GNU bug report logs - #78861
[PATCH] Avoid calendar flicker

Previous Next

Full log

Message #23 received at 78861 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Stephen Berman <stephen.berman <at> gmx.net>
Cc: manuel <at> ledu-giraud.fr, 78861 <at> debbugs.gnu.org
Subject: Re: bug#78861: [PATCH] Avoid calendar flicker
Date: Sun, 22 Jun 2025 17:38:12 +0300

> From: Stephen Berman <stephen.berman <at> gmx.net>
> Cc: Manuel Giraud <manuel <at> ledu-giraud.fr>,  78861 <at> debbugs.gnu.org
> Date: Sun, 22 Jun 2025 15:55:26 +0200
> 
> I don't see any flickering or redrawing with that recipe, but in my
> calendar and diary configuration I do see what looks like delayed
> fontification of certain date marking.  I've narrowed the issue down to
> a combination of marking lunar phases and having a sufficiently large
> number of diary entries (in my case due to including several todo-mode
> files).  Here is a recipe:
> 
> 0. Make ~/.emacs.d/diary consist of the following lines:
> -------------------------------
> %%(diary-lunar-phases 'warning)
> Jun 22, 2025 test
> -------------------------------
> and then repeat the second line a large number of times (5000 shows the
> issue clearly on my machine, 1000 shows it too, but not as clearly).
> 1. emacs -Q
> 2. M-x calendar
> 3. Hit 'm' and then alternatively '>' and '<'.
> 
> On typing 'm' there is a noticeable delay before the dates are marked,
> on the first scroll command also a noticeable delay but not as long, on
> subsequent scroll commands much less delay but enough to see the dates
> first with default face, then change to warning face.  With Manuel's
> patch let-binding 'inhibit-redisplay', there are still delays when
> scrolling but the lunar phase dates are shown in warning face as soon as
> the scroll happens.

Is this an interesting case?  Do people frequently have thousands of
such lines in their ~/diary files?

Anyway, what triggers the fontifications that are evidently done after
the initial display?  Are there any timers involved, perhaps?  IOW,
why isn't the buffer fontified immediately?

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.