【PyQt实例6】渐变效果

#-*- coding:utf-8 -*-

import sys

import math

from PyQt4.QtCore import *

from PyQt4.QtGui import *

QTextCodec.setCodecForTr(QTextCodec.codecForName("utf-8"))

class StockDialog(QWidget):

def __init__(self, parent=None):

super(StockDialog, self).__init__(parent)

self.setWindowTitle(self.tr("渐变效果"))

self.startColor = Qt.green

self.endColor = Qt.blue

self.style = QGradient.LinearGradient

self.spread = QGradient.PadSpread

mainSplitter = QSplitter(Qt.Horizontal)

mainSplitter.setOpaqueResize(True)

frame = QFrame(mainSplitter)

mainLayout = QGridLayout(frame)

mainLayout.setMargin(10)

mainLayout.setSpacing(6)

stack1 = QStackedWidget()

stack1.setFrameStyle(QFrame.Panel|QFrame.Raised)

mainSplitter1 = QSplitter(Qt.Horizontal)

mainSplitter1.setOpaqueResize(True)

self.area = PaintArea(self)

stack1.addWidget(self.area)

frame1 = QFrame(mainSplitter1)

mainLayout1 = QVBoxLayout(frame1)

mainLayout1.setMargin(10)

mainLayout1.setSpacing(6)

mainLayout1.addWidget(stack1)

self.startPushButton = QPushButton(self.tr("start"))

self.startPushButton.setAutoFillBackground(True)

self.startPushButton.setPalette(QPalette(Qt.green))

self.endPushButton = QPushButton(self.tr("end"))

self.endPushButton.setAutoFillBackground(True)

self.endPushButton.setPalette(QPalette(Qt.blue))

self.connect(self.startPushButton,SIGNAL("clicked()"),self.slotStartColor)

self.connect(self.endPushButton,SIGNAL("clicked()"),self.slotEndColor)

self.grdientComboBox = QComboBox()

self.grdientComboBox.addItem(self.tr("Linear Gradient"),QGradient.LinearGradient)

self.grdientComboBox.addItem(self.tr("Radial Gradient"),QGradient.RadialGradient)

self.grdientComboBox.addItem(self.tr("Conical Gradient"),QGradient.ConicalGradient)

self.connect(self.grdientComboBox,SIGNAL("activated(int)"),self.slotSetStyle)

self.spreadComboBox = QComboBox()

self.spreadComboBox.addItem(self.tr("PadSpread"),QGradient.PadSpread)

self.spreadComboBox.addItem(self.tr("RepeatSpread"),QGradient.RepeatSpread)

self.spreadComboBox.addItem(self.tr("ReflctSpread"),QGradient.ReflectSpread)

self.connect(self.spreadComboBox,SIGNAL("activated(int)"),self.slotSetSpread)

mainLayout.addWidget(self.startPushButton,1,0)

mainLayout.addWidget(self.endPushButton,1,1)

mainLayout.addWidget(self.grdientComboBox,1,2)

mainLayout.addWidget(self.spreadComboBox,1,3)

layout = QGridLayout(self)

layout.addWidget(mainSplitter1,0,0)

layout.addWidget(mainSplitter,1,0)

self.setLayout(layout)

def slotStartColor(self):

self.startColor = QColorDialog.getColor(Qt.green)

self.startPushButton.setPalette(QPalette(self.startColor))

self.area.setPen(QPen(self.startColor))

def slotEndColor(self):

self.endColor = QColorDialog.getColor(Qt.blue)

self.endPushButton.setPalette(QPalette(self.endColor))

self.area.setPen(QPen(self.endColor))

def slotSetStyle(self,value):

self.style = self.grdientComboBox.itemData(value,Qt.UserRole).toInt()[0]

def slotSetSpread(self,value):

self.spread = self.spreadComboBox.itemData(value,Qt.UserRole).toInt()[0]

class PaintArea(QWidget):

def __init__(self,StockDialog):

super(PaintArea,self).__init__()

self.setPalette(QPalette(Qt.white))

self.setAutoFillBackground(True)

self.setMinimumSize(400,400)

self.startPoint = QPointF(0,0)

self.endPoint = QPointF(400,400)

self.pen = QPen()

self.sd = StockDialog

def setPen(self,p):

self.pen = p

self.update()

def mousePressEvent(self,e):

self.startPoint = QPointF(e.pos())

def mouseReleaseEvent(self,e):

self.endPoint = QPointF(e.pos())

self.update()

def paintEvent(self,QPaintEvent):

p = QPainter(self)

r = self.rect()

p.setPen(self.pen)

if(self.sd.style == QGradient.LinearGradient):

linearGradient = QLinearGradient(self.startPoint,self.endPoint)

linearGradient.setColorAt(0.0,self.sd.startColor)

linearGradient.setColorAt(1.0,self.sd.endColor)

linearGradient.setSpread(self.sd.spread)

p.setBrush(linearGradient)

elif(self.sd.style == QGradient.RadialGradient):

rr = math.sqrt(math.pow(self.endPoint.x() - self.startPoint.x(),2) + math.pow(self.endPoint.y() - self.startPoint.y(),2))

radialGradient = QRadialGradient(self.startPoint,rr,self.startPoint)

radialGradient.setColorAt(0.0,self.sd.startColor)

radialGradient.setColorAt(1.0,self.sd.endColor)

radialGradient.setSpread(self.sd.spread)

p.setBrush(radialGradient)

elif(self.sd.style == QGradient.ConicalGradient):

angle = math.atan2(self.endPoint.y() - self.startPoint.y(),self.endPoint.x() - self.startPoint.x())

conicalGradient = QConicalGradient(self.startPoint,-(180 * angle)/math.pi)

conicalGradient.setColorAt(0.0,self.sd.startColor)

conicalGradient.setColorAt(1.0,self.sd.endColor)

p.setBrush(conicalGradient)

p.drawRect(r)

if __name__=='__main__':

app = QApplication(sys.argv)

form = StockDialog()

form.show()

app.exec_()