From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#18793: 24.4; zero width rectangular selection displaces text Date: Fri, 06 May 2022 16:50:23 +0300 Message-ID: <8335hm22jk.fsf@gnu.org> References: <82ppdk41k5.fsf@gmail.com> <87fslop1af.fsf@gnus.org> <837d702b1w.fsf@gnu.org> <87czgrnei8.fsf@gnus.org> <83k0az0wfz.fsf@gnu.org> <878rreor92.fsf@gnus.org> <83ilqi29ic.fsf@gnu.org> <87sfpmnben.fsf@gnus.org> <83h76228cu.fsf@gnu.org> <878rrelt6e.fsf@gnus.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="3579"; mail-complaints-to="usenet@ciao.gmane.io" Cc: carlosjosepita@gmail.com, monnier@iro.umontreal.ca, 18793@debbugs.gnu.org To: Lars Ingebrigtsen Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Fri May 06 15:54:37 2022 Return-path: Envelope-to: geb-bug-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 1nmyPk-0000jb-8V for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 06 May 2022 15:54:36 +0200 Original-Received: from localhost ([::1]:53870 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nmyPi-00051s-Sz for geb-bug-gnu-emacs@m.gmane-mx.org; Fri, 06 May 2022 09:54:34 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34438) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nmyMI-0007fr-GW for bug-gnu-emacs@gnu.org; Fri, 06 May 2022 09:51:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:53643) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nmyMI-0006Jy-6e for bug-gnu-emacs@gnu.org; Fri, 06 May 2022 09:51:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1nmyMI-0007tz-5p for bug-gnu-emacs@gnu.org; Fri, 06 May 2022 09:51:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Fri, 06 May 2022 13:51:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 18793 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: confirmed Original-Received: via spool by 18793-submit@debbugs.gnu.org id=B18793.165184504430348 (code B ref 18793); Fri, 06 May 2022 13:51:02 +0000 Original-Received: (at 18793) by debbugs.gnu.org; 6 May 2022 13:50:44 +0000 Original-Received: from localhost ([127.0.0.1]:47540 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1nmyM0-0007tQ-Ao for submit@debbugs.gnu.org; Fri, 06 May 2022 09:50:44 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:40992) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1nmyLy-0007tB-6Y for 18793@debbugs.gnu.org; Fri, 06 May 2022 09:50:42 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:45622) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nmyLs-0006H2-Fa; Fri, 06 May 2022 09:50:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=ETCcIirIuWQKyEFWSp83FUv8MsFMpjVi2DyYiDa4BAk=; b=gHp0up8OCxhm zqLoq457UVkKxkVOsW4SlODHQ6ARJx8i9m1JwnftqwXJYH7YVTyn2RFNZdAySf39kWNsMgO7bgczQ fc6YDfNJvwTO3JdnZXSZMCfIIqOZzIwptZK3y0uqn+lgLztedhDlnKClZRrIS0pTVbOGTW3utlDvY SZNJP1APx1E1GCAU2VhQBy7Avctw4+04Wbo+mNsUaWKePmwcvtBXTMWR9SXyL+l8d6LWpP/dPfD9g Ttk0sfFWBInIZD4tN6HoDtCPjPwcd1EtrY0JSf+wOhDH7TatK+HPn65tA/biJ9NOsxJgoHeAbWwz7 9LuAzgDySYS27844kOKe/Q==; Original-Received: from [87.69.77.57] (port=3764 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nmyLr-0002ql-Qs; Fri, 06 May 2022 09:50:36 -0400 In-Reply-To: <878rrelt6e.fsf@gnus.org> (message from Lars Ingebrigtsen on Fri, 06 May 2022 14:52:25 +0200) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:231511 Archived-At: > From: Lars Ingebrigtsen > Cc: monnier@iro.umontreal.ca, carlosjosepita@gmail.com, 18793@debbugs.gnu.org > Date: Fri, 06 May 2022 14:52:25 +0200 > > > Adding capabilities to the Emacs display that operate on > > sub-character-cell resolution will mean serious complications. For > > example, what would we do when displaying color Emoji at that place? > > Or what about images? Or what if the character in question is > > currently highlighted by mouse-face? > > > > IOW, I'm asking whether these marginal features are worth a serious > > surgery and complications in the display engine, which currently has > > the canvas-based design? > > display-fill-column-indicator-mode was the only one that sprang > immediately to mind, but I think it could be useful when displaying > tabular data, and you want to mark boundaries without taking up extra > space, for instance. I think trying to display text in tables without taking space for the borders will introduce significant complications into our display code. Text in a table and its borders need to be aligned separately. > And speaking off the fill indicator -- bug#54598 talks a bit about the > problems with the current implementation. Sure, there are limitations to how we can stretch our current display code. But the solution is not to stretch it more, IMNSHO, it's to replace it with a completely new and different design, which could allow that much more easily. > But that mode does show how a box cursor and a region could behave > with these vertical lines. It does? AFAIK, we don't show the vertical line when there's a character at that column, and consequently displaying the cursor doesn't need to cope with any issues caused by that. > And I don't think colour emojis or images would represent that much of a > problem -- I think we'd draw the line on top of the glyph? The line itself is not the problem; the problem is the color of that line. How do you draw a vertical line of a given color over images and Emoji that have their inherent colors? Do we just overwrite those colors? Won't that be ugly? There will also be complications with characters whose glyphs "invade" cells of neighboring characters: Emacs draws characters one by one, so adding such vertical lines will need to come back after text was drawn and draw the line, as opposed to doing that as part of drawing individual glyphs that we do now. Bottom line: it sounds like a lot of complications for a minor issue with a minor feature.