def METHOD_NAME(self, ev):
    ev.accept()
    if ev.isStart():
        self.startPos = self.pos()
    elif ev.isFinish():
        self.setPos(*list(map(int, self.pos())))
    else:
        self.setPos(self.startPos + ev.pos() - ev.buttonDownPos())
    self.CrossHairMoved.emit()