Print preview page orientation in Pyside6

Question

I am messing around with the print preview of a QGraphicsView instance in Pyside6. I tried many things, but can't get it right.

def onPreview(self):
    printer = QtPrintSupport.QPrinter(QtPrintSupport.QPrinter.HighResolution)
    layout = QtGui.QPageLayout()
    layout.setOrientation(QtGui.QPageLayout.Landscape)
    layout.setPageSize(QtGui.QPageSize.A3)
    printer.setPageLayout(layout)

    preview = QtPrintSupport.QPrintPreviewDialog(printer, self.parent)
    preview.paintRequested.connect(self.handlePaintRequest)
    preview.exec_()

# handle paint request
def handlePaintRequest(self, printer):
    # render QGraphicsView
    self.parent.view.render(QtGui.QPainter(printer))

The snippet works without throwing an error, but the page orientation in the preview is always portrait. Also the page size doesn't work when printing. For sure I handle this in the wrong manner.