Re: Question about display engine

[Ergus]

On Thu, Aug 08, 2019 at 09:25:45AM +0200, martin rudalics wrote:
> > And I think we need to consider the case of the region using one of
> > the attributes that are not in the list.
>
> I now think it would make more sense to add an 'extend-to-window-edge'
> attribute in the face definition itself.

I like that option as a concept, but it adds a new flag to a general
struct like the face for something that only affects the region face
now. But it is very general, so maybe could be useful in the future; but
it worth to make the face even more complex?.

BTW:

Looking at the merge_face function could anyone please explain better
what means: realized face and lface_id and please direct me to where is
documented how emacs uses the faces internally; the functionalities
available and specially the merge rules?

> Also, when looking at what
> applications like Thunderbird or Firefox do, I nowhere see their
> "region faces" extend to the right edges of their "windows" in "normal
> text".  Admittedly, these two applications do not highlight an empty
> space at the left edge of a window either and I'm fully aware of the
> fact that I'm comparing apples and oranges here.  Still I think that
> our users should be given the possibility to customize their regions
> in a similar way as they do.
>
> martin