Sort the root file items in alphabetical order if
        'sort_files_alphabetically' is True, else order the items as
        specified in the 'self.ordered_editor_ids' list.

def __sort_toplevel_items(self):
        """
        Sort the root file items in alphabetical order if
        'sort_files_alphabetically' is True, else order the items as
        specified in the 'self.ordered_editor_ids' list.
        """
        if self.show_all_files is False:
            return

        current_ordered_items = [self.topLevelItem(index) for index in
                                 range(self.topLevelItemCount())]
        if self.sort_files_alphabetically:
            new_ordered_items = sorted(
                current_ordered_items,
                key=lambda item: osp.basename(item.path.lower()))
        else:
            new_ordered_items = [
                self.editor_items.get(e_id) for e_id in
                self.ordered_editor_ids if
                self.editor_items.get(e_id) is not None]

        if current_ordered_items != new_ordered_items:
            selected_items = self.selectedItems()
            self.save_expanded_state()
            for index in range(self.topLevelItemCount()):
                self.takeTopLevelItem(0)
            for index, item in enumerate(new_ordered_items):
                self.insertTopLevelItem(index, item)
            self.restore_expanded_state()
            self.clearSelection()
            if selected_items:
                selected_items[-1].setSelected(True)