'Enable or disable default antialiasing.
Note that this will only affect items that do not specify their own antialiasing options.'

def setAntialiasing(self, aa):

    if aa:
        self.setRenderHints((self.renderHints() | QtGui.QPainter.Antialiasing))
    else:
        self.setRenderHints((self.renderHints() & (~ QtGui.QPainter.Antialiasing)))
