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#include "qdaytimeduration_p.h"

#include "qfocus_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

Focus::Focus(const DynamicContext::Ptr &prevContext) : DelegatingDynamicContext(prevContext),
                                                       m_contextSizeCached(-1)
{
    Q_ASSERT(prevContext);
    Q_ASSERT(prevContext != this);
}

xsInteger Focus::contextPosition() const
{
    Q_ASSERT(m_focusIterator);
    return m_focusIterator->position();
}

Item Focus::contextItem() const
{
    Q_ASSERT(m_focusIterator);
    return m_focusIterator->current();
}

xsInteger Focus::contextSize()
{
    Q_ASSERT(m_focusIterator);
    if(m_contextSizeCached == -1)
        m_contextSizeCached = m_focusIterator->copy()->count();

    Q_ASSERT_X(m_contextSizeCached == m_focusIterator->copy()->count(), Q_FUNC_INFO,
               "If our cache is not the same as the real count, something is wrong.");

    return m_contextSizeCached;
}

void Focus::setFocusIterator(const Item::Iterator::Ptr &it)
{
    Q_ASSERT(it);
    m_focusIterator = it;
}

Item::Iterator::Ptr Focus::focusIterator() const
{
    return m_focusIterator;
}

Item Focus::currentItem() const
{
    /* In the case that there is no top level expression that creates a focus,
     * fn:current() should return the focus. This logic achieves this.
     * Effectively we traverse up our "context stack" through recursion, and
     * start returning when we've found the top most focus. */

    const Item current(m_prevContext->currentItem());

    if(current.isNull())
        return m_focusIterator->current();
    else
        return current;
}

QT_END_NAMESPACE