Double dialog problem

double-dlg.rkt

#lang racket
(require racket/gui)

;; Sequence of events to illustrate the problem:
;;
;; 1. Open Dialog 1
;;
;; 2. Open Dialog 2
;;
;; 3. Close Dialog 2 -- notice that dialog 1 now has focus
;;
;; 4. Close Dialog 1 -- notice that the main window is now at the bottom of
;; the window stack and does not have focus
;;
;; This sequence of events works correctly:
;;
;; 1. Open Dialog 1
;;
;; 2. Close Dialog 1 -- notice that the main window has focus

(define toplevel (new frame%
                      [label "Hello World"]
                      [width 800]
                      [height 600]))
(define dialog-1 (new dialog%
                      [parent toplevel]
                      [label "Dialog 1"]
                      [width 400]
                      [height 300]))
(define dialog-2 (new dialog%
                      [parent dialog-1]
                      [label "Dialog 2"]
                      [width 200]
                      [height 150]))

(define (on-open-dialog1 button event)
  (send dialog-1 show #t))

(define (on-close-dialog1 button event)
  (send dialog-1 show #f))

(define (on-open-dialog2 button event)
  (send dialog-2 show #t))

(define (on-close-dialog2 button event)
  (send dialog-2 show #f))

(define b1 (new button%
                [parent toplevel]
                [label "Open Dialog 1..."]
                [callback on-open-dialog1]))
(define b2 (new button%
                [parent dialog-1]
                [label "Open Dialog 2..."]
                [callback on-open-dialog2]))
(define b3 (new button%
                [parent dialog-1]
                [label "Close Dialog 1"]
                [callback on-close-dialog1]))
(define b4 (new button%
                [parent dialog-2]
                [label "Close Dialog 2"]
                [callback on-close-dialog2]))

(send toplevel show #t)