GtkRadioAction: GtkRadioAction
Description
An action of which only one in a group can be activeHierarchy
\link{GObject}
   +----\link{GtkAction}
         +----\link{GtkToggleAction}
               +----GtkRadioActionDetailed Description
A GtkRadioAction is similar to GtkRadioMenuItem. A number of radio
actions can be linked together so that only one may be active at any 
one time.References
http://developer.gnome.org/doc/API/2.0/gtk/GtkRadioAction.html