:right-sidebar: True

CellAreaContext
===================================================================

.. currentmodule:: gi.repository.Gtk





.. deprecated:: 4.10

   This object will be removed in GTK 5



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


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





Stores geometrical information for a series of rows in a GtkCellArea

The ``GtkCellAreaContext`` object is created by a given ``GtkCellArea``
implementation via its ``GtkCellAreaClass.create_context()`` virtual
method and is used to store cell sizes and alignments for a series of
``GtkTreeModel`` rows that are requested and rendered in the same context.

``GtkCellLayout`` widgets can create any number of contexts in which to
request and render groups of data rows. However, it’s important that the
same context which was used to request sizes for a given ``GtkTreeModel``
row also be used for the same row when calling other ``GtkCellArea`` APIs
such as gtk_cell_area_render() and :func:`~gi.repository.Gtk.CellArea.event`.





Methods
-------

.. rst-class:: interim-class

.. class:: CellAreaContext
   :no-index:


   .. method:: allocate(width: int, height: int) -> None

      Allocates a width and/or a height for all rows which are to be
      rendered with ``context``.

      Usually allocation is performed only horizontally or sometimes
      vertically since a group of rows are usually rendered side by
      side vertically or horizontally and share either the same width
      or the same height. Sometimes they are allocated in both horizontal
      and vertical orientations producing a homogeneous effect of the
      rows. This is generally the case for ``GtkTreeView`` when
      ``GtkTreeView:fixed-height-mode`` is enabled.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




      :param width: the allocated width for all ``GtkTreeModel`` rows rendered
         with ``context``, or -1


      :param height: the allocated height for all ``GtkTreeModel`` rows rendered
         with ``context``, or -1





   .. method:: get_allocation() -> tuple[int, int]

      Fetches the current allocation size for ``context``.

      If the context was not allocated in width or height, or if the
      context was recently reset with :func:`~gi.repository.Gtk.CellAreaContext.reset`,
      the returned value will be -1.






      .. deprecated:: 4.10

         This object will be removed in GTK 5







   .. method:: get_area() -> ~gi.repository.Gtk.CellArea

      Fetches the ``GtkCellArea`` this ``context`` was created by.

      This is generally unneeded by layouting widgets; however,
      it is important for the context implementation itself to
      fetch information about the area it is being used for.

      For instance at ``GtkCellAreaContextClass.allocate()`` time
      it’s important to know details about any cell spacing
      that the ``GtkCellArea`` is configured with in order to
      compute a proper allocation.






      .. deprecated:: 4.10

         This object will be removed in GTK 5







   .. method:: get_preferred_height() -> tuple[int, int]

      Gets the accumulative preferred height for all rows which have been
      requested with this context.

      After :func:`~gi.repository.Gtk.CellAreaContext.reset` is called and/or before ever
      requesting the size of a ``GtkCellArea``, the returned values are 0.






      .. deprecated:: 4.10

         This object will be removed in GTK 5







   .. method:: get_preferred_height_for_width(width: int) -> tuple[int, int]

      Gets the accumulative preferred height for ``width`` for all rows
      which have been requested for the same said ``width`` with this context.

      After :func:`~gi.repository.Gtk.CellAreaContext.reset` is called and/or before ever
      requesting the size of a ``GtkCellArea``, the returned values are -1.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




      :param width: a proposed width for allocation





   .. method:: get_preferred_width() -> tuple[int, int]

      Gets the accumulative preferred width for all rows which have been
      requested with this context.

      After :func:`~gi.repository.Gtk.CellAreaContext.reset` is called and/or before ever
      requesting the size of a ``GtkCellArea``, the returned values are 0.






      .. deprecated:: 4.10

         This object will be removed in GTK 5







   .. method:: get_preferred_width_for_height(height: int) -> tuple[int, int]

      Gets the accumulative preferred width for ``height`` for all rows which
      have been requested for the same said ``height`` with this context.

      After :func:`~gi.repository.Gtk.CellAreaContext.reset` is called and/or before ever
      requesting the size of a ``GtkCellArea``, the returned values are -1.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




      :param height: a proposed height for allocation





   .. method:: push_preferred_height(minimum_height: int, natural_height: int) -> None

      Causes the minimum and/or natural height to grow if the new
      proposed sizes exceed the current minimum and natural height.

      This is used by ``GtkCellAreaContext`` implementations during
      the request process over a series of ``GtkTreeModel`` rows to
      progressively push the requested height over a series of
      :func:`~gi.repository.Gtk.CellArea.get_preferred_height` requests.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




      :param minimum_height: the proposed new minimum height for ``context``


      :param natural_height: the proposed new natural height for ``context``





   .. method:: push_preferred_width(minimum_width: int, natural_width: int) -> None

      Causes the minimum and/or natural width to grow if the new
      proposed sizes exceed the current minimum and natural width.

      This is used by ``GtkCellAreaContext`` implementations during
      the request process over a series of ``GtkTreeModel`` rows to
      progressively push the requested width over a series of
      :func:`~gi.repository.Gtk.CellArea.get_preferred_width` requests.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




      :param minimum_width: the proposed new minimum width for ``context``


      :param natural_width: the proposed new natural width for ``context``





   .. method:: reset() -> None

      Resets any previously cached request and allocation
      data.

