def stop_sound_device(self):
        if self._pipeline is None:
            return

        self._pipeline.set_state(Gst.State.NULL)
        power.get_power_manager().restore_suspend()
        self.emit('stop')

    def pause_sound_device(self):
        if self._pipeline is None:
            return

        self._pipeline.set_state(Gst.State.PAUSED)
        power.get_power_manager().restore_suspend()
        self.emit('pause')

    def restart_sound_device(self):
        if self._pipeline is None:
            logging.debug('Trying to restart not initialized sound device')
            return

        power.get_power_manager().inhibit_suspend()
        self._pipeline.set_state(Gst.State.PLAYING)
        self.emit('play')

    def _complete_close(self):
        self.destroy()

        if self.shared_activity:
            self.shared_activity.leave()

        self._cleanup_jobject()

        # Make the exported object inaccessible
        dbus.service.Object.remove_from_connection(self._bus)

        self._session.unregister(self)
        power.get_power_manager().shutdown()

    def __joined_cb(self, activity, success, err):
        """Callback when join has finished"""
        logging.debug('Activity.__joined_cb %r' % success)
        self.shared_activity.disconnect(self._join_id)
        self._join_id = None
        if not success:
            logging.debug('Failed to join activity: %s' % err)
            return

        power_manager = power.get_power_manager()
        if power_manager.suspend_breaks_collaboration():
            power_manager.inhibit_suspend()

        self.reveal()
        self.emit('joined')
        self.__privacy_changed_cb(self.shared_activity, None)

    def __share_cb(self, ps, success, activity, err):
        if not success:
            logging.debug('Share of activity %s failed: %s.' %
                          (self._activity_id, err))
            return

        logging.debug('Share of activity %s successful, PS activity is %r.' %
                      (self._activity_id, activity))

        activity.props.name = self._jobject.metadata['title']

        power_manager = power.get_power_manager()
        if power_manager.suspend_breaks_collaboration():
            power_manager.inhibit_suspend()

        self.shared_activity = activity
        self.shared_activity.connect('notify::private',
                                     self.__privacy_changed_cb)
        self.emit('shared')
        self.__privacy_changed_cb(self.shared_activity, None)

        self._send_invites()

 def __pipe_message_cb(self, bus, message):
     if message.type in (Gst.MessageType.EOS, Gst.MessageType.ERROR):
         self._pipeline.set_state(Gst.State.NULL)
         self._pipeline = None
         power.get_power_manager().restore_suspend()
         self.emit('stop')