/*

 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)

 * Copyright (C) 2003, 2004, 2006, 2007 Apple Inc.  All right reserved.

 *

 * 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 BidiContext_h

#define BidiContext_h

#include <wtf/Assertions.h>

#include <wtf/RefPtr.h>

#include <wtf/unicode/Unicode.h>

namespace WebCore {

// Used to keep track of explicit embeddings.

class BidiContext {

public:

    BidiContext(unsigned char level, WTF::Unicode::Direction direction, bool override = false, BidiContext* parent = 0)

        : m_level(level)

        , m_direction(direction)

        , m_override(override)

        , m_parent(parent)

        , m_refCount(0)

    {

        ASSERT(direction == WTF::Unicode::LeftToRight || direction == WTF::Unicode::RightToLeft);

    }

    void ref() const { m_refCount++; }

    void deref() const

    {

        m_refCount--;

        if (m_refCount <= 0)

            delete this;

    }

    BidiContext* parent() const { return m_parent.get(); }

    unsigned char level() const { return m_level; }

    WTF::Unicode::Direction dir() const { return static_cast<WTF::Unicode::Direction>(m_direction); }

    bool override() const { return m_override; }

private:

    unsigned char m_level;

    unsigned m_direction : 5; // Direction

    bool m_override : 1;

    RefPtr<BidiContext> m_parent;

    mutable int m_refCount;

};

bool operator==(const BidiContext&, const BidiContext&);

} // namespace WebCore

#endif // BidiContext_h