question: public void clipRect ( int x , int y , int width , int height ) { mGraphics . clipRect ( x , y , width , height ) ; }
target:  Intersects the current clip with the specified rectangle. The resulting clipping area is the intersection of the current clipping area and the specified rectangle. This method can only be used to make the current clip smaller. To set the current clip larger, use any of the setClip methods. Rendering operations have no effect outside of the clipping area.