| /**************************************************************************** |
| ** |
| ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). |
| ** All rights reserved. |
| ** Contact: Nokia Corporation (qt-info@nokia.com) |
| ** |
| ** This file is part of the QtXmlPatterns module of the Qt Toolkit. |
| ** |
| ** $QT_BEGIN_LICENSE:LGPL$ |
| ** GNU Lesser General Public License Usage |
| ** 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 will be met: |
| ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. |
| ** |
| ** In addition, as a special exception, Nokia gives you certain additional |
| ** rights. These rights are described in the Nokia Qt LGPL Exception |
| ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. |
| ** |
| ** GNU General Public License Usage |
| ** Alternatively, this file may be used under the terms of the GNU General |
| ** Public License version 3.0 as published by the Free Software Foundation |
| ** and appearing in the file LICENSE.GPL included in the packaging of this |
| ** file. Please review the following information to ensure the GNU General |
| ** Public License version 3.0 requirements will be met: |
| ** http://www.gnu.org/copyleft/gpl.html. |
| ** |
| ** Other Usage |
| ** Alternatively, this file may be used in accordance with the terms and |
| ** conditions contained in a signed written agreement between you and Nokia. |
| ** |
| ** |
| ** |
| ** |
| ** |
| ** $QT_END_LICENSE$ |
| ** |
| ****************************************************************************/ |
| |
| // |
| // 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_EmptyIterator_H |
| #define Patternist_EmptyIterator_H |
| |
| #include "qabstractxmlforwarditerator_p.h" |
| #include "qprimitives_p.h" |
| |
| QT_BEGIN_HEADER |
| |
| QT_BEGIN_NAMESPACE |
| |
| namespace QPatternist |
| { |
| |
| /** |
| * @short An QAbstractXmlForwardIterator which always is empty. |
| * |
| * EmptyIterator is an QAbstractXmlForwardIterator over the type @c T, which always is empty. Other |
| * iterators can also be empty(or, at least behave as they are empty), but this |
| * class is special designed for this purpose and is therefore fast. |
| * |
| * EmptyIterator's constructor is protected, instances is retrieved from CommonValues. |
| * |
| * @author Frans Englich <frans.englich@nokia.com> |
| * @ingroup Patternist_iterators |
| */ |
| template<typename T> class EmptyIterator : public QAbstractXmlForwardIterator<T> |
| { |
| public: |
| /** |
| * @returns always a default constructed value, T(). |
| */ |
| virtual T next() |
| { |
| return T(); |
| } |
| |
| /** |
| * @returns always a default constructed value, T(). |
| */ |
| virtual T current() const |
| { |
| return T(); |
| } |
| |
| /** |
| * @returns always 0. |
| */ |
| virtual xsInteger position() const |
| { |
| return 0; |
| } |
| |
| /** |
| * @returns always @c this, the reverse of <tt>()</tt> is <tt>()</tt>. |
| */ |
| virtual typename QAbstractXmlForwardIterator<T>::Ptr toReversed() |
| { |
| return typename QAbstractXmlForwardIterator<T>::Ptr(const_cast<EmptyIterator<T> *>(this)); |
| } |
| |
| /** |
| * @returns always 0 |
| */ |
| virtual xsInteger count() |
| { |
| return 0; |
| } |
| |
| /** |
| * @returns @c this |
| */ |
| virtual typename QAbstractXmlForwardIterator<T>::Ptr copy() const |
| { |
| return typename QAbstractXmlForwardIterator<T>::Ptr(const_cast<EmptyIterator *>(this)); |
| } |
| |
| protected: |
| friend class CommonValues; |
| }; |
| |
| template<typename T> |
| static inline |
| typename QAbstractXmlForwardIterator<T>::Ptr |
| makeEmptyIterator() |
| { |
| return typename QAbstractXmlForwardIterator<T>::Ptr(new EmptyIterator<T>()); |
| } |
| |
| } |
| |
| QT_END_NAMESPACE |
| |
| QT_END_HEADER |
| |
| #endif |