make blur widget to blur everything under it

AmrCoder

Hi,
I am trying to make a widget blur effect so it blurs everything under it on the desktop, what I tried is to make opacity 0.4 something less than 1 to show what is under it from other desktop widgets, and then try to use the QGraphicsBlurEffect and add this class to my widget using this code in my widget constructor.

setWindowFlags(Qt::WindowTitleHint | Qt::WindowCloseButtonHint);
QGraphicsBlurEffect *blur = new QGraphicsBlurEffect;
blur->setBlurRadius(250);
blur->setBlurHints(QGraphicsBlurEffect::QualityHint);
setGraphicsEffect(blur);

but the output not as I wanted, and also it seems I am not on the right direction, so any suggestion, please?

this what it looks like

alt text

but what I try to just blur the text under the widget or anything on my desktop.

Thanks.