/**
 * This file is part of the html renderer for KDE.
 *
 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * $Id: bidi.h,v 1.7 2000/07/14 21:39:46 knoll Exp $
 */
#ifndef BIDI_H
#define BIDI_H

#include <qstring.h>

namespace khtml {
    class RenderFlow;
    class RenderObject;

    class BidiContext {
    public:
	BidiContext(unsigned char level, QChar::Direction embedding, BidiContext *parent = 0, bool override = false);
	~BidiContext();

	void ref() const;
	void deref() const;

	unsigned char level;
	bool override : 1;
	QChar::Direction dir : 5;
	QChar::Direction basicDir : 5;
	
	BidiContext *parent;


	// refcounting....
	mutable int count;
    };

    struct BidiRun {
	BidiRun(int _start, int _stop, RenderObject *_obj, BidiContext *context, QChar::Direction dir) {
	    start = _start;
	    stop = _stop;
	    obj = _obj;
	    if(dir == QChar::DirON) dir = context->dir;

	    level = context->level;

	    // add level of run (cases I1 & I2)
	    if( level % 2 ) {
		if(dir == QChar::DirL || dir == QChar::DirAN)
		    level++;
	    } else {
		if( dir == QChar::DirR )
		    level++;
		else if( dir == QChar::DirAN )
		    level += 2;
	    }

	    yOffset = 0;
	    width = 0;
	}

	int start;
	int stop;
	RenderObject *obj;

	// explicit + implicit levels here
	uchar level;
	int yOffset;
	int width;
    };

    // an iterator which goes through a BidiParagraph
    class BidiIterator
    {
    public:
	BidiIterator();
	BidiIterator(RenderFlow *par);
	BidiIterator(RenderFlow *par, RenderObject *_obj, int _pos = 0);

	BidiIterator(const BidiIterator &it);
	BidiIterator &operator = (const BidiIterator &it);

	void operator ++ ();

	bool atEnd();

	const QChar &current();
	QChar::Direction direction();

	RenderFlow *par;
	RenderObject *obj;
	unsigned int pos;

    };

    struct BidiStatus {
	BidiStatus() {
	    eor = QChar::DirON;
	    lastStrong = QChar::DirON;
	    last = QChar:: DirON;
	}
	QChar::Direction eor 		: 5;
	QChar::Direction lastStrong 	: 5;
	QChar::Direction last		: 5;
    };

};

#endif
