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#include "qitem_p.h"

#include "qunioniterator_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

UnionIterator::UnionIterator(const Item::Iterator::Ptr &it1,

                             const Item::Iterator::Ptr &it2) : m_it1(it1),

                                                               m_it2(it2),

                                                               m_position(0),

                                                               m_node1(m_it1->next()),

                                                               m_node2(m_it2->next())

{

    Q_ASSERT(m_it1);

    Q_ASSERT(m_it2);

}

Item UnionIterator::next()

{

    ++m_position;

    if(m_node1 && m_node2)

    {

        if(m_node1.asNode().model() != m_node2.asNode().model())

        {

            m_current = m_node1;

            m_node1 = m_it1->next();

            return m_current;

        }

        switch(m_node1.asNode().compareOrder(m_node2.asNode()))

        {

            case QXmlNodeModelIndex::Precedes:

            {

                m_current = m_node1;

                m_node1 = m_it1->next();

                return m_current;

            }

            case QXmlNodeModelIndex::Follows:

            {

                m_current = m_node2;

                m_node2 = m_it2->next();

                return m_current;

            }

            default:

            {

                m_current = m_node2;

                m_node1 = m_it1->next();

                m_node2 = m_it2->next();

                return m_current;

            }

        }

    }

    if(m_node1)

    {

        m_current = m_node1;

        m_node1 = m_it1->next();

        return m_current;

    }

    if(m_node2)

    {

        m_current = m_node2;

        m_node2 = m_it2->next();

        return m_current;

    }

    m_current.reset();

    m_position = -1;

    return Item();

}

Item UnionIterator::current() const

{

    return m_current;

}

xsInteger UnionIterator::position() const

{

    return m_position;

}

Item::Iterator::Ptr UnionIterator::copy() const

{

    return Item::Iterator::Ptr(new UnionIterator(m_it1->copy(), m_it2->copy()));

}

QT_END_NAMESPACE