/****************************************************************************

**

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** This file is part of the QtXmlPatterns module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

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**

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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 QABSTRACTXMLFORWARDITERATOR_H

#define QABSTRACTXMLFORWARDITERATOR_H

#include <QtCore/QList>

#include <QtCore/QVector>

#include <QtCore/QSharedData>

#include <QtCore/QString>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(XmlPatterns)

template<typename T> class QVector;

/* In this file we in some cases do not use QAbstractXmlForwardIterator's Ptr typedef.

 * This is a compiler workaround for MS VS 6.0. */

template<typename T>

inline bool qIsForwardIteratorEnd(const T &unit)

{

    return !unit;

}

/**

 * @short Helper class for StringSplitter

 *

 * Needed by the QAbstractXmlForwardIterator sub-class.

 *

 * @relates StringSplitter

 */

template<>

inline bool qIsForwardIteratorEnd(const QString &unit)

{

    return unit.isNull();

}

template<typename T> class QAbstractXmlForwardIterator;

class QAbstractXmlForwardIteratorPrivate;

template<typename T>

class QAbstractXmlForwardIterator : public QSharedData

{

public:

    typedef QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<T> > Ptr;

    typedef QList<QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<T> > > List;

    typedef QVector<QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<T> > > Vector;

    inline QAbstractXmlForwardIterator() : d_ptr(0) {}

    virtual ~QAbstractXmlForwardIterator() {}

    virtual T next() = 0;

    virtual T current() const = 0;

    virtual qint64 position() const = 0;

    virtual typename QAbstractXmlForwardIterator<T>::Ptr toReversed();

    virtual QList<T> toList();

    virtual typename QAbstractXmlForwardIterator<T>::Ptr copy() const;

    virtual T last();

    virtual bool isEmpty();

    virtual qint64 count();

    virtual qint64 sizeHint() const;

private:

    Q_DISABLE_COPY(QAbstractXmlForwardIterator<T>)

    QAbstractXmlForwardIteratorPrivate *d_ptr; /* Currently not used. */

};

/* The namespace QPatternist and its members are internal, not part of the public API, and

 * unsupported. Using them leads to undefined behavior. */

namespace QPatternist

{

    class DeduplicateIterator;

    template<typename InputType,

             typename OutputType,

             typename Derived,

             typename ListType = QList<InputType> >

    class ListIteratorPlatform : public QAbstractXmlForwardIterator<OutputType>

    {

        /* This declaration is a workaround for a set of GCC versions on OS X,

         * amongst others powerpc-apple-darwin8-gcc-4.0.1 (GCC) 4.0.1. In

         * DeduplicateIterator, it fails to see the protected inheritance. */

        friend class DeduplicateIterator;

    public:

        virtual OutputType next()

        {

            if(m_position == -1)

                return OutputType();

            if(m_position == m_list.count())

            {

                m_position = -1;

                m_current = OutputType();

                return OutputType();

            }

            m_current = static_cast<const Derived *>(this)->inputToOutputItem(m_list.at(m_position));

            ++m_position;

            return m_current;

        }

        virtual OutputType current() const

        {

            return m_current;

        }

        virtual qint64 position() const

        {

            return m_position;

        }

        virtual qint64 count()

        {

            return m_list.count();

        }

        virtual typename QAbstractXmlForwardIterator<OutputType>::Ptr copy() const

        {

            return QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<OutputType> >(new ListIteratorPlatform<InputType, OutputType, Derived, ListType>(m_list));

        }

    protected:

        inline ListIteratorPlatform(const ListType &list) : m_list(list)

                                                           , m_position(0)

        {

        }

        const ListType  m_list;

        qint64          m_position;

        OutputType      m_current;

    };

    template<typename T,

             typename ListType = QList<T> >

    class ListIterator : public ListIteratorPlatform<T, T, ListIterator<T, ListType>, ListType>

    {

	/*

	 * This declaration is needed for MSVC 2005, 14.00.50727.42 for 80x86.

	 */

	friend class IteratorVector;

        using ListIteratorPlatform<T, T, ListIterator<T, ListType>, ListType>::m_list;

        static inline QVector<T> toVector(const QVector<T> &vector)

        {

            return vector;

        }

        static inline QVector<T> toVector(const QList<T> &list)

        {

            return list.toVector();

        }

        static inline QList<T> toList(const QVector<T> &vector)

        {

            return vector.toList();

        }

        static inline QList<T> toList(const QList<T> &list)

        {

            return list;

        }

    public:

        inline ListIterator(const ListType &list) : ListIteratorPlatform<T, T, ListIterator<T, ListType>, ListType>(list)

        {

        }

        virtual QList<T> toList()

        {

            return toList(m_list);

        }

        virtual QVector<T> toVector()

        {

            return toVector(m_list);

        }

    private:

        inline const T &inputToOutputItem(const T &inputType) const

        {

            return inputType;

        }

        friend class ListIteratorPlatform<T, T, ListIterator<T, ListType>, ListType>;

        // needed for MSVC 2005

        friend class DeduplicateIterator;

    };

    template<typename T>

    inline

    typename QAbstractXmlForwardIterator<T>::Ptr

    makeListIterator(const QList<T> &list)

    {

        return typename ListIterator<T>::Ptr(new ListIterator<T>(list));

    }

    template<typename T>

    inline

    typename QAbstractXmlForwardIterator<T>::Ptr

    makeVectorIterator(const QVector<T> &vector)

    {

        return typename ListIterator<T, QVector<T> >::Ptr(new ListIterator<T, QVector<T> >(vector));

    }

}

template<typename T>

QList<T> QAbstractXmlForwardIterator<T>::toList()

{

    QList<T> result;

    T item(next());

    while(!qIsForwardIteratorEnd(item))

    {

        result.append(item);

        item = next();

    }

    return result;

}

template<typename T>

qint64 QAbstractXmlForwardIterator<T>::count()

{

    qint64 retval = 0;

    while(!qIsForwardIteratorEnd(next()))

        ++retval;

    return retval;

}

template<typename T>

typename QAbstractXmlForwardIterator<T>::Ptr QAbstractXmlForwardIterator<T>::toReversed()

{

    T item(next());

    QList<T> result;

    while(!qIsForwardIteratorEnd(item))

    {

        result.prepend(item);

        item = next();

    }

    return QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<T> >(new QPatternist::ListIterator<T>(result));

}

template<typename T>

T QAbstractXmlForwardIterator<T>::last()

{

    T item(next());

    while(!qIsForwardIteratorEnd(item))

        item = next();

    return item;

}

template<typename T>

typename QAbstractXmlForwardIterator<T>::Ptr QAbstractXmlForwardIterator<T>::copy() const

{

    Q_ASSERT_X(false, Q_FUNC_INFO,

               "This function is internal, unsupported, and should never be called.");

    return typename QAbstractXmlForwardIterator<T>::Ptr();

}

template<typename T>

bool QAbstractXmlForwardIterator<T>::isEmpty()

{

    return qIsForwardIteratorEnd(next());

}

template<typename T>

qint64 QAbstractXmlForwardIterator<T>::sizeHint() const

{

    Q_ASSERT_X(false, Q_FUNC_INFO, "This function is currently not expected to be used.");

    return -1;

}

QT_END_NAMESPACE

QT_END_HEADER

#endif