From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: [Patch]: Allow overlay arrows to be inserted before the text at column zero rather than splatting it. Date: Sun, 18 Aug 2019 17:34:09 +0300 Message-ID: <83mug6mtjy.fsf@gnu.org> References: <20190818134804.GA31509@ACM> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="188870"; mail-complaints-to="usenet@blaine.gmane.org" Cc: emacs-devel@gnu.org To: Alan Mackenzie Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Aug 18 16:34:21 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hzMGB-000mzo-BT for ged-emacs-devel@m.gmane.org; Sun, 18 Aug 2019 16:34:19 +0200 Original-Received: from localhost ([::1]:41418 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzMGA-00034G-7i for ged-emacs-devel@m.gmane.org; Sun, 18 Aug 2019 10:34:18 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:55385) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzMG2-00031s-OW for emacs-devel@gnu.org; Sun, 18 Aug 2019 10:34:11 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:59656) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hzMG2-0007D2-A8; Sun, 18 Aug 2019 10:34:10 -0400 Original-Received: from [176.228.60.248] (port=4152 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1hzMG1-0001rc-No; Sun, 18 Aug 2019 10:34:10 -0400 In-reply-to: <20190818134804.GA31509@ACM> (message from Alan Mackenzie on Sun, 18 Aug 2019 13:48:04 +0000) 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:239437 Archived-At: > Date: Sun, 18 Aug 2019 13:48:04 +0000 > From: Alan Mackenzie > > Currently, when there are no fringes, inserting an overlay arrow > overwrites the first two characters on the pertinent line. This is fine > for things like edebug, where the text is usually indented many columns > anyway, and only whitespace gets overwritten. > > This is less good for things like compilation-mode, where this arrow > would obliterate the first two characters of a file name. > > The following amendment fixes this by allowing the arrow to be displayed > at the BOL, displacing the rest of the line two characters to the right. > To do this, a new buffer local boolean variable, overlay-arrow-insert is > introduced. If you want the arrow be displayed before the line's text, why didn't you just put a before-string at the beginning of the line, instead of implementing this in the display engine? AFAIU, that would give you most of the patch for free, e.g. you wouldn't need to mess with the set_cursor_from_row hair. What am I missing?