Re: Extent boundaries inconsistent w.r.t. extent properties
On Sat, 13 Apr 2002, Michael Toomim yowled:
Nix wrote:
> (Please, if possible make the begin-glyph visible if the text is
> invisible, too: this lets us emulate Emacs's `display' property
> sanely. If the end-glyph and begin-glyph and other glyphs at those
> points were consistently made invisible when the text was invisible,
> preview-latex would be unimplementable on XEmacs...)
I don't quite understand what you mean here. Do you want the
begin-glyph of an extent to be visible even if the extent has the
'invisible' property set to t? Are you saying that you'd like glyphs
to always be visible?
That is useful, yes: it lets us easily emulate the `display' property,
which replaces the range of text covered by an overlay temporarily with
an image.
The way it works right now is that if you have two extents
<-- A --><-- B -->
and B is invisible and A is not, and A has an end-glyph, then A's
end-glyph gets hidden.
If B has a begin-glyph, then it is hidden too: if it has an *end* glyph,
then it is not hidden. This strikes me as bizarre, and even though
preview-latex relies upon the end-glyph not being hidden when the text
is invisible, I'd prefer it if neither were hidden.
After all, the documentation says
,----
| `invisible'
| (Boolean) If `t', text under this extent will not be displayed -
| it will look as if the text is not there at all.
`----
and the begin- and end-glyphs are not (necessarily) textual.
This area needs better specs. :)
--
`Unless they've moved it since I last checked, travelling between
England and America does not involve crossing the equator.'
--- pir