android - how to change the intent when ball touch the bottom or top the canvas -

in game ball moves top bottom , bottom top,my requirement when ball touches top edge or bottom edge want print toast message "game over".later want move control other intent.to animate ball using following code

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:                  = 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 , y give touch coordinates                   = 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:                  = 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();     } }