From mboxrd@z Thu Jan  1 00:00:00 1970
Path: news.gmane.org!.POSTED!not-for-mail
From: Javier <invalid@invalid.invalid>
Newsgroups: gmane.emacs.help
Subject: changing the display of formfeed characters
Date: Fri, 31 Aug 2018 11:22:59 +0000 (UTC)
Organization: Aioe.org NNTP Server
Message-ID: <pmb8ej$1dnm$1@gioia.aioe.org>
NNTP-Posting-Host: blaine.gmane.org
Mime-Version: 1.0
X-Trace: blaine.gmane.org 1535714776 8573 195.159.176.226 (31 Aug 2018 11:26:16 GMT)
X-Complaints-To: usenet@blaine.gmane.org
NNTP-Posting-Date: Fri, 31 Aug 2018 11:26:16 +0000 (UTC)
User-Agent: tin/2.2.1-20140504 ("Tober an Righ") (UNIX) (Linux/3.18.6-1-ARCH
	(x86_64))
To: help-gnu-emacs@gnu.org
Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Aug 31 13:26:12 2018
Return-path: <help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org>
Envelope-to: geh-help-gnu-emacs@m.gmane.org
Original-Received: from lists.gnu.org ([208.118.235.17])
	by blaine.gmane.org with esmtp (Exim 4.84_2)
	(envelope-from <help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org>)
	id 1fvhZ5-000263-5P
	for geh-help-gnu-emacs@m.gmane.org; Fri, 31 Aug 2018 13:26:11 +0200
Original-Received: from localhost ([::1]:53109 helo=lists.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org>)
	id 1fvhbA-0001QC-93
	for geh-help-gnu-emacs@m.gmane.org; Fri, 31 Aug 2018 07:28:20 -0400
X-Received: by 2002:a1c:e902:: with SMTP id q2-v6mr532876wmc.5.1535714581102; 
	Fri, 31 Aug 2018 04:23:01 -0700 (PDT)
Original-Path: usenet.stanford.edu!q200-v6no3056136wmd.0!news-out.google.com!z184-v6ni207wmz.0!nntp.google.com!proxad.net!feeder1-2.proxad.net!news.mixmin.net!aioe.org!.POSTED!not-for-mail
Original-Newsgroups: gnu.emacs.help
Original-Lines: 20
Original-NNTP-Posting-Host: aPJVVR0E0beUwQdJulDzVg.user.gioia.aioe.org
Original-X-Complaints-To: abuse@aioe.org
X-Notice: Filtered by postfilter v. 0.8.3
Original-Xref: usenet.stanford.edu gnu.emacs.help:223677
X-BeenThere: help-gnu-emacs@gnu.org
X-Mailman-Version: 2.1.21
Precedence: list
List-Id: Users list for the GNU Emacs text editor <help-gnu-emacs.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/help-gnu-emacs>,
	<mailto:help-gnu-emacs-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/help-gnu-emacs/>
List-Post: <mailto:help-gnu-emacs@gnu.org>
List-Help: <mailto:help-gnu-emacs-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/help-gnu-emacs>,
	<mailto:help-gnu-emacs-request@gnu.org?subject=subscribe>
Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org
Original-Sender: "help-gnu-emacs"
	<help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org>
Xref: news.gmane.org gmane.emacs.help:117802
Archived-At: <http://permalink.gmane.org/gmane.emacs.help/117802>

There are several suggested ways to display form feed (^L)

http://www.emacswiki.org/emacs/PageBreaks
http://www.emacswiki.org/emacs/PrettyControlL
https://www.emacswiki.org/emacs/pp-c-l.el
http://ergoemacs.org/emacs/modernization_formfeed.html

However all them break whitespace-mode.  Is there a way to display
formfeed ^L without interfering with whitespace-mode?

The issue has been known for long time.

http://lists.gnu.org/archive/html/help-gnu-emacs/2011-03/msg00891.html
https://www.emacswiki.org/emacs/pp-c-l.el

Has somebody come with any idea how to display ^L in some way without
breaking whitespace-mode?

Would it do the trick modifying the display table for ^L with a fixed width string?
Like "=========" and avoiding to dynamically adjust for window width.