;;; -*-Scheme-*-

(require 'xlib)

(define (pic)
(let*
  ( (display (open-display))
    (black   (black-pixel display))
    (white   (white-pixel display))
    (window  (create-window 'parent (display-root-window display)
                            'width 400 'height 400
                            'background-pixel white
                            'event-mask '(exposure button-press))) ;*events
    (g-con   (create-gcontext 'window window
                              'background white
                              'foreground black))
    (draw    (lambda () (draw-line window g-con 10 10 100 20)))
    (button  (lambda () (draw-line window g-con 100 20 200 200)))
  )

  (map-window window)
  (unwind-protect
    (handle-events display #t #f
       (expose       (lambda args (draw) #f))
       (button-press (lambda args (button) #f))
    )
    (close-display display))))

(pic)
