// -*- C++ -*-
/* This file is part of
 * ======================================================
 * 
 *           LyX, The Document Processor
 * 	 
 *           Copyright 1995 Matthias Ettrich
 *           Copyright 1995-1999 The LyX Team.
 *
 * ====================================================== */

#ifndef UNDO_H
#define UNDO_H

#ifdef __GNUG__
#pragma interface
#endif

#include <list>
using std::list;

#include "lyxparagraph.h"


///
class Undo {
public:
	/// The undo kinds
	enum undo_kind {
		///
		INSERT,
		///
		DELETE,
		///
		EDIT,
		///
		FINISH
	};
	///
	undo_kind kind;
	///
	int number_of_before_par;
	///
	int number_of_behind_par;
	///
	int number_of_cursor_par;
	///
	int cursor_pos; // valid if >= 0
	///
	LyXParagraph * par;
	///
	Undo(undo_kind kind_arg,
	     int number_before_arg, int number_behind_arg,
	     int cursor_par_arg, int cursor_pos_arg,
	     LyXParagraph * par_arg)
	{
		kind = kind_arg;
		number_of_before_par = number_before_arg;
		number_of_behind_par = number_behind_arg;
		number_of_cursor_par = cursor_par_arg;
		cursor_pos = cursor_pos_arg;
		par = par_arg;
	}
	///
	~Undo() {
		LyXParagraph * tmppar;
		while (par) {
			tmppar = par;
			par = par->next;
			delete tmppar;
		}
	}
};


/// A limited Stack for the undo informations.
class UndoStack{
private:
	///
	typedef list<Undo*> Stakk;
	///
	Stakk stakk;
	/// the maximum number of undo steps stored.
	Stakk::size_type limit;
public:
	///
	UndoStack();
	///
	Undo * pop();
	///
	Undo * top();
	///
	bool empty() const { return stakk.empty(); }
	///
	~UndoStack();
	///
	void clear();
	///
	void SetStackLimit(Stakk::size_type l);
	///
	void push(Undo * undo_arg);
};

#endif