From: Marcin Borkowski <mbork@mbork.pl>
To: Michael Heerdegen <michael_heerdegen@web.de>
Cc: help-gnu-emacs@gnu.org
Subject: Re: How to temporarily show an image in an Emacs buffer?
Date: Sat, 11 Mar 2023 09:14:07 +0100 [thread overview]
Message-ID: <87fsabogc0.fsf@mbork.pl> (raw)
In-Reply-To: <87sfefi4b0.fsf@web.de>
On 2023-03-08, at 17:41, Michael Heerdegen <michael_heerdegen@web.de> wrote:
> Marcin Borkowski <mbork@mbork.pl> writes:
>
>> On 2023-03-08, at 05:53, Marcin Borkowski <mbork@mbork.pl> wrote:
>>
>> > Alternatively, it _may_ change the buffer contents but in a way that is
>> > not recorded in `buffer-undo-list'. Is that possible?
>>
>> I did some experimenting, and this
>>
>> (defvar no-undo-marker (make-marker))
>> (defun no-undo-insert ()
>> "Test undo."
>> (save-excursion
>> (let ((buffer-undo-list))
>> (set-marker no-undo-marker (point))
>> (insert "this can't be undone\n"))))
>> [...]
>
> Regardless of what has already been said, just for the sake of
> completeness: AFAIK the intended way to inhibit the recording of undo
> is to bind buffer-undo-list to t (not to nil).
Thanks, I missed that.
> There are lots of use case in the sources - see e.g.
> `image-toggle-display-text'.
I didn't experiment with this, but I'm afraid that interlacing changes
to the buffer done by the user (when recording undo changes) and by the
Elisp code (while `buffer-undo-list' is bound to `t') may result in
undoing being impossible.
Anyway, I solved /my/ particular problem using overlays. Thanks!
--
Marcin Borkowski
http://mbork.pl
next prev parent reply other threads:[~2023-03-11 8:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-08 4:53 How to temporarily show an image in an Emacs buffer? Marcin Borkowski
2023-03-08 5:23 ` Marcin Borkowski
2023-03-08 6:19 ` Ruijie Yu via Users list for the GNU Emacs text editor
2023-03-08 16:01 ` Marcin Borkowski
2023-03-08 16:41 ` Michael Heerdegen
2023-03-11 8:14 ` Marcin Borkowski [this message]
2023-03-12 3:37 ` Michael Heerdegen
2023-03-12 7:46 ` Marcin Borkowski
2023-03-08 13:38 ` Eli Zaretskii
2023-03-08 16:00 ` Marcin Borkowski
2023-03-13 8:29 ` Jean Louis
2023-03-13 9:27 ` Marcin Borkowski
2023-04-01 15:57 ` Marcin Borkowski
2023-03-10 16:26 ` Stefan Monnier via Users list for the GNU Emacs text editor
2023-03-11 8:15 ` Marcin Borkowski
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