Re: Changing font weight with buffer-face-mode-invoke

[Heime <heimeborgia@protonmail.com>]

On Wednesday, June 26th, 2024 at 6:39 PM, Eli Zaretskii <eliz@gnu.org> wrote:

> > Date: Wed, 26 Jun 2024 17:08:40 +0000
> > From: Heime heimeborgia@protonmail.com
> > Cc: help-gnu-emacs@gnu.org
> > 
> > > Use standard weights: regular, medium, bold. Some font families have
> > > also additional weights: light, semi-light, semi-bold, extra-bold.
> > > The full list of weight values is in the ELisp manual, in the node
> > > "Face Attributes".
> > 
> > Some faces, e.g. "URW Chancery L" have "Medium Italic" and "Bold Italic".
> > And not all faces have the weights declared in the list. Could there be
> > an elisp function that returns a list of the available weights and styles
> > for each entry in the list of font families ?
> 
> 
> I think you want list-fonts. See the node "Low-Level Font" in the
> ELisp manual, it describes this stuff.

Could there be support functions (font-height-list :family family) and 
(font-weight-list :family family) so they can be used with

(buffer-face-mode-invoke 
  `(:family ,face-family :height ,face-height :weight ,face-weight) t)

As the height and weight are customarily asked by users wanting to change
font.  If one can get the specific values available for a specific family,
one would not run in the frequent difficulty of supplying non-existent
values, resulting in no changes being applied.