From: Marcin Borkowski <mbork@mbork.pl>
To: Help Gnu Emacs mailing list <help-gnu-emacs@gnu.org>
Subject: Re: How to temporarily show an image in an Emacs buffer?
Date: Wed, 08 Mar 2023 06:23:45 +0100 [thread overview]
Message-ID: <87a60nerz2.fsf@mbork.pl> (raw)
In-Reply-To: <87bkl3etd1.fsf@mbork.pl>
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"))))
(defun no-undo-uninsert ()
(save-excursion
(goto-char no-undo-marker)
(let ((buffer-undo-list))
(when (looking-at-p "this can't be undone\n")
(delete-char 21)))))
seems to do the trick, but depending on the order of typing and calling
these functions, the undo list becomes corrupted (I get "primitive-undo:
Changes to be undone are outside visible portion of buffer").
Any hints?
--
Marcin Borkowski
http://mbork.pl
next prev parent reply other threads:[~2023-03-08 5:23 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 [this message]
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
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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