s c h e m e w i k i . o r g

(use-module "jlib/Swing.scm")
(import "java.awt.event.MouseEvent")

(define c (canvas 400 400))
(define w (window "test" c))
(.pack w)
(.show w)

(.addMouseMotionListener c 
 (Listener. 
   (lambda(e) 
     (if (equal? (.getID e) 
                 MouseEvent.MOUSE_DRAGGED$) 
       (let (
             (x (.getX e))
             (y (.getY e))
             (g (.bufferg$ c))
            )
         (.fillOval g (- x 2) (- y 2) 4 4)
         (.repaint c)
        )))))