/****************************************************************************
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** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
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** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
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//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
#ifndef Patternist_Focus_H
#define Patternist_Focus_H
#include "qdelegatingdynamiccontext_p.h"
QT_BEGIN_HEADER
QT_BEGIN_NAMESPACE
namespace QPatternist
{
/**
* @short A DynamicContext that maintains the focus, a sequence
* of items.
*
* Focus implements both the outer and inner focus. The focus is one of
* the things that characterizes the XPath language. The focus is what's
* iterated over in a predicate, whose current item can be received
* via the context item expression, .(the dot),
* and whose size is retrievable via the function fn:last().
*
* @author Frans Englich
*/
class Focus : public DelegatingDynamicContext
{
public:
Focus(const DynamicContext::Ptr &prevContext);
virtual xsInteger contextPosition() const;
virtual Item contextItem() const;
virtual xsInteger contextSize();
virtual void setFocusIterator(const Item::Iterator::Ptr &it);
virtual Item::Iterator::Ptr focusIterator() const;
/**
* If there is no top level expression that sets the current item,
* the focus should be used. This implementation ensures that.
*/
virtual Item currentItem() const;
private:
Item::Iterator::Ptr m_focusIterator;
xsInteger m_contextSizeCached;
};
}
QT_END_NAMESPACE
QT_END_HEADER
#endif