anchor.diff:    (window-clear pane)
     (dispatch-repaint pane (sheet-region pane)))
   
  -(defclass clx-text-field-pane (text-field-pane) ())
  -
  -
   ;;
   ;; TEXT-EDITOR gadget
   ;;
  
positive.code:    (drag-up-page-callback :initarg :drag-up-page-callback
  			  :reader scroll-bar-drag-up-page-callback)))
  
  (defclass clx-scroll-bar-pane (scroll-bar-pane) ())
  
  (defmethod drag-callback ((pane scroll-bar-pane) client gadget-id value)
    (declare (ignore client gadget-id))
    (funcall (scroll-bar-drag-callback pane) pane value))
  
negative.code: 
  (defclass menu-button-pane (menu-button) ())
  
  (defmethod repaint-sheet ((pane menu-button-pane) region)
    (declare (ignore region))
    (let ((text (gadget-label pane))
  	(region (sheet-region pane)))
      (multiple-value-bind (x1 y1 x2 y2) (bounding-rectangle* region)
        (let ((w (- x2 x1))
  	    (h (- y2 y1)))
  	(cond ((slot-value pane 'armed)
  	       (draw-rectangle* pane 0 0 w h
  				:ink (gadget-highlighted-color pane)
  				:filled t)
  	       (draw-edges-lines* pane (1- w) (1- h) 1 1))
  	      (t
  	       (draw-rectangle* pane 0 0 w h
  				:ink (gadget-normal-color pane)
  				:filled t)))
  	(draw-text* pane text (round w 2) (round h 2)
  		    :align-x :center
  		    :align-y :center)))))
  
  ;;
  ;; SCROLL-BAR gadget
  