Python QPainterPath.quadTo方法代码示例

# 需要导入模块: from AnyQt.QtGui import QPainterPath [as 别名]
# 或者: from AnyQt.QtGui.QPainterPath import quadTo [as 别名]
    def paintArc(self, painter, option, widget):
        assert self.source is self.dest
        node = self.source
        def best_angle():
            """...is the one furthest away from all other angles"""
            angles = [QLineF(node.pos(), other.pos()).angle()
                      for other in chain((edge.source for edge in node.edges
                                          if edge.dest == node and edge.source != node),
                                         (edge.dest for edge in node.edges
                                          if edge.dest != node and edge.source == node))]
            angles.sort()
            if not angles:  # If this self-constraint is the only edge
                return 225
            deltas = np.array(angles[1:] + [360 + angles[0]]) - angles
            return (angles[deltas.argmax()] + deltas.max()/2) % 360

        angle = best_angle()
        inf = QPointF(-1e20, -1e20)  # Doesn't work with real -np.inf!
        line0 = QLineF(node.pos(), inf)
        line1 = QLineF(node.pos(), inf)
        line2 = QLineF(node.pos(), inf)
        line0.setAngle(angle)
        line1.setAngle(angle - 13)
        line2.setAngle(angle + 13)

        p0 = shape_line_intersection(node.shape(), node.pos(), line0)
        p1 = shape_line_intersection(node.shape(), node.pos(), line1)
        p2 = shape_line_intersection(node.shape(), node.pos(), line2)
        path = QPainterPath()
        path.moveTo(p1)
        line = QLineF(node.pos(), p0)
        line.setLength(3*line.length())
        pt = line.p2()
        path.quadTo(pt, p2)

        line = QLineF(node.pos(), pt)
        self.setLine(line)  # This invalidates DeviceCoordinateCache
        painter.drawPath(path)

        # Draw arrow head
        line = QLineF(pt, p2)
        self.arrowHead.clear()
        for point in self._arrowhead_points(line):
            self.arrowHead.append(point)
        painter.setBrush(self.pen().color())
        painter.drawPolygon(self.arrowHead)

        # Update label position
        self.label.setPos(path.pointAtPercent(.5))
        if 90 < angle < 270:  # Right-align the label
            pos = self.label.pos()
            x, y = pos.x(), pos.y()
            self.label.setPos(x - self.label.boundingRect().width(), y)
        self.squares.placeBelow(self.label)

# 需要导入模块: from AnyQt.QtGui import QPainterPath [as 别名]
# 或者: from AnyQt.QtGui.QPainterPath import quadTo [as 别名]
def arrow_path_concave(line, width):
    """
    Return a :class:`QPainterPath` of a pretty looking arrow.
    """
    path = QPainterPath()
    p1, p2 = line.p1(), line.p2()

    if p1 == p2:
        return path

    baseline = QLineF(line)
    # Require some minimum length.
    baseline.setLength(max(line.length() - width * 3, width * 3))

    start, end = baseline.p1(), baseline.p2()
    mid = (start + end) / 2.0
    normal = QLineF.fromPolar(1.0, baseline.angle() + 90).p2()

    path.moveTo(start)
    path.lineTo(start + (normal * width / 4.0))

    path.quadTo(mid + (normal * width / 4.0),
                end + (normal * width / 1.5))

    path.lineTo(end - (normal * width / 1.5))
    path.quadTo(mid - (normal * width / 4.0),
                start - (normal * width / 4.0))
    path.closeSubpath()

    arrow_head_len = width * 4
    arrow_head_angle = 50
    line_angle = line.angle() - 180

    angle_1 = line_angle - arrow_head_angle / 2.0
    angle_2 = line_angle + arrow_head_angle / 2.0

    points = [p2,
              p2 + QLineF.fromPolar(arrow_head_len, angle_1).p2(),
              baseline.p2(),
              p2 + QLineF.fromPolar(arrow_head_len, angle_2).p2(),
              p2]

    poly = QPolygonF(points)
    path_head = QPainterPath()
    path_head.addPolygon(poly)
    path = path.united(path_head)
    return path