ResInsight/Fwk/AppFwk/cafProjectDataModel/cafPdmXml/cafPdmDefaultObjectFactory.h

//##################################################################################################
//
//   Custom Visualization Core library
//   Copyright (C) 2011-2013 Ceetron AS
//
//   This library may be used under the terms of either the GNU General Public License or
//   the GNU Lesser General Public License as follows:
//
//   GNU General Public License Usage
//   This library is free software: you can redistribute it and/or modify
//   it under the terms of the GNU General Public License as published by
//   the Free Software Foundation, either version 3 of the License, or
//   (at your option) any later version.
//
//   This library is distributed in the hope that it will be useful, but WITHOUT ANY
//   WARRANTY; without even the implied warranty of MERCHANTABILITY or
//   FITNESS FOR A PARTICULAR PURPOSE.
//
//   See the GNU General Public License at <<http://www.gnu.org/licenses/gpl.html>>
//   for more details.
//
//   GNU Lesser General Public License Usage
//   This library is free software; you can redistribute it and/or modify
//   it under the terms of the GNU Lesser General Public License as published by
//   the Free Software Foundation; either version 2.1 of the License, or
//   (at your option) any later version.
//
//   This library is distributed in the hope that it will be useful, but WITHOUT ANY
//   WARRANTY; without even the implied warranty of MERCHANTABILITY or
//   FITNESS FOR A PARTICULAR PURPOSE.
//
//   See the GNU Lesser General Public License at <<http://www.gnu.org/licenses/lgpl-2.1.html>>
//   for more details.
//
//##################################################################################################

#pragma once

#include "cafPdmObjectFactory.h"

#include "cafAssert.h"

#include <QString>

#include <map>
#include <vector>

namespace caf
{
//==================================================================================================
/// "Private" class for implementation of a factory for PdmObjectBase derived objects
/// Every PdmObject must register with this factory to be readable
/// This class can be considered private in the Pdm system
//==================================================================================================

class PdmDefaultObjectFactory : public PdmObjectFactory
{
public:
    static PdmDefaultObjectFactory* instance();

    static void createSingleton();
    static void deleteSingleton();

    PdmObjectHandle* create( const QString& classNameKeyword ) override;

    template <typename PdmObjectBaseDerivative>
    bool registerCreator();

    std::vector<QString> classKeywords() const override;

private:
    ~PdmDefaultObjectFactory() override;

    static PdmDefaultObjectFactory* sm_singleton;

    // Internal helper classes

    class PdmObjectCreatorBase
    {
    public:
        PdmObjectCreatorBase()            = default;
        virtual ~PdmObjectCreatorBase()   = default;
        virtual PdmObjectHandle* create() = 0;
    };

    template <typename PdmObjectBaseDerivative>
    class PdmObjectCreator : public PdmObjectCreatorBase
    {
    public:
        PdmObjectHandle* create() override { return new PdmObjectBaseDerivative(); }
    };

    // Map to store factory
    std::map<QString, PdmObjectCreatorBase*> m_factoryMap;
};

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
template <typename PdmObjectBaseDerivative>
bool caf::PdmDefaultObjectFactory::registerCreator()
{
    std::vector<QString> classNameKeywords = PdmObjectBaseDerivative::classKeywordAliases();

    for ( const QString& classNameKeyword : classNameKeywords )
    {
        auto entryIt = m_factoryMap.find( classNameKeyword );
        if ( entryIt != m_factoryMap.end() )
        {
            CAF_ASSERT( classNameKeyword != entryIt->first ); // classNameKeyword has already been used
            CAF_ASSERT( false ); // To be sure ..
            return false; // never hit;
        }
    }
    auto object = new PdmObjectCreator<PdmObjectBaseDerivative>();
    for ( const QString& classNameKeyword : classNameKeywords )
    {
        m_factoryMap[classNameKeyword] = object;
    }
    return true;
}

} // End of namespace caf