Warning: HBox is deprecated since 3.2. Use Box.
HBox is a container that organizes child widgets into a single row.
Use the Box packing interface to determine the arrangement, spacing, width, and alignment of HBox children.
All children are allocated the same height.
GtkHBox has been deprecated. You can use Box instead, which is a very quick and easy change. If you have derived your own classes from GtkHBox, you can simply change the inheritance to derive directly from Box. No further changes are needed, since the default value of the orientation property is gtk_orientation_horizontal.
If you have a grid-like layout composed of nested boxes, and you don’t need first-child or last-child styling, the recommendation is to switch to Grid. For more information about migrating to Grid, see Migrating from other containers to GtkGrid.