TreeExpander

Object Hierarchy:

Description:

[ CCode ( type_id = "gtk_tree_expander_get_type ()" ) ]
public class TreeExpander : Widget, Accessible, Buildable, ConstraintTarget

GtkTreeExpander is a widget that provides an expander for a list.

It is typically placed as a bottommost child into a ListView to allow users to expand and collapse children in a list with a TreeListModel. It will provide the common UI elements, gestures and keybindings for this purpose.

On top of this, the "listitem.expand", "listitem.collapse" and "listitem.toggle-expand" actions are provided to allow adding custom UI for managing expanded state.

The TreeListModel must be set to not be passthrough. Then it will provide TreeListRow items which can be set via set_list_row on the expander. The expander will then watch that row item automatically. set_child sets the widget that displays the actual row contents.

CSS nodes

treeexpander
├── [indent]*
├── [expander]
╰── <child>

has zero or one CSS nodes with the name "expander" that should display the expander icon. The node will be `GtkTreeExpander:checked` when it is expanded. If the node is not expandable, an "indent" node will be displayed instead.

For every level of depth, another "indent" node is prepended.

Namespace: Gtk

Package: gtk4

Content:

Properties:

public Widget child { get; set; }
The child widget with the actual contents
public Object item { get; }
The item held by this expander's row
public TreeListRow list_row { get; set; }
The list row to track for expander state

Creation methods:

public TreeExpander ()
Creates a new TreeExpander

Methods:

public unowned Widget? get_child ()
Gets the child widget displayed by this.
public void* get_item ()
Forwards the item set on the TreeListRow that this is managing.
public unowned TreeListRow? get_list_row ()
Gets the list row managed by this.
public void set_child (Widget? child)
Sets the content widget to display.
public void set_list_row (TreeListRow? list_row)
Sets the tree list row that this expander should manage.

Inherited Members:

All known members inherited from class Gtk.Widget

All known members inherited from class GLib.Object

All known members inherited from interface Gtk.Accessible

All known members inherited from interface Gtk.Buildable