android - Speed up bitmap animation in custom View -

in custom view have 1 animation need run @ demand (on tile click). using method:

 public boolean ontouchevent(motionevent event) {             switch(event.getaction()){              case motionevent.action_down:     //check tile clicked                     gethandler().removecallbacks(explosionthread);                      gethandler().post(explosionthread);                     }                  }             break;         }         return super.ontouchevent(event);      } 

so calling (or sending view thread, specific) runnable calls self until comes end of image...

private runnable explosionthread=new runnable(){         @override         public void run() {             invalidate();             if(expcount<15){             gethandler().postdelayed(this, 10);             }         }        }; 

in ondraw() method implemented logic go threw bitmap , draw on screen ( using cnavas.drawbitmap(bitmap,srcrect,destrect,paint)....

now, want avoid using surfaceview (i have 1 animation , view uses less resources). think animation slow because ondraw needs draw whole screen each time invalidate() called witch can slow ( drawing 64 tiles png images). know there overload of invalidate method, invalidate(rect dirty) don't know how use it. if u think that answer please write how avoid drawing whole ondraw method ( or method can overwrite used invalidate(rect) method, if there any).

if have other better way speed animation post plz. in advance....

that's right. 1 of way speed rendering through canvas use invalidate(rect). rect passed invalidate method defines area redrawn. ondraw called after invalidate clipping region being set on canvas. "drawbitmap" clipped rect.