listener question

Hello,

I'm trying to create a GNOME panel applet to control a certain music 
player application through bonobo.  The applet attaches itself as a 
listener to the application's property bag notification events.

The thing is that the applet (the listener) is long lived and the event 
source is not.

I think one way to handle this is to:
  1. poll bonobo_activation_query for an active event source
  2. attach listener to event source
  3. process notification events
  4. [event source destroyed] remove listener and goto 1.

Is there a better way to do this?  If not, what is the best way to do 4? 
    Is there a signal emitted when the event source is destroyed?

I'm very new to bonobo and will greatly appreciate any advice you may have.

Thanks,
Jon