.java

public void scrollTo(int x,int y) {
    if (mScrollX != x || mScrollY != y) {
       int oldX = mScrollX;
       int oldY = mScrollY;
       mScrollX = x;
       mScrollY = y;
       invalidateParentCaches();        
       onScrollChanged(mScrollX,mScrollY,oldX,oldY);
       if (!awakenScrollBars()) {
           postInvalidateOnAnimation();
       }
    }
}

public void scrollBy(int x,int y) {
    scrollTo(mScrollX + x,mScrollY + y);
}