def update_line(self):
overlapping_arcs = [
arc for arc in self.rel_item.arc_items
if arc.obj_item == self.obj_item
]
count = len(overlapping_arcs)
path = QPainterPath(self.rel_item.pos())
if count == 1:
path.lineTo(self.obj_item.pos())
else:
rank = overlapping_arcs.index(self)
line = QLineF(self.rel_item.pos(), self.obj_item.pos())
line.setP1(line.center())
line = line.normalVector()
line.setLength(self._width * count)
line.setP1(2 * line.p1() - line.p2())
t = rank / (count - 1)
ctrl_point = line.pointAt(t)
path.quadTo(ctrl_point, self.obj_item.pos())
self.setPath(path)
def calculatePerpendicularPoint(self, startingPoint, distance, line):
labelHelperLine = QLineF()
labelHelperLine.setP1(startingPoint)
labelHelperLine.setAngle(line.angle() + 90)
labelHelperLine.setLength(distance)
return labelHelperLine.p2()