      When underlying ``GtkTreeModel`` data changes its
      important to reset the context if the content
      size is allowed to shrink. If the content size
      is only allowed to grow (this is usually an option
      for views rendering large data stores as a measure
      of optimization), then only the row that changed
      or was inserted needs to be (re)requested with
      :func:`~gi.repository.Gtk.CellArea.get_preferred_width`.

      When the new overall size of the context requires
      that the allocated size changes (or whenever this
      allocation changes at all), the variable row
      sizes need to be re-requested for every row.

      For instance, if the rows are displayed all with
      the same width from top to bottom then a change
      in the allocated width necessitates a recalculation
      of all the displayed row heights using
      :func:`~gi.repository.Gtk.CellArea.get_preferred_height_for_width`.






      .. deprecated:: 4.10

         This object will be removed in GTK 5











Properties
----------

.. rst-class:: interim-class

.. class:: CellAreaContext
   :no-index:
   

   .. attribute:: props.area
      :type: ~gi.repository.Gtk.CellArea

      The ``GtkCellArea`` this context was created by






      .. deprecated:: 4.10

         This object will be removed in GTK 5




   .. attribute:: props.minimum_height
      :type: int

      The minimum height for the ``GtkCellArea`` in this context
      for all ``GtkTreeModel`` rows that this context was requested
      for using :func:`~gi.repository.Gtk.CellArea.get_preferred_height`.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




   .. attribute:: props.minimum_width
      :type: int

      The minimum width for the ``GtkCellArea`` in this context
      for all ``GtkTreeModel`` rows that this context was requested
      for using :func:`~gi.repository.Gtk.CellArea.get_preferred_width`.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




   .. attribute:: props.natural_height
      :type: int

      The natural height for the ``GtkCellArea`` in this context
      for all ``GtkTreeModel`` rows that this context was requested
      for using :func:`~gi.repository.Gtk.CellArea.get_preferred_height`.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




   .. attribute:: props.natural_width
      :type: int

      The natural width for the ``GtkCellArea`` in this context
      for all ``GtkTreeModel`` rows that this context was requested
      for using :func:`~gi.repository.Gtk.CellArea.get_preferred_width`.






      .. deprecated:: 4.10

         This object will be removed in GTK 5










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

.. rst-class:: interim-class

.. class:: CellAreaContext
   :no-index:
   

   .. method:: do_allocate(width: int, height: int) -> None

      Allocates a width and/or a height for all rows which are to be
      rendered with ``context``.

      Usually allocation is performed only horizontally or sometimes
      vertically since a group of rows are usually rendered side by
      side vertically or horizontally and share either the same width
      or the same height. Sometimes they are allocated in both horizontal
      and vertical orientations producing a homogeneous effect of the
      rows. This is generally the case for ``GtkTreeView`` when
      ``GtkTreeView:fixed-height-mode`` is enabled.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




      :param width: the allocated width for all ``GtkTreeModel`` rows rendered
         with ``context``, or -1


      :param height: the allocated height for all ``GtkTreeModel`` rows rendered
         with ``context``, or -1





   .. method:: do_get_preferred_height_for_width(width: int) -> tuple[int, int]

      Gets the accumulative preferred height for ``width`` for all rows
      which have been requested for the same said ``width`` with this context.

      After :func:`~gi.repository.Gtk.CellAreaContext.reset` is called and/or before ever
      requesting the size of a ``GtkCellArea``, the returned values are -1.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




      :param width: a proposed width for allocation





   .. method:: do_get_preferred_width_for_height(height: int) -> tuple[int, int]

      Gets the accumulative preferred width for ``height`` for all rows which
      have been requested for the same said ``height`` with this context.

      After :func:`~gi.repository.Gtk.CellAreaContext.reset` is called and/or before ever
      requesting the size of a ``GtkCellArea``, the returned values are -1.






      .. deprecated:: 4.10

         This object will be removed in GTK 5




      :param height: a proposed height for allocation





   .. method:: do_reset() -> None

      Resets any previously cached request and allocation
      data.

      When underlying ``GtkTreeModel`` data changes its
      important to reset the context if the content
      size is allowed to shrink. If the content size
      is only allowed to grow (this is usually an option
      for views rendering large data stores as a measure
      of optimization), then only the row that changed
      or was inserted needs to be (re)requested with
      :func:`~gi.repository.Gtk.CellArea.get_preferred_width`.

      When the new overall size of the context requires
      that the allocated size changes (or whenever this
      allocation changes at all), the variable row
      sizes need to be re-requested for every row.

      For instance, if the rows are displayed all with
      the same width from top to bottom then a change
      in the allocated width necessitates a recalculation
      of all the displayed row heights using
      :func:`~gi.repository.Gtk.CellArea.get_preferred_height_for_width`.






      .. deprecated:: 4.10

         This object will be removed in GTK 5











Fields
------

.. rst-class:: interim-class

.. class:: CellAreaContext
   :no-index:
   

   .. attribute:: parent_instance