GtkHBox A horizontal container box GtkHBox is a container that organizes child widgets into a single row. Use the #GtkBox packing interface to determine the arrangement, spacing, width, and alignment of GtkHBox children. All children are allocated the same height. #GtkVBox a sister class that organizes widgets into a column. Creates a new GtkHBox. @homogeneous: %TRUE if all children are to be given equal space allotments. @spacing: the number of pixels to place by default between children. @Returns: a new GtkHBox.