Could someone please explain why there is an invisible canvas in this
example?
Env:
Linux 2.6.31-23-generic Ubuntu i686 GNU/Linux
racket 5.1.0.4
#lang racket
(require racket/gui)
(define bitmap-canvas%
(class canvas%
(init-field [bitmap #f])
(inherit get-dc)
(define/override (on-paint)
(send (get-dc) draw-bitmap bitmap 0 0))
(super-new)))
(define bitmap (read-bitmap "data/image_0.jpg"))
(define f (new frame% [label "foo"] [width 100] [height 100]))
(define p (new panel% [parent f]))
(define p2 (new vertical-panel% [parent f]))
;; why is this invisible?
(define invisible-canvas (new bitmap-canvas%
[parent p]
[bitmap bitmap]))
(define visible-canvas (new bitmap-canvas%
[parent p2]
[bitmap bitmap]))
(send f show #t)
--
Eduardo Bellani
omnia mutantur, nihil interit.
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