public class HeaderBar : Widget, Accessible, Buildable, ConstraintTarget
GtkHeaderBar is similar to a horizontal Box.
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 Window (see set_titlebar), as it gives features typical of titlebars while allowing the addition of child widgets.
The GtkHeaderBar implementation of the Buildable 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 Label displaying the title of the window it is contained in as the title widget, equivalent to the following UI definition:
<property name="label" translatable="yes">Label</property>
ins a windowhandle subnode, which contains a box subnode, which contains two box subnodes at the start and end of the headerbar, as well as a center node that represents the title.
│ ├── windowcontrols.start
│ ╰── [other children]
├── [Title Widget]
├── [other children]
Each of the boxes contains a windowcontrols subnode, see WindowControls for details, as well as other children.