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Highliting menu items

    Date: Thu, 17 Oct 91 15:12 MET
    From: "Berthe Y. Choueiry" <choueiry@liasun6.epfl.ch>


    My question is about how to change the background of some command
    "buttons" in the command menu in order to attract the attention of the
    user.  I have a command in the menu that when hit, displays a list.
    Basically, what I need is having the command highlighted (either by
    changing its background or "its ink") whenever the list is not empty.
    Is there a simple way for doing that with CLIM?

Unfortunately, the short answer is no.  That is, the CLIM command
menu displaying code doesn't have any provision for this.
However, the command menu displaying code is just a display
function like any other, so you can write your own command menu
displayer to customize the appearance.  Unfortunatly (again),
CLIM doesn't quite export enough of the command-table mechanism
to give you access to all the information you need.

I am enclosing a simple demo program that has
optionally-highlighted command menu items.  It uses some CLIM
internal functions and data structures, so it is not going to
work in the long term (those internals will surely change from
CLIM 1 to CLIM 2).  But for now, you might be able to make use of
it.  The unsupported stuff is marked by the CLIM:: package
prefixes or the use of SLOT-VALUE.

(in-package :clim-user)

;;; Simple application with a standard command menu at the top,
;;; and a customized command menu below it.
(define-application-frame test
  ()
  ()
  (:panes ((menu :command-menu)
           (my-menu :application
                    :scroll-bars nil
                    :display-function 'display-my-menu)
           (interactor :interactor)))
  (:layout
   ((default
      (:column 1
               (menu :compute)
               (my-menu 1/3)
               (interactor :rest)))))
  (:command-definer t))

(defvar *highlight-commands* nil)

(define-test-command (com-one :menu "One")
                     ()
  (setq *highlight-commands* t))

(define-test-command (com-two :menu "Two")
                     ()
  (setq *highlight-commands* nil))

;;; The display function for the customized menu.  It puts the
;;; menu items in BOLD when the *highlight-commands* flag is set.
(defmethod display-my-menu ((frame test) stream)
  (let* ((command-table
          (find-command-table (frame-command-table frame)))
	 ;; ***INTERNALS***
         (menu (slot-value command-table 'clim::menu)))
    (multiple-value-bind (max-width max-height)
                         (window-inside-size stream)
      (formatting-item-list (stream
                             :n-rows 1
                             :max-width max-width :max-height max-height)
        ;; ***INTERNALS***  (both the DOVECTOR function and the format
	;; of an element.
	(clim::dovector (element menu)
                        (let ((name (first element)))
                          (when name
                            (formatting-cell (stream)
			      ;; Conditional BOLD text display.
                              (with-text-face ((if *highlight-commands*
                                                 ':bold
                                                 ':roman)
                                               stream)
                                ;; ***INTERNALS***
				(present element 'clim::command-menu-element
                                         :stream stream :single-box t))))))))))

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