QMouseEvent, received unexpected type

问题

I'm trying to link a mouse press event to displaying the coordinates of the mouse when clicked in a QLabel. A few problems... when I was passing a generic QWidget.mousePressEvent, the coordinates would only display the first time clicked. When I tried to make the mouse event specific to a GraphicsScene(self.p1), I get the following error:

Traceback (most recent call last):
  File "C:\Users\Tory\Desktop\DIDSONGUIDONOTCHANGE.py", line 59, in mousePressEvent
    self.p1.mousePressEvent(event)
TypeError: QGraphicsWidget.mousePressEvent(QGraphicsSceneMouseEvent): argument 1 has unexpected type 'QMouseEvent'

This is the code I'm using... I know it's off but I'm new to this and a bit lost at where to begin.

def mousePressEvent(self, event):
    self.p1.mousePressEvent(event)
    x=event.x()
    y=event.y()
    if event.button()==Qt.LeftButton:
        self.label.setText("x=%0.01f,y=%0.01f" %(x,y))

How do I get the mouse click to display the coordinates of the graphics scene self.p1?

回答1:

It looks like an event filter may do what you want.

Here's a simple demo:

from PyQt4 import QtGui, QtCore

class Window(QtGui.QWidget):
    def __init__(self):
        QtGui.QWidget.__init__(self)
        self.scene = QtGui.QGraphicsScene(self)
        self.scene.addPixmap(QtGui.QPixmap('image.jpg'))
        self.scene.installEventFilter(self)
        self.view = QtGui.QGraphicsView(self)
        self.view.setScene(self.scene)
        self.label = QtGui.QLabel(self)
        layout = QtGui.QVBoxLayout(self)
        layout.addWidget(self.view)
        layout.addWidget(self.label)

    def eventFilter(self, source, event):
        if (source is self.scene and
            event.type() == QtCore.QEvent.GraphicsSceneMouseRelease and
            event.button() == QtCore.Qt.LeftButton):
            pos = event.scenePos()
            self.label.setText('x=%0.01f,y=%0.01f' % (pos.x(), pos.y()))
        return QtGui.QWidget.eventFilter(self, source, event)

if __name__ == '__main__':

    import sys
    app = QtGui.QApplication(sys.argv)
    window = Window()
    window.show()
    sys.exit(app.exec_())

来源：https://stackoverflow.com/questions/12116073/qmouseevent-received-unexpected-type

标签

python

pyqt

qgraphicsscene