Reimplements the :meth:`QWidget.closeEvent` method.

        :param event: QEvent.
        :type event: QEvent

def closeEvent(self, event):
        """
        Reimplements the :meth:`QWidget.closeEvent` method.

        :param event: QEvent.
        :type event: QEvent
        """

        self.__interrupt_search()
        super(SearchInFiles, self).closeEvent(event)