Completion table and document/DTD association (bug #127125)

Hello,

After having been looking at the bug in
http://bugzilla.gnome.org/show_bug.cgi?id=127125,
I was asking if it was possible to modify some things in order for the
completion table 
to be hidden or to hide itself if it is not usable, when no DTD is
associated with the document
(when no completion is possible).

I think the needs would be simple for the API : the view, or the
completion table, needs to
know if completion is possible, if a DTD is associated with a document,
and needs to receive
a signal when completion becomes possible (or maybe impossible), when a
DTD is associated
with a document. 

I don't know exactly how to code such an API, and I don't know if it is
that simple. But I
think it would be useful for the GUI's usability.

So I just want to know all your opinions about this problem. 

Thanks,

Nicolas Centa

PS : thanks to Baptiste who has reported the bug.