Re: [RFC] Add :invisible face attribute

[Jim Porter]

On 12/21/2024 10:28 AM, Ihor Radchenko wrote:
> Jim Porter <jporterbugs@gmail.com> writes:
>
> > I'm just brainstorming here, but could Org use a display spec with
> > specified spaces[1] to make Emacs render a space of the appropriate
> > width? That requires a bit of computation, but it's how
> > 'visual-wrap-prefix-mode' and SHR handle (roughly) similar sorts of things.
>
> If one uses display spec, editing the text underneath will become
> tricky. Org mode is first and foremost a text format and should remain
> editable using normal text editing commands.

Hmm. Doing a bit of testing in a scratch buffer, I think if each hidden 
character had its own display spec, editing seems to work ok. At least 
in the sense that I can delete each character like I'd expect. There 
might be other problems with this though, e.g. keeping the display specs 
updated, or performance issues...

For a completely different idea, I seem to recall some discussion around 
an :opacity face attribute. That would be useful for themes, e.g. to 
de-emphasize some text by reducing the opacity, and then here we could 
just set the :opacity to zero. I can't find the thread about this, but I 
recall there being some debate about how it should work; for example, if 
instead we should support RGBA for :foreground.