A vertical box for organizing child widgets.
The GtkVBox container is designed to organize child widgets along
a single column, allocating the same width to all children. This overrides any child
requisition size, and child widgets that take up less than the allocated width are vertically
centered by default.
Adding child widgets to a GtkVBox is done by packing methods that are
either inherited from the GtkBox class, such as
pack_start() , or by the less flexible
add() , common to all container widgets.
GtkHBox, GtkTable, GtkButtonBox,
Creates a container for arranging widgets vertically.
([bool homogeneous = false
[, int spacing = 0