Memento.h

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#pragma once
#ifndef __MEMENTO_H__
#define __MEMENTO_H__
 
#include <memory>
#include <string>
 
namespace DesignPatternExamples_cpp
{
 
    struct IMemento
    {
        using shared_ptr_t = std::shared_ptr<IMemento>;
 
        virtual ~IMemento() {}
 
        virtual std::string Name() = 0;
    };
 
 
    //########################################################################
    //########################################################################
 
 
    class Memento_TextObject
    {
    private:
        //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
        // Inner class Memento
 
        class Memento : public IMemento
        {
            std::string _name;
 
            std::string _text;
 
        public:
            Memento(std::string name, std::string text)
            {
                _name = name;
                _text = text;
            }
 
 
            std::string Text()
            {
                return _text;
            }
 
            std::string Name() override
            {
                return _name;
            }
        };
 
        // End of Inner class Memento
        //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
        //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
 
        //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
        // Private data of the Memento_TextObject class.
 
        std::string _text;
 
        // End private data of the Memento_TextObject class.
        //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
        //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
    public:
 
        Memento_TextObject(std::string text)
        {
            _text = text;
        }
 
        std::string Text()
        {
            return _text;
        }
 
        void SetText(const std::string& value)
        {
            _text = value;
        }
 
        IMemento::shared_ptr_t GetMemento(std::string operationName)
        {
            return std::make_shared<Memento>(operationName, _text);
        }
 
 
        void RestoreMemento(IMemento::shared_ptr_t memento)
        {
            if (memento != nullptr)
            {
                _text = dynamic_cast<Memento*>(memento.get())->Text();
            }
        }
 
 
        std::string ToString()
        {
            return _text;
        }
    };
 
} // end namespace
 
#endif // __MEMENTO_H__