From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: sbaugh@catern.com Newsgroups: gmane.emacs.devel Subject: Re: Horizontal centering in the display engine Date: Wed, 14 Apr 2021 09:28:53 -0400 Message-ID: <87tuo9uh9m.fsf@catern.com> References: <87fszuvy7p.fsf@catern.com> <83czuy112a.fsf@gnu.org> <877dl6vvax.fsf@catern.com> <83blai0y3i.fsf@gnu.org> <8735vtx62w.fsf@catern.com> <8335vt1hiw.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="16296"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) To: emacs-devel@gnu.org Cancel-Lock: sha1:HvzEuTRidZv30BsswKxigRBcNGE= Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Apr 14 15:29:39 2021 Return-path: Envelope-to: ged-emacs-devel@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 1lWfaN-00048z-OJ for ged-emacs-devel@m.gmane-mx.org; Wed, 14 Apr 2021 15:29:39 +0200 Original-Received: from localhost ([::1]:57304 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lWfaM-0000nG-QT for ged-emacs-devel@m.gmane-mx.org; Wed, 14 Apr 2021 09:29:38 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52668) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lWfZm-0000MK-Kl for emacs-devel@gnu.org; Wed, 14 Apr 2021 09:29:02 -0400 Original-Received: from ciao.gmane.io ([116.202.254.214]:55406) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lWfZl-00046j-5P for emacs-devel@gnu.org; Wed, 14 Apr 2021 09:29:02 -0400 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1lWfZi-0003Av-46 for emacs-devel@gnu.org; Wed, 14 Apr 2021 15:28:58 +0200 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=ged-emacs-devel@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:268042 Archived-At: Eli Zaretskii writes: >> > E.g., are you planning on centering each line separately, or >> > everything together, or something else? >> >> Each line separately. > > So each line should have a different value of :align-to? If they each had a different value of :align-to, then I'd have to update those values of align-to every time text size or window size changes, which is something I want to avoid. > And if we go one level higher, I guess you intend to write a > post-command-hook that recalculates the :align-to specs whenever text > changes, is that right? Or how did you plan on taking text changes > into consideration? No, I want my :align-to specs to stay the same as text changes. If that's not possible with :align-to specs, then I'd use some other feature to implement the centering. As I mentioned in my initial email, it's entirely possible to center text in Emacs today, even by just inserting spaces. But that doesn't update automatically when text or window size changes; those spaces (or :align-to specs, in your proposal - they're basically the same) need to be updated by Lisp code running in post-command-hook or elsewhere, as you say. I want this centering display to be handled by the display engine, as other similar things are.