From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings via "Bug reports for GNU Emacs, the Swiss army knife of text editors" Newsgroups: gmane.emacs.bugs Subject: bug#42307: Feature request: Visual block attribute for overlays Date: Tue, 14 Jul 2020 17:20:21 +0000 Message-ID: References: <83k0z6n7w6.fsf@gnu.org> <83eepem9im.fsf@gnu.org> <837dv6m4xm.fsf@gnu.org> <835zaqm394.fsf@gnu.org> Reply-To: Gregory Heytings Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="24361"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Alpine 2.21 (NEB 202 2017-01-01) To: 42307@debbugs.gnu.org Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Tue Jul 14 19:22:52 2020 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 1jvOdo-0006FT-Se for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 14 Jul 2020 19:22:52 +0200 Original-Received: from localhost ([::1]:52990 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jvOdn-0005LT-Pn for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 14 Jul 2020 13:22:51 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:60806) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jvOc3-0003gn-S3 for bug-gnu-emacs@gnu.org; Tue, 14 Jul 2020 13:21:05 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:39973) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jvOc2-0004yd-EL for bug-gnu-emacs@gnu.org; Tue, 14 Jul 2020 13:21:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jvOc2-0004Es-As for bug-gnu-emacs@gnu.org; Tue, 14 Jul 2020 13:21:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Gregory Heytings Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 14 Jul 2020 17:21:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 42307 X-GNU-PR-Package: emacs Original-Received: via spool by 42307-submit@debbugs.gnu.org id=B42307.159474723116234 (code B ref 42307); Tue, 14 Jul 2020 17:21:02 +0000 Original-Received: (at 42307) by debbugs.gnu.org; 14 Jul 2020 17:20:31 +0000 Original-Received: from localhost ([127.0.0.1]:51519 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jvObX-0004Dm-Cd for submit@debbugs.gnu.org; Tue, 14 Jul 2020 13:20:31 -0400 Original-Received: from mx.sdf.org ([205.166.94.24]:49668) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jvObU-0004Da-7Q for 42307@debbugs.gnu.org; Tue, 14 Jul 2020 13:20:29 -0400 Original-Received: from sdf.org (IDENT:ghe@faeroes.freeshell.org [205.166.94.9]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 06EHKOsP006597 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits) verified NO); Tue, 14 Jul 2020 17:20:25 GMT Original-Received: (from ghe@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 06EHKOTS017231; Tue, 14 Jul 2020 17:20:24 GMT In-Reply-To: <835zaqm394.fsf@gnu.org> 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:183000 Archived-At: > >> In fact, I'm not entirerly sure that explaining (or implementing) that >> behavior with regexpes or character is the best thing to do. It's a >> matter of visual representation. Perhaps the following explanation is >> clearer (or more precise): draw the overlay with :extend t, and remove >> pixel columns on the left and on the right that are displayed in the >> same way as a whitespace character would have been displayed. > > Well, it's not that simple. For starters, there's no "pixel columns" in > the display engine, at least not on GUI frames. > That's what I thought indeed. My explanation was a specification, not an implementation hint ;-) > > More to the point, I think the feature you requested will be not very > simple to implement, because it requires the display code to do > look-ahead: when it lays out leading whitespace, it should consider > characters after that. That calls for some complications, because the > display code basically inspects characters one by one and makes (almost) > all the decisions on the fly. > > So someone will have fun implementing this. Patches welcome. > I'm not sure I have the necessary background to do this (it's a euphemism), but I'll try to see what I can do. Gregory