Python PyQt5.QtCore.Qt 模块，RoundJoin() 实例源码

def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        painter.scale(self.width() / 100.0, self.height() / 100.0)
        painter.translate(50.0, 50.0)
        painter.rotate(-self.rotationAngle)
        painter.translate(-50.0, -50.0)

        painter.setPen(
                QPen(self.penColor, self.penWidth, Qt.SolidLine, Qt.RoundCap,
                        Qt.RoundJoin))
        gradient = QLinearGradient(0, 0, 0, 100)
        gradient.setColorAt(0.0, self.fillColor1)
        gradient.setColorAt(1.0, self.fillColor2)
        painter.setBrush(QBrush(gradient))
        painter.drawPath(self.path)

def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        painter.scale(self.width() / 100.0, self.height() / 100.0)
        painter.translate(50.0, 50.0)
        painter.rotate(-self.rotationAngle)
        painter.translate(-50.0, -50.0)

        painter.setPen(
                QPen(self.penColor, self.penWidth, Qt.SolidLine, Qt.RoundCap,
                        Qt.RoundJoin))
        gradient = QLinearGradient(0, 0, 0, 100)
        gradient.setColorAt(0.0, self.fillColor1)
        gradient.setColorAt(1.0, self.fillColor2)
        painter.setBrush(QBrush(gradient))
        painter.drawPath(self.path)

def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        painter.scale(self.width() / 100.0, self.height() / 100.0)
        painter.translate(50.0, 50.0)
        painter.rotate(-self.rotationAngle)
        painter.translate(-50.0, -50.0)

        painter.setPen(
                QPen(self.penColor, self.penWidth, Qt.SolidLine, Qt.RoundCap,
                        Qt.RoundJoin))
        gradient = QLinearGradient(0, 0, 0, 100)
        gradient.setColorAt(0.0, self.fillColor1)
        gradient.setColorAt(1.0, self.fillColor2)
        painter.setBrush(QBrush(gradient))
        painter.drawPath(self.path)

def paint(self, painter, option, widget):
        if not self.source or not self.dest:
            return

        # Draw the line itself.
        line = QLineF(self.sourcePoint, self.destPoint)

        if line.length() == 0.0:
            return

        painter.setPen(QPen(Qt.black, 1, Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin))
        painter.drawLine(line)

        # Draw the arrows if there's enough room.
        angle = math.acos(line.dx() / line.length())
        if line.dy() >= 0:
            angle = VGraphEdge.TwoPi - angle

        sourceArrowP1 = self.sourcePoint + QPointF(math.sin(angle + VGraphEdge.Pi / 3) * self.arrowSize,
                                                          math.cos(angle + VGraphEdge.Pi / 3) * self.arrowSize)
        sourceArrowP2 = self.sourcePoint + QPointF(math.sin(angle + VGraphEdge.Pi - VGraphEdge.Pi / 3) * self.arrowSize,
                                                          math.cos(angle + VGraphEdge.Pi - VGraphEdge.Pi / 3) * self.arrowSize);
        destArrowP1 = self.destPoint + QPointF(math.sin(angle - VGraphEdge.Pi / 3) * self.arrowSize,
                                                      math.cos(angle - VGraphEdge.Pi / 3) * self.arrowSize)
        destArrowP2 = self.destPoint + QPointF(math.sin(angle - VGraphEdge.Pi + VGraphEdge.Pi / 3) * self.arrowSize,
                                                      math.cos(angle - VGraphEdge.Pi + VGraphEdge.Pi / 3) * self.arrowSize)

        painter.setBrush(Qt.black)
        painter.drawPolygon(QPolygonF([line.p1(), sourceArrowP1, sourceArrowP2]))
        painter.drawPolygon(QPolygonF([line.p2(), destArrowP1, destArrowP2]))

def init_ui(self):
        self.pen = QPen()
        self.pen.setWidth(self.width)
        self.pen.setJoinStyle(Qt.RoundJoin)
        self.pen.setCapStyle(Qt.RoundCap)
        self.setPen(self.pen)
        self.setFlag(QGraphicsItem.ItemIsMovable)
        self.setFlag(QGraphicsItem.ItemIsSelectable)

def drawLineTo(self, endPoint):
        painter = QPainter(self.image)
        painter.setPen(QPen(self.myPenColor, self.myPenWidth, Qt.SolidLine,
                Qt.RoundCap, Qt.RoundJoin))
        painter.drawLine(self.lastPoint, endPoint)
        self.modified = True

        rad = self.myPenWidth / 2 + 2
        self.update(QRect(self.lastPoint, endPoint).normalized().adjusted(-rad, -rad, +rad, +rad))
        self.lastPoint = QPoint(endPoint)

def drawLineTo(self, endPoint):
        painter = QPainter(self.image)
        painter.setPen(QPen(self.myPenColor, self.myPenWidth, Qt.SolidLine,
                Qt.RoundCap, Qt.RoundJoin))
        painter.drawLine(self.lastPoint, endPoint)
        self.modified = True

        rad = self.myPenWidth / 2 + 2
        self.update(QRect(self.lastPoint, endPoint).normalized().adjusted(-rad, -rad, +rad, +rad))
        self.lastPoint = QPoint(endPoint)

def drawLineTo(self, endPoint):
        painter = QPainter(self.image)
        painter.setPen(QPen(self.myPenColor, self.myPenWidth, Qt.SolidLine,
                Qt.RoundCap, Qt.RoundJoin))
        painter.drawLine(self.lastPoint, endPoint)
        self.modified = True

        rad = self.myPenWidth / 2 + 2
        self.update(QRect(self.lastPoint, endPoint).normalized().adjusted(-rad, -rad, +rad, +rad))
        self.lastPoint = QPoint(endPoint)