@func will be called exactly once when transitioning out of %GST_PROMISE_RESULT_PENDING into any of the other #GstPromiseResult states.
a #GstPromiseChangeFunc to call
argument to call @func with
notification function that @user_data is no longer needed
a new #GstPromise
ConstructionException GTK+ fails to create the object.
1.14
See Implementation
@func will be called exactly once when transitioning out of %GST_PROMISE_RESULT_PENDING into any of the other #GstPromiseResult states.