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#20180: Missing documentation about redisplay. Date: Mon, 23 Mar 2015 18:49:08 +0200 Message-ID: <83oanjr75n.fsf@gnu.org> References: <20150323160850.GA23576@acm.fritz.box> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1427129427 15940 80.91.229.3 (23 Mar 2015 16:50:27 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 23 Mar 2015 16:50:27 +0000 (UTC) Cc: 20180@debbugs.gnu.org To: Alan Mackenzie Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Mar 23 17:50:16 2015 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 1Ya5YO-0006oP-18 for geb-bug-gnu-emacs@m.gmane.org; Mon, 23 Mar 2015 17:50:16 +0100 Original-Received: from localhost ([::1]:57083 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ya5YN-0003wG-72 for geb-bug-gnu-emacs@m.gmane.org; Mon, 23 Mar 2015 12:50:15 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:48101) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ya5YH-0003w2-IQ for bug-gnu-emacs@gnu.org; Mon, 23 Mar 2015 12:50:10 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ya5YC-0000q1-5w for bug-gnu-emacs@gnu.org; Mon, 23 Mar 2015 12:50:09 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:44277) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ya5YC-0000pc-3W for bug-gnu-emacs@gnu.org; Mon, 23 Mar 2015 12:50:04 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1Ya5YB-0004GC-HY for bug-gnu-emacs@gnu.org; Mon, 23 Mar 2015 12:50:03 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Mon, 23 Mar 2015 16:50:03 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 20180 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 20180-submit@debbugs.gnu.org id=B20180.142712937016334 (code B ref 20180); Mon, 23 Mar 2015 16:50:03 +0000 Original-Received: (at 20180) by debbugs.gnu.org; 23 Mar 2015 16:49:30 +0000 Original-Received: from localhost ([127.0.0.1]:34053 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Ya5Xe-0004FK-3Y for submit@debbugs.gnu.org; Mon, 23 Mar 2015 12:49:30 -0400 Original-Received: from mtaout27.012.net.il ([80.179.55.183]:46047) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Ya5Xb-0004F3-Kk for 20180@debbugs.gnu.org; Mon, 23 Mar 2015 12:49:28 -0400 Original-Received: from conversion-daemon.mtaout27.012.net.il by mtaout27.012.net.il (HyperSendmail v2007.08) id <0NLO00100BO1HI00@mtaout27.012.net.il> for 20180@debbugs.gnu.org; Mon, 23 Mar 2015 18:44:05 +0200 (IST) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by mtaout27.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0NLO001S8BTHI200@mtaout27.012.net.il>; Mon, 23 Mar 2015 18:44:05 +0200 (IST) In-reply-to: <20150323160850.GA23576@acm.fritz.box> 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:100846 Archived-At: > Date: Mon, 23 Mar 2015 16:08:50 +0000 > From: Alan Mackenzie > > The elisp manual doesn't contain adequate documentation about > (re)display. > > The topics not covered include They include much more. Describing the display engine to any depth is a research project, not a bug report. Maybe if you had more specific questions, they could be answered. The closest thing to what you are asking for is in the large commentary at the beginning of xdisp.c. > 1. What triggers redisplay. See below: this is already covered. > 2. What portions of the frame/all frames get redisplayed when a > redisplay occurs, and how does this relate to the answer to 1.. > > There is a partial answer to 1. on the page "Forcing Redisplay" which > states that "Emacs normally tries to redisplay the screen whenever it > waits for input.", but this is clearly incomplete - redisplay also > happens in the absence of input (e.g. by context fontification). I don't udnerstand what you are saying here: "waiting for input" and "there's no input" is not a contradiction, on the contrary: yo uwait for input when there's none. And what is "context fontification"? > One clearly needs an answer to 2. if one ever wants to cause the > redisplay of a particular part of a window or frame. To do that, you need to change the text of that part or the text properties/overlays that affect how that part looks on display. But you most probably already know that, so I'm again not sure what the question is.