bug#47313: 27.1; highlight functions should accept colors too

bug#47313: 27.1; highlight functions should accept colors too

[scame via Bug reports for GNU Emacs, the Swiss army knife of text editors]

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I wanted to use highlight-regexp to color some lines gray, but the command
did not accept the color, it only accept faces, so I had to look for a suitable
face.

These highlight-* commands should accept color names too if the user
wants a specific color, not a specific face,

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bug#47313: 27.1; highlight functions should accept colors too

[Eli Zaretskii]

> Date: Mon, 22 Mar 2021 09:29:24 +0000
> From:  scame via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> I wanted to use highlight-regexp to color some lines gray, but the command
> did not accept the color, it only accept faces, so I had to look for a suitable
> face.
> 
> These highlight-* commands should accept color names too if the user
> wants a specific color, not a specific face,

Faces are not just colors, they have many additional attributes.

I'm not sure it is a good idea to make these commands accept both
faces and colors, as this could make the UI confusing and error prone.
It may be better to provide new commands, similar to the existing
ones, but which will accept only the colors instead of faces.

(You could of course define a face which specifies just the color, and
use that with highlight-* commands, but that is less user-friendly.)

bug#47313: 27.1; highlight functions should accept colors too

[scame via Bug reports for GNU Emacs, the Swiss army knife of text editors]

>
> I'm not sure it is a good idea to make these commands accept both
> faces and colors, as this could make the UI confusing and error prone.
> It may be better to provide new commands, similar to the existing
> ones, but which will accept only the colors instead of faces.

I thought people only used colors to temporarily highlight certain phrases,
etc. If it's not true then you have a point that faces can do more.

At least, the face completion prompt should be improved, so that it shows
the face's style inline like with list-faces-display.This could solve
the color selection problem, because if the face's style is instantly
visible then the user can simply choose a face which is similar to the
color he wants.

bug#47313: 27.1; highlight functions should accept colors too

[Eli Zaretskii]

> Date: Mon, 22 Mar 2021 17:44:40 +0000
> From: scame <laszlomail@protonmail.com>
> Cc: "47313@debbugs.gnu.org" <47313@debbugs.gnu.org>
> 
> At least, the face completion prompt should be improved, so that it shows
> the face's style inline like with list-faces-display.This could solve
> the color selection problem, because if the face's style is instantly
> visible then the user can simply choose a face which is similar to the
> color he wants.

We could try that, but I fear that the result of showing many faces in
the same buffer one besides the other will look ugly, while displaying
them one face per line would make a very long buffer, scrolling
through which could be impractical.

bug#47313: 27.1; highlight functions should accept colors too

[scame via Bug reports for GNU Emacs, the Swiss army knife of text editors]

>
> We could try that, but I fear that the result of showing many faces in
> the same buffer one besides the other will look ugly, while displaying
> them one face per line would make a very long buffer, scrolling
> through which could be impractical.

It can't be uglier than the completions of read-color which is pretty bad.
It's a cacophony of colors and some of them are hard to read:

https://i.imgur.com/NtIDihs.png

IMO the list-colors-display UI is much better even if it's longer (and if
it's a completion list then it's easy to narrow it down):

https://www.valenciatech.com/wp-content/uploads/2019/08/gnu-emacs-list-colors-display.png

bug#47313: 27.1; highlight functions should accept colors too

[Eli Zaretskii]

> Date: Mon, 22 Mar 2021 18:39:11 +0000
> From: scame <laszlomail@protonmail.com>
> Cc: "47313@debbugs.gnu.org" <47313@debbugs.gnu.org>
> 
> > We could try that, but I fear that the result of showing many faces in
> > the same buffer one besides the other will look ugly, while displaying
> > them one face per line would make a very long buffer, scrolling
> > through which could be impractical.
> 
> It can't be uglier than the completions of read-color which is pretty bad.

I think it can.  But again, you are welcome to try that, perhaps I'm
wrong.

> It's a cacophony of colors and some of them are hard to read:
> 
> https://i.imgur.com/NtIDihs.png

I don't see any cacophony, and have no difficulty reading the names.
Besides, when you see the color itself, why does it matter how it is
named?

> 
> IMO the list-colors-display UI is much better even if it's longer (and if
> it's a completion list then it's easy to narrow it down):
> 
> https://www.valenciatech.com/wp-content/uploads/2019/08/gnu-emacs-list-colors-display.png

FWIW, I'd be annoyed by the length of this long before I found the
color I was after.  But that's me.

bug#47313: 27.1; highlight functions should accept colors too

[Lars Ingebrigtsen]

scame <laszlomail@protonmail.com> writes:

> I thought people only used colors to temporarily highlight certain phrases,
> etc. If it's not true then you have a point that faces can do more.

I think it makes sense to continue to use faces here (and not
colours) -- people may want underlining or overstrike or whatever.

Adding colours in addition to faces would be a confusing interface, I
think, so I don't think that would work well.  So I'm closing this bug
report.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no