pyqt QbuttonGroup: Passing user data on buttonClicked

Question

I have defined my own class that inherits QbuttonGroup

class TupleButtonGroup(QtGui.QButtonGroup):
    def __init__(self,parent, tuple_pair):
        super(TupleButtonGroup, self).__init__(parent)
        self.tuple_pair = tuple_pair

And on buttonclicked i want to access the user data tuple_pair and corresponding button clicked in the button group

button_group.buttonClicked[QtGui.QAbstractButton].connect(self.labelchanged)

def labelchanged(self, button):
   print button.text()

The function receives the button clicked but i don't know how to access the user data in the callback

Answer 1

All buttons have a group() method that allows you to get a reference to whatever group (if any) that they have been added to. So your code can simply be:

button_group.buttonClicked.connect(self.labelchanged)

def labelchanged(self, button):
    print button.text()
    print button.group().tuple_pair

And note that you dont need to specifiy QAbstractButton when connecting the signal, because that is the default overload.

Answer 2

You could do it a couple of ways.

You could catch the buttonClicked signal in your subclass and emit your own signal that contains the tuple_pair.

class TupleButtonGroup(QtGui.QButtonGroup):
    buttonClickedWithData = QtCore.pyqtSignal(tuple, QtGui.QAbstractButton)

    def __init__(self,parent, tuple_pair):
        super(TupleButtonGroup, self).__init__(parent)
        self.tuple_pair = tuple_pair
        self.buttonClicked[QtGui.QAbstractButton].connect(self.on_buttonClicked)

    @QtCore.pyqtSlot(QtGui.QAbstractButton)
    def on_buttonClicked(self, button):
        self.buttonClickedWithData.emit(self.tuple_pair, button)

Then just connect to that new signal

button_group.buttonClickedWithData.connect(self.labelchanged)

@QtCore.pyqtSlot(tuple, QtGui.QAbstractButton)
def labelchanged(self, tuple_pair, button):
    print tuple_pair
    print button.text()

The other option is to use your existing class, signals and slots, and use the .sender() method to get a reference to the button group from within the slot method.

@QtCore.pyqtSlot(QtGui.QAbstractButton)
def labelchanged(self, button):
    btngroup = self.sender()
    print btngroup.tuple_pair
    print button.text()