question: public void smoothScrollContentTo ( int targetOffset , float velocity ) { setCurrentState ( STATE_SCROLL ) ; int distance = targetOffset - mCurrentContentOffset ; velocity = Math . abs ( velocity ) ; int duration = 400 ; if ( velocity > 0 ) { duration = 3 * Math . round ( 1000 * Math . abs ( distance / velocity ) ) ; } duration = Math . min ( duration , MAX_DURATION ) ; mScroller . abortAnimation ( ) ; mScroller . startScroll ( mCurrentContentOffset , 0 , distance , 0 , duration ) ; invalidate ( ) ; }
target:  Perform a smooth slide of content, the offset of content will limited to menu width