GtkRadioAction an action of which only one in a group can be active 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. The GtkRadioAction struct contains only private members and should not be accessed directly. @action: @Returns: @action: @group: @action: @Returns: @radioaction: the object which received the signal. @arg1: