[Qt扒手2] PyQt5 路径绘画例子

【说明】

此例扒自 Qt 官网，原例是 C++ 代码，我把它改写成了 Python + PyQt5 版本。

有了前一个例子的成功，这个例子改写的非常之快。记得第一个例子花了我几天的时间，而这个例子只花了半个小时。

当然，过程中也遇到了一些新问题，比如 renderAreas 被定义成 QList类，而QList类的迭代，调试了几次都报错。没有办法，干脆把renderAreas 修改定义为Python的 list 类型，然后就OK了！！

本例基于： Win7 + Python 3.4 + PyQt5

【效果图】

对比原C++界面：

【源代码】

 # File: Painter Paths Example.py
 # Author: Robin
 # Date: 2015.2.9
 # C++: http://doc.qt.io/qt-5/qtwidgets-painting-painterpaths-example.html

 import math
 from PyQt5.QtCore import *
 from PyQt5.QtGui import *
 from PyQt5.QtWidgets import *

 class RenderArea(QWidget):
     def __init__(self, path, parent=None):
         super(RenderArea, self).__init__(parent)
         self.penWidth = 1
         self.rotationAngle = 0
         self.path = path
         self.setBackgroundRole(QPalette.Base)
         self.setAutoFillBackground(True)

     def minimumSizeHint(self):
         return QSize(50, 50)

     def sizeHint(self):
         return QSize(100, 100)

     def setFillRule(self, rule):
         self.path.setFillRule(rule)
         self.update()

     def setFillGradient(self, color1, color2):
         self.fillColor1 = color1
         self.fillColor2 = color2
         self.update()

     def setPenWidth(self, width):
         self.penWidth = width
         self.update()

     def setPenColor(self, color):
         self.penColor = color
         self.update()

     def setRotationAngle(self, degrees):
         self.rotationAngle = degrees
         self.update()

     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(gradient)
         painter.drawPath(self.path)

 class MyWindow(QWidget):

     def __init__(self):
         super(MyWindow, self).__init__()
         #self.setUi()
         #self.Pi = 3.1415926
         # 矩形路径
         self.rectPath = QPainterPath()
         self.rectPath.moveTo(20.0, 30.0)
         self.rectPath.lineTo(80.0, 30.0)
         self.rectPath.lineTo(80.0, 70.0)
         self.rectPath.lineTo(20.0, 70.0)
         self.rectPath.closeSubpath()
         # 圆角矩形路径
         self.roundRectPath = QPainterPath()
         self.roundRectPath.moveTo(80.0, 35.0)
         self.roundRectPath.arcTo(70.0, 30.0, 10.0, 10.0, 0.0, 90.0)
         self.roundRectPath.lineTo(25.0, 30.0)
         self.roundRectPath.arcTo(20.0, 30.0, 10.0, 10.0, 90.0, 90.0)
         self.roundRectPath.lineTo(20.0, 65.0)
         self.roundRectPath.arcTo(20.0, 60.0, 10.0, 10.0, 180.0, 90.0)
         self.roundRectPath.lineTo(75.0, 70.0)
         self.roundRectPath.arcTo(70.0, 60.0, 10.0, 10.0, 270.0, 90.0)
         self.roundRectPath.closeSubpath()
         # 椭圆路径
         self.ellipsePath = QPainterPath()
         self.ellipsePath.moveTo(80.0, 50.0)
         self.ellipsePath.arcTo(20.0, 30.0, 60.0, 40.0, 0.0, 360.0)
         # 饼图路径
         self.piePath = QPainterPath()
         self.piePath.moveTo(50.0, 50.0)
         self.piePath.arcTo(20.0, 30.0, 60.0, 40.0, 60.0, 240.0)
         self.piePath.closeSubpath()
         # 多边形路径
         self.polygonPath = QPainterPath()
         self.polygonPath.moveTo(10.0, 80.0)
         self.polygonPath.lineTo(20.0, 10.0)
         self.polygonPath.lineTo(80.0, 30.0)
         self.polygonPath.lineTo(90.0, 70.0)
         self.polygonPath.closeSubpath()
         # 组合路径
         self.groupPath = QPainterPath()
         self.groupPath.moveTo(60.0, 40.0)
         self.groupPath.arcTo(20.0, 20.0, 40.0, 40.0, 0.0, 360.0)
         self.groupPath.moveTo(40.0, 40.0)
         self.groupPath.lineTo(40.0, 80.0)
         self.groupPath.lineTo(80.0, 80.0)
         self.groupPath.lineTo(80.0, 40.0)
         self.groupPath.closeSubpath()
         # 文字路径
         self.textPath = QPainterPath()
         self.timesFont = QFont("Times", 50)
         self.timesFont.setStyleStrategy(QFont.ForceOutline)
         self.textPath.addText(10, 70, self.timesFont, "Qt")
         # 贝兹尔路径
         self.bezierPath = QPainterPath()
         self.bezierPath.moveTo(20, 30)
         self.bezierPath.cubicTo(80, 0, 50, 50, 80, 80)

         self.starPath = QPainterPath()
         self.starPath.moveTo(90, 50)
         for i in range(5):
             self.starPath.lineTo(50 + 40 * math.cos(0.8 * i * math.pi),
                             50 + 40 * math.sin(0.8 * i * math.pi))
         self.starPath.closeSubpath()

         self.renderAreas = []
         self.renderAreas.append(RenderArea(self.rectPath))
         self.renderAreas.append(RenderArea(self.roundRectPath))
         self.renderAreas.append(RenderArea(self.ellipsePath))
         self.renderAreas.append(RenderArea(self.piePath))
         self.renderAreas.append(RenderArea(self.polygonPath))
         self.renderAreas.append(RenderArea(self.groupPath))
         self.renderAreas.append(RenderArea(self.textPath))
         self.renderAreas.append(RenderArea(self.bezierPath))
         self.renderAreas.append(RenderArea(self.starPath))

