"Toolbar check buttons" mapped to menu objects, anyone?

Hi!

In one of my projects I have a toolbar which has one button that
should behave like a check button, i.e. pressing it toggles a state (a
global variable *DATA-MODE* which can be 'TMP or 'DB).  The button's
image is supposed to show the current state.  Furthermore there's a
menu entry which can also be used to toggle this state and which is
also supposed to show the state (with a checkmark).

Below are the excerpts from my code that implement this.  I think this
is quite ugly and I hope there's a more elegant way to do it.
Specifically, I was hoping that there's a way to couple the button and
the menu object with :REMAPPED.  And maybe there's a way to create a
kind of "toolbar check button" that changes its image automatically?
Extra bonus points for not using a toolbar component which is visually
separated from the surrounding toolbar buttons.

Any ideas?

Thanks,
Edi.



(capi:define-interface ...

  (:panes
    (toolbar
      capi:toolbar
      :accessor main-toolbar
      :items (list (make-instance 'capi:toolbar-button
                                  :name 'mode-button
                                  ;; PIC is a utility function which returns images
                                  ;; created with GP:READ-EXTERNAL-IMAGE
                                  :image (pic (ecase *data-mode*
                                                (tmp "tmpmode.bmp")
                                                (db "dbmode.bmp")))
                                  :callback-type :item-interface
                                  :callback 'gui-change-mode)
                    ...)

  ...

  (:menus
   (change-mode-component
    :component
    (("DB Mode"
      :name 'mode-menu-object
      :selected (eq *data-mode* 'db)
      :callback-type :item-interface
      :callback 'gui-change-mode))
    :accessor change-mode-component
    :interaction :multiple-selection)
   (options-menu
    "Options"
    (change-mode-component))

  ...


(defun find-mode-button (interface)
  (find 'mode-button (capi:collection-items (main-toolbar interface))
        :key #'capi:capi-object-name))

(defun gui-change-mode (item interface)
  (let ((from-button-p (typep item 'capi:toolbar-button)))
    (ecase *data-mode*
      (tmp
       (setf *data-mode* 'db
             (capi:toolbar-button-image (find-mode-button interface))
             (pic "dbmode.bmp"))
       (when from-button-p
         (setf (capi:choice-selection (change-mode-component interface))
               (list 0))))
      (db
       (setf *data-mode* 'tmp
             (capi:toolbar-button-image (find-mode-button interface))
             (pic "tmpmode.bmp"))
       (when from-button-p
         (setf (capi:choice-selection (change-mode-component interface))
               nil))))))