Shutdown.py 文件源码

def _prepair(self):
        '''Try to connect to the given dbus services. If successful it will
        return a callable dbus proxy and those arguments.
        '''
        try:
            sessionbus = dbus.SessionBus()
            systembus  = dbus.SystemBus()
        except:
            return (None, None)
        for dbus_props in self.DBUS_SHUTDOWN.values():
            try:
                if dbus_props['bus'] == SESSION_BUS:
                    bus = sessionbus
                else:
                    bus = systembus
                interface = bus.get_object(dbus_props['service'],
                                           dbus_props['objectPath'])
                proxy = interface.get_dbus_method(dbus_props['method'],
                                                  dbus_props['interface'])
                return (proxy, dbus_props['arguments'])
            except dbus.exceptions.DBusException:
                continue
        return (None, None)