[racket] Second display monitor issue

From: Kieron Hardy (kieron.hardy at gmail.com)
Date: Thu May 24 20:08:07 EDT 2012

Hi all,

On one of my client's laptops (Windows 7), the attached code detects the
second display monitor (get-display-count returns 2), but prints exactly
the same values for the location and size of the two displays. i.e. The
top-left coordinate and size values returned ((0,0)  and 1024 x 768)  are
the same for both monitors. This effectively maps the second monitor
underneath(?) the main monitor, making it inaccessible to Racket.

In this particular case the second monitor is a TV connected through the
laptop's s-video port. Windows itself sees the two displays and is
configured to extend the desktop over both of them and 'Identify monitors'
works as expected. At least one other program can see and use the TV
without problems.

Racket has no problems seeing and using a second display monitor on this
same laptop when that second monitor is a video converter box connected
through the laptop's VGA port. Also Racket has no problems seeing and using
a TV as a second display monitor when connected to my (Vista) laptop's HDMI

What can I do to troubleshoot this problem? I have searched the source for
both 'get-display-left-top-inset' and 'monitor' and only find something
relevant in .html and .js document files. Where in the source should I be

Thanks in advance for any help.




#lang racket/gui

(printf "display-count:~a\n" (get-display-count))
(printf "display-depth:~a\n" (get-display-depth))

(for ([m (in-range 0 (get-display-count))])
  (let-values ([(mx my) (get-display-left-top-inset #f #:monitor m)]
               [(mxwob mywob) (get-display-left-top-inset #t #:monitor m)]
               [(mw mh) (get-display-size #f #:monitor m)]
               [(mwfs mhfs) (get-display-size #t #:monitor m)]
    (printf "monitor:~a (~a ~a) (~a ~a) (~a ~a) (~a ~a)~n" m mx my mxwob
mywob mw mh mwfs mhfs)
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