public void drawOnBitmap(DrawListener drawRoutine_) {
   if (drawRoutine_ != null && _Source != null) {
     RelativeViewAbstract nullView = new RelativeViewAbstract("nullView");
     nullView.setWH(_BitmapRect.width(), _BitmapRect.height());
     Canvas cBitmap = new Canvas(_Source);
     RelativeCanvas rCanvas = new RelativeCanvas(cBitmap, new Rect(0, 0, width(), height()));
     drawRoutine_.onCustomDraw(rCanvas, nullView);
     cBitmap = null;
     rCanvas.destroy();
     rCanvas = null;
     nullView.destroy();
     nullView = null;
   }
 }