/*
 * This file is part of the html renderer for KDE.
 *
 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
 * Copyright (C) 2003 Apple Computer, Inc.
 *
 * 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., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */
#ifndef BIDI_H
#define BIDI_H

#include <QtCore/QString>
#include "rendering/render_object.h"

namespace khtml
{
class RenderArena;
class RenderObject;
class InlineBox;

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), box(0), nextRun(0)
    {
        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 || dir == QChar::DirEN) {
                level++;
            }
        } else {
            if (dir == QChar::DirR) {
                level++;
            } else if (dir == QChar::DirAN || dir == QChar::DirEN) {
                level += 2;
            }
        }
    }

    void detach(RenderArena *renderArena);

    // Overloaded new operator.
    void *operator new(size_t sz, RenderArena *renderArena) throw();

    // Overridden to prevent the normal delete from being called.
    void operator delete(void *ptr, size_t sz);

private:
    // The normal operator new is disallowed.
    void *operator new(size_t sz) throw();

public:
    int start;
    int stop;

    RenderObject *obj;
    InlineBox *box;

    // explicit + implicit levels here
    uchar level;

    bool compact : 1;

    BidiRun *nextRun;
};

struct BidiIterator;
struct BidiState;

struct BidiStatus {
    BidiStatus() : eor(QChar::DirON), lastStrong(QChar::DirON), last(QChar::DirON) {}

    QChar::Direction eor;
    QChar::Direction lastStrong;
    QChar::Direction last;
};

struct InlineMinMaxIterator {
    /* InlineMinMaxIterator is a class that will iterate over all render objects that contribute to
       inline min/max width calculations.  Note the following about the way it walks:
       (1) Positioned content is skipped (since it does not contribute to min/max width of a block)
       (2) We do not drill into the children of floats or replaced elements, since you can't break
           in the middle of such an element.
       (3) Inline flows (e.g., <a>, <span>, <i>) are walked twice, since each side can have
           distinct borders/margin/padding that contribute to the min/max width.
    */
    RenderObject *parent;
    RenderObject *current;
    bool endOfInline;
    bool skipPositioned;
    InlineMinMaxIterator(RenderObject *p, RenderObject *o, bool eOI = false, bool skipPos = true)
        : parent(p), current(o), endOfInline(eOI), skipPositioned(skipPos) {}
    inline RenderObject *next();
};

inline RenderObject *InlineMinMaxIterator::next()
{
    RenderObject *result = 0;
    bool oldEndOfInline = endOfInline;
    endOfInline = false;
    while (current != 0 || (current == parent)) {
        //qDebug() << "current = " << current;
        if (!oldEndOfInline &&
                (current == parent ||
                 (!current->isFloating() && !current->isReplaced() && !current->isPositioned()))) {
            result = current->firstChild();
        }
        if (!result) {
            // We hit the end of our inline. (It was empty, e.g., <span></span>.)
            if (!oldEndOfInline && current->isInlineFlow()) {
                result = current;
                endOfInline = true;
                break;
            }
            while (current && current != parent) {
                result = current->nextSibling();
                if (result) {
                    break;
                }
                current = current->parent();
                if (current && current != parent && current->isInlineFlow()) {
                    result = current;
                    endOfInline = true;
                    break;
                }
            }
        }

        if (!result) {
            break;
        }

        if ((!skipPositioned || !result->isPositioned()) && (result->isText() || result->isBR() ||
                result->isFloatingOrPositioned() || result->isReplaced() || result->isGlyph() || result->isInlineFlow())) {
            break;
        }

        current = result;
        result = 0;
    }

    // Update our position.
    current = result;
    return current;
}
}

#endif
