question: public boolean onScrollChanged ( int scrollY ) { boolean isPullingDownNow = scrollY < lastScrollY ; latestPullingDown . offer ( isPullingDownNow ) ; if ( latestPullingDown . size ( ) > PULLING_DOWN_TIME_MAX ) { latestPullingDown . poll ( ) ; } lastScrollY = scrollY ; return getPullingDownTime ( ) >= PULLING_DOWN_TIME_THRESHOLD ; }
target:  Call this when scroll changed