--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/iterators/qitemmappingiterator_p.h Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,190 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 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.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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
+** 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+// 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_ItemMappingIterator_H
+#define Patternist_ItemMappingIterator_H
+
+#include "qabstractxmlforwarditerator_p.h"
+#include "qdynamiccontext_p.h"
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+namespace QPatternist
+{
+ /**
+ * @short Proxies another QAbstractXmlForwardIterator, and for each item, returns the
+ * Item returned from a mapping function.
+ *
+ * ItemMappingIterator is practical when the items in an QAbstractXmlForwardIterator needs to
+ * be translated to another sequence, while still doing it in a pipe-lined
+ * fashion.
+ *
+ * This is achieved by that ItemMappingIterator's constructor takes
+ * an instance of a class, that must have the following member:
+ *
+ * @code
+ * TResult::Ptr mapToItem(const TSource &item,
+ * const Context &context) const
+ * @endcode
+ *
+ * For each item in the QAbstractXmlForwardIterator ItemMappingIterator proxies, this function is
+ * called and its return value becomes the return value of the ItemMappingIterator. If the
+ * mapping function returns null, ItemMappingIterator maps the next item in the source sequence
+ * such that a contiguous sequence of items is returned.
+ *
+ * Declaring the mapToItem() function as inline, can be a good way to improve performance.
+ *
+ * @see SequenceMappingIterator
+ * @author Frans Englich <frans.englich@nokia.com>
+ * @ingroup Patternist_iterators
+ */
+ template<typename TResult, typename TSource, typename TMapper, typename Context = DynamicContext::Ptr>
+ class ItemMappingIterator : public QAbstractXmlForwardIterator<TResult>
+ {
+ public:
+ /**
+ * Constructs an ItemMappingIterator.
+ *
+ * @param mapper the object that has the mapToItem() sequence.
+ * @param iterator the QAbstractXmlForwardIterator whose items should be mapped.
+ * @param context the context that will be passed to the map function.
+ * May be null.
+ */
+ ItemMappingIterator(const TMapper &mapper,
+ const typename QAbstractXmlForwardIterator<TSource>::Ptr &iterator,
+ const Context &context) : m_mapper(mapper)
+ , m_it(iterator)
+ , m_context(context)
+ , m_position(0)
+ {
+ Q_ASSERT(mapper);
+ Q_ASSERT(iterator);
+ }
+
+ /**
+ * @returns the next item in the sequence, or
+ * @c null if the end have been reached.
+ */
+ virtual TResult next()
+ {
+ const TSource sourceItem(m_it->next());
+
+ if(qIsForwardIteratorEnd(sourceItem))
+ {
+ m_current = TResult();
+ m_position = -1;
+ return TResult();
+ }
+ else
+ {
+ m_current = m_mapper->mapToItem(sourceItem, m_context);
+ if(qIsForwardIteratorEnd(m_current))
+ return next(); /* The mapper returned null, so continue with the next in the source. */
+ else
+ {
+ ++m_position;
+ return m_current;
+ }
+ }
+ }
+
+ virtual TResult current() const
+ {
+ return m_current;
+ }
+
+ virtual xsInteger position() const
+ {
+ return m_position;
+ }
+
+ virtual typename QAbstractXmlForwardIterator<TResult>::Ptr copy() const
+ {
+ return typename QAbstractXmlForwardIterator<TResult>::Ptr
+ (new ItemMappingIterator<TResult, TSource, TMapper, Context>(m_mapper, m_it->copy(), m_context));
+ }
+
+ private:
+ const TMapper m_mapper;
+ const typename QAbstractXmlForwardIterator<TSource>::Ptr m_it;
+ const Context m_context;
+ TResult m_current;
+ xsInteger m_position;
+ };
+
+ /**
+ * @short An object generator for ItemMappingIterator.
+ *
+ * makeItemMappingIterator() is a convenience function for avoiding specifying
+ * the full template instantiation for ItemMappingIterator. Conceptually, it
+ * is identical to Qt's qMakePair().
+ *
+ * @relates ItemMappingIterator
+ */
+ template<typename TResult, typename TSource, typename TMapper, typename Context>
+ static inline
+ typename QAbstractXmlForwardIterator<TResult>::Ptr
+ makeItemMappingIterator(const TMapper &mapper,
+ const QExplicitlySharedDataPointer<QAbstractXmlForwardIterator<TSource> > &source,
+ const Context &context)
+ {
+ return typename QAbstractXmlForwardIterator<TResult>::Ptr
+ (new ItemMappingIterator<TResult, TSource, TMapper, Context>(mapper, source, context));
+ }
+}
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif