bug#24594: 24.5; `variable-pitch-mode': accept FACE arg instead of hardcoding the face

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 2 Oct 2016 20:48:19 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> 
> > > See http://emacs.stackexchange.com/a/27527/105: the user wants to use a
> > > different face from face `variable-pitch'.  That seems reasonable.
> > 
> > That's not how I read it.  I think they just want to change the look of
> > Emacs after invoking variable-pitch-mode, and customizing the variable-pitch
> > face seems like the right approach for that.
> 
> The question as posed is ambiguous, but it specifically asks how to use a different face.

No, he asks how to use a different _font_, and customizing the face
(as you have suggested there) is the way to achieve that.

> > > Please consider adding an optional FACE argument, defaulting to face
> > > `variable-pitch'.
> > 
> > I don't really see why the function should be called variable-pitch-mode any
> > more.  Maybe select-buffer-face? IIUC this wouldn't have anything to do with
> > variable pitches any more, except for the default value, maybe?
> 
> Agreed.  Unless there is some particular use for limiting the accepted FACE to variable-pitch faces.  In that case, additional logic/control would be needed.

We already have buffer-face-mode.

> Was there some particular reason that a mode was written specifically for variable-pitch (whether the face `variable-pitch' or variable-pitch faces in general), rather than providing a mode for any face?  If not then agreed: a name change would be appropriate.

The variable-pitch face is a very general face: it stands for a face
using any variable-pitch font, of which there are gazillions.