public delegate bool BusFunc
Specifies the type of function passed to
add_watch_full, which is called from the mainloop when a message is
available on the bus.
The message passed to the function will be unreffed after execution of this function so it should not be freed in the function.
Note that this function is used as a GSourceFunc which means that returning FALSE will remove the GSource from the mainloop.
||the Bus that sent the message
||user data that has been given, when registering the handler
false if the event source should be removed.