anchor.diff:                                  :show-value-p t
                                   :number-of-quanta (- high low)
                                   :value-changed-callback
  -                                (lambda (pane item)
  -                                  (declare (ignore pane))
  -                                  (%standard-value-changed-callback (round item)))))
  +                                (%standard-value-changed-callback query-identifier #'round)))
   
   ;;; text-field
   
  
positive.code:                                   :choices buttons
                                    :current-selection selection
                                    :value-changed-callback
                                    (lambda (pane item)
                                      (declare (ignore pane))
                                      (%standard-value-changed-callback
                                       (map 'list #'gadget-id item))))))
  
  ;;; option-pane-view
  
  
negative.code:       (with-output-as-gadget (stream)
          gadget))))
  
  (defun %standard-value-changed-callback (query-identifier &optional value-transform)
    ;; Return a function to be used as value-changed-callback of a
    ;; gadget.  The returned function changes the value of the query
    ;; associated with the gadget inside a dialog. The query is
    ;; identified by QUERY-IDENTIFIER.  If VALUE-TRANSFORM is NIL the
    ;; new value of the query will be the value of the gadget, otherwise
    ;; the VALUE-TRANSFORM function will be called with the value of the
    ;; gadget as argument and the returned value will be the new value
    ;; of the query.
    (lambda (pane value)
      (declare (ignore pane))
      (let ((new-value (if value-transform
                           (funcall value-transform value)
                           value)))
        (throw-object-ptype `(com-change-query ,query-identifier ,new-value)
                            '(command :command-table accept-values)))))
  
  ;;; Use textual-dialog-view as default for Views not implemented
  
  