ComboBox
========
A :class:`Gtk.ComboBox` allows for the selection of an item from a dropdown menu.
They are preferable to having many radio buttons on screen as they take up less
room. If appropriate, it can show extra information about each item, such as text,
a picture, a checkbox, or a progress bar.

:class:`Gtk.ComboBox` is very similar to :class:`Gtk.TreeView`, as both use the
model-view pattern; the list of valid choices is specified in the form of a tree
model, and the display of the choices can be adapted to the data in the model by
using :ref:`cell renderers <cellrenderers>`.
If the combo box contains a large number of items, it may be better to display
them in a grid rather than a list. This can be done by calling
:meth:`Gtk.ComboBox.set_wrap_width`.

A default value can be set by calling :meth:`Gtk.ComboBox.set_active` with the index
of the desired value.

The :class:`Gtk.ComboBox` widget usually
restricts the user to the available choices, but it can optionally have an
:class:`Gtk.Entry`, allowing the user to enter arbitrary text if none of the
available choices are suitable. To do this, use one of the static methods
:meth:`Gtk.ComboBox.new_with_entry` or :meth:`Gtk.ComboBox.new_with_model_and_entry`
to create an :class:`Gtk.ComboBox` instance.

For a simple list of textual choices, the model-view API of :class:`Gtk.ComboBox`
can be a bit overwhelming. In this case, :class:`Gtk.ComboBoxText` offers a simple
alternative. Both :class:`Gtk.ComboBox` and :class:`Gtk.ComboBoxText` can contain
an entry.

Example
-------

.. image:: ../images/combobox_example.png

.. literalinclude:: ../examples/combobox_example.py
    :linenos: