code: def OnActivateCard(self, card):
          
          SimpleSCardAppEventObserver.OnActivateCard(self, card)
          self.feedbacktext.SetLabel('Activated card: ' + repr(card))
          self.transmitbutton.Enable()
docs: 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.