A #GstEvent to inspect.
Pointer to a gdouble to receive the x coordinate of the mouse movement.
Pointer to a gdouble to receive the y coordinate of the mouse movement.
Pointer to a gdouble to receive the delta_x coordinate of the mouse movement.
Pointer to a gdouble to receive the delta_y coordinate of the mouse movement.
TRUE if all coordinates could be extracted, otherwise FALSE.
Inspect a #GstNavigation mouse scroll event and extract the coordinates of the event.