:right-sidebar: True

Promise
===================================================================

.. currentmodule:: gi.repository.Gst


.. versionadded:: 1.14




.. class:: Promise(**kwargs)
   :no-contents-entry:






:Constructors:

::

    Promise()
    new() -> Gst.Promise
    new_with_change_func(func:Gst.PromiseChangeFunc, user_data=None) -> Gst.Promise



Constructors
------------

.. rst-class:: interim-class

.. class:: Promise
   :no-index:


   .. classmethod:: new() -> ~gi.repository.Gst.Promise

      


      .. versionadded:: 1.14








   .. classmethod:: new_with_change_func(func: ~typing.Callable[[...], None], *user_data: ~typing.Any) -> ~gi.repository.Gst.Promise

      ``func`` will be called exactly once when transitioning out of
      :const:`~gi.repository.Gst.PromiseResult.PENDING` into any of the other :obj:`~gi.repository.Gst.PromiseResult`
      states.



      .. versionadded:: 1.14





      :param func: a :obj:`~gi.repository.Gst.PromiseChangeFunc` to call


      :param user_data: argument to call ``func`` with









Methods
-------

.. rst-class:: interim-class

.. class:: Promise
   :no-index:


   .. method:: expire() -> None

      Expire a ``promise``.  This will wake up any waiters with
      :const:`~gi.repository.Gst.PromiseResult.EXPIRED`.  Called by a message loop when the parent
      message is handled and/or destroyed (possibly unanswered).



      .. versionadded:: 1.14








   .. method:: get_reply() -> ~gi.repository.Gst.Structure | None

      Retrieve the reply set on ``promise``.  ``promise`` must be in
      :const:`~gi.repository.Gst.PromiseResult.REPLIED` and the returned structure is owned by ``promise``



      .. versionadded:: 1.14








   .. method:: interrupt() -> None

      Interrupt waiting for a ``promise``.  This will wake up any waiters with
      :const:`~gi.repository.Gst.PromiseResult.INTERRUPTED`.  Called when the consumer does not want
      the value produced anymore.



      .. versionadded:: 1.14








   .. method:: reply(s: ~gi.repository.Gst.Structure | None = None) -> None

      Set a reply on ``promise``.  This will wake up any waiters with
      :const:`~gi.repository.Gst.PromiseResult.REPLIED`.  Called by the producer of the value to
      indicate success (or failure).

      If ``promise`` has already been interrupted by the consumer, then this reply
      is not visible to the consumer.



      .. versionadded:: 1.14





      :param s: a :obj:`~gi.repository.Gst.Structure` with the the reply contents





   .. method:: wait() -> ~gi.repository.Gst.PromiseResult

      Wait for ``promise`` to move out of the :const:`~gi.repository.Gst.PromiseResult.PENDING` state.
      If ``promise`` is not in :const:`~gi.repository.Gst.PromiseResult.PENDING` then it will return
      immediately with the current result.



      .. versionadded:: 1.14


















Fields
------

.. rst-class:: interim-class

.. class:: Promise
   :no-index:
   

   .. attribute:: parent

      Parent :obj:`~gi.repository.Gst.MiniObject`