/*

 * Copyright (C) 2007, 2008 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 "RenderBlock.h"

#include "htmlediting.h"

namespace WebCore {

using namespace HTMLNames;

PositionIterator::operator Position() const

{

    if (m_nodeAfterPositionInAnchor) {

        ASSERT(m_nodeAfterPositionInAnchor->parentNode() == m_anchorNode);

        return positionInParentBeforeNode(m_nodeAfterPositionInAnchor);

    }

    if (m_anchorNode->hasChildNodes())

        return lastDeepEditingPositionForNode(m_anchorNode);

    return Position(m_anchorNode, m_offsetInAnchor);

}

void PositionIterator::increment()

{

    if (!m_anchorNode)

        return;

    if (m_nodeAfterPositionInAnchor) {

        m_anchorNode = m_nodeAfterPositionInAnchor;

        m_nodeAfterPositionInAnchor = m_anchorNode->firstChild();

        m_offsetInAnchor = 0;

        return;

    }

    if (!m_anchorNode->hasChildNodes() && m_offsetInAnchor < lastOffsetForEditing(m_anchorNode))

        m_offsetInAnchor = Position::uncheckedNextOffset(m_anchorNode, m_offsetInAnchor);

    else {

        m_nodeAfterPositionInAnchor = m_anchorNode;

        m_anchorNode = m_nodeAfterPositionInAnchor->parentNode();

        m_nodeAfterPositionInAnchor = m_nodeAfterPositionInAnchor->nextSibling();

        m_offsetInAnchor = 0;

    }

}

void PositionIterator::decrement()

{

    if (!m_anchorNode)

        return;

    if (m_nodeAfterPositionInAnchor) {

        m_anchorNode = m_nodeAfterPositionInAnchor->previousSibling();

        if (m_anchorNode) {

            m_nodeAfterPositionInAnchor = 0;

            m_offsetInAnchor = m_anchorNode->hasChildNodes() ? 0 : lastOffsetForEditing(m_anchorNode);

        } else {

            m_nodeAfterPositionInAnchor = m_nodeAfterPositionInAnchor->parentNode();

            m_anchorNode = m_nodeAfterPositionInAnchor->parentNode();

            m_offsetInAnchor = 0;

        }

        return;

    }

    if (m_anchorNode->hasChildNodes()) {

        m_anchorNode = m_anchorNode->lastChild();

        m_offsetInAnchor = m_anchorNode->hasChildNodes()? 0: lastOffsetForEditing(m_anchorNode);

    } else {

        if (m_offsetInAnchor)

            m_offsetInAnchor = Position::uncheckedPreviousOffset(m_anchorNode, m_offsetInAnchor);

        else {

            m_nodeAfterPositionInAnchor = m_anchorNode;

            m_anchorNode = m_anchorNode->parentNode();

        }

    }

}

bool PositionIterator::atStart() const

{

    if (!m_anchorNode)

        return true;

    if (m_anchorNode->parentNode())

        return false;

    return (!m_anchorNode->hasChildNodes() && !m_offsetInAnchor) || (m_nodeAfterPositionInAnchor && !m_nodeAfterPositionInAnchor->previousSibling());

}

bool PositionIterator::atEnd() const

{

    if (!m_anchorNode)

        return true;

    if (m_nodeAfterPositionInAnchor)

        return false;

    return !m_anchorNode->parentNode() && (m_anchorNode->hasChildNodes() || m_offsetInAnchor >= lastOffsetForEditing(m_anchorNode));

}

bool PositionIterator::atStartOfNode() const

{

    if (!m_anchorNode)

        return true;

    if (!m_nodeAfterPositionInAnchor)

        return !m_anchorNode->hasChildNodes() && !m_offsetInAnchor;

    return !m_nodeAfterPositionInAnchor->previousSibling();

}

bool PositionIterator::atEndOfNode() const

{

    if (!m_anchorNode)

        return true;

    if (m_nodeAfterPositionInAnchor)

        return false;

    return m_anchorNode->hasChildNodes() || m_offsetInAnchor >= lastOffsetForEditing(m_anchorNode);

}

bool PositionIterator::isCandidate() const

{

    if (!m_anchorNode)

        return false;

    RenderObject* renderer = m_anchorNode->renderer();

    if (!renderer)

        return false;

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

        return false;

    if (renderer->isBR())

        return !m_offsetInAnchor && !Position::nodeIsUserSelectNone(m_anchorNode->parent());

    if (renderer->isText())

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

    if (isTableElement(m_anchorNode) || editingIgnoresContent(m_anchorNode))

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

    if (!m_anchorNode->hasTagName(htmlTag) && renderer->isBlockFlow()) {

        if (toRenderBlock(renderer)->height() || m_anchorNode->hasTagName(bodyTag)) {

            if (!Position::hasRenderedNonAnonymousDescendantsWithHeight(renderer))

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

            return m_anchorNode->isContentEditable() && !Position::nodeIsUserSelectNone(m_anchorNode) && Position(*this).atEditingBoundary();

        }

    }

    return false;

}

} // namespace WebCore