Looks for the Esc key to close the popup.
        
        :param      event | <QKeyEvent>

def keyPressEvent( self, event ):
        """
        Looks for the Esc key to close the popup.
        
        :param      event | <QKeyEvent>
        """
        if ( event.key() == Qt.Key_Escape ):
            self.reject()
            event.accept()
            return
        
        elif ( event.key() in (Qt.Key_Return, Qt.Key_Enter) ):
            if self._autoDefault:
                self.accept()
                event.accept()
            return
        
        super(XPopupWidget, self).keyPressEvent(event)