Outlines in ConTeXt?

[Giuseppe Bilotta <bourbaki@bigfoot.com>]

Hello,

Yet Another Dirty Question: my next requirement is "outlines". I
really don't know if such a thing is possible in ConTeXt (or in
TeX) though.

By outline I mean a text (usually a list) which contains subtext
that can be expanded and contracted:

1. item one
2. item two
3. item three

 ||
 ||
 \/

1. item one
   This is item one expanded

2. item two
   This is item two expanded

3. item three
   This is item three expanded

When I ask for outlines in ConTeXt of course I ask for
*interactive* outlines: you click on one item, and the expansion
show; you click again on it, and they roll up again. Something
like help screens, but without hiding the current page.

Such a thing ought to be used together with "elastic" page length
(a page is longer when items are expanded).

The only way I could think of to achieve a similar behavior is by
typesetting the text repeatedly, expanding the various items, and
then creating appropriate links. This is extremely long, slow,
inefficient (unless objects are *heavily* reused), creates very
big documents and provides just an "emulation".

So the question is: is there any (probably JavaScript) way to
implement "real" outlines?

--
Giuseppe "Oblomov" Bilotta