[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: elisp programming questions
From: |
Barry Margolin |
Subject: |
Re: elisp programming questions |
Date: |
Thu, 25 Oct 2012 05:24:35 -0400 |
User-agent: |
MT-NewsWatcher/3.5.3b3 (Intel Mac OS X) |
In article <mailman.11660.1351139989.855.help-gnu-emacs@gnu.org>,
Evan Driscoll <driscoll@cs.wisc.edu> wrote:
> I have a question: I'm working on a (major) mode, and when I make
> changes to the keymap, they don't "stick" until I restart emacs. It'd
> be nice to know how to fix this, but as I was typing it, I realized
> there may be a better way to solve this problem anyway; see below.
>
> To demo my problem:
>
> 1. Save the code below to a file, open in emacs
> 2. M-x eval-buffer
> 3. M-x say-hi-mode
> 4. Press [left]; note how the minibuffer says hi
> Press [right]; note how the cursor moves
> 5. M-x revert-buffer
> 6. Uncomment the second define-key on line 8
> 7. M-x eval-buffer
> 8. Repeat steps 3 and 4. Note how [right] still
> moves the cursor instead of saying hi
>
> Can someone tell me if there's a way to make the changes take effect?
>
> -----
>
> ALTERNATELY: is there some hook or something I can use which will get
> called whenever (after) the point is moved by any means? I will be
> overriding the cursor controls, but really what I want is just to
> display some stuff related to the point's new location, and ideally it'd
> work whether the user uses arrow keys, C-p/C-n/etc., the mouse, or
> anything else.
>
> Thanks,
> Evan
>
> -----
>
> The code:
>
> (defun say-hi ()
> (interactive)
> (message "Hello!"))
>
> (defvar say-hi-mode-map
> (let ((map (make-keymap)))
> (define-key map [left] 'say-hi)
> ;;(define-key map [right] 'say-hi)
> map
> ))
DEFVAR only assigns the variable if it doesn't already have a value. So
when you run it the second time, it doesn't do anything because the
variable is already initialized. Change it to:
(defvar say-hi-mode-map (make-keymap))
(define-key map [left] 'say-hi)
(define-key map [right] 'say-hi)
>
> (define-derived-mode say-hi-mode
> special-mode "Trace"
> "Major mode for viewing IO traces"
> (use-local-map say-hi-mode-map))
--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***