Re: Should invisible imply intangible?

[David Kastrup]

Eli Zaretskii <address@hidden> writes:

> On 19 Mar 2002, David Kastrup wrote:
> 
> > As Stefan (or was it Miles?) has already remarked, the default
> > display of cursors should preferably be such that an insertion of new
> > characters will occur at the location where the cursor is visible.
> 
> Mostly unrelated to the current discussion, but I thought I'd raise
> that anyway: the principle that insertion should happen at cursor
> location is not carved in stone.  It will possibly not hold with
> bidirectional editing: when typing bidirectional text, it sometimes
> makes sense to insert characters not at the cursor (some editors do
> that).
> 
> So I think the possibility that insertion happens not at cursor
> should not be discarded right away: perhaps it makes sense to users
> in some situations.  (I'm not saying that the situations you are
> discussing are such cases.)

We have not discarded it right away, it currently is happening.  But
the usual semantics should be "least element of surprise".  In case
where a certain application would have different requirements, it
would be better to add appropriate hooks instead of relying on
undocumented artifacts that are surprising in their default
behaviour.  One could probably work with pre-command-hook and the
like if one wanted to achieve something like that.  That would seem
more appropriate than trying to fiddle around with the before-string
property of overlays.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum
Email: address@hidden