public class ComboBox : Widget, Accessible, Buildable, CellEditable, CellLayout, ConstraintTarget
A `GtkComboBox` is a widget that allows the user to choose from a list of valid choices.
![An example GtkComboBox](combo-box.png)
The `GtkComboBox` displays the selected choice; when activated, the `GtkComboBox` displays a popup which allows the user to make a new choice.
The `GtkComboBox` uses 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 cell renderers, as you would in a tree view. This is possible since `GtkComboBox` implements the [iface@Gtk.CellLayout] interface. The tree model holding the valid choices is not restricted to a flat list, it can be a real tree, and the popup will reflect the tree structure.
To allow the user to enter values not in the model, the [property@Gtk.ComboBox:has-entry] property allows the `GtkComboBox` to contain a [ class@Gtk.Entry]. This entry can be accessed by calling [method@Gtk.ComboBox.get_child] on the combo box.
For a simple list of textual choices, the model-view API of `GtkComboBox` can be a bit overwhelming. In this case, [class@Gtk.ComboBoxText] offers a simple alternative. Both `GtkComboBox` and `GtkComboBoxText` can contain an entry.
``` combobox ├── box.linked │ ╰── button.combo │ ╰── box │ ├── cellview │ ╰── arrow ╰── window.popup ```
A normal combobox contains a box with the .linked class, a button with the .combo class and inside those buttons, there are a cellview and an arrow.
``` combobox ├── box.linked │ ├── entry.combo │ ╰── button.combo │ ╰── box │ ╰── arrow ╰── window.popup ```
A `GtkComboBox` with an entry has a single CSS node with name combobox. It contains a box with the .linked class. That box contains an entry and a button, both with the .combo class added. The button also contains another node with name arrow.
`GtkComboBox` uses the gtk_accessible_role_combo_box role.