anchor.diff:        (setf pressedp nil)
         (dispatch-repaint pane +everywhere+))))
   
  -; factor out the box code and reuse as a border mixin
   (defmethod handle-repaint ((pane pixie-push-button-pane) region)
     (declare (ignore region))
     (with-slots (armed dragging pressedp) pane
  
positive.code:    (drag-delta
       :initform 0)
     (bounce-value
       :initform 0))
    (:default-initargs
      :border-style :inset
      :border-width 1))
  
  (defmethod vertical-gadget-orientation-transformation ((pane gadget))
    (ecase (gadget-orientation pane)
  
negative.code: (defconstant +pixie-scroll-bar-thumb-half-width+   8)
  
  (defclass pixie-scroll-bar-pane (pixie-slider-pane) (
     (drag-callback
       :initarg :drag-callback
       :initform nil
       :reader scroll-bar-drag-callback)
     (scroll-to-bottom-callback
       :initarg :scroll-to-bottom-callback
       :initform nil
       :reader scroll-bar-scroll-to-bottom-callback)
     (scroll-to-top-callback
       :initarg :scroll-to-top-callback
       :initform nil
       :reader scroll-bar-scroll-to-top-callback)
     (scroll-down-line-callback
       :initarg :scroll-down-line-callback
       :initform nil
       :reader scroll-bar-scroll-down-line-callback)
     (scroll-up-line-callback
       :initarg :scroll-up-line-callback
       :initform nil
       :reader scroll-bar-scroll-up-line-callback)
     (scroll-down-page-callback
       :initarg :scroll-down-page-callback
       :initform nil
       :reader scroll-bar-scroll-down-page-callback)
     (scroll-up-page-callback
       :initarg :scroll-up-page-callback
       :initform nil
       :reader scroll-bar-scroll-up-page-callback)
     (thumb-size
       :initarg :thumb-size
       :initform 1/4
       :accessor gadget-thumb-size))
    (:default-initargs
       :value 0
       :min-value 0
       :max-value 1
       :orientation :vertical))
  
  (defmethod compose-space ((pane pixie-scroll-bar-pane) &key width height)
    (declare (ignore width height))
    (if (eq (gadget-orientation pane) :vertical)
        (make-space-requirement :min-width   1
  			      :width       *scrollbar-thickness*
  			      :min-height (* 3 *scrollbar-thickness*)
  			      :height     (* 4 *scrollbar-thickness*))
        (make-space-requirement :min-height  1
  			      :height      *scrollbar-thickness*
  			      :min-width  (* 3 *scrollbar-thickness*)
  			      :width      (* 4 *scrollbar-thickness*))))
  
  (defmethod drag-callback ((pane pixie-scroll-bar-pane) client gadget-id value)
    (declare (ignore client gadget-id))
  