[Erc-help] Re: define-minor-mode

[Adrian A. <ad...@xe...>]

>>>>> "Alex" == Alex Schroeder <al...@em...> writes:

    Alex> Is there a define-minor-mode in the latest XEmacs, or the lastest
    Alex> fsf-compat package?  If not, I have a simple (untested) proposal that

Hi Alex,

I can find it in easy-mmode.el, which is part of the xemacs-base
package.

Adrian

    Alex> should do enough to be usable for ERC, and IRC client for Emacs and
    Alex> XEmacs.

    Alex> Here it is:

    Alex> (defmacro define-minor-mode (mode doc &optional init-value lighter keymap &rest body)
    Alex>   "Define a minor mode like in Emacs."
    Alex>   `(progn
    Alex>      (devar ,mode ,init-value "Non-nil if the corresponding mode is enabled.")
    Alex>      (defun ,mode (&optional arg)
    Alex> 	    ,doc
    Alex> 	    (setq ,mode (if arg
    Alex> 			   (> (prefix-numeric-value arg) 0)
    Alex> 			 (not foo)))
    Alex> 	    ,@body
    Alex> 	    ,mode)
    Alex>      (add-minor-mode ,mode ,lighter ,keymap)))

    Alex> Here is the result:

    Alex> (pp (macroexpand '(define-minor-mode foo "doc" 'init " f" 'map (goo) (gaa)))
    Alex>     (current-buffer))

    Alex> (progn
    Alex>   (devar foo
    Alex> 	 'init "Non-nil if the corresponding mode is enabled.")
    Alex>   (defun foo
    Alex>     (&optional arg)
    Alex>     "doc"
    Alex>     (setq foo
    Alex> 	  (if arg
    Alex> 	      (>
    Alex> 	       (prefix-numeric-value arg)
    Alex> 	       0)
    Alex> 	    (not foo)))
    Alex>     (goo)
    Alex>     (gaa)
    Alex>     foo)
    Alex>   (add-minor-mode foo " f"
    Alex> 		  'map))

    Alex> Here is the result for Emacs.  Note that it does hooks, and keymap
    Alex> stuff, which we currently do not need, so I did not bother.

    Alex> (pp (macroexpand '(define-minor-mode foo "doc" 'init " f" 'map (goo) (gaa)))
    Alex>     (current-buffer))

    Alex> (progn
    Alex>   (progn
    Alex>     (defvar foo 'init "Non-nil if foo mode is enabled.\nUse the command `foo' to change this variable.")
    Alex>     (make-variable-buffer-local 'foo))
    Alex>   (defun foo
    Alex>     (&optional arg)
    Alex>     "doc"
    Alex>     (interactive)
    Alex>     (setq foo
    Alex> 	  (if arg
    Alex> 	      (>
    Alex> 	       (prefix-numeric-value arg)
    Alex> 	       0)
    Alex> 	    (not foo)))
    Alex>     (goo)
    Alex>     (gaa)
    Alex>     (run-hooks 'foo-hook
    Alex> 	       (if foo 'foo-on-hook 'foo-off-hook))
    Alex>     (if
    Alex> 	(interactive-p)
    Alex> 	(message "foo mode %sabled"
    Alex> 		 (if foo "en" "dis")))
    Alex>     (force-mode-line-update)
    Alex>     foo)
    Alex>   :autoload-end
    Alex>   (defcustom foo-hook nil "Hook run at the end of function `foo'." :group 'foo :type 'hook)
    Alex>   (defvar foo-map
    Alex>     (let
    Alex> 	((m 'map))
    Alex>       (cond
    Alex>        ((keymapp m)
    Alex> 	m)
    Alex>        ((listp m)
    Alex> 	(easy-mmode-define-keymap m))
    Alex>        (t
    Alex> 	(error "Invalid keymap %S" 'map))))
    Alex>     "Keymap for `foo'.")
    Alex>   (add-minor-mode 'foo
    Alex> 		  '#(" f" 0 2
    Alex> 		     (local-map
    Alex> 		      (keymap
    Alex> 		       (header-line keymap
    Alex> 				    (down-mouse-3 . mode-line-mode-menu-1))
    Alex> 		       (mode-line keymap
    Alex> 				  (down-mouse-3 . mode-line-mode-menu-1)))
    Alex> 		      help-echo "mouse-3: minor mode menu"))
    Alex> 		  foo-map)
    Alex>   nil)

    Alex> And the doc string, in case you are interested:

    Alex> define-minor-mode is a Lisp macro in `easy-mmode'.
    Alex> (define-minor-mode MODE DOC &optional INIT-VALUE LIGHTER KEYMAP &rest BODY)

    Alex> Define a new minor mode MODE.
    Alex> This function defines the associated control variable MODE, keymap MODE-map,
    Alex> toggle command MODE, and hook MODE-hook.

    Alex> DOC is the documentation for the mode toggle command.
    Alex> Optional INIT-VALUE is the initial value of the mode's variable.
    Alex> Optional LIGHTER is displayed in the modeline when the mode is on.
    Alex> Optional KEYMAP is the default (defvar) keymap bound to the mode keymap.
    Alex>   If it is a list, it is passed to `easy-mmode-define-keymap'
    Alex>   in order to build a valid keymap.  It's generally better to use
    Alex>   a separate MODE-map variable than to use this argument.
    Alex> The above three arguments can be skipped if keyword arguments are
    Alex> used (see below).

    Alex> BODY contains code that will be executed each time the mode is (dis)activated.
    Alex>   It will be executed after any toggling but before running the hooks.
    Alex>   BODY can start with a list of CL-style keys specifying additional arguments.
    Alex>   The following keyword arguments are supported:
    Alex> :group   Followed by the group name to use for any generated `defcustom'.
    Alex> :global  If non-nil specifies that the minor mode is not meant to be
    Alex>          buffer-local.  By default, the variable is made buffer-local.
    Alex> :init-value  Same as the INIT-VALUE argument.
    Alex> :lighter  Same as the LIGHTER argument.



-- 
Adrian Aichner
 mailto:ad...@xe...
 http://www.xemacs.org/