:right-sidebar: True

LayoutManager
===================================================================

.. currentmodule:: gi.repository.Gtk





.. class:: LayoutManager(**properties: ~typing.Any)
   :no-contents-entry:


Superclasses: :class:`~gi.repository.GObject.Object`


Subclasses: :class:`~gi.repository.Gtk.BinLayout`, :class:`~gi.repository.Gtk.BoxLayout`, :class:`~gi.repository.Gtk.CenterLayout`, :class:`~gi.repository.Gtk.ConstraintLayout`, :class:`~gi.repository.Gtk.CustomLayout`, :class:`~gi.repository.Gtk.FixedLayout`, :class:`~gi.repository.Gtk.GridLayout`, :class:`~gi.repository.Gtk.OverlayLayout`




:Constructors:

::

    LayoutManager(**properties)





Methods
-------

.. rst-class:: interim-class

.. class:: LayoutManager
   :no-index:


   .. method:: allocate(widget: ~gi.repository.Gtk.Widget, width: int, height: int, baseline: int) -> None

      Assigns the given ``width``, ``height``, and ``baseline`` to
      a ``widget``, and computes the position and sizes of the children of
      the ``widget`` using the layout management policy of ``manager``.







      :param widget: the ``GtkWidget`` using ``manager``


      :param width: the new width of the ``widget``


      :param height: the new height of the ``widget``


      :param baseline: the baseline position of the ``widget``, or -1





   .. method:: get_layout_child(child: ~gi.repository.Gtk.Widget) -> ~gi.repository.Gtk.LayoutChild

      Retrieves a ``GtkLayoutChild`` instance for the ``GtkLayoutManager``,
      creating one if necessary.

      The ``child`` widget must be a child of the widget using ``manager``.

      The ``GtkLayoutChild`` instance is owned by the ``GtkLayoutManager``,
      and is guaranteed to exist as long as ``child`` is a child of the
      ``GtkWidget`` using the given ``GtkLayoutManager``.







      :param child: a ``GtkWidget``





   .. method:: get_request_mode() -> ~gi.repository.Gtk.SizeRequestMode

      Retrieves the request mode of ``manager``.










   .. method:: get_widget() -> ~gi.repository.Gtk.Widget | None

      Retrieves the ``GtkWidget`` using the given ``GtkLayoutManager``.










   .. method:: layout_changed() -> None

      Queues a resize on the ``GtkWidget`` using ``manager``, if any.

      This function should be called by subclasses of ``GtkLayoutManager``
      in response to changes to their layout management policies.










   .. method:: measure(widget: ~gi.repository.Gtk.Widget, orientation: ~gi.repository.Gtk.Orientation, for_size: int) -> tuple[int, int, int, int]

      Measures the size of the ``widget`` using ``manager``, for the
      given ``orientation`` and size.

      See the :obj:`~gi.repository.Gtk.Widget` documentation on layout management for
      more details.







      :param widget: the ``GtkWidget`` using ``manager``


      :param orientation: the orientation to measure


      :param for_size: Size for the opposite of ``orientation``; for instance, if
         the ``orientation`` is :const:`~gi.repository.Gtk.Orientation.HORIZONTAL`, this is the height
         of the widget; if the ``orientation`` is :const:`~gi.repository.Gtk.Orientation.VERTICAL`, this
         is the width of the widget. This allows to measure the height for the
         given width, and the width for the given height. Use -1 if the size
         is not known













Virtual Methods
---------------

.. rst-class:: interim-class

.. class:: LayoutManager
   :no-index:
   

   .. method:: do_allocate(widget: ~gi.repository.Gtk.Widget, width: int, height: int, baseline: int) -> None

      Assigns the given ``width``, ``height``, and ``baseline`` to
      a ``widget``, and computes the position and sizes of the children of
      the ``widget`` using the layout management policy of ``manager``.







      :param widget: the ``GtkWidget`` using ``manager``


      :param width: the new width of the ``widget``


      :param height: the new height of the ``widget``


      :param baseline: the baseline position of the ``widget``, or -1





   .. method:: do_create_layout_child(widget: ~gi.repository.Gtk.Widget, for_child: ~gi.repository.Gtk.Widget) -> ~gi.repository.Gtk.LayoutChild

      Create a ``GtkLayoutChild`` instance for the given ``for_child`` widget.







      :param widget: the widget using the ``manager``


      :param for_child: the child of ``widget``





   .. method:: do_get_request_mode(widget: ~gi.repository.Gtk.Widget) -> ~gi.repository.Gtk.SizeRequestMode

      a virtual function, used to return the preferred
      request mode for the layout manager; for instance, "width for height"
      or "height for width"; see ``GtkSizeRequestMode``







      :param widget: 




   .. method:: do_measure(widget: ~gi.repository.Gtk.Widget, orientation: ~gi.repository.Gtk.Orientation, for_size: int) -> tuple[int, int, int, int]

      Measures the size of the ``widget`` using ``manager``, for the
      given ``orientation`` and size.

      See the :obj:`~gi.repository.Gtk.Widget` documentation on layout management for
      more details.







      :param widget: the ``GtkWidget`` using ``manager``


      :param orientation: the orientation to measure


      :param for_size: Size for the opposite of ``orientation``; for instance, if
         the ``orientation`` is :const:`~gi.repository.Gtk.Orientation.HORIZONTAL`, this is the height
         of the widget; if the ``orientation`` is :const:`~gi.repository.Gtk.Orientation.VERTICAL`, this
         is the width of the widget. This allows to measure the height for the
         given width, and the width for the given height. Use -1 if the size
         is not known





   .. method:: do_root() -> None

      a virtual function, called when the widget using the layout
      manager is attached to a ``GtkRoot``










   .. method:: do_unroot() -> None

      a virtual function, called when the widget using the layout
      manager is detached from a ``GtkRoot``














Fields
------

.. rst-class:: interim-class

.. class:: LayoutManager
   :no-index:
   

   .. attribute:: parent_instance