From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#17678: 24.4.50; Feature Request -- calculate new `window-start` & `window-end` before visual redisplay Date: Fri, 13 Jun 2014 23:59:33 +0300 Message-ID: <838up0wmoa.fsf@gnu.org> References: <831tuvz3n8.fsf@gnu.org> <83ha3qxbcc.fsf@gnu.org> <8361k5xra8.fsf@gnu.org> <83r42tvt0l.fsf@gnu.org> <83ha3ox3vk.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1402693228 25679 80.91.229.3 (13 Jun 2014 21:00:28 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 13 Jun 2014 21:00:28 +0000 (UTC) Cc: esq@lawlist.com, 17678@debbugs.gnu.org To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Fri Jun 13 23:00:20 2014 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WvYaC-0006dC-5F for geb-bug-gnu-emacs@m.gmane.org; Fri, 13 Jun 2014 23:00:20 +0200 Original-Received: from localhost ([::1]:33156 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WvYaB-00023C-Q3 for geb-bug-gnu-emacs@m.gmane.org; Fri, 13 Jun 2014 17:00:19 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:53822) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WvYa3-0001zE-46 for bug-gnu-emacs@gnu.org; Fri, 13 Jun 2014 17:00:15 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WvYZy-00081I-9M for bug-gnu-emacs@gnu.org; Fri, 13 Jun 2014 17:00:11 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:55853) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WvYZy-00080c-67 for bug-gnu-emacs@gnu.org; Fri, 13 Jun 2014 17:00:06 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1WvYZx-0007jH-H1 for bug-gnu-emacs@gnu.org; Fri, 13 Jun 2014 17:00:05 -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, 13 Jun 2014 21:00:05 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 17678 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 17678-submit@debbugs.gnu.org id=B17678.140269319529659 (code B ref 17678); Fri, 13 Jun 2014 21:00:05 +0000 Original-Received: (at 17678) by debbugs.gnu.org; 13 Jun 2014 20:59:55 +0000 Original-Received: from localhost ([127.0.0.1]:47003 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1WvYZm-0007iI-Am for submit@debbugs.gnu.org; Fri, 13 Jun 2014 16:59:54 -0400 Original-Received: from mtaout27.012.net.il ([80.179.55.183]:40536) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1WvYZj-0007hv-3Q for 17678@debbugs.gnu.org; Fri, 13 Jun 2014 16:59:52 -0400 Original-Received: from conversion-daemon.mtaout27.012.net.il by mtaout27.012.net.il (HyperSendmail v2007.08) id <0N7400000JM1V600@mtaout27.012.net.il> for 17678@debbugs.gnu.org; Fri, 13 Jun 2014 23:56:43 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by mtaout27.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0N7400KNVKUJYF90@mtaout27.012.net.il>; Fri, 13 Jun 2014 23:56:43 +0300 (IDT) In-reply-to: X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 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.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:90358 Archived-At: > From: Stefan Monnier > Cc: esq@lawlist.com, 17678@debbugs.gnu.org > Date: Fri, 13 Jun 2014 14:47:05 -0400 > > >> > Not necessarily: there are the w->optional_new_start and > >> > w-> force_start flags, which determine what redisplay does with > >> > window-start in these cases. > >> > Also, the window-start could be set to a value that leaves point out > >> > of the displayed area, in which case it won't be in effect. > >> Right, but these fall back into the case where redisplay performs > >> a second pass trough the window/buffer, so it's similar to the scrolling > >> case, right? > > Not necessarily, AFAIR. Sometimes these situations are detected and > > handled on the fly. > > Aha! Could you add comment somewhere in xdisp.c discussing the above > issues about how/when is window-start obeyed and when it's not and > when that causes a second pass and when that's handled on the fly? I will see what I can do. > Could be. But I already find it hard to know what can be done with > window-scroll-functions because it's not clear exactly when it's called, > in 2 sense: > - it's not clear exactly when it is called and when it is not. > - it's not clear exactly at which stage of redisplay it is called > (e.g. what has already been processed, what hasn't; will any and all > modifications caused by window-scroll-functions be reflected on screen > at the end of the current redisplay, or will some of it only be > handled by the next redisplay? If so, which do and which don't?) I'm not sure I follow. Redisplay, at the level we are talking, has no stages. It goes through all the windows on every frame, and does for each window what it thinks has to be done in that window. A process of redisplaying a window is done in one go, there are no stages or phases in it. The window-scroll-functions are called when redisplay thinks it will scroll the window in order to redisplay it. Which modifications in window-scroll-functions did you have in mind?