Re: defface/defcustom question

[Per Abrahamsen <abraham@dina.kvl.dk>]

Alan Shutko <ats@acm.org> writes:

> Simon Josefsson <jas@extundo.com> writes:
>
>> True.  Hm.  Using both a variable and a face seem to be common
>> practice though, I wonder if there are other reasons.  Maybe face
>> inheritance is a recent feature?  I dunno.
>
> I believe it is.  The custom attribute is only from 2000, and I know
> these faces are a lot older than that. 

Faces are oldest, customize in between, and face inheritance is
newest.

Emacs never really been consistent about whether to use variables to
hold the faces, but before customize there was a great incentive to do
so, as the pre-customize face API sucked.

Often one would just do

(defvar some-package-face 'bold
  "Face used by some package.")

in order to avoid the problem of creating a face.  If the user wanted
some package to use italic instead, he'd 

(setq some-package-face 'italic)

It had a nice feature that if bold looked ugly with his favorite face,
he could change the bold face to something else, and many occurrences
of bold in Emacs would adjust.

It is probably simpler to just use a defface for new options these
days, but if we remove the old variables we will break user
customizations with setq like the above.