  public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
      float velocityY) {
    // TODO Auto-generated method stub
    // e1：第1个ACTION_DOWN MotionEvent  
    // e2：最后一个ACTION_MOVE MotionEvent  
    // velocityX：X轴上的移动速度（像素/秒）  
    // velocityY：Y轴上的移动速度（像素/秒）  

    // X轴的坐标位移大于FLING_MIN_DISTANCE，且移动速度大于FLING_MIN_VELOCITY个像素/秒  
    //向左 
    if (e1.getY() - e2.getY() > FLING_MIN_DISTANCE){   
//           && Math.abs(velocityX) > FLING_MIN_VELOCITY) {   
      collapse();
       }  
    //向上 
    if (e2.getY() - e1.getY() > FLING_MIN_DISTANCE   
           && Math.abs(velocityX) > FLING_MIN_VELOCITY) {

    }   
      return false;   
  } 
}