Gtk.TreeExpander – gtk4 Reference Manual

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 `GtkListView` to allow users to expand and collapse children in a list with a [ [email protected]]. `GtkTreeExpander` provides 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 `GtkTreeListModel` must be set to not be passthrough. Then it will provide [[email protected]] items which can be set via [ [email protected]_list_row] on the expander. The expander will then watch that row item automatically. [ [email protected]_child] sets the widget that displays the actual row contents.

CSS nodes

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

`GtkTreeExpander` 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.

Accessibility

`GtkTreeExpander` uses the gtk_accessible_role_group role. The expander icon is represented as a gtk_accessible_role_button, labelled by the expander's child, and toggling it will change the gtk_accessible_state_expanded state.

Namespace: Gtk

Package: gtk4

Content:

Properties:

public Widget child { get; set; }
The child widget with the actual contents.
public bool indent_for_icon { get; set; }
TreeExpander indents the child by the width of an expander-icon if it is not expandable.
public Object item { owned 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 `GtkTreeExpander`

Methods:

public unowned Widget? get_child ()
Gets the child widget displayed by this .
public bool get_indent_for_icon ()
TreeExpander indents the child by the width of an expander-icon if it is not expandable.
public Object? get_item ()
Forwards the item set on the `GtkTreeListRow` 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_indent_for_icon (bool indent_for_icon)
Sets if the TreeExpander should indent the child by the width of an expander-icon when it is not expandable.
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

@get
@new
@ref
@set
add_toggle_ref
add_weak_pointer
bind_property
connect
constructed
disconnect
dispose
dup_data
dup_qdata
force_floating
freeze_notify
get_class
get_data

get_property
get_qdata
get_type
getv
interface_find_property
interface_install_property
interface_list_properties
is_floating
new_valist
new_with_properties
newv
notify
notify_property
ref_count
ref_sink
remove_toggle_ref
remove_weak_pointer

replace_data
replace_qdata
set_data
set_data_full
set_property
set_qdata
set_qdata_full
set_valist
setv
steal_data
steal_qdata
thaw_notify
unref
watch_closure
weak_ref
weak_unref

All known members inherited from interface Gtk.Accessible

All known members inherited from interface Gtk.Buildable

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