set-scroll-pos

Sets the current value of a manual scrollbar. (This method has no effect on automatic scrollbars.)

The value of the canvas's scrollbar can be changed by the user scrolling, and such changes do not go through this method; use on-scroll to monitor scrollbar value changes.

See also init-manual-scrollbars and scroll.

• (send a-canvas set-scroll-pos which value) -> void
      which : symbol in '(horizontal vertical)
      value : exact integer in [0, 10000]

  The which argument is either 'horizontal or 'vertical, indicating whether to set the value of the horizontal or vertical scrollbar set, repsectively.