From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Scrolling commands and skipping redisplay, was: Re: emacs rendering comparisson between emacs23 and emacs26.3 Date: Fri, 10 Apr 2020 18:47:24 +0300 Message-ID: <83h7xrmjg3.fsf@gnu.org> References: <20200403174757.GA8266@ACM> <20200404104553.GA5329@ACM> <07fe3b69-3ab2-3173-0696-cb17809e2b91@gmx.at> <83blo7v68b.fsf@gnu.org> <1845d7aa-9ae4-3d95-6a30-c7b1d8d8adec@gmx.at> <83a73qt6zs.fsf@gnu.org> <97c4254e-ff43-8402-3645-f713c408c245@gmx.at> <83y2r9syby.fsf@gnu.org> <20200405195753.GG5049@ACM> <542b48ba-4dfa-820f-ba50-4b147ab6d8e2@yandex.ru> <0a5f70aa-4985-8f8d-81d6-6ac4a60a94f9@yandex.ru> <838sj8sphk.fsf@gnu.org> <834ktwsmfw.fsf@gnu.org> <83imibqsmm.fsf@gnu.org> <478c2aab-a5fc-61c2-02e2-2d9846b95273@yandex.ru> <83v9m9nltx.fsf@gnu.org> <4c5ebff1-39ab-3d63-6118-42befc93b862@yandex.ru> <6914ebb2-2dfa-efdc-1181-c42259219bca@yandex.ru> <83zhbjna0q.fsf@gnu.org> <903b7d31-bd0e-e2dc-a981-d090ed959ccb@yandex.ru> <83pncfmpme.fsf@gnu.org> <94ee576f-ff26-cad9-3e22-b75299ff9cdb@yandex.ru> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="91797"; mail-complaints-to="usenet@ciao.gmane.io" Cc: rms@gnu.org, emacs-devel@gnu.org, rudalics@gmx.at, rrandresf@gmail.com, monnier@iro.umontreal.ca, acm@muc.de To: Dmitry Gutov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Apr 10 17:48:37 2020 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 1jMvtV-000NmP-Jb for ged-emacs-devel@m.gmane-mx.org; Fri, 10 Apr 2020 17:48:37 +0200 Original-Received: from localhost ([::1]:36010 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jMvtU-0002CW-JM for ged-emacs-devel@m.gmane-mx.org; Fri, 10 Apr 2020 11:48:36 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:60051) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jMvsl-0001nw-7V for emacs-devel@gnu.org; Fri, 10 Apr 2020 11:47:52 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:52793) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1jMvsj-0007oL-Qx; Fri, 10 Apr 2020 11:47:49 -0400 Original-Received: from [176.228.60.248] (port=4296 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jMvsc-0007mo-Ix; Fri, 10 Apr 2020 11:47:43 -0400 In-Reply-To: <94ee576f-ff26-cad9-3e22-b75299ff9cdb@yandex.ru> (message from Dmitry Gutov on Fri, 10 Apr 2020 17:34:57 +0300) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] 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:246774 Archived-At: > Cc: monnier@iro.umontreal.ca, acm@muc.de, rrandresf@gmail.com, > emacs-devel@gnu.org, rms@gnu.org, rudalics@gmx.at > From: Dmitry Gutov > Date: Fri, 10 Apr 2020 17:34:57 +0300 > > On 10.04.2020 16:34, Eli Zaretskii wrote: > > It doesn't flicker here. Maybe the double-buffering is the reason? > > Double-buffering decreases the number of display updates, so it hardly > can be the cause of this. What else could be the reason of differences between what we see on our respective systems? > As we've discussed with Stefan, the implementation is likely the reason. That sounds like a request to stop interfering with the discussion between you and Stefan. > It doesn't flicker while scrolling because it simply shows unfontified > screenfuls of code. Which is unacceptable for default behavior. Showing unfontified text _is_ the intended effect of jit-lock-defer-time. On slow machines, I fail to see how this could be worse than having Emacs hang for many seconds. > And I'd hesitate to recommend it to anyone even to deal with > performance problems. Not sure why would you hesitate. > It *does* flicker afterwards (e.g. 0.5 sec after I depress C-v), because > that's what deferred jit-lock does: it applies syntax highlighting with > a delay. Highlighting shouldn't flicker; it doesn't here. It just paints the text with colors. Redisplay is smart enough to redraw on the glass only those parts whose colors have changed, and that shouldn't cause any flicker. > So I type, wait 0.5sec, and syntax highlighting arrives. It's a > less-aggravating kind of flicker because of its laid-back pace, but I > still wouldn't call it acceptable user experience. I guess we disagree here. And I don't really see what better solution could be provided, when Emacs is unable to keep up with keyboard auto-repeat. The only solution is to do less, and jit-lock-defer-time does just that.