GtkSizeGroupAn object for forcing a group of widgets to request the same size.
Hierarquia de Objetos
GtkSizeGroup provides a mechanism for grouping a number of widgets together so they all request the same amount of space. This is typically useful when you want a column of widgets to have the same size, but you can't use a GtkTable widget.
In detail, the size requested for each widget in a GtkSizeGroup is the maximum of the sizes that would have been requested for each widget in the size group if they were not in the size group. The mode of the size group (see set_mode() ) determines whether this applies to the horizontal size, the vertical size, or both sizes.
Note that size groups only affect the amount of space requested, not the size that the widgets finally receive. If you want the widgets in a GtkSizeGroup to actually be the same size, you need to pack them in such a way that they get the size they request and not more. For example, if you are packing your widgets into a table, you would not include the Gtk::FILL flag.