From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: The future of Follow Mode - a proposal. Date: Thu, 25 Feb 2016 20:30:12 +0000 Message-ID: <20160225203012.GC19742@acm.fritz.box> References: <83wppzo7lf.fsf@gnu.org> <20160223231156.GA26899@acm.fritz.box> <83a8mqhvym.fsf@gnu.org> <837fhthq5z.fsf@gnu.org> <834mcxhnaq.fsf@gnu.org> <83lh68g3fh.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1456432084 1829 80.91.229.3 (25 Feb 2016 20:28:04 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 25 Feb 2016 20:28:04 +0000 (UTC) Cc: Stefan Monnier , emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Feb 25 21:27:55 2016 Return-path: Envelope-to: ged-emacs-devel@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 1aZ2Vt-0003jh-3x for ged-emacs-devel@m.gmane.org; Thu, 25 Feb 2016 21:27:53 +0100 Original-Received: from localhost ([::1]:45672 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZ2Vs-0006Sz-C2 for ged-emacs-devel@m.gmane.org; Thu, 25 Feb 2016 15:27:52 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:50847) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZ2Vo-0006Sa-H8 for emacs-devel@gnu.org; Thu, 25 Feb 2016 15:27:49 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aZ2Vk-0007Ql-WB for emacs-devel@gnu.org; Thu, 25 Feb 2016 15:27:48 -0500 Original-Received: from mail.muc.de ([193.149.48.3]:27441) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZ2Vk-0007QZ-Mv for emacs-devel@gnu.org; Thu, 25 Feb 2016 15:27:44 -0500 Original-Received: (qmail 73622 invoked by uid 3782); 25 Feb 2016 20:27:43 -0000 Original-Received: from acm.muc.de (p548A4868.dip0.t-ipconnect.de [84.138.72.104]) by colin.muc.de (tmda-ofmipd) with ESMTP; Thu, 25 Feb 2016 21:27:41 +0100 Original-Received: (qmail 11401 invoked by uid 1000); 25 Feb 2016 20:30:12 -0000 Content-Disposition: inline In-Reply-To: <83lh68g3fh.fsf@gnu.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-Delivery-Agent: TMDA/1.1.12 (Macallan) X-Primary-Address: acm@muc.de X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x X-Received-From: 193.149.48.3 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:200677 Archived-At: Hello, Eli. On Thu, Feb 25, 2016 at 06:28:18PM +0200, Eli Zaretskii wrote: > > From: Stefan Monnier > > Cc: emacs-devel@gnu.org > > Date: Wed, 24 Feb 2016 19:30:55 -0500 > > I live in a world where wrapped lines are sufficiently rare that I don't > > really care and rarely think about what can happen in those cases. > > But now that I think about it: I'm not sure how vertical-motion could > > handle a "multiple-window" case where the windows don't have the same > > width (same thing in other similar cases, such as with overlays with > > a `window' property that make them only apply to some of the multiple > > windows, or when the windows aren't all in the same frame and don't use > > the same font). The desired semantic seems undefined except for the > > case where the vertical motion is applied to the "currently displayed > > state" (so we know when to use which window data). > Actually, vertical-motion completely breaks in that case. I don't > even see a way that will allow to solve that situation in principle, > except in some very specific and restricted use cases. Which is why I > strongly suggest to change Follow Mode so that it forces all of its > windows be of the same width. With the current pixelwise control of > window dimensions, this is easy. On a tty, a pixel has the thickness of a character. It could easily happen that to make all the windows of equal width, it's necessary to put a "terminator" vertical line on the RH window, or even double width window separators in. This would be ugly. > I think this will magically remove many of the problems that currently > plague Follow Mode, and leave us with something we can reasonably easy > to solve and maintain. > However, Alan disagrees, and insists on supporting windows of unequal > width. If it can be done without undue difficulty, then yes. -- Alan Mackenzie (Nuremberg, Germany).