Pass an argument with QtCore.SIGNAL

Question

Code:

class Text(QtGui.QLabel):
    def __init__(self,parent):
        QtGui.QLabel.__init__(self,parent)

    def mouseReleaseEvent(self,evt):
        pos = evt.pos()
        if pos.x() < 0 or pos.y() < 0 or pos.x() > self.width() or pos.y() > self.height():
            return
        self.parent().update()
        self.emit(QtCore.SIGNAL('clicked()'))

    def updateText(self, txt):
        self.setText(txt)

class Window(QtGui.QMainWindow):
    def createNews(self):
        self.a1 = Text(self)
        self.a1.updateText("Test")
        self.a1.setFixedWidth(200)
        self.a1.move(23, 173)
        self.a1.show()
        self.connect(self.a1, QtCore.SIGNAL("clicked()"), self.OpenURL)

    def OpenURL(self, URL):
        QtGui.QDesktopServices.openUrl(QtCore.QUrl(str(URL)))

I'm trying to make a "clickable" label, so that if I click it, it will open a URL passed in the argument via self.connect(self.a1, QtCore.SIGNAL("clicked()"), self.OpenURL).

The question is, if it's possible to pass an argument (url) to self.OpenURL() so it could open the URL?

Answer 1

Firstly, you should get rid of the old-style signal syntax, and define a custom clicked signal, like this:

class Text(QtGui.QLabel):
    clicked = QtCore.pyqtSignal()

    def mouseReleaseEvent(self, evt):
        ...
        self.clicked.emit()

Then use a lambda to send the argument with the signal:

    self.a1.clicked.connect(lambda: self.OpenURL(url))

More information about new-style signal/slot syntax can be found here.