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bug#57693: 29.0.50; Is there a more reliable version of `char-displayabl
From: |
Eli Zaretskii |
Subject: |
bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'? |
Date: |
Sat, 18 Feb 2023 13:56:24 +0200 |
> From: Ihor Radchenko <yantar92@posteo.net>
> Cc: Stefan Kangas <stefankangas@gmail.com>, yantar92@gmail.com,
> 57693@debbugs.gnu.org
> Date: Sat, 18 Feb 2023 11:32:56 +0000
>
> Eli Zaretskii <eliz@gnu.org> writes:
>
> >> (defun insert-char-safely (ch repl)
> >> "Insert character CH, if it can be displayed; otherwise insert REPL.
> >> On TTY frames, always insert REPL."
> >> (if (not (display-graphic-p))
> >> (insert repl)
> >> (insert ch)
> >> (unless (font-at (1- (point)))
> >> (delete-char -1)
> >> (insert repl))))
> >
> > We could, but IME typical uses of fancy characters do not insert them
> > into a buffer, but use them in header-line, overlay strings, and
> > suchlikes.
>
> `font-at' accepts optional third argument STRING.
> For example, (font-at 0 nil "🧠a")
My comment was because Stefan suggested a function that inserts a
character into a buffer, not because font-at by default reports about
a character at point.
> As an alternative thought, may Emacs display engine accept a text
> property like 'display-alternative to display some fallback
> character/string if some parts of the displayed text cannot be
> displayed?
We already have something like that: see glyphless-char-display and
glyphless-char-display-mode. The problem is that (a) on GUI displays
the replacement will be displayed in a box; (b) the replacement must
be an ASCII character; and (c) the char-table we use for that is
global, i.e. it affects the entire session. But if someone wants a
more flexible feature which lifts some of those restrictions, that's
the place to start nonetheless.
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Stefan Kangas, 2023/02/17
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Eli Zaretskii, 2023/02/17
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Stefan Kangas, 2023/02/17
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Eli Zaretskii, 2023/02/18
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Stefan Kangas, 2023/02/18
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Eli Zaretskii, 2023/02/18
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Ihor Radchenko, 2023/02/18
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?,
Eli Zaretskii <=
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Ihor Radchenko, 2023/02/19
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Eli Zaretskii, 2023/02/19
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Ihor Radchenko, 2023/02/19
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Eli Zaretskii, 2023/02/19
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Ihor Radchenko, 2023/02/19
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Eli Zaretskii, 2023/02/19
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Ihor Radchenko, 2023/02/18
- bug#57693: 29.0.50; Is there a more reliable version of `char-displayable-p'?, Eli Zaretskii, 2023/02/18