How to limit the bound of Scrolling While using onScroll method?

Question

I am trying to achieve scrolling of layout by overriding onScroll method of Gesture Listener

    @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2,
                float distanceX, float distanceY) {
            Log.d("Scroll"," X " + this.get +" Y " + this.getScrollY()  );

                            // this- Relative Layout
            this.scrollBy((int)distanceX,(int)distanceY);

             invalidate();
                return false;
        }

With the above code I am able to scroll the layout but my layout's background is moving out of bound i.e. screen ? How will I limit it ? I tried various thing by getScrolly() , getLeft() but i am not getting any link by which I can go ahead ? please help me ...