Re: [PATCH] Re: About the :distant-foreground face attribute

[Daniel Colascione]

On 01/14/2014 01:34 AM, Jan D. wrote:
> > > Given the use case at hand, we know for a fact that the background is
> > > the region background, so I don't understand why a calculated foreground
> > > is needed.  Just pick one that matches the background.
> > > There might be other use cases where a calculated foreground makes
> > > sense, but my imagination fails me here.
> >
> > Calculated foreground colors look better: they resemble the font-lock
> > colors on which they're based.
>
> For the region case, that would imply the possibility of different
> foregrounds for marked text, none which is the actual font-lock color.

It *is* the same color in the sense that the code we generate has the 
same hue. How on earth is that worse than changing arbitrary font-locked 
pieces of text to the system selection foreground color?

You seem to object to any feature that renders a face in a color other 
than what's literally written in the face spec. But that's exactly what 
happens when we put gtk_selection_bg_color in a color spec! Why are you 
fine with allowing gtk_selection_bg_color as a color (producing a color 
that's presumably workable but unknown to a theme writer) but adamantly 
opposed to a feature that selects good colors another way?

I've produced working code that allows Emacs to act how you prefer *and* 
how I prefer based on user configuration. What is your problem with that 
code? Have you responded to the numerous objections to 
:distant-foreground with anything other than retrenchment?

> Also, "look better" is just subjective, a theme
> designer should deside what looks best, not Emacs code.

And a theme designer can opt not to use the feature or to explicitly 
turn it off --- but a theme designer should never have to bother, 
because the feature only activates when the contrast is awful, which 
happens only when a theme designer screws up or deliberately relies on 
system colors.

Theme designers can specify what exactly gets rendered in both systems. 
Why do you care so much about letting theme designers loosen bounds 
using a special-purpose face attribute (which you don't even bother to 
mirror for changing backgrounds) instead of a general-purpose mechanism?

> > > Again, I really don't see this use case.  Do you have one?
> >
> > I just mentioned one. See my other email, the one where I laid out the
> > options for Emacs configuration defaults.
>
> That is not a use case.  A use case describes what an actual user does
> and in what situation automatically calculates colors enters the picture.

This entire thread describes the use case. There are abundant examples. 
Your objection here is baseless.

> > > > We should push policy to user customization when
> > > > possible instead of hardcoding policy in the logic of face attributes.
> > >
> > > I don't think we do that, users can still customize faces as they see
> > > fit.
> >
> > :distant-foreground has far too narrow a justification to warrant being
> > a face property by itself.
>
> Also, just an opinion, not based on some documented design rule in any
> Emacs or GNU document.

So only GNU documents count now, not reasoned arguments? What 
"documented design rule in any Emacs or GNU document" justifies 
:distant-foreground?

>  IMHO :stipple is as narrow.

:stipple is nothing like what we're talking about.