Closing top level windows

[-JM]

I've run into a "reversed chicken-and-egg problem" when attempting to 
close down an applicaiton. The application has a typical MVC design, 
where its various windows act as views/controllers onto a model, which 
is based on the internal data objects manipulated by my app.

This applicaiton has an Open command to open a new data file. It can 
only have a single file open at a time. Hence, in order to open a new 
file, I need to close down the old one first. Before I can dispose of 
the data model, however, I need to get rid of any views/controllers 
(ie, windows) attached to it. The windows attach to the model in their 
ctors, and detatch in the dtors. They're not designed to "live" without 
an associated model.

Now to the problem. When closing the old document, I first need to get 
rid of its windows, before I can safely dispose of the underlying data 
model. However, I've found no way to dispose of the windows explicitly. 
I'm not supposed to simply delete them (and if I do, wierd things 
happen). The kosher wxWidgets way is to call Destroy on the window. 
However, this doesn't actually delete the window object, but merely 
queue them for future deletion. They're still alive. So I can't delete 
the data model, as its still being attached to the windows.

How can I synchronously accomplish this? Can I, for example, call some 
Yield method that will provide "idle time" allowing the queued window 
tear-down mechanism to kick in, after which I can know that the windows 
are gone entirely, so I can procede tearing down the old data model and 
loaing up the new one?

I really don't want to turn things "inside out" here. I merely want t 
way to "synchonously" close and get rid of a bunch of windows. One 
would think that's doable somehow.

-JM