def indented_short_title(self, item):
        """
        Generate a short title for an object, indent it depending on
        the object's depth in the hierarchy.
        """
        mptt_opts = item._mptt_meta
        r = ""
        try:
            url = item.get_absolute_url()
        except (AttributeError,):
            url = None

        if url:
            r = (
                '<input type="hidden" class="medialibrary_file_path"'
                ' value="%s" id="_refkey_%d" />'
            ) % (url, item.pk)

        changeable_class = ""
        if not self.changeable(item):
            changeable_class = " tree-item-not-editable"
        tree_root_class = ""
        if not item.parent_id:
            tree_root_class = " tree-root"

        r += (
            '<span id="page_marker-%d" class="page_marker%s%s"'
            ' style="width: %dpx;">&nbsp;</span>&nbsp;'
        ) % (
            item.pk,
            changeable_class,
            tree_root_class,
            14 + getattr(item, mptt_opts.level_attr) * 18,
        )

        #        r += '<span tabindex="0">'
        if hasattr(item, "short_title") and callable(item.short_title):
            r += escape(item.short_title())
        else:
            r += escape("%s" % item)
        #        r += '</span>'
        return mark_safe(r)

        Generate a short title for an object, indent it depending on
        the object's depth in the hierarchy.
        
feincms/admin/tree_editor.py