question: @ Override public void onViewPositionChanged ( View changedView , int left , int top , int dx , int dy ) { super . onViewPositionChanged ( changedView , left , top , dx , dy ) ; mDragOffset = Math . abs ( top ) ; float fractionScreen = ( float ) mDragOffset / mAudioView . getmVerticalDragRange ( ) ; mAudioView . onViewPositionChanged ( fractionScreen >= 1 ? 1 : fractionScreen ) ; }
target:  Override method used notify the drag value based on position and dragRange