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

**

** 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.

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** $QT_END_LICENSE$

**

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

//

//  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_SequenceReceiver_H

#define Patternist_SequenceReceiver_H

#include <QSharedData>

#include "qitem_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist

{

    /**

     * @short A push interface for the XPath Data Model. Similar to SAX's

     * ContentHandler.

     *

     * @ingroup Patternist_xdm

     * @author Frans Englich <frans.englich@nokia.com>

     */

    class QAbstractXmlReceiver : public QSharedData

    {

    public:

        typedef QExplicitlySharedDataPointer<QAbstractXmlReceiver> Ptr;

        inline QAbstractXmlReceiver()

        {

        }

        virtual ~QAbstractXmlReceiver();

        /**

         * @short Signals the start of an element by name @p name.

         */

        virtual void startElement(const QXmlName name) = 0;

        /**

         * @short Signals the presence of the namespace declaration @p nb.

         *

         * This event is received @c after startElement(), as opposed to

         * SAX, and before any attribute() events.

         */

        virtual void namespaceBinding(const QXmlName &nb) = 0;

        /**

         * @short Signals the end of the current element.

         */

        virtual void endElement() = 0;

        /**

         * @short Signals the presence of an attribute node.

         *

         * This function is guaranteed by the caller to always be

         * called after a call to startElement() or attribute().

         *

         * @param name the name of the attribute. Guaranteed to always be

         * non-null.

         * @param value the value of the attribute. Guaranteed to always be

         * non-null.

         */

        virtual void attribute(const QXmlName name,

                               const QString &value) = 0;

        virtual void processingInstruction(const QXmlName name,

                                           const QString &value) = 0;

        virtual void comment(const QString &value) = 0;

        /**

         * @short Sends an Item to this QAbstractXmlReceiver that may be a QXmlNodeModelIndex or an

         * AtomicValue.

         */

        virtual void item(const Item &item) = 0;

        /**

         * Sends a text node with value @p value. Adjascent text nodes

         * may be sent. There's no restrictions on @p value, beyond that it

         * must be valid XML characters. For instance, @p value may contain

         * only whitespace.

         *

         * @see whitespaceOnly()

         */

        virtual void characters(const QString &value) = 0;

        /**

         * This function may be called instead of characters() if, and only if,

         * @p value consists only of whitespace.

         *

         * The caller gurantees that @p value, is not empty.

         *

         * By whitespace is meant a sequence of characters that are either

         * spaces, tabs, or the two new line characters, in any order. In

         * other words, the whole of Unicode's whitespace category is not

         * considered whitespace.

         *

         * However, there's no guarantee or requirement that whitespaceOnly()

         * is called for text nodes containing whitespace only, characters()

         * may be called just as well. This is why the default implementation

         * for whitespaceOnly() calls characters().

         *

         * @see characters()

         */

        virtual void whitespaceOnly(const QStringRef &value);

        /**

         * Start of a document node.

         */

        virtual void startDocument() = 0;

        /**

         * End of a document node.

         */

        virtual void endDocument() = 0;

    protected:

        /**

         * Treats @p outputItem as an node and calls the appropriate function,

         * such as attribute() or comment(), depending on its QXmlNodeModelIndex::NodeKind.

         *

         * This a helper function sub-classes can use to multi-plex Nodes received

         * via item().

         *

         * @param outputItem must be a QXmlNodeModelIndex.

         */

        void sendAsNode(const Item &outputItem);

    private:

        /**

         * Call sendAsNode() for each child of @p node. As consistent with the

         * XPath Data Model, this does not include attribute nodes.

         */

        template<const QXmlNodeModelIndex::Axis axis>

        inline void sendFromAxis(const QXmlNodeModelIndex &node);

        Q_DISABLE_COPY(QAbstractXmlReceiver)

    };

}

QT_END_NAMESPACE

QT_END_HEADER

#endif