GtkEntry update problems. Or: How do I force a widget to loose focus?

[Toralf Lund <toralf procaptura com>]

In one of our applications, we have lots of GtkEntry widgets that 
"mirror" values also stored in variables. For reasons I won't go into 
here, we don't want to change the variables in question each and every 
time a character is typed, so we are doing updates on the "activate" and 
"focus-out", which means that values are synchronised if the user moves 
the cursor e.g. to another GtkEntry field, and an update may also be 
forced by pressing Enter. That's very nearly what we want, but not 
quite. The problem is that the "focus-out" event only occurs if the user 
selects another that will accept focus. This is not the case for e.g. 
menu items or toolbar items, so no variables are updated when those are 
selected - and we want them to be.

So, is there any way at all I can make sure my variable is updated in 
all cases where the user stops entering text and selects anther GUI 
item? Essentially, the problem would be solved if I could force the 
focus to be taken away from the GtkEntry widget, but how? I might use 
the "grab_focus" call, of course, but I would have to add this to 
signals on all other widgets, then, and even that may not help, since I 
don't necessarily have a widget that can accept focus. And I don't "see" 
the GtkEntry in question from inside signal handers for buttons, menu 
items etc, of course...

Ideas, anyone?

- Toralf