// $Revision: 1.2 $
//------------------------------------------------------------------------------
//
// Copyright (C) 1994, 1995 Taligent, Inc. All rights reserved.
//
// Project:			Atomic Model
// File:			AtomicModel.h
// Build/Version:	1.0.0
//
// Description:		MAtomicModelOn serves an abstract base class for model
//					objects that hold one, atomic piece of data.
//
//					MAtomicSelectionOn serves as abstract base class for
//					selection objects that specify the entire value object
//					owned by an atomic model object. MAtomicSelectionOn
//					contains the abstract protocol required to access the
//					model data from a selection. If possible, use it as the
//					target of your command.  That way your command will 
// 					work with other kinds of models which implement
//					MAtomicSelectionOn's methods in other ways.
//
//					TAtomicModelOn is a templatized concrete model wrapper
//					for a single polymorphic object of any type. AType
// 					must have the Taligent Type Extension macros. Here are
//					some possible instantiations:
//						TAtomicModelOn<TCollectibleLong> myModel;
//						TAtomicModelOn<MGraphic> myGraphicModel;
//						TAtomicModelOn<TText> myTextModel;
//
//					TAtomicSelectionOn is a whole-model selection for an
//					atomic model on a value object of any type.
//
//					TAtomicModelException defines the errors that can be
//					generated by the Atomic Model classes.
//
//------------------------------------------------------------------------------

#ifndef TaligentSamples_ATOMICMODEL
#define TaligentSamples_ATOMICMODEL

#ifndef Taligent_COMPOUNDDOCUMENT
#include <Taligent/CompoundDocument.h>
#endif

#ifndef Taligent_BASICDOCUMENTCOMMAND
#include <Taligent/BasicDocumentCommand.h>
#endif

#ifndef Taligent_COMPOUNDDOCUMENTCOMMAND
#include <Taligent/CompoundDocumentCommand.h>
#endif

template <class AType>
class MAtomicSelectionOn;

//==============================================================================
// MAtomicModelOn

template <class AType>
class MAtomicModelOn {
public:
	TaligentTypeExtensionTemplateDeclarationsMacro_Abstract(MAtomicModelOn,AType)
	
public:
	virtual					~MAtomicModelOn();
	
	virtual	const AType*	GetValueForReading() const = 0;
	virtual	AType*			GetValueForWriting() = 0;
	virtual	void			SetValue(const AType& newValue) = 0;
	virtual	AType*			CopyValue() const = 0;
	virtual	void			AdoptValue(AType* adoptedNewValue) = 0;
	virtual	AType*			SwapValue(AType* adoptedNewValue) = 0;
	virtual	void			SwapContents(MAtomicModelOn<AType>& other) = 0;
	virtual MAtomicSelectionOn<AType>*
							CreateAtomicSelectionOn() const = 0;
	virtual void			NotifyValueChanged() = 0;	// Produces SelectedContentsReplaced notification.

	//..........................................................................
	// Lookup functions

	static const MAtomicModelOn<AType>*
							LookupForReading(const TModelReference& model);
	static MAtomicModelOn<AType>*
							LookupForWriting(const TModelReference& model);

protected:
							MAtomicModelOn();
};

//==============================================================================
// MAtomicSelectionOn

template <class AType>
class MAtomicSelectionOn {
public:
	TaligentTypeExtensionTemplateDeclarationsMacro_Abstract(MAtomicSelectionOn,AType)

public:
	virtual					~MAtomicSelectionOn();
	
	virtual const MAtomicModelOn<AType>*
							GetAtomicModelOnForReading() const = 0;
	virtual MAtomicModelOn<AType>*
							GetAtomicModelOnForWriting() = 0;

	//..........................................................................
	// These functions delegate to the model protocol, with an
	// additional check for the selection being empty or undefined.)

	virtual	const AType*	GetValueForReading() const;
	virtual	AType*			GetValueForWriting();
	virtual	void			SetValue(const AType& newValue);
	virtual	AType*			CopyValue() const;
	virtual	void			AdoptValue(AType* adoptedNewValue);
	virtual	AType*			SwapValue(AType* adoptedNewValue);
	virtual	void			SwapContents(MAtomicModelOn<AType>& other);

protected:
							MAtomicSelectionOn();

	void					CheckValueSelected() const;
};

