:right-sidebar: True

SectionModel
===================================================================

.. currentmodule:: gi.repository.Gtk


.. versionadded:: 4.12




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





Implementations: :class:`~gi.repository.Gtk.FilterListModel`, :class:`~gi.repository.Gtk.FlattenListModel`, :class:`~gi.repository.Gtk.MapListModel`, :class:`~gi.repository.Gtk.MultiSelection`, :class:`~gi.repository.Gtk.NoSelection`, :class:`~gi.repository.Gtk.SingleSelection`, :class:`~gi.repository.Gtk.SliceListModel`, :class:`~gi.repository.Gtk.SortListModel`


``GtkSectionModel`` is an interface that adds support for sections to list models.

A ``GtkSectionModel`` groups successive items into so-called sections. List widgets
like ``GtkListView`` and ``GtkGridView`` then allow displaying section headers for
these sections by installing a header factory.

Many GTK list models support sections inherently, or they pass through the sections
of a model they are wrapping.

When the section groupings of a model change, the model will emit the
:obj:`~gi.repository.Gtk.SectionModel.signals.sections_changed` signal by calling the
:obj:`~gi.repository.Gtk.SectionModel.sections_changed` function. All sections in the given range
then need to be queried again.
The :obj:`~gi.repository.Gio.ListModel.signals.items_changed` signal has the same effect, all sections in
that range are invalidated, too.




Methods
-------

.. rst-class:: interim-class

.. class:: SectionModel
   :no-index:


   .. method:: get_section(position: int) -> ~typing.Tuple[int, int]

      Query the section that covers the given position. The number of
      items in the section can be computed by ``out_end - out_start``\.

      If the position is larger than the number of items, a single
      range from n_items to G_MAXUINT will be returned.


      .. versionadded:: 4.12





      :param position: the position of the item to query




   .. method:: sections_changed(position: int, n_items: int) -> None

      This function emits the :obj:`~gi.repository.Gtk.SectionModel.signals.sections_changed`
      signal to notify about changes to sections.

      It must cover all positions that used to be a section start or that
      are now a section start. It does not have to cover all positions for
      which the section has changed.

      The :obj:`~gi.repository.Gio.ListModel.signals.items_changed` implies the effect of the
      :obj:`~gi.repository.Gtk.SectionModel.signals.sections_changed` signal for all the items
      it covers.

      It is recommended that when changes to the items cause section changes
      in a larger range, that the larger range is included in the emission
      of the :obj:`~gi.repository.Gio.ListModel.signals.items_changed` instead of emitting
      two signals.


      .. versionadded:: 4.12





      :param position: the first changed item

      :param n_items: the number of changed items










Signals
-------

.. rst-class:: interim-class

.. class:: SectionModel.signals
   :no-index:
   

   .. method:: sections_changed(position: int, n_items: int) -> None

      The type of the None singleton.



      .. versionadded:: 4.12





      :param position: The first item that may have changed

      :param n_items: number of items with changes








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

.. rst-class:: interim-class

.. class:: SectionModel
   :no-index:
   

   .. method:: do_get_section(position: int) -> ~typing.Tuple[int, int]

      Query the section that covers the given position. The number of
      items in the section can be computed by ``out_end - out_start``\.

      If the position is larger than the number of items, a single
      range from n_items to G_MAXUINT will be returned.


      .. versionadded:: 4.12





      :param position: the position of the item to query