Update only works once; MainLoop effectively call update again whenever it is required.

Of course, if you sleep for 10 seconds in a callback routine, control will not return to MainLoop for 10 seconds and no updates will be handled during that time.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re^3: Perl/Tk window contents disappear when obscured then revealed by BrowserUk
in thread Perl/Tk window contents disappear when obscured then revealed by Another Ed

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