anchor.diff:  ; We don't have implemented the difference of appearence whether the 
   ; indicator-type is :one-of or :some-of
   
  +(defmethod initialize-instance :before ((pane toggle-button-pane) &rest rest)
  +  (declare (ignore rest))
  +  (setf (gadget-label-align-x pane) :center
  +	(gadget-label-align-y pane) :center))
  +
   (defmethod handle-event ((pane toggle-button-pane) (event pointer-enter-event))
     (with-slots (armed) pane
       (unless armed
         (setf armed t)
         (unless (gadget-value pane)
  -	(setf (gadget-current-color pane) (gadget-highlighted-color pane))
  -	(dispatch-repaint pane (sheet-region pane)))
  +	(setf (gadget-current-color pane) (gadget-highlighted-color pane)))
         (armed-callback pane (gadget-client pane) (gadget-id pane)))))
   
   (defmethod handle-event ((pane toggle-button-pane) (event pointer-exit-event))
  
positive.code: (defclass push-button (labelled-gadget-mixin action-gadget) ())
    
  (defclass push-button-pane  (push-button)
    ((show-as-default-p :type (member '(t nil))
  		      :initform nil
  		      :initarg :show-as-default-p
  		      :accessor push-button-show-as-default-p)))
  
  (defmethod handle-event ((pane push-button-pane) (event pointer-enter-event))
    (with-slots (armed) pane
  
negative.code: 		 :initarg :show-value-p
  		 :accessor gadget-show-value-p)))
  
  (defmethod drag-callback ((pane slider-pane) client gadget-id value)
    (declare (ignore client gadget-id))
    (when (slider-drag-callback pane)
  