anchor.diff:  					   (pointer-event-x event))))
         (dispatch-repaint pane (sheet-region pane)))))
   
  -#+NIL
  -(defmethod handle-event ((pane slider-pane) (event window-repaint-event))
  -  (dispatch-repaint pane (sheet-region pane)))
   
   (defmethod convert-position-to-value ((pane slider-pane) dim)
     (multiple-value-bind (x1 y1 x2 y2) (bounding-rectangle* (sheet-region pane))
  
positive.code:                     ((:top) (+ y1 as))
                      ((:center) (/ (+ y1 y2 (- as ds)) 2))
                      ((:bottom) (- y2 ds))
                      (otherwise (/ (+ y1 y2 (- as ds)) 2))))))) ;defensive programming
  
  ;;;; ------------------------------------------------------------------------------------------
  ;;;;
  
negative.code: 
  ;; - It seems that 3D-BORDER-MIXIN is only used for the scroll-bar, so
  ;;   remove it
  
  ;; - Somehow engrafting the push button's medium does not work. The
  ;;   text-style initarg does not make it to the sheets medium.
  
  ;; - make NIL a valid label, and take it into account when applying
  ;;   spacing.
  
  ;;;; ------------------------------------------------------------------------------------------
  ;;;;
  