Transparent widgets

[incapacitant]

Does a transparent widget's class exist for pushbutton ?
Where can I find sample code doing transparent pushbotton ?
I this cannot grasp all of this theory and I like examples as distributed by the open source edition of QT4.1.1. They explain much of the theory.
Anyway they should even be part of QT. It could be also handled by the QT about the background resize means.