Re: Format av menu keymaps

[Lennart Borgman <lennart.borgman.073@student.lu.se>]

Stefan Monnier wrote:

>>I am loooking for the format of a menu keymap. There seem to be several
>>different formats that are possible for a submenu, but I can not find where
>>these are described.  Are there any functions to check if an entry in
>>a keymap list is a submenu?
>>    
>>
>
>Any keymap is potentially a menu. It depends on whether you use it like one
>or not (e.g. if you pass it to x-popup-menu or bind it to some mouse event).
>So I think the question is wrongly phrased.  Could you give us some context
>and more concrete details of what you're trying to do?
>
I am trying to "reuse submenu keymaps".

Let us say I have defined a little minor mode that adds a submenu to the 
menu-bar. I may later want to use this submenu in another place, say in 
another submenu on the menu-bar. I may also want to use it in a popup menu.

Is this clear enough or does it just sound crazy? Maybe an example can help:


**** I have a menu keymap like this that can be used by itself (which is 
a good thing):
(defconst xhtml-help-mode-keymap
  (let ((map (make-sparse-keymap "Xhtml-Help")))
    (define-key map [menu-bar xh-help] (cons "Xhtml-Help" 
(make-sparse-keymap "second")))
    (define-key map [menu-bar xh-help css-help] '("CSS Help" . 
xhtml-help-show-css-ref))
    (define-key map [menu-bar xh-help tag-help] '("Xhtml Tag Help" . 
xhtml-help-show-tag-ref))
    map))

**** However now I decided I want to use that in another submenu in 
menu-bar. Then I do something like this:
      (when (featurep 'xhtml-help)
        (let ((menu-bar-entry (cdr (assoc 'menu-bar 
xhtml-help-mode-keymap))))
          (when menu-bar-entry
            (map-keymap
             (lambda(binding command)
               (let* ((tit-map (appmenu-get-submenu command))
                      (subtitle (car tit-map))
                      (submenu  (cdr tit-map)))
                 (define-key map
                   [nxhtml-xhtml-help]
                   (list 'menu-item
                         subtitle submenu
                         :help "XHTML help access"))))
             menu-bar-entry)
            (define-key map [nxhtml-nxhtml-help-separator] (list 
'menu-item "--"))

***** Where this little function tries to get the submenu:
(defun appmenu-get-submenu(menu-command)
  (let (subtitle submenumap)
    (if (eq 'menu-item (car menu-command))
        (progn (setq subtitle   (cadr  menu-command))
               (setq submenumap (caddr menu-command)))
      (setq subtitle   (car menu-command))
      (setq submenumap (cdr menu-command)))
    (unless (keymapp submenumap) (error "submenu not a keymap=%s" submenu))
    (cons subtitle submenumap)))


There are two things I do not really like, appmenu-get-submenu and the 
use of map-keymap. I do not know what to do instead. For 
appmenu-get-submenu I would like at least some documentation for how to 
write this. Even better would be defun in Emacs for something like it. 
Since we are close to a release (I hope) I really just wanted to say 
that it seems to me like documentation is missing.

And if the code looks wrong then of course I would like some hints.