sequence-dialog-item type-in search?

[Dimitri Simos <dim@lissys.demon.co.uk>]

Hi folks,
I would like to implement a sequence-dialog-item subclass which
will behave like the one in the standard open file dialog, 
so that when you type some characters it will automatically
scroll to, and select, the cell whose name starts with the
given characters.

It isn't that simple I suppose, because you need to account
for delays between typed characters etc.

To be even nastier, I would like to have two of these inside a
single dialog. It would seem to me that the one which has the
cursor on it at any given time should be the one responding
to the type-in. Or does this make Apple Human Interface
Guideline Gurus feel faint?

Any code / neat solutions / hints?
Cheers,

________________________________________________________
Dimitri Simos, Lissys Ltd.  Tel&Fax: UK (+44) 509 235620