Defines the slot triggered on Framework close.

def on_close(self):
        """
        Defines the slot triggered on Framework close.
        """

        LOGGER.debug("> Calling '{0}' Component Framework 'on_close' method.".format(self.__class__.__name__))

        map(self.unregister_file, self.list_files())

        if self.store_session() and self.close_all_files(leave_first_editor=False):
            return True