feature request: the state of a viewport (open, hidden or closed)

Would it be possible to add a procedure to library graphics/graphics showing the state of a viewport (open, hidden or closed)? When closing a viewport in the title bar (upper right corner) while the program is waiting for a mouse-click or a key-press, the program keeps waiting without warning and doing nothing. When a viewport has been closed no such event can be posted. Just issuing a warning when closing a viewport would do as well. The following program not halt after the user has closed the viewport and confirmed so in the message box:

(require graphics/graphics  racket/gui)

(open-graphics)

(define vp (open-viewport "close me" 100 100))

(let loop ()
  (unless
    (eq? (message-box "Question" "Did you close the viewport?" #f '(yes-no)) 'yes)
    (loop)))

(get-mouse-click vp)

It was the first time using graphics in Racket. I have looked into "https://docs.racket-lang.org/gui/index.html". I do like the callback facilities, but find it quite complicated. I want full control over the locations of buttons. My program is at "https://github.com/joskoot/hanoi".

Thanks.

Start by reading the graphics/graphics library and the Racket GUI documentation, then reproduce the example with get-mouse-click and a viewport closed from its title bar. Trace how viewport closure is represented while input is pending. Done means a closed viewport can be detected or the waiting operation clearly warns or exits instead of hanging.