#ifndef TPERSIST_INCLUDED

#define TPERSIST_INCLUDED

//#include "tsmartpointer.h"

//#include "tpixel.h"

#include "tcommon.h"

#undef DVAPI

#undef DVVAR

#ifdef TSTREAM_EXPORTS

#define DVAPI DV_EXPORT_API

#define DVVAR DV_EXPORT_VAR

#else

#define DVAPI DV_IMPORT_API

#define DVVAR DV_IMPORT_VAR

#endif

//===================================================================

class TPersistDeclaration;

class TIStream;

class TOStream;

//===================================================================

//! This is an abstract class for load and save data from and to the file system (i.e files on the disk)

class DVAPI TPersist

{

public:

	virtual ~TPersist(){};

	/*!

		This is a pure virtual function and must be overridden with a method that implements 

		the object loading from a stream (i.e take the object's features from a formatted data stream). 

		For example the TStageObject class use his implementation to take the values of the parameters 

		that characterizes a stage object as name, coordinates, etc... from a file.

		\a is is an input file stream

	*/

	virtual void loadData(TIStream &is) = 0;

	/*!

		This is a pure virtual function and must be overridden with a method that implements 

		the object saving to a data stream (i.e put the object's features on a formatted data stream). 

		For example the TStageObject class use his implementation to save the values of the parameters 

		that characterizes a stage object as name, coordinates, etc... on a file

		\a os is an output file stream.

	*/

	virtual void saveData(TOStream &os) = 0;

	/*!

		Returns the string identifier of the object. For example a TXsheet object is identified by "xsheet", 

		a TStageObjectTree is identified by PegbarTree.

	*/

	inline string getStreamTag() const;

	/*!

		This pure virtual method is used to define a global pointer to the object.

		This method is overridden with the macro PERSIST_DECLARATION(T).

	\n	For example:

		\code

class DVAPI TStageObjectTree : public TPersist {

PERSIST_DECLARATION(TStageObjectTree)

public:

...

		\endcode 

	*/

	virtual const TPersistDeclaration *getDeclaration() const = 0;

	typedef TPersist *CreateProc();

	static void declare(CreateProc *);

	/*!

		If the object identified by \a name doesn't exist,

		this method creates it through TPersistDeclarationT class template.

		\sa getDeclaration()

	*/

	static TPersist *create(const string &name);

};

//===================================================================

/*!

		This class is used to store and retrieve the id associated to an object.

		\sa TPersist::getStreamTag().

		The class is istantiated by the macro  PERSIST_DECLARATION(T).

	*/

class DVAPI TPersistDeclaration

{

	string m_id;

public:

	TPersistDeclaration(const string &id);

	virtual ~TPersistDeclaration() {}

	string getId() const { return m_id; };

	virtual TPersist *create() const = 0;

};

//-------------------------------------------------------------------

inline string TPersist::getStreamTag() const { return getDeclaration()->getId(); }

//-------------------------------------------------------------------

/*!

		This template class is used to create an istance of the class \a T.

	*/

template <class t=""></class>

class TPersistDeclarationT : public TPersistDeclaration

{

public:

	/*!

		This is the constructor. Its argument is the id of the object.

		\sa TPersist::getStreamTag()

	*/

	TPersistDeclarationT(const string &id) : TPersistDeclaration(id) {}

	/*!

		Returns a pointer to a newly created object of type TPersist.

		This template class is called by the macro PERSIST_DECLARATION(T).

		A class that calls PERSIST_DECLARATION(T) must inherits TPersist.

	*/

	TPersist *create() const { return new T; };

};

//-------------------------------------------------------------------

/*!	\file tpersist.h  

	*/

/*!

		This macro must be included at the beginning of a class declaration,

		and permits to create a new object of type T with the use of template 

		class TPersistDeclarationT

	*/

#define PERSIST_DECLARATION(T)                        \

private:                                              \

	static TPersistDeclarationT<t> m_declaration;     \</t>

                                                      \

public:                                               \

	const TPersistDeclaration *getDeclaration() const \

	{                                                 \

		return &m_declaration;                        \

	}

#define PERSIST_IDENTIFIER(T, I) \

	TPersistDeclarationT<t> T::m_declaration(I);</t>

//===================================================================

#endif