swingbuilder - linking actions to events

Hi all,

  How do I attach a Action to one of the many events swing has besides the obvious ones that are referred to by "action" in swingbuilder?

  I figured out (by guessing) one way below but my syntax "windowClosing: exit.closure" seems a little odd.  I wanted to make sure there isn't another syntax.  



                def exit= builder.action(
                        name:'Exit', closure: {System.exit(0)}
                        )
                       
                def frame=
                builder.frame(
                                title:'Catalog',
                                windowClosing: exit.closure,
                            size: [screenWidth -50, screenHeight -50],
                                location: [19,4],
                                show: true,
                                )
                {
                    menuBar() {
                        menu(text: "File", mnemonic: 'F') {
                            menuItem(text: "Exit", mnemonic: 'X', action: exit )
                        }
                    }
                }


Thanks!
Glen