application modality vs. window modality

[Christopher Blizzard <blizzard redhat com>]

There's a bug in Mozilla* that got me thinking.  It might be very nice 
to have the ability to set a window ( a dialog or whatever ) as modal to 
a specific parent window.  There are cases where you need a decision 
made in an application's window where other windows that are in that 
application don't need to be blocked.

Right now I'm pretty sure that all we have is the concept of 
application-wide modality.  I think that right now you can create a 
transient dialog for a window but putting a grab on that window so that 
events can't be sent to the parent window doesn't work without blocking 
all of the windows in the app.

From an API standpoint I'm thinking along the same lines of how you set 
transient parents for dialogs.

What do people think?  I think it would be a useful addition and it 
shouldn't be too tough to do from an implementation standpoint.

--Chris

* The bug is http://bugzilla.mozilla.org/show_bug.cgi?id=65521 for 
anyone who cares.