[Texmacs-dev] tmEgg and TeXmacs: notification on events

[Lionel Elie Mamane]

On Tue, Aug 08, 2006 at 12:44:55PM +0200, Henri Lesourd wrote:
> Lionel Elie Mamane wrote:

>> I'd like my code to get notified (and be able to do stuff) when
>> text in an <input> of a Coq session is modified / deleted, as well
>> as when a whole <input> or a whole Coq <session> is deleted (or
>> cut) or pasted. Is there any way to do this in TeXmacs currently,
>> or would it be rather straightforward to add

> This is definitely a feature for which I see a need, for reasons
> rather similar to your concerns.

> As far as I know, this is thus a natural extension of TeXmacs
> programming, but before, we must stabilize simpler features which
> have been implemented over the last year,() .... I would say that
> after this, features like notification are next on the list.

Aha, good.


> As for me, what I do currently to solve these kinds
> of problems is retaining a copy of the relevant chunks
> of the document at one point in time, and when I need
> it, comparing them to the current version.

Yes, this was my backup plan, but:

> For implementing this, you only need (...)  and to be able to know
> when the comparison should be done. This latter one is the critical
> point, which depends on your application : as for me, what I do is
> that I check changes when an "action" occurs, namely, when the users
> hits Ctrl-Return inside a session

That was roughly my plan, except that I just do it in the serializer
instead of overriding the whole action, so I avoid this problem:

> the problem with this is that for example in a session, because I
> hook (i.e., I replace) the action which previously implemented the
> sending of the current line to the plugin, I must also reimplement
> the low-level machinery for adding a new line if the user is doing a
> submit when located on the last line, or either just put the cursor
> to the next line and update the output just above with the result
> computed by my plugin.


The only remaining problem is that I notice the changes later than I'd
like, but it is not catastrophic.


Thanks for all,

-- 
Lionel