[plt-scheme] MrEd: creating an inactive child

Robert Bruce Findler writes:
 > (define evtspc (make-eventspace))
 > 
 > (define frame 
 >   (parameterize ((current-eventspace evtspc))
 >     (make-object frame% "Test")))
 > 
 > (define m1 (make-object message% "1" frame))
 > (define m2 (make-object message% "2" frame))
 > (define m3 (make-object message% "3" frame))
 > (send frame show #t)
 > 
 > (define m4 #f)
 > (define (test)
 >   (parameterize ([current-eventspace evtspc])
 >     (queue-callback
 >      (lambda ()
 >        (send frame begin-container-sequence)
 >        (set! m4 (make-object message% "4" frame))
 >        (sleep 2)
 >        (send frame delete-child m4)
 >        (send frame change-children
 >              (lambda (children) (list m1 m2 m4)))
 >        (send frame end-container-sequence)))))

In X, this program ends up blanking out the "1" for 2 seconds every
time test is called.  But not in Windows, hmm....

--dougo at ccs.neu.edu