Re: Enriched/Org is a colorful Org

[Eli Zaretskii <eliz@gnu.org>]

> From: Carsten Dominik <carsten.dominik@gmail.com>
> Date: Thu, 11 Apr 2013 04:58:15 +0200
> Cc: "emacs-orgmode@gnu.org List" <emacs-orgmode@gnu.org>,
>  Eli Zaretskii <eliz@gnu.org>
> 
> > I guess Eli simply means, in a general way, that overlays do negatively impact
> > display performance, as you said as well a couple of times:
> 
> Yes, but Eli says that Org already severely tests the
> display engine, and he uses the word "mess", even though
> we mostly use text properties for faces and other
> display-related things.

Well, don't interpret "mess" too literally ;-)

> Of course, Org already uses overlays, for example for
> folding (as does outline.el), and for temporary marking
> of text like during src block editing.  But as your digging
> shows, I ave avoided them in the past, and we are also not
> using them for org-indent.el, for example.
> 
> The reason why I said "overlays would be better" is simply
> that they would allow to add display properties in a
> persistent way that would not interfere that our
> font-lock-unfontify-region function removes face and
> invisibility text properties.  So they are "better" for
> implementing hand-made faces selection that should overrule
> font-lock.

Overlays should be OK as long as they aren't too many, and as long as
you don't move them around too much, particularly in post-command-hook
or some such.