Using an alpha transparent mask on a QWidget?

Question

Is it possible to assign an alpha-transparent mask to a QWidget? I know how to set a mask using setMask but it seems it only supports black&white masks. Is it p

Answer 1

I think your best route is in QPainter's composition modes.

For example:

QPixmap PixmapToBeMasked(Size);
PixmapToBeMasked.fill(QColor(255, 255, 255, 120));

QPixmap Mask = DoSomethingToGetAMask();

QPainter Painter(&PixmapToBeMasked);
Painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
Painter.drawPixmap(0, 0, Mask.width(), Mask.height(), Mask);

That will handle drawing your widget nicely. If you still need to mask mouse events you might need to do some extra work though.