#!/usr/local/bin/sbcl --script

(define-alien-routine gtk_application_window_new (* t) (app (* t)))

(define-alien-routine gtk_application_new (* t) (txt c-string) (flags int))

(define-alien-routine g_application_run int
  (app (* t)) (argc int) (argv (* t)))

(define-alien-routine g_signal_connect_data int ;
  (instance (* t)) (sig c-string)
  (cback (function void (* t) int))
  (data (* t)) (unusedptr (* t)) (unusedint int))

(define-alien-routine gtk_window_set_title void (win (* t)) (ttl (c-string)))

(define-alien-routine gtk_window_set_default_size void
  (win (* t)) (x int) (y int))

(define-alien-routine gtk_widget_show_all void (win (* t)))
​

(sb-alien::define-alien-callback mycallback void ((app (* t)) (u int))
                                 (with-alien ((win (* t)))
                                   (setf win (gtk_application_window_new app))
                                   (gtk_window_set_title win "This")
                                   (gtk_window_set_default_size win 100 100)
                                   (gtk_widget_show_all win)))

(load-shared-object "/usr/lib/x86_64-linux-gnu/libgtk-3.so.0")

(with-alien ((app (* t)) (status int))
  (setf app (gtk_application_new nil 0))
  (g_signal_connect_data app "activate" mycallback nil nil 0)
  (g_application_run app 0 nil))

​