Re: overlays vs text properties

[Eli Zaretskii <eliz@gnu.org>]

> From: Eric Abrahamsen <eric@ericabrahamsen.net>
> Cc: help-gnu-emacs@gnu.org
> Date: Wed, 13 Jul 2011 00:23:23 -0700
> 
> 1. I'll have a buffer and an indirect buffer on the same file. Each
>    buffer will have a single "active" paragraph at any one time, but
>    only one. So I don't think scaling is too much of an issue. I'm
>    trying to create a "follow" situation, where a paragraph in the
>    source buffer is matched to a paragraph in the indirect buffer, and
>    these two paragraphs have (different) properties. But only the two
>    paragraphs at one time, moving in unison.
> 2. This is mostly a visual effect (hence my leaning towards overlays),
>    and copying text properties is not necessary. In fact, it would be
>    annoying.
> 3. Overlapping would not be an issue -- within the "active" paragraphs
>    there might be other properties present, but they would be separate
>    from the overall paragraph property.
> 
> I am trying to create a translation environment, by modifying an org-mode
> file so that I can move through one subtree while the indirect buffer
> displays mirror paragraphs in another subtree. I want to link
> source-language paragraphs with target-language paragraphs, so it's
> pretty crucial that movement be covered: wherever point goes in the main
> buffer, it should be tracked and mirrored in the indirect buffer.

Sounds like overlays are better suited for this job, unless I'm
missing something.