/*

 * Copyright (C) 2007 Apple Inc.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

 */

#include "config.h"

#include "LayoutState.h"

#include "RenderArena.h"

#include "RenderLayer.h"

#include "RenderView.h"

namespace WebCore {

LayoutState::LayoutState(LayoutState* prev, RenderBox* renderer, const IntSize& offset)

{

    ASSERT(prev);

    m_next = prev;

    bool fixed = renderer->isPositioned() && renderer->style()->position() == FixedPosition;

    if (fixed) {

        int fixedX = 0;

        int fixedY = 0;

        renderer->view()->absolutePosition(fixedX, fixedY, true);

        m_offset = IntSize(fixedX, fixedY) + offset;

    } else

        m_offset = prev->m_offset + offset;

    if (renderer->isRelPositioned()) {

        int relX = 0;

        int relY = 0;

        renderer->layer()->relativePositionOffset(relX, relY);

        m_offset += IntSize(relX, relY);

    } else if (renderer->isPositioned() && !fixed) {

        if (RenderObject* container = renderer->container())

            m_offset += renderer->offsetForPositionedInContainer(container);

    }

    m_clipped = !fixed && prev->m_clipped;

    if (m_clipped)

        m_clipRect = prev->m_clipRect;

    if (renderer->hasOverflowClip()) {

        int x = m_offset.width();

        int y = m_offset.height();

        RenderLayer* layer = renderer->layer();

        IntRect clipRect(x, y, layer->width(), layer->height());

        if (m_clipped)

            m_clipRect.intersect(clipRect);

        else {

            m_clipRect = clipRect;

            m_clipped = true;

        }

        layer->subtractScrollOffset(x, y);

        m_offset = IntSize(x, y);

    }

    // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.

}

LayoutState::LayoutState(RenderObject* root)

{

    RenderObject* container = root->container();

    m_clipped = true;

    m_clipRect = container->absoluteClippedOverflowRect();

    int x = 0;

    int y = 0;

    container->absolutePosition(x, y);

    m_offset = IntSize(x, y);

    m_next = 0;

}

#ifndef NDEBUG

static bool inLayoutStateDestroy;

#endif

void LayoutState::destroy(RenderArena* renderArena)

{

#ifndef NDEBUG

    inLayoutStateDestroy = true;

#endif

    delete this;

#ifndef NDEBUG

    inLayoutStateDestroy = false;

#endif

    renderArena->free(*(size_t*)this, this);

}

void* LayoutState::operator new(size_t sz, RenderArena* renderArena) throw()

{

    return renderArena->allocate(sz);

}

void LayoutState::operator delete(void* ptr, size_t sz)

{

    ASSERT(inLayoutStateDestroy);

    *(size_t*)ptr = sz;

}

} // namespace WebCore