Listens for the left/right keys and the escape key to control
        the slides.
        
        :param      event | <QtCore.Qt.QKeyEvent>

def keyPressEvent(self, event):
        """
        Listens for the left/right keys and the escape key to control
        the slides.
        
        :param      event | <QtCore.Qt.QKeyEvent>
        """
        if event.key() == QtCore.Qt.Key_Escape:
            self.cancel()
        elif event.key() == QtCore.Qt.Key_Left:
            self.goBack()
        elif event.key() == QtCore.Qt.Key_Right:
            self.goForward()
        elif event.key() == QtCore.Qt.Key_Home:
            self.restart()
        
        super(XWalkthroughWidget, self).keyPressEvent(event)