Sent when display angles in a multi-angle feature (such as a multiangle DVD) change - either angles have appeared or disappeared.
Sent when the set of available commands changes and should re-queried by interested applications.
Sent when a navigation event was not handled by any element in the pipeline (Since: 1.6)
Returned from
gst_navigation_message_get_type() when the passed message is not a
navigation message.
Sent when the mouse moves over or leaves a clickable region of the output, such as a DVD menu button.
A set of notifications that may be received on the bus when navigation related status changes.