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bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual)
From: |
Noam Postavsky |
Subject: |
bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual) |
Date: |
Fri, 19 Apr 2019 17:47:55 -0400 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) |
Sebastian Urban <mrsebastianurban@gmail.com> writes:
> According to help-gnu-emacs thread
> (lists.gnu.org/archive/html/help-gnu-emacs/2019-03/msg00205.html) this
> is normal behaviour, but from perspective of beginner it looks like
> a bug. Therefore I suggest a sentence or two, perhaps in chapter
> "11.12 Font lock mode", about how Font lock takes over control of
> faces when user switches to mode with defined font-lock faces leaving
> only those from this mode and turning off others (unless they have
> also property font-lock-face).
So I've been looking at this, and I think maybe the only manual change
needed is in the Elisp manual to more strongly recommend using
font-lock-face for this sort of thing:
>From 12148e9d93f885fd6e4e82f485c319486c1e9652 Mon Sep 17 00:00:00 2001
From: Noam Postavsky <npostavs@gmail.com>
Date: Fri, 19 Apr 2019 00:55:14 -0400
Subject: [PATCH] Recommend using font-lock-face over face (Bug#35044)
* doc/lispref/modes.texi (Precalculated Fontification): Explain
advantages of using font-lock-face over face.
---
doc/lispref/modes.texi | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/doc/lispref/modes.texi b/doc/lispref/modes.texi
index 919816f3de..0ff13d72e2 100644
--- a/doc/lispref/modes.texi
+++ b/doc/lispref/modes.texi
@@ -3201,7 +3201,12 @@ is disabled, @code{font-lock-face} has no effect on the
display.
It is ok for a mode to use @code{font-lock-face} for some text and
also use the normal Font Lock machinery. But if the mode does not use
the normal Font Lock machinery, it should not set the variable
-@code{font-lock-defaults}.
+@code{font-lock-defaults}. In this case the @code{face} property will
+not be overriden, so using the @code{face} property could work too.
+However, using @code{font-lock-face} is generally preferable as it
+allows the user to control the fontification by toggling
+@code{font-lock-mode}, and lets the code work regardless of whether
+the mode uses Font Lock machinery or not.
@node Faces for Font Lock
@subsection Faces for Font Lock
--
2.11.0
> Also the behaviour of reappearing table-cell face after switch back to
> fundamental-mode or text-mode seems to be not quite right, shouldn't it
> reappear in every cell at once (just like it disappears)?
If I understand correctly, this is rather a bug in table.el: it should
use 'font-lock-face instead of 'face, and then all this buggy behaviour
will go away. Perhaps you'd like to send a patch?
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Sebastian Urban, 2019/04/16
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual),
Noam Postavsky <=
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Eli Zaretskii, 2019/04/20
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Sebastian Urban, 2019/04/22
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Noam Postavsky, 2019/04/22
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Sebastian Urban, 2019/04/24
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Noam Postavsky, 2019/04/26
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Sebastian Urban, 2019/04/27
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Noam Postavsky, 2019/04/27
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Sebastian Urban, 2019/04/28
- bug#35044: 25.2; Description of "disappearing" faces (Emacs Manual), Noam Postavsky, 2019/04/28