【PyQt4实例10】地图浏览器

#-*- coding:utf-8 -*-from PyQt4.QtCore import *from PyQt4.QtGui import *import mathQTextCodec.setCodecForTr(QTextCodec.codecForName("utf-8"))class MapWidget(QGraphicsView):    def __init__(self):        super(MapWidget,self).__init__()        self.zoom = 50        self.map = QPixmap()        self.x1 = QString()        self.x2 = QString()        self.y1 = QString()        self.y2 = QString()        self.readMap()        self.width = self.map.width()        self.height = self.map.height()                self.scene = QGraphicsScene(self)        self.scene.setSceneRect(-self.width/2,-self.height/2,self.width,self.height)        self.setScene(self.scene)        self.setCacheMode(self.CacheBackground)                self.slider = QSlider()        self.slider.setOrientation(Qt.Vertical)        self.slider.setRange(1,100)        self.slider.setTickInterval(10)        self.slider.setValue(50)        self.connect(self.slider,SIGNAL("valueChanged(int)"),self.slotZoom)                self.zoominLabel = QLabel()        self.zoominLabel.setScaledContents(True)        self.zoominLabel.setPixmap(QPixmap("image/zoomin.png"))                self.zoomoutLabel = QLabel()        self.zoomoutLabel.setScaledContents(True)        self.zoomoutLabel.setPixmap(QPixmap("image/deflate.png"))                self.coordFrame = QFrame()        self.label1 = QLabel(self.tr("GraphicsView:"))                self.viewCoord = QLabel()        self.label2 = QLabel(self.tr("GraphicsScene:"))                self.sceneCoord = QLabel()        self.label3 = QLabel(self.tr("map:"))        self.mapCoord = QLabel()                self.grid = QGridLayout()        self.grid.addWidget(self.label1,0,0)        self.grid.addWidget(self.viewCoord,0,1)        self.grid.addWidget(self.label2,1,0)        self.grid.addWidget(self.sceneCoord,1,1)        self.grid.addWidget(self.label3,2,0)        self.grid.addWidget(self.mapCoord,2,1)        self.grid.setSizeConstraint(QLayout.SetFixedSize)        self.coordFrame.setLayout(self.grid)                self.zoomLayout = QVBoxLayout()        self.zoomLayout.addWidget(self.zoominLabel)        self.zoomLayout.addWidget(self.slider)        self.zoomLayout.addWidget(self.zoomoutLabel)                self.coordLayout = QVBoxLayout()        self.coordLayout.addWidget(self.coordFrame)        self.coordLayout.addStretch()                self.layout = QHBoxLayout()        self.layout.addLayout(self.zoomLayout)        self.layout.addLayout(self.coordLayout)         self.layout.addStretch()        self.layout.setMargin(30)        self.layout.setSpacing(10)        self.setLayout(self.layout)                self.setWindowTitle(self.tr("地图浏览器"))        self.setMinimumSize(600,400)                    def drawBackground(self,painter,rect):        painter.drawPixmap(int(self.sceneRect().left()),int(self.sceneRect().top()),self.map)            def readMap(self):        mapFile = QFile("maps.txt")        mapName = QString()                ok = mapFile.open(QIODevice.ReadOnly)        if(ok is True):            t = QTextStream(mapFile)            if(t.atEnd() is False):                t >> mapName                t >> self.x1 >> self.y1 >> self.x2 >> self.y2        self.map.load(mapName)        def slotZoom(self,v):        if(v > self.zoom):            s = math.pow(1.01,(v - self.zoom))        else:            s = math.pow((1/1.01),(self.zoom - v))        self.scale(s,s)        self.zoom = v        def mouseMoveEvent(self,event):        viewPoint = event.pos()        self.viewCoord.setText(QString.number(viewPoint.x()) + "," + QString.number(viewPoint.y()))                scenePoint = self.mapToScene(viewPoint)        self.sceneCoord.setText(QString.number(scenePoint.x()) + "," + QString.number(scenePoint.y()))                latLon = self.mapToMap(scenePoint)        self.mapCoord.setText(QString.number(latLon.x()) + "," + QString.number(latLon.y()))        def mapToMap(self,p):        latLon = QPointF()        w = self.sceneRect().width()        h = self.sceneRect().height()        self.x1= float(self.x1)        self.x2= float(self.x2)        self.y1= float(self.y1)        self.y2= float(self.y2)                lon = self.y1 - ((h/2 + p.y()) * abs(self.y1 - self.y2)/h)        lat = self.x1 + ((w/2 + p.x()) * abs(self.x1 - self.x2)/w)        latLon.setX(lat)        latLon.setY(lon)        return latLon        if __name__ == '__main__':    import sys    app = QApplication(sys.argv)    mainwindow = MapWidget()    mainwindow.show()    sys.exit(app.exec_())

上述代码中的maps.txt文件如下：

aa.png 114.4665527 35.96022297 119.9597168 31.3911575