Re: [DISCUSSION] Face priority in Org fontification (was: [BUG] org dates, radio links, and special keywords override heading backgrounds [9.7 (9.7-??-902dacb @ /home/st/.config/emacs/.local/straight/build-30.0.50/org/)])

[Protesilaos Stavrou <info@protesilaos.com>]

> From: Ihor Radchenko <yantar92@posteo.net>
> Date: Wed, 13 Mar 2024 14:27:18 +0000

> [... 16 lines elided]

>>> CCing Protesilaos. This discussion might be of interest for him.
>>
>> I think it makes sense to not override the background because otherwise
>> the heading can look visually "broken". See attached screenshot for an
>> example: it is called "demo-org-heading-with-background.png". In that
>> screenshot I include an overline for the heading, to show how this is
>> not limited to the background colour but extends to all face attributes.
>> To this end, I also attach "demo-org-heading-with-more-height.png" which
>> shows how the date is not scaling to match the heading's increased text
>> height.
>
> I agree that override (what we do now) is clearly not good.
> The question, however, is whether we should prioritize object face over
> the containing element face or vice versa:
>
> Should link properties take precedence over headline or should headline
> properties take precedence?
>
> For example, if link explicitly sets face height to be smaller, should
> we honor it? Or should we honor the headline face height, if set?
> Similar for background. In your example, the white background override
> does not really look nice when heading has its own background.

This can get tricky, I know.

The idea is to make this behave how all faces relate to the 'default'
face with regard to their 'undefined' attributes. Namely, if a face
defines an attribute, then it overrides the 'default' face, otherwise it
falls back to it for the value of the given attribute.

In the case of the headlines then, every other element should attain the
attributes of the heading unless it explicitly overrides them. So a link
with an 'undefined' height will be as high as the heading, but a link
with a height of, say, 1.0 will keep that height even if the heading is
at a 2.0 height (or whatever).

Same idea for all face attributes.

Now the tricky part is to figure out which combinations can work this
way. Headings and source blocks are two obvious ones. Maybe there are
more, but I cannot think of one right now.

-- 
Protesilaos Stavrou
https://protesilaos.com