+ /// end the current undo group and set UndoElement::cur_after if necessary.
+ void endUndoGroup(CursorData const & cur_after);
+ /// end abruptly the current group and create a new one wih the same nesting level
+ void splitUndoGroup(CursorData const & cur);
+ /// return true if an undo group is open and contains at least one element
+ bool activeUndoGroup() const;
+
+ /// The general case: record undo information for an arbitrary range.
+ /**
+ * Record undo information - call with the current cursor and
+ * the 'other end' of the range of changed paragraphs. So we
+ * give an inclusive range. This is called before you make the
+ * changes to the paragraph, and it will record the original
+ * information of the paragraphs in the undo stack.
+ * Kind of undo is always ATOMIC_UNDO.
+ */
+ void recordUndo(CursorData const & cur, pit_type from, pit_type to);