     #def setUi(self):
         self.fillRuleComboBox = QComboBox()
         self.fillRuleComboBox.addItem("Odd Even", Qt.OddEvenFill)
         self.fillRuleComboBox.addItem("Winding", Qt.WindingFill)

         self.fillRuleLabel = QLabel("Fill &Rule:")
         self.fillRuleLabel.setBuddy(self.fillRuleComboBox)

         self.fillColor1ComboBox = QComboBox()
         self.populateWithColors(self.fillColor1ComboBox)
         self.fillColor1ComboBox.setCurrentIndex(self.fillColor1ComboBox.findText("mediumslateblue"))

         self.fillColor2ComboBox = QComboBox()
         self.populateWithColors(self.fillColor2ComboBox)
         self.fillColor2ComboBox.setCurrentIndex(self.fillColor2ComboBox.findText("cornsilk"))

         self.fillGradientLabel = QLabel("&Fill Gradient:")
         self.fillGradientLabel.setBuddy(self.fillColor1ComboBox)

         self.fillToLabel = QLabel("to")
         self.fillToLabel.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed)

         self.penWidthSpinBox = QSpinBox()
         self.penWidthSpinBox.setRange(0, 20)

         self.penWidthLabel = QLabel("&Pen Width:")
         self.penWidthLabel.setBuddy(self.penWidthSpinBox)

         self.penColorComboBox = QComboBox()
         self.populateWithColors(self.penColorComboBox)
         self.penColorComboBox.setCurrentIndex(self.penColorComboBox.findText("darkslateblue"))

         self.penColorLabel = QLabel("Pen &Color:")
         self.penColorLabel.setBuddy(self.penColorComboBox)

         self.rotationAngleSpinBox = QSpinBox()
         self.rotationAngleSpinBox.setRange(0, 359)
         self.rotationAngleSpinBox.setWrapping(True)
         self.rotationAngleSpinBox.setSuffix("°")

         self.rotationAngleLabel = QLabel("&Rotation Angle:")
         self.rotationAngleLabel.setBuddy(self.rotationAngleSpinBox)

         self.fillRuleComboBox.activated.connect(self.fillRuleChanged)
         self.fillColor1ComboBox.activated.connect(self.fillGradientChanged)
         self.fillColor2ComboBox.activated.connect(self.fillGradientChanged)
         self.penColorComboBox.activated.connect(self.penColorChanged)

         for it in self.renderAreas:
             self.penWidthSpinBox.valueChanged.connect(it.setPenWidth)
             self.rotationAngleSpinBox.valueChanged.connect(it.setRotationAngle)

         topLayout = QGridLayout()

         i = 0
         for i, it in enumerate(self.renderAreas):
             topLayout.addWidget(it, i // 3, i % 3)

         mainLayout = QGridLayout()
         mainLayout.addLayout(topLayout, 0, 0, 1, 4)
         mainLayout.addWidget(self.fillRuleLabel, 1, 0)
         mainLayout.addWidget(self.fillRuleComboBox, 1, 1, 1, 3)
         mainLayout.addWidget(self.fillGradientLabel, 2, 0)
         mainLayout.addWidget(self.fillColor1ComboBox, 2, 1)
         mainLayout.addWidget(self.fillToLabel, 2, 2)
         mainLayout.addWidget(self.fillColor2ComboBox, 2, 3)
         mainLayout.addWidget(self.penWidthLabel, 3, 0)
         mainLayout.addWidget(self.penWidthSpinBox, 3, 1, 1, 3)
         mainLayout.addWidget(self.penColorLabel, 4, 0)
         mainLayout.addWidget(self.penColorComboBox, 4, 1, 1, 3)
         mainLayout.addWidget(self.rotationAngleLabel, 5, 0)
         mainLayout.addWidget(self.rotationAngleSpinBox, 5, 1, 1, 3)
         self.setLayout(mainLayout)

         self.fillRuleChanged()
         self.fillGradientChanged()
         self.penColorChanged()
         self.penWidthSpinBox.setValue(2)

         self.setWindowTitle("Painter Paths")

     def fillRuleChanged(self):
         rule = self.currentItemData(self.fillRuleComboBox)
         for it in self.renderAreas:
             it.setFillRule(rule)

     def fillGradientChanged(self):
         color1 = self.currentItemData(self.fillColor1ComboBox)
         color2 = self.currentItemData(self.fillColor2ComboBox)
         for it in self.renderAreas:
             it.setFillGradient(color1, color2)

     def penColorChanged(self):
         color = self.currentItemData(self.penColorComboBox)
         for it in self.renderAreas:
             it.setPenColor(color)

     @staticmethod
     def populateWithColors(comboBox):
         colorNames = QColor.colorNames()
         for name in colorNames:
             comboBox.addItem(name, QColor(name))

     @staticmethod
     def currentItemData(comboBox):
         return comboBox.itemData(comboBox.currentIndex(),Qt.UserRole)

 if __name__ == "__main__":
     import sys
     app = QApplication(sys.argv)
     win = MyWindow()
     win.show()
     sys.exit(app.exec_())