#ifndef _K_UNDOBUFFER_H
#define _K_UNDOBUFFER_H


#include <List.h>


enum undo_type{
        K_INSERTED,
        K_DELETED,
        K_REPLACED
};


class KUndoItem
{
public:
                                                        KUndoItem(const char* text, int32 length,
                                                                int32 offset, undo_type history,
                                                                int32 cursor_pos);
                                                        ~KUndoItem();

                        void                    Merge(const char* text, int32 length);
                        status_t                InitCheck();

                        int32                   Offset;
                        int32                   Length;
                        char*                   RedoText;
                        undo_type               History;
                        int32                   CursorPos;

private:
                        status_t                fStatus;
};


class KUndoBuffer : public BList
{
public:
                                                        KUndoBuffer();
                                                        ~KUndoBuffer();

                        bool                    AddItem(KUndoItem* item, int32 index);
                        bool                    AddItem(KUndoItem* item);
                        void                    MakeEmpty(void);
                        KUndoItem*              RemoveItem(int32 index);
                        KUndoItem*              ItemAt(int32 index) const;

                        status_t                AddUndo(const char* redo_text, int32 length,
                                                                int32 offset, undo_type history,
                                                                int32 cursor_pos);

                        status_t                MakeNewUndoItem();

                        status_t                Undo(char** text, int32* length, int32* offset,
                                                                undo_type* history, int32* cursor_pos);

                        status_t                Redo(char** text, int32* length, int32* offset,
                                                                undo_type* history, int32* cursor_pos,
                                                                bool* replaced);

                        void                    PrintToStream();
                        void                    On();
                        void                    Off();

private:
                        int32                   fIndex;
                        bool                    fNewItem;
                        bool                    fNoTouch;

                        status_t                NewUndo(const char* text, int32 length,
                                                                int32 offset, undo_type history,
                                                                int32 cursor_pos);
};


#endif  // _K_UNDOBUFFER_H