anchor.diff:       :documentation "Index of the first item to be rendered. This changes in
   response to scroll wheel events.")
      (visible-items :initarg :visible-items ; Clim 2.0 compatibility
  -                  :accessor visible-items
                     :documentation "Maximum number of visible items in list"))
     (:default-initargs :text-style (make-text-style :sans-serif :roman :normal)
                        :background +white+ :foreground +black+))
  
positive.code:               last-index
                (reduce #'max
                        (mapcar #'(lambda (item) (position item (generic-list-pane-item-values gadget) :test test))
                                (gadget-value gadget)))))))
    (unless (slot-boundp gadget 'visible-items)
      (setf (visible-items gadget) (generic-list-pane-items-length gadget))))
  
  (defgeneric generic-list-pane-item-strings (generic-list-pane))
  
  
negative.code: (defmethod generic-list-pane-item-height ((pane generic-list-pane))
    (+ (text-style-ascent  (pane-text-style pane) pane)
       (text-style-descent (pane-text-style pane) pane)))
  
  (defmethod visible-items ((pane generic-list-pane))
    (if (slot-boundp pane 'visible-items)
        (visible-items pane)
        (generic-list-pane-items-length pane)))
  
  (defmethod (setf visible-items) (new-value (pane generic-list-pane))
    (check-type new-value fixnum)
    (setf (slot-value pane 'visible-items) new-value))
  
  (defmethod compose-space ((pane generic-list-pane) &key width height)
    (declare (ignore width height))
  