From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Marcin Borkowski Newsgroups: gmane.emacs.help Subject: Re: How to temporarily show an image in an Emacs buffer? Date: Wed, 08 Mar 2023 17:00:11 +0100 Message-ID: <878rg7dyii.fsf@mbork.pl> References: <87bkl3etd1.fsf@mbork.pl> <835ybb5pn0.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="23385"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: mu4e 1.1.0; emacs 30.0.50 Cc: help-gnu-emacs@gnu.org To: Eli Zaretskii Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Wed Mar 08 17:01:15 2023 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pZwE6-0005vX-Mr for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 08 Mar 2023 17:01:14 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pZwDb-0008Bm-I2; Wed, 08 Mar 2023 11:00:43 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pZwDO-00084U-H4 for help-gnu-emacs@gnu.org; Wed, 08 Mar 2023 11:00:38 -0500 Original-Received: from mail.mojserwer.eu ([195.110.48.8]) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pZwDK-00035k-HV; Wed, 08 Mar 2023 11:00:29 -0500 Original-Received: from localhost (localhost [127.0.0.1]) by mail.mojserwer.eu (Postfix) with ESMTP id 7942F64A19E; Wed, 8 Mar 2023 17:00:21 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at mail.mojserwer.eu Original-Received: from mail.mojserwer.eu ([127.0.0.1]) by localhost (mail.mojserwer.eu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5TgoLn6fzj_i; Wed, 8 Mar 2023 17:00:16 +0100 (CET) Original-Received: from localhost (91-227-196-3.net4me.pl [91.227.196.3]) by mail.mojserwer.eu (Postfix) with ESMTPSA id 1ADC268BE02; Wed, 8 Mar 2023 17:00:15 +0100 (CET) In-reply-to: <835ybb5pn0.fsf@gnu.org> Received-SPF: pass client-ip=195.110.48.8; envelope-from=mbork@mbork.pl; helo=mail.mojserwer.eu X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:142948 Archived-At: On 2023-03-08, at 14:38, Eli Zaretskii wrote: >> From: Marcin Borkowski >> Date: Wed, 08 Mar 2023 05:53:46 +0100 >> >> I need to insert an image in the buffer in a way that doesn't interfere >> with the undo mechanism. In other words, `insert-image' won't help me >> because (as I understand it) it needs to insert a space or some other >> string so that it can put display property on it. How to achieve this? > > You can put a display property on the existing text in the buffer > without inserting any new text. See the node "Other Display > Properties" in the ELisp manual, where it describes the > =E2=80=98(image . IMAGE-PROPS)=E2=80=99 display property spec. You're right, of course, but it's a bit more complex than that. Since an overlay with the `image' property "hides" the text beneath it, the key is to create an overlay with a `before-string' property whose value is a dummy string (say, a space), and put the `image' /text/ property on that very string. I did some experiments and it seems to work, though I'll have a (hopefully) working prototype by the end of the week (no more time for this today). Thanks a lot! (Also, once I have it working, I will definitely describe it on my blog; I may also copy it here if someone is interested.) Best, --=20 Marcin Borkowski http://mbork.pl