+(gtk:within-main-loop
+ (make-instance 'gtk:window
+; :type :toplevel
+ :title "Test"
+ :border-width 5
+ :visible t :show-children t
+ :child (make-instance 'gtk:button
+ :label "Hello World!"
+ :signal (list 'clicked
+ #'(lambda ()
+ (write-line "Hello World!"))))
+ :signal (list 'delete-event
+ #'(lambda (event)
+ (declare (ignore event))
+ (write-line "Destroying window")
+ nil ; Returning NIL generates a destroy event
+ ))))