The GtkBox describes an instance of GtkBox and contains the following fields. (These fields should be considered read-only. They should never be set by an application.) GList * children; a list of children belonging the GtkBox. The data is a list of structures of type GtkBoxChild. gint16 spacing; the number of pixels to put between children of the GtkBox, zero by default. Use gtk_box_set_spacing() to set this field. guint homogeneous; a flag that if TRUE forces all children to get equal space in the GtkBox; FALSE by default. Use gtk_box_set_homogeneous() to set this field.