\f
;;;; Utilities.
+(defun scroll-bar-event-ratio (event)
+ "Given a scroll bar event EVENT, return the scroll bar position as a ratio.
+The value is a cons cell (PORTION . WHOLE) containing two integers
+whose ratio gives the event's vertical position in the scroll bar, with 0
+referring to the top and 1 to the bottom."
+ (nth 2 event))
+
(defun scroll-bar-scale (num-denom whole)
"Given a pair (NUM . DENOM) and WHOLE, return (/ (* NUM WHOLE) DENOM).
This is handy for scaling a position on a scroll bar into real units,