如何在球触到底部或顶部画布时改变意图

Question

在我的游戏球中从上到下，从下到上移动，我的要求是当球接触上边缘或下边缘时我想打印像“游戏结束”之类的祝酒消息。我希望移动控制其他一些意图。使用以下代码为球设置动画

public class AnimatedView extends ImageView{


    static int count=0;
    private Context mContext;
    int x = 130;
    int y = 450;
    private float a,b;
    private int xVelocity = 25;
    private int yVelocity = 20;
    private Handler h;
    private final int FRAME_RATE = 30;
    BitmapDrawable ball;
    boolean touching;
    boolean dm_touched = false;
    float move=3;
    int bm_x = 0, bm_y = 0, bm_offsetx, bm_offsety,bm_w,bm_h;
    boolean paused;


    public AnimatedView(Context context, AttributeSet attrs)  {  
        super(context, attrs);  
        mContext = context;  
        h = new Handler();
        } 

    @Override
    public void buildDrawingCache() {
        // TODO Auto-generated method stub
        super.buildDrawingCache();
    }
    private Runnable r = new Runnable() {
        @Override
        public void run() {
            //Log.e("game","run called");
            if(touching = true)
            invalidate(); 
        }
    };


    @Override
    protected void onDraw(Canvas c) {  
        BitmapDrawable ball = (BitmapDrawable) mContext.getResources().getDrawable(R.drawable.ball);  
        if (x<0 && y <0) {
            //x = this.getWidth()/2;
            y = c.getHeight()/2;


        } else {
            y += yVelocity;

            if (y >( this.getHeight() - ball.getBitmap().getHeight()) ||y <0) {
                yVelocity = yVelocity*-1;
            }
        }
        c.drawBitmap(ball.getBitmap(), x, y, null);  
       //Log.e("sarat",""+touching);
      if(touching){
         // Log.e("game","iftouch called called");
        h.postDelayed(r, FRAME_RATE);    
        bm_w=ball.getBitmap().getWidth();
        bm_h=ball.getBitmap().getHeight();
      }

    }
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        // Log.d("game","ontouch called");
        int touchType = event.getAction();

         switch(touchType){
            case MotionEvent.ACTION_MOVE: 
                a = event.getX();
                b = event.getY();
                touching = true;
                if ((a > x) && (a < bm_w + x) && (b > y) && (b < bm_h + y)) 
                  {
                    if(bm_h+a>600 ||bm_h+b<0){ 
                      Toast.makeText(getContext(),"game over",Toast.LENGTH_LONG).show();
                  }
                break;

             case MotionEvent.ACTION_DOWN: 
                 //x and y give you your touch coordinates
                  a = event.getX();
                  b = event.getY();
                  touching = true;

                  Log.e("s",""+ a);
                  Log.e("s",""+ b);
                  Log.e("s",""+ x);
                  Log.e("s",""+ y);
                  Log.e("s",""+ bm_w);
                  Log.e("s",""+ bm_h);
                  if ((a > x) && (a < bm_w + x) && (b > y) && (b < bm_h + y)) { 
                      count++;
                    MainActivity.setCount(count);

                      Log.i("score",""+count);

                    }
                  if (dm_touched) {
                      if ((a > x) && (a < bm_w + x) && (b > y) && (b < bm_h + y)) { 
                      move+=2;

                      y = yVelocity*-1;

                    }}

             case MotionEvent.ACTION_UP:
                 a = event.getX();
                  b = event.getY();
                 if(a>x+20&&a<330&&b<=y+320&&b>y){
                 invalidate();}
                 if ((a > x) && (a < bm_w + x) && (b > y) && (b < bm_h + y)) { 
                    Log.e("game","clicked");
                }

                default:

                    dm_touched = true;

                }

                return true;
    }

    @Override
    public void destroyDrawingCache() {

        count=0;
        super.destroyDrawingCache();
    }
}