/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
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** accordance with the commercial license agreement provided with the
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** General Public License version 3 as published by the Free Software
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** ensure the GNU Lesser General Public License version 3 requirements
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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 Patternist_SourceLocationReflection_H
#define Patternist_SourceLocationReflection_H

QT_BEGIN_NAMESPACE

class QString;

namespace QPatternist
{
    /**
     * @short Base class for all instances that represents something
     * at a certain location.
     *
     * SourceLocationReflection does not provide the source location itself,
     * the address to an instance is the mark for it, that in turn can be used
     * for looking up the source location where that mapping is provided.
     *
     * However, this SourceLocationReflection is not itself the mark. The real
     * mark is retrieved by calling actualReflection(). This mechanism
     * allows a SourceLocationReflection sub-class to delegate, or be an alias,
     * for another source location mark.
     *
     * If sourceLocation() returns a non-null object, it will be used instead
     * of looking up via actualReflection().
     *
     * @author Frans Englich <frans.englich@nokia.com>
     * @ingroup Patternist_expressions
     */
    class Q_AUTOTEST_EXPORT SourceLocationReflection
    {
    public:
        inline SourceLocationReflection()
        {
        }

        virtual ~SourceLocationReflection()
        {
        }

        virtual const SourceLocationReflection *actualReflection() const = 0;

        /**
         * A description of what represents the source code location, for
         * human consumption. Must be translated, as appropriate.
         */
        virtual QString description() const
        {
            return QString();
        }

        virtual QSourceLocation sourceLocation() const;

    private:
        Q_DISABLE_COPY(SourceLocationReflection)
    };

    class DelegatingSourceLocationReflection : public SourceLocationReflection
    {
    public:
        inline DelegatingSourceLocationReflection(const SourceLocationReflection *const r) : m_r(r)
        {
            Q_ASSERT(r);
        }

        virtual const SourceLocationReflection *actualReflection() const;
        virtual QString description() const;

    private:
        const SourceLocationReflection *const m_r;
    };

}

QT_END_NAMESPACE

#endif
