### Class

# Gtk HeaderBar

#### Description [src]

    final class Gtk.HeaderBar : Gtk.Widget
      implements Gtk.Accessible, Gtk.Buildable, Gtk.ConstraintTarget {
      /* No available fields */
    }

`GtkHeaderBar` is a widget for creating custom title bars for windows.

`GtkHeaderBar` is similar to a horizontal `GtkCenterBox`. It allows children to be placed at the start or the end. In addition, it allows the window title to be displayed. The title will be centered with respect to the width of the box, even if the children at either side take up different amounts of space.

`GtkHeaderBar` can add typical window frame controls, such as minimize, maximize and close buttons, or the window icon.

For these reasons, `GtkHeaderBar` is the natural choice for use as the custom titlebar widget of a `GtkWindow` (see `gtk_window_set_titlebar()`), as it gives features typical of titlebars while allowing the addition of child widgets.

## GtkHeaderBar as GtkBuildable

The `GtkHeaderBar` implementation of the `GtkBuildable` interface supports adding children at the start or end sides by specifying “start” or “end” as the “type” attribute of a `<child>` element, or setting the title widget by specifying “title” value.

By default the `GtkHeaderBar` uses a `GtkLabel` displaying the title of the window it is contained in as the title widget, equivalent to the following UI definition:

    <object class="GtkHeaderBar">
      <property name="title-widget">
        <object class="GtkLabel">
          <property name="label" translatable="yes">Label</property>
          <property name="single-line-mode">True</property>
          <property name="ellipsize">end</property>
          <property name="width-chars">5</property>
          <style>
            <class name="title"/>
          </style>
        </object>
      </property>
    </object>

# CSS nodes

    headerbar
    ╰── windowhandle
        ╰── box
            ├── box.start
            │   ├── windowcontrols.start
            │   ╰── [other children]
            ├── [Title Widget]
            ╰── box.end
                ├── [other children]
                ╰── windowcontrols.end

A `GtkHeaderBar`‘s CSS node is called `headerbar`. It contains a `windowhandle` subnode, which contains a `box` subnode, which contains two `box` subnodes at the start and end of the header bar, as well as a center node that represents the title.

Each of the boxes contains a `windowcontrols` subnode, see `GtkWindowControls` for details, as well as other children.

# Accessibility

`GtkHeaderBar` uses the `GTK_ACCESSIBLE_ROLE_GROUP` role.

#### Ancestors

- GtkWidget
- GInitiallyUnowned
- GObject

#### Implements

- GtkAccessible
- GtkBuildable
- GtkConstraintTarget

#### Constructors

###### gtk_header_bar_new

Creates a new `GtkHeaderBar` widget.

#### Instance methods

###### gtk_header_bar_get_decoration_layout

Gets the decoration layout of the `GtkHeaderBar`.

###### gtk_header_bar_get_show_title_buttons

Returns whether this header bar shows the standard window title buttons.

###### gtk_header_bar_get_title_widget

Retrieves the title widget of the header.

###### gtk_header_bar_pack_end

Adds `child` to `bar`, packed with reference to the end of the `bar`.

###### gtk_header_bar_pack_start

Adds `child` to `bar`, packed with reference to the start of the `bar`.

###### gtk_header_bar_remove

Removes a child from the `GtkHeaderBar`.

###### gtk_header_bar_set_decoration_layout

Sets the decoration layout for this header bar.

###### gtk_header_bar_set_show_title_buttons

Sets whether this header bar shows the standard window title buttons.

###### gtk_header_bar_set_title_widget

Sets the title for the `GtkHeaderBar`.

##### Methods inherited from GtkWidget (162)

Please see GtkWidget for a full list of methods.

##### Methods inherited from GObject (43)

Please see GObject for a full list of methods.

##### Methods inherited from GtkAccessible (19)

###### gtk_accessible_announce

Requests the user’s screen reader to announce the given message.

since: 4.14

###### gtk_accessible_get_accessible_parent

Retrieves the accessible parent for an accessible object.

since: 4.10

###### gtk_accessible_get_accessible_role

Retrieves the accessible role of an accessible object.

###### gtk_accessible_get_at_context

Retrieves the accessible implementation for the given `GtkAccessible`.

since: 4.10

###### gtk_accessible_get_bounds

Queries the coordinates and dimensions of this accessible.

since: 4.10

###### gtk_accessible_get_first_accessible_child

Retrieves the first accessible child of an accessible object.

since: 4.10

###### gtk_accessible_get_next_accessible_sibling

Retrieves the next accessible sibling of an accessible object.

since: 4.10

###### gtk_accessible_get_platform_state

Query a platform state, such as focus.

since: 4.10

###### gtk_accessible_reset_property

Resets the accessible `property` to its default value.

###### gtk_accessible_reset_relation

Resets the accessible `relation` to its default value.

###### gtk_accessible_reset_state

Resets the accessible `state` to its default value.

###### gtk_accessible_set_accessible_parent

Sets the parent and sibling of an accessible object.

since: 4.10

###### gtk_accessible_update_next_accessible_sibling

Updates the next accessible sibling of `self`.

since: 4.10

###### gtk_accessible_update_property

Updates a list of accessible properties.

