multiplot.py 文件源码

def paint(self, painter, option, parent):
        if self.line.length() == 0.:
            return
        painter.setPen(self.arrow_pen)
        painter.setRenderHint(QtGui.QPainter.Antialiasing)
        painter.setCompositionMode(QtGui.QPainter.CompositionMode_SourceOver)

        arrow_length = self.line.length() * .3
        d = self.line.angle()
        head_p1 = self.p2 - QtCore.QPointF(
            num.sin(d*d2r + num.pi/3) * arrow_length,
            num.cos(d*d2r + num.pi/3) * arrow_length)

        head_p2 = self.p2 - QtCore.QPointF(
            num.sin(d*d2r + num.pi - num.pi/3) * arrow_length,
            num.cos(d*d2r + num.pi - num.pi/3) * arrow_length)

        painter.drawLine(self.line)
        painter.drawPolyline([head_p1, self.p2, head_p2])