Focus Frame only visible on MacOS X

[Markus]

Dear all,

I have a simple custom class derived from QWidget. On Mac OS X it gets a blue focus frame drawn as soon as it get the focus. This frame does no show on Windows. I use:

setFocusPolicy(Qt::StrongFocus);
setAttribute( Qt::WA_MacShowFocusRect);

setFocusPolicy(Qt::StrongFocus);
setAttribute( Qt::WA_MacShowFocusRect);

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Any suggestion on how to get that or a similar focus frame shown on windows?

Thanks
Markus