datareference.h

// Copyright (C) 2008,2009,2010 by Philipp Münzel. All rights reserved.
// Released under the terms of the license described in license.txt

#ifndef DATAREFERENCE_H
#define DATAREFERENCE_H

#include "dllexport.h"

#include <string>
#include <boost/date_time.hpp>
#include <boost/function.hpp>

#include "canaerometadata.h"

namespace SCS {

class DLL_PUBLIC TypelessDataReference {
public:

    virtual ~TypelessDataReference() {}

    virtual void update() = 0;

    virtual void readFromCan(const CanAeroMetadata& meta, const can_t& can) = 0;

    virtual std::vector<can_t> write(const CanAeroMetadata& meta) = 0;

    virtual bool needRequest() const = 0;

    virtual void requested() = 0;

    virtual bool hasChanged() const = 0;

    virtual bool isSelfPublished() const = 0;
};


template <typename T>
class DLL_PUBLIC DataReference : public TypelessDataReference
{
public:
    typedef boost::function<void (const T&)> func;

    DataReference(bool own, T* ptr);

    DataReference(bool own, func func_ptr);

    DataReference(bool own, func func_ptr, T* ptr);

    void update();

    virtual void readFromCan(const CanAeroMetadata& meta, const can_t& can);

    std::vector<can_t> write(const CanAeroMetadata& meta);

    bool needRequest() const;

    void requested();

    bool hasChanged() const;

    bool isSelfPublished() const { return m_is_self_published; }

protected:
    unsigned long m_number_of_losses;
    T m_cached_value;
    T m_history_value;

private:
    void checkMessageCode(const CanAeroMetadata& meta, uint8_t msg_code);
    void received();
    std::vector<can_t> writeCan(const CanAeroMetadata& meta, const T&);
    void init();

private:
    T* m_ptr;
    func m_func_ptr;
    bool m_was_requested;
    bool m_has_changed;
    bool m_is_self_published;
    boost::posix_time::ptime m_last_received;

};


}
#endif // DATAREFERENCE_H