Re: Highlighting discontinuous spans of text on mouseover

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 11 Apr 2024 09:21:02 +0100
> From: hugo@heagren.com
> 
> Now my problem: For reasons made clear in the spec, any two links in
> the same terminal buffer with the same id param /and/ uri must be
> highlighted together, regardless of whether the text of the two links
> is continuous. So if there are two, discontinuous links with the same
> uri and id, and I mouseover one, both should be highlighted. When I
> mouse off, neither should be highlighted. Thus they should appear to
> the user as one link (though discontinuous on the screen). Just using
> buttons and mouse-face doesn't handle this. *Is there a
> standard/expected way to do this?*

The Emacs display engine supports mouse-highlight only of a single
contiguous portion of buffer text or string.  (The highlighted portion
can be non-contiguous on display due to bidi reordering, but it must
be contiguous in the order of the buffer or string positions.)
Supporting more than one highlighted portion would require changes of
the display code on the C level.