def paintEvent(self, a0: QPaintEvent) -> None:
super().paintEvent(a0)
painter = QPainter(self)
painter.save()
painter.setRenderHint(QPainter.Antialiasing)
rect = QRectF(self.margin, self.margin,
self.width() - self.margin * 2,
self.height() - 2 * self.margin)
painter.setBrush(Qt.white)
painter.setPen(Qt.white)
painter.drawRect(rect)
painter.restore()
painter.save()
painter.setRenderHint(QPainter.Antialiasing)
pen = QPen()
pen.setWidth(3)
painter.setPen(pen)
path = QPainterPath()
height, width = rect.height() + self.margin, rect.width() + self.margin
path.moveTo(self.margin, height)
path.cubicTo(height * 0.5, width * 0.9, height * 0.9, width * 0.5,
height, self.margin)
painter.drawPath(path)
painter.restore()
def cubic_path(geom):
source, sink = geom.source, geom.sink
c1, c2 = geom.points_c1_c2()
# cubic spline
cubic = QPainterPath(source)
cubic.cubicTo(c1, c2, sink)
return cubic
