/*

 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights 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 RenderOverflow_h

#define RenderOverflow_h

#include "IntRect.h"

namespace WebCore

{

// RenderOverflow is a class for tracking content that spills out of a box.  This class is used by RenderBox and

// InlineFlowBox.

//

// There are two types of overflow: layout overflow (which is expected to be reachable via scrolling mechanisms) and

// visual overflow (which is not expected to be reachable via scrolling mechanisms).

//

// Layout overflow examples include other boxes that spill out of our box,  For example, in the inline case a tall image

// could spill out of a line box. 

// Examples of visual overflow are shadows, text stroke (and eventually outline and border-image).

// This object is allocated only when some of these fields have non-default values in the owning box.

class RenderOverflow : public Noncopyable {

public:

    RenderOverflow(const IntRect& defaultRect = IntRect()) 

        : m_topLayoutOverflow(defaultRect.y())

        , m_bottomLayoutOverflow(defaultRect.bottom())

        , m_leftLayoutOverflow(defaultRect.x())

        , m_rightLayoutOverflow(defaultRect.right())

        , m_topVisualOverflow(defaultRect.y())

        , m_bottomVisualOverflow(defaultRect.bottom())

        , m_leftVisualOverflow(defaultRect.x())

        , m_rightVisualOverflow(defaultRect.right())

    {

    }

    int topLayoutOverflow() const { return m_topLayoutOverflow; }

    int bottomLayoutOverflow() const { return m_bottomLayoutOverflow; }

    int leftLayoutOverflow() const { return m_leftLayoutOverflow; }

    int rightLayoutOverflow() const { return m_rightLayoutOverflow; }

    IntRect layoutOverflowRect() const;

    int topVisualOverflow() const { return m_topVisualOverflow; }

    int bottomVisualOverflow() const { return m_bottomVisualOverflow; }

    int leftVisualOverflow() const { return m_leftVisualOverflow; }

    int rightVisualOverflow() const { return m_rightVisualOverflow; }

    IntRect visualOverflowRect() const;

    IntRect visibleOverflowRect() const;

    void setTopLayoutOverflow(int overflow) { m_topLayoutOverflow = overflow; }

    void setBottomLayoutOverflow(int overflow) { m_bottomLayoutOverflow = overflow; }

    void setLeftLayoutOverflow(int overflow) { m_leftLayoutOverflow = overflow; }

    void setRightLayoutOverflow(int overflow) { m_rightLayoutOverflow = overflow; }

    void setTopVisualOverflow(int overflow) { m_topVisualOverflow = overflow; }

    void setBottomVisualOverflow(int overflow) { m_bottomVisualOverflow = overflow; }

    void setLeftVisualOverflow(int overflow) { m_leftVisualOverflow = overflow; }

    void setRightVisualOverflow(int overflow) { m_rightVisualOverflow = overflow; }

    void move(int dx, int dy);

    void addLayoutOverflow(const IntRect&);

    void addVisualOverflow(const IntRect&);

    void resetLayoutOverflow(const IntRect& defaultRect);

private:

    int m_topLayoutOverflow;

    int m_bottomLayoutOverflow;

    int m_leftLayoutOverflow;

    int m_rightLayoutOverflow;

    int m_topVisualOverflow;

    int m_bottomVisualOverflow;

    int m_leftVisualOverflow;

    int m_rightVisualOverflow;

};

inline IntRect RenderOverflow::layoutOverflowRect() const

{

    return IntRect(m_leftLayoutOverflow, m_topLayoutOverflow, m_rightLayoutOverflow - m_leftLayoutOverflow, m_bottomLayoutOverflow - m_topLayoutOverflow);

}

inline IntRect RenderOverflow::visualOverflowRect() const

{

    return IntRect(m_leftVisualOverflow, m_topVisualOverflow, m_rightVisualOverflow - m_leftVisualOverflow, m_bottomVisualOverflow - m_topVisualOverflow);

}

inline IntRect RenderOverflow::visibleOverflowRect() const

{

    IntRect combinedRect(layoutOverflowRect());

    combinedRect.unite(visualOverflowRect());

    return combinedRect;

}

inline void RenderOverflow::move(int dx, int dy)

{

    m_topLayoutOverflow += dy;

    m_bottomLayoutOverflow += dy;

    m_leftLayoutOverflow += dx;

    m_rightLayoutOverflow += dx;

    m_topVisualOverflow += dy;

    m_bottomVisualOverflow += dy;

    m_leftVisualOverflow += dx;

    m_rightVisualOverflow += dx;

}

inline void RenderOverflow::addLayoutOverflow(const IntRect& rect)

{

    m_topLayoutOverflow = std::min(rect.y(), m_topLayoutOverflow);

    m_bottomLayoutOverflow = std::max(rect.bottom(), m_bottomLayoutOverflow);

    m_leftLayoutOverflow = std::min(rect.x(), m_leftLayoutOverflow);

    m_rightLayoutOverflow = std::max(rect.right(), m_rightLayoutOverflow);

}

inline void RenderOverflow::addVisualOverflow(const IntRect& rect)

{

    m_topVisualOverflow = std::min(rect.y(), m_topVisualOverflow);

    m_bottomVisualOverflow = std::max(rect.bottom(), m_bottomVisualOverflow);

    m_leftVisualOverflow = std::min(rect.x(), m_leftVisualOverflow);

    m_rightVisualOverflow = std::max(rect.right(), m_rightVisualOverflow);

}

inline void RenderOverflow::resetLayoutOverflow(const IntRect& rect)

{

    m_topLayoutOverflow = rect.y();

    m_bottomLayoutOverflow = rect.bottom();

    m_leftLayoutOverflow = rect.x();

    m_rightLayoutOverflow = rect.right();

}

} // namespace WebCore

#endif // RenderOverflow_h