//==============================================================================
// TAtomicModelOn

template <class AType>
class TAtomicModelOn : public TModel, public MAtomicModelOn<AType> {
public:
	TaligentTypeExtensionTemplateDeclarationsMacro(TAtomicModelOn,AType)

public:
								TAtomicModelOn(AType* adopt);
								TAtomicModelOn(const AType& copy);
								TAtomicModelOn(const TAtomicModelOn<AType>& source);
	virtual						~TAtomicModelOn();
	
	TAtomicModelOn<AType>&		operator=(const TAtomicModelOn<AType>& source);
	virtual	TStream &			operator>>=(TStream& toStream) const;
	virtual	TStream &			operator<<=(TStream& fromStream);

	//..........................................................................
	// TModel overides

	virtual	TModelSelection*	CreateSelection() const;	// Returns default selection (non-empty, defined).
	virtual HashResult			ContentHash() const;
	virtual bool				IsContentEqual(const TModel& other) const;
	virtual bool				IsOrphanable() const;		// Returns false

	//..........................................................................
	// MAtomicModelOn overrides

	virtual const AType*		GetValueForReading() const;
	virtual AType*				GetValueForWriting();
	virtual void				SetValue(const AType& newValue);
	virtual AType*				CopyValue() const;
	virtual	void				AdoptValue(AType* adoptedNewValue);
	virtual	AType*				SwapValue(AType* adoptedNewValue);
	virtual	void				SwapContents(MAtomicModelOn<AType>& other);
	virtual MAtomicSelectionOn<AType>*
								CreateAtomicSelectionOn() const;
	void						NotifyValueChanged();	// SelectedContentsReplaced

	//..........................................................................
	// Lookup functions

	static const TAtomicModelOn<AType>*
								LookupForReading(const TModelReference& model);
	static TAtomicModelOn<AType>*
								LookupForWriting(const TModelReference& model);

protected:
								TAtomicModelOn();		// For streaming only.

private:
	enum						{kOriginalVersion};

	AType*						fValue;
};

//==============================================================================
// TAtomicSelectionOn

template <class AType>
class TAtomicSelectionOn : public TModelSelection, public MDataExchanger,
	public MAtomicSelectionOn<AType> {
public:
	TaligentTypeExtensionTemplateDeclarationsMacro(TAtomicSelectionOn,AType)
		
public:
								TAtomicSelectionOn(
									const TModelReference& theModel);
								TAtomicSelectionOn(
									const TAtomicSelectionOn<AType>& other);
	virtual						~TAtomicSelectionOn();

	TAtomicSelectionOn<AType>&	operator=(const TAtomicSelectionOn<AType>& other);
	
	//..........................................................................
	// MAtomicValueOn overrides - If the selection is empty or undefined,
	// these methods will throw TAtomicModelException::kNoValueSelected.

	virtual const MAtomicModelOn<AType>*
								GetAtomicModelOnForReading() const;
	virtual MAtomicModelOn<AType>*
								GetAtomicModelOnForWriting();

protected:
								TAtomicSelectionOn();

	//..........................................................................
	// MDataExchanger overrides

	virtual	TModel*				HandleCopyData(const TTypeDescription& type) const;
	virtual	void				HandleCopyDataInto(TModel& otherModel) const;
	virtual	TModel*				HandleReplaceData(TModel* adoptedNewData);
	virtual	TModel*				HandleOrphanData();

private:
	enum						{kOriginalVersion};
};

//==============================================================================
// TAtomicModelException

class TAtomicModelException : public TStandardException {
public:
	TaligentTypeExtensionDeclarationsMacro(TAtomicModelException)

public:
	enum ErrorCode {
	    kCannotStoreNIL = 0x01,
	    kCannotOrphanData = 0x02,
	    kNoValueSelected = 0x03
	};

								TAtomicModelException(const TAtomicModelException& source);
								TAtomicModelException(ErrorCode error);
	virtual						~TAtomicModelException();
	
	TAtomicModelException&		operator=(const TAtomicModelException& source);
	virtual void				Throw() const;
	ErrorCode					GetReason() const;

protected:
								TAtomicModelException();	// For streaming only.
};

#ifndef TaligentSamples_ATOMICMODELIMP
#include <AtomicModelImp.h>
#endif

#endif