question: public void componentResized ( ComponentEvent e ) { JScrollBar bar = getVerticalScrollBar ( ) ; int incr = ( int ) ( getSize ( ) . getHeight ( ) - ( bar . getUnitIncrement ( 1 ) * 3 ) ) ; getVerticalScrollBar ( ) . setBlockIncrement ( incr ) ; }
target:  Invoked when the component's size changes. Reset scrollable increment, because page-down/up is relative to current view size.