Re: "modern" colors Re: Changes for emacs 28

[Yuri Khan]

On Tue, 15 Sep 2020 at 23:06, Robert Pluim <rpluim@gmail.com> wrote:

>     Yuri> On Tue, 15 Sep 2020 at 21:54, Robert Pluim <rpluim@gmail.com> wrote:
>     Eli> Is that because we don't know how to query GTK for the themes default
>     Eli> colors?
>     >>
>     >> If by 'we' you mean Emacs, then yes. (I donʼt know how either, and I
>     >> find the GTK docs unhelpful).
>
>     Yuri> Some time ago someone over at Bugzilla (Firefox’s bug tracker) said
>     Yuri> it’s generally not possible to query about that.
>
> Would you have a bugzilla bug number?

Okay, I went to look for a reference and it turns out I misremembered.
What actually happened is I asked on the GTK mailing lists whether an
application can programmatically detect if the user is using a light
or dark variant of a theme.

https://mail.gnome.org/archives/gtk-app-devel-list/2018-November/msg00006.html

In the reply, I was told this:

  The only way to respect the GTK theme is to use GTK to render UI elements
  according to that theme—using the `gtk_render_*` API. Anything else is, by
  and large, impossible unless you literally parse the CSS with your own CSS
  parser, determine the colours of every UI element you care about, and then
  detect whether those colours are "light" or "dark".