anchor.diff:  
   (defmethod gfw:event-move ((self sheet-event-dispatcher) mirror pnt)
     (enqueue (port self)
  -           (generate-configuration-event mirror pnt (gfw:size mirror))))
  +           (generate-configuration-event mirror pnt (gfw:client-size mirror))))
   
   (defclass gadget-event (window-event) ())
   (defclass button-pressed-event (gadget-event) ())
  
positive.code: ;;; mirror methods
  ;;;
  
  (defmethod port-set-mirror-region ((port graphic-forms-port) (mirror gf-mirror-mixin) region)
    (setf (gfw:size mirror)
          (gfs:make-size :width (round-coordinate (bounding-rectangle-width region))
  
negative.code:     (setf (gfw:location mirror)
            (gfs:make-point :x (round-coordinate x)
                            :y (round-coordinate y)))))
  
  (defmethod port-set-mirror-transformation ((port graphic-forms-port) (mirror gfw-menu) transformation)
    (declare (ignore port mirror transformation)))
  