###### gtk_accessible_update_property_value

Updates an array of accessible properties.

###### gtk_accessible_update_relation

Updates a list of accessible relations.

###### gtk_accessible_update_relation_value

Updates an array of accessible relations.

###### gtk_accessible_update_state

Updates a list of accessible states. See the `GtkAccessibleState` documentation for the value types of accessible states.

###### gtk_accessible_update_state_value

Updates an array of accessible states.

##### Methods inherited from GtkBuildable (1)

###### gtk_buildable_get_buildable_id

Gets the ID of the `buildable` object.

#### Properties

###### Gtk.HeaderBar:decoration-layout

The decoration layout for buttons.

###### Gtk.HeaderBar:show-title-buttons

Whether to show title buttons like close, minimize, maximize.

###### Gtk.HeaderBar:title-widget

No description available.

##### Properties inherited from GtkWidget (34)

###### Gtk.Widget:can-focus

Whether the widget or any of its descendents can accept the input focus.

###### Gtk.Widget:can-target

Whether the widget can receive pointer events.

###### Gtk.Widget:css-classes

A list of css classes applied to this widget.

###### Gtk.Widget:css-name

The name of this widget in the CSS tree.

###### Gtk.Widget:cursor

The cursor used by `widget`.

###### Gtk.Widget:focus-on-click

Whether the widget should grab focus when it is clicked with the mouse.

###### Gtk.Widget:focusable

Whether this widget itself will accept the input focus.

###### Gtk.Widget:halign

How to distribute horizontal space if widget gets extra space.

###### Gtk.Widget:has-default

Whether the widget is the default widget.

###### Gtk.Widget:has-focus

Whether the widget has the input focus.

###### Gtk.Widget:has-tooltip

Enables or disables the emission of the ::query-tooltip signal on `widget`.

###### Gtk.Widget:height-request

Override for height request of the widget.

###### Gtk.Widget:hexpand

Whether to expand horizontally.

###### Gtk.Widget:hexpand-set

Whether to use the `hexpand` property.

###### Gtk.Widget:layout-manager

The `GtkLayoutManager` instance to use to compute the preferred size of the widget, and allocate its children.

###### Gtk.Widget:margin-bottom

Margin on bottom side of widget.

###### Gtk.Widget:margin-end

Margin on end of widget, horizontally.

###### Gtk.Widget:margin-start

Margin on start of widget, horizontally.

###### Gtk.Widget:margin-top

Margin on top side of widget.

###### Gtk.Widget:name

The name of the widget.

###### Gtk.Widget:opacity

The requested opacity of the widget.

###### Gtk.Widget:overflow

How content outside the widget’s content area is treated.

###### Gtk.Widget:parent

The parent widget of this widget.

###### Gtk.Widget:receives-default

Whether the widget will receive the default action when it is focused.

###### Gtk.Widget:root

The `GtkRoot` widget of the widget tree containing this widget.

###### Gtk.Widget:scale-factor

The scale factor of the widget.

###### Gtk.Widget:sensitive

Whether the widget responds to input.

###### Gtk.Widget:tooltip-markup

Sets the text of tooltip to be the given string, which is marked up with Pango markup.

###### Gtk.Widget:tooltip-text

Sets the text of tooltip to be the given string.

###### Gtk.Widget:valign

How to distribute vertical space if widget gets extra space.

###### Gtk.Widget:vexpand

Whether to expand vertically.

###### Gtk.Widget:vexpand-set

Whether to use the `vexpand` property.

###### Gtk.Widget:visible

Whether the widget is visible.

###### Gtk.Widget:width-request

Override for width request of the widget.

##### Properties inherited from GtkAccessible (1)

###### GtkAccessible:accessible-role

The accessible role of the given `GtkAccessible` implementation.

#### Signals

##### Signals inherited from GtkWidget (13)

###### GtkWidget::destroy

Signals that all holders of a reference to the widget should release the reference that they hold.

###### GtkWidget::direction-changed

Emitted when the text direction of a widget changes.

###### GtkWidget::hide

Emitted when `widget` is hidden.

###### GtkWidget::keynav-failed

Emitted if keyboard navigation fails.

###### GtkWidget::map

Emitted when `widget` is going to be mapped.

###### GtkWidget::mnemonic-activate

Emitted when a widget is activated via a mnemonic.

###### GtkWidget::move-focus

Emitted when the focus is moved.

###### GtkWidget::query-tooltip

Emitted when the widget’s tooltip is about to be shown.

###### GtkWidget::realize

Emitted when `widget` is associated with a `GdkSurface`.

###### GtkWidget::show

Emitted when `widget` is shown.

###### GtkWidget::state-flags-changed

Emitted when the widget state changes.

###### GtkWidget::unmap

Emitted when `widget` is going to be unmapped.

###### GtkWidget::unrealize

Emitted when the `GdkSurface` associated with `widget` is destroyed.

##### Signals inherited from GObject (1)

###### GObject::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.