/*

 * 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 "PositionIterator.h"

#include "Node.h"

#include "RenderObject.h"

#include "htmlediting.h"

namespace WebCore {

using namespace HTMLNames;

void PositionIterator::increment()

{

    if (!m_parent)

        return;

    if (m_child) {

        m_parent = m_child;

        m_child = m_parent->firstChild();

        m_offset = 0;

        return;

    }

    if (!m_parent->hasChildNodes() && m_offset < maxDeepOffset(m_parent))

        m_offset = m_parent->nextOffset(m_offset);

    else {

        m_child = m_parent;

        m_parent = m_child->parentNode();

        m_child = m_child->nextSibling();

        m_offset = 0;

    }

}

void PositionIterator::decrement()

{

    if (!m_parent)

        return;

    if (m_child) {

        m_parent = m_child->previousSibling();

        if (m_parent) {

            m_child = 0;

            m_offset = m_parent->hasChildNodes() ? 0 : maxDeepOffset(m_parent);

        } else {

            m_child = m_child->parentNode();

            m_parent = m_child->parentNode();

            m_offset = 0;

        }

        return;

    }

    if (m_offset) {

        m_offset = m_parent->previousOffset(m_offset);

    } else {

        if (m_parent->hasChildNodes()) {

            m_parent = m_parent->lastChild();

            if (!m_parent->hasChildNodes())

                m_offset = maxDeepOffset(m_parent);

        } else {

            m_child = m_parent;

            m_parent = m_parent->parentNode();

        }

    }

}

bool PositionIterator::atStart() const

{

    if (!m_parent)

        return true;

    if (m_parent->parentNode())

        return false;

    return !m_parent->hasChildNodes() && !m_offset || m_child && !m_child->previousSibling();

}

bool PositionIterator::atEnd() const

{

    if (!m_parent)

        return true;

    if (m_child)

        return false;

    return !m_parent->parentNode() && (m_parent->hasChildNodes() || m_offset >= maxDeepOffset(m_parent));

}

bool PositionIterator::atStartOfNode() const

{

    if (!m_parent)

        return true;

    if (!m_child)

        return !m_parent->hasChildNodes() && !m_offset;

    return !m_child->previousSibling();

}

bool PositionIterator::atEndOfNode() const

{

    if (!m_parent)

        return true;

    if (m_child)

        return false;

    return m_parent->hasChildNodes() || m_offset >= maxDeepOffset(m_parent);

}

bool PositionIterator::isCandidate() const

{

    if (!m_parent)

        return false;

    RenderObject* renderer = m_parent->renderer();

    if (!renderer)

        return false;

    if (renderer->style()->visibility() != VISIBLE)

        return false;

    if (renderer->isBR())

        return !m_offset && !Position::nodeIsUserSelectNone(m_parent->parent());

    if (renderer->isText())

        return Position(*this).inRenderedText() && !Position::nodeIsUserSelectNone(m_parent);

    if (isTableElement(m_parent) || editingIgnoresContent(m_parent))

        return (atStartOfNode() || atEndOfNode()) && !Position::nodeIsUserSelectNone(m_parent->parent());

    if (!m_parent->hasTagName(htmlTag) && renderer->isBlockFlow() && !Position::hasRenderedNonAnonymousDescendantsWithHeight(renderer) &&

       (renderer->height() || m_parent->hasTagName(bodyTag)))

        return atStartOfNode() && !Position::nodeIsUserSelectNone(m_parent);

    return false;

}

} // namespace WebCore