Re: Automatic face setting based on contrast?

[Eli Zaretskii <eliz@gnu.org>]

> From: Tim Cross <theophilusx@gmail.com>
> Date: Fri, 08 Oct 2021 11:49:06 +1100
> 
> Over the years, I've seen a considerable growth in the number of faces
> defined, which has made consistent definitions of themes somewhat
> challenging. Running M-x list-display-faces on my system shows over 1100
> face definitions, which seems excessive.

In "emacs -Q", I see only 114 faces in that display.

> While many of these do use
> inheritance, many don't. This is unfortunate. It would be great if all
> modes which define faces by default inherit from one of the semantic
> font lock faces, allowing basic theme definitions to be possible by just
> tweaking the much smaller number of semantic faces and leaving tweaking
> of mode specific derived faces to the user when desired.

I think tweaking 100+ faces is not much easier than tweaking 1000.
Both border on the impractical.

> It would also be useful if there was some way of listing the defined
> faces which showed which face they are derived/inherited from to make it
> easier to see exactly what would be affected if you modify the 'parent'
> face and which faces are not defined to inherit from one of the semantic
> faces (and could be a possible candidate for redefining to inherit from
> a semantic face).

That sounds like a simple Grep job to me.

Eventually, I don't think there's a good solution to color contrast
that relies on manual tweaking of the faces.