+ Undo(Buffer &);
+
+ ~Undo();
+
+ /// Clear out all undo/redo contents.
+ void clear();
+
+ /// this will undo the last action - returns false if no undo possible
+ bool textUndo(CursorData &);
+
+ /// this will redo the last undo - returns false if no redo possible
+ bool textRedo(CursorData &);
+
+ /// End a sequence of INSERT_UNDO or DELETE_UNDO type of undo
+ /// operations (grouping of consecutive characters insertion/deletion).
+ void finishUndo();
+
+ ///
+ bool hasUndoStack() const;
+ ///
+ bool hasRedoStack() const;
+
+ /// Mark all the elements of the undo and redo stacks as dirty
+ void markDirty();
+
+ /// open a new group of undo operations.
+ /**
+ * Groups can be nested. Such a nested group e.g. { {} {} } is undone in
+ * a single step. This means you can add a group whenever you are not sure.
+ */
+ void beginUndoGroup();
+ /// open a new group as above and specify a cursor to set as cur_before
+ /// of the group's undo elements.
+ /**
+ * This cursor takes precedence over what is passed to recordUndo.
+ * In the case of nested groups, only the first cur_before is
+ * taken into account. The cursor is reset at the end of the
+ * top-level group.
+ */
+ void beginUndoGroup(CursorData const & cur_before);
+ /// end the current undo group.
+ void endUndoGroup();
+ /// end the current undo group and set UndoElement::cur_after if necessary.
+ void endUndoGroup(CursorData const & cur_after);
+
+ /// 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);
+
+ /// Convenience: record undo information for the single
+ /// paragraph or cell containing the cursor.
+ void recordUndo(CursorData const & cur, UndoKind kind = ATOMIC_UNDO);
+
+ /// prepare undo for the inset containing the cursor
+ void recordUndoInset(CursorData const & cur, Inset const * inset);
+
+ /// Convenience: record undo for buffer parameters
+ void recordUndoBufferParams(CursorData const & cur);
+
+ /// Convenience: prepare undo for the whole buffer
+ void recordUndoFullBuffer(CursorData const & cur);
+
+private:
+ struct Private;
+ Private * const d;
+};