Transcript PowerPoint 프레젠테이션

;MAKING FRAME WINDOW, CANVAS, and DC
(define frame (new frame% [label "Paint Language Example"]
[width 300]
[height 334]))
(define canvas (new canvas% [parent frame]
[paint-callback
(lambda (canvas dc)
(send dc set-pen red-pen)
(send dc set-brush no-brush)
(on-paint))]))
(define red-pen (make-object pen% "RED" 2 'solid))
(define no-brush (make-object brush% "BLACK" 'transparent))
(define dc (send canvas get-dc))
;DRAWING A LINE ON THE CANVAS USING DC
(send dc draw-line (xcor b2) (ycor b2) (xcor e2) (ycor e2))))
;DEFINE CALLBACK PAINT PROCEDURE
(define (on-paint) (george-mix rect))
;MAKING THE FRAME VISIBLE
(send frame show #t)