scroll-to

Called (indirectly) by snips within the editor: it causes the editor to be scrolled so that a given location range within a given snip is visible. If the editor is scrolled, #t is returned, otherwise #f is returned.

• (send an-editor scroll-to snip localx localy width height refresh? bias) -> boolean
      snip : snip% object
      localx : real number
      localy : real number
      width : non-negative real number
      height : non-negative real number
      refresh? : boolean
      bias = Symbolnone : symbol in '(start end none)

  The localx, localy, width, and height arguments specify the area that needs to be viisble in snip's coordinate system.

  When the specified region cannot fit in the visible area, bias indicates which end of the region to display. When bias is 'start, then the top-left of the region is displayed. When bias is 'end, then the bottom-right of the region is displayed. Otherwise, bias must be 'none.