anchor.diff:    (note-input-focus-changed (sheet-child pane) state))
   
   ;;;;
  -;;;; SCROLLER-PANE
  +;;;; SCROLLER PANE
   ;;;;
   
   ;;; How scrolling is done
  
positive.code:                     (- width border-width border-width)
                      (- height border-width border-width)))))
  
  ;;; OUTLINED-PANE
  
  ;; same as SPACING-PANE but a different default background.
  
  
negative.code: 
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
  ;;; BASIC PANE
  
  (defclass basic-pane (;; layout-protocol-mixin
                        standard-space-requirement-options-mixin
  