def lessThan(self, left, right):
sourceModel = self.sourceModel()<EOL>if sourceModel:<EOL><INDENT>leftItem = sourceModel.item(left)<EOL>rightItem = sourceModel.item(right)<EOL>if (isinstance(leftItem, Directory)<EOL>and not isinstance(rightItem, Directory)):<EOL><INDENT>return self.sortOrder() == Qt.AscendingOrder<EOL><DEDENT>elif (not isinstance(leftItem, Directory)<EOL>and isinstance(rightItem, Directory)):<EOL><INDENT>return self.sortOrder() == Qt.DescendingOrder<EOL><DEDENT><DEDENT>return super(FilesystemSortProxy, self).lessThan(left, right)<EOL>
Return ordering of *left* vs *right*.