The ui.gadgets.scrollers vocabulary implements scroller gadgets. A scroller displays a gadget which is larger than the visible area.
scroller

<scroller> ( gadget -- scroller )


Getting and setting the scroll position:
scroll-position ( scroller -- loc )

set-scroll-position ( value scroller -- )


Writing scrolling-aware gadgets:
scroll>bottom ( gadget -- )

scroll>top ( gadget -- )

scroll>rect ( rect gadget -- )

find-scroller ( gadget -- scroller/f )