Signal for property changes

[Curtis Maloney]

Rob Taylor wrote:
>> We have something almost identical in our own framework (which I, too, have been 
>> considering moving to the "generic" interfaces).
>>
>> The only difference is ours emits the old as well as the new value.  This has 
>> proven to be invaluable in our application.
> 
> What's your usecase for this?

When we want to watch for a specific state change on a particular object type, 
we can set a signal watch and do the test without having to hold any state.

We're using dbus as the backbone of a turnstile access control system.  When, 
for instance, an access token changes location, various modules are interested 
in where it was as much as where it has moved to.

-- 
Curtis Maloney
cmaloney at cardgate.net