I have a mostly portable implementation of ACCEPT-VALUES-PANE running in Lispworks CLIM. For those that don't know, the accept-values-pane is a gadget based non modal dialog.
A display function for an accept-values-pane might contain code like this:
(with-slots (some-value) pane (setq some-value (accept '(member A B C) :stream pane :default some-value :view '(radio-box-view :orientation :vertical) :prompt "Pick one")))
ACCEPT is supposed to do apply MAKE-INSTANCE to the CAR and CDR of the :view parameter and the stuff in the cdr is passed on to the gadget. In this example the presentation method ACCEPT-PRESENT-DEFAULT calls (apply 'MAKE-PANE 'RADIO-BOX-PANE <stuff> VIEW-OPTIONS). But, there is no defined way to get the supplied values. Lispworks CLIM has an internal function named CLIM-INTERNALS::VIEW-GADGET-INITARGS that retrieves them.
It seems that the VIEW class has only two functions. The first is to be a class so generic functions can specialize on subclasses of it, and the second is to pass gadget options via the :view keyword to ACCEPT.
This functionality is pretty important for usable gadget based dialogs so I hope the McCLIM architects can consider how this can be added to the code base.
Paul