:right-sidebar: True

ExpressionWatch
===================================================================

.. currentmodule:: gi.repository.Gtk





.. class:: ExpressionWatch(*args, **kwargs)
   :no-contents-entry:






An opaque structure representing a watched ``GtkExpression``.

The contents of ``GtkExpressionWatch`` should only be accessed through the
provided API.





Methods
-------

.. rst-class:: interim-class

.. class:: ExpressionWatch
   :no-index:


   .. method:: evaluate(value: ~typing.Any) -> bool

      Evaluates the watched expression and on success stores the result
      in ``value``.

      This is equivalent to calling :obj:`~gi.repository.Gtk.Expression.evaluate` with the
      expression and this pointer originally used to create ``watch``.







      :param value: an empty ``GValue`` to be set





   .. method:: unwatch() -> None

      Stops watching an expression.

      See :obj:`~gi.repository.Gtk.Expression.watch` for how the watch
      was established.