Qt Balloon Window from QFrame

I would like to create my own Balloon window for tips in Qt. I'm starting by creating a window with round corners.

I'm using a class inherited from QFrame. The class's constructor contains:

this->setWindowFlags(Qt::Window | Qt::FramelessWindowHint);
Pal.setColor(QPalette::Background, Qt::yellow);
this->setAutoFillBackground(true);
this->setPalette(Pal);
this->setStyleSheet("QFrame {border-style: solid; border-width: 10px;"
                    "border-radius: 100px;"
                    "min-width: 10em; background-clip: padding; background-origin: content;}");

But this is not creating round corners when showing using the show() member function. I'm getting this:

How can I get rid of those rectangular edges and have them transpararent colored?

If you require any additional information, please ask.

If my guess is correct you are looking for something like setMask !

Basically what you need to do is draw a rectangle with your desired radius and then convert it to QRegion to use it with setMask. See below one way:

QPainterPath path;
path.addRoundedRect(rect(), 100, 100);
QRegion region = QRegion(path.toFillPolygon().toPolygon());
setMask(region);

And that will be the result:

Hope that helps!