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

**

** Copyright (C) 2010 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.

**

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** 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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** $QT_END_LICENSE$

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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 QPatternist_ResourceDelegator_p_H

#define QPatternist_ResourceDelegator_p_H

#include <QSet>

#include <QUrl>

#include "qdeviceresourceloader_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist

{

    /**

     * @short Delegates to another ResourceLoader, but in case a URI is in an

     * exception list, it delegates to a different loader.

     *

     * This is used for handling device variables, since when a device variable

     * is rebound, a resource loader needs to carry that binding, while the

     * resource loader for the other query remains as is.

     *

     * @since 4.5

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

     */

    class ResourceDelegator : public DeviceResourceLoader

    {

    public:

        ResourceDelegator(const QSet<QUrl> &needsOverride,

                          const ResourceLoader::Ptr &parentLoader,

                          const ResourceLoader::Ptr &forDeviceLoader) : m_needsOverride(needsOverride)

                                                                      , m_parentLoader(parentLoader)

                                                                      , m_forDeviceLoader(forDeviceLoader)

        {

            Q_ASSERT(m_parentLoader);

        }

        virtual bool isUnparsedTextAvailable(const QUrl &uri,

                                             const QString &encoding);

        virtual ItemType::Ptr announceUnparsedText(const QUrl &uri);

        virtual Item openUnparsedText(const QUrl &uri,

                                      const QString &encoding,

                                      const ReportContext::Ptr &context,

                                      const SourceLocationReflection *const where);

        virtual Item openDocument(const QUrl &uri,

                                  const ReportContext::Ptr &context);

        virtual SequenceType::Ptr announceDocument(const QUrl &uri, const Usage usageHint);

        virtual bool isDocumentAvailable(const QUrl &uri);

        virtual Item::Iterator::Ptr openCollection(const QUrl &uri);

        virtual SequenceType::Ptr announceCollection(const QUrl &uri);

        /**

         * Returns the union of the deviceURIs() that ResourceDelegator's two

         * resource loaders has.

         */

        virtual QSet<QUrl> deviceURIs() const;

    private:

        const QSet<QUrl> m_needsOverride;

        const ResourceLoader::Ptr m_parentLoader;

        const ResourceDelegator::Ptr m_forDeviceLoader;

    };

}

QT_END_NAMESPACE

QT_END_HEADER

#endif