Called when a card is activated by double-clicking
        on the card or reader tree control or toolbar.
        In this sample, we just connect to the card on the first activation.

def OnActivateCard(self, card):
        """Called when a card is activated by double-clicking
        on the card or reader tree control or toolbar.
        In this sample, we just connect to the card on the first activation."""
        SimpleSCardAppEventObserver.OnActivateCard(self, card)
        self.feedbacktext.SetLabel('Activated card: ' + repr(card))
        self.transmitbutton.Enable()