From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Chong Yidong Newsgroups: gmane.emacs.devel Subject: Re: pos-visible-in-window-p at ellipsis Date: Thu, 17 Jan 2008 09:59:21 -0500 Message-ID: <87hchcbira.fsf@stupidchicken.com> References: <87sl0zunl2.fsf@stupidchicken.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1200582283 3002 80.91.229.12 (17 Jan 2008 15:04:43 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 17 Jan 2008 15:04:43 +0000 (UTC) Cc: david.reitter@gmail.com, emacs-devel@gnu.org To: rms@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Jan 17 16:05:01 2008 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1JFWIU-0002jx-Ma for ged-emacs-devel@m.gmane.org; Thu, 17 Jan 2008 16:04:50 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JFWI6-0007R3-2o for ged-emacs-devel@m.gmane.org; Thu, 17 Jan 2008 10:04:26 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1JFWI2-0007OG-7p for emacs-devel@gnu.org; Thu, 17 Jan 2008 10:04:22 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1JFWI0-0007JY-Gk for emacs-devel@gnu.org; Thu, 17 Jan 2008 10:04:21 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JFWHz-0007Ib-Lb for emacs-devel@gnu.org; Thu, 17 Jan 2008 10:04:20 -0500 Original-Received: from cyd.mit.edu ([18.115.2.24]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1JFWHv-0002wi-H8; Thu, 17 Jan 2008 10:04:15 -0500 Original-Received: by cyd.mit.edu (Postfix, from userid 1000) id 00CB44E3C1; Thu, 17 Jan 2008 09:59:21 -0500 (EST) In-Reply-To: (Richard Stallman's message of "Thu\, 17 Jan 2008 09\:10\:42 -0500") User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1.50 (gnu/linux) X-detected-kernel: by monty-python.gnu.org: Linux 2.6 (newer, 2) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:87020 Archived-At: Richard Stallman writes: > This happens because the pixel position reported by pos_visible_p can > overshoot when there is invisible text (see the comment in > xdisp.c:1321). It would be rather complicated to compensate for this > (and potentially buggy since pos_visible_p is used by many other > functions). > > Why is invisible text difficult? Can't it just skip to the > next visible character? (The comment doesn't say what is hard.) It *does* skip, and that's the problem. That means that to determine the actual upper-left pixel position, you need to backtrack to compensate for the skipping. That's why invisible text is difficult.