Data commit

Task/Colour-bars-Display/Racket/colour-bars-display.rkt

@@ -0,0 +1,24 @@
+#lang racket/gui
+
+(define-values [W H] (get-display-size #t))
+
+(define colors
+  '("Black" "Red" "Green" "Blue" "Magenta" "Cyan" "Yellow" "White"))
+
+(define (paint-pinstripe canvas dc)
+  (send dc set-pen "black" 0 'transparent)
+  (for ([x (in-range 0 W (/ W (length colors)))] [c colors])
+    (send* dc (set-brush c 'solid) (draw-rectangle x 0 W H))))
+
+(define full-frame%
+  (class frame%
+    (define/override (on-subwindow-char r e)
+      (when (eq? 'escape (send e get-key-code))
+        (send this show #f)))
+    (super-new
+     [label "Color bars"] [width W] [height H]
+     [style '(no-caption no-resize-border hide-menu-bar no-system-menu)])
+    (define c (new canvas% [parent this] [paint-callback paint-pinstripe]))
+    (send this show #t)))
+
+(void (new full-frame%))