
#ifndef _MFnBase
#define _MFnBase
//
//-
// ==========================================================================
// Copyright  (C)  Alias Systems,  a division  of  Silicon Graphics  Limited.
// All rights  reserved.  These coded  instructions,  statements and computer
// programs  contain  unpublished information  proprietary to  Alias Systems,
// a  division  of  Silicon  Graphics  Limited,  which  is  protected by  the
// Canadian  and  US federal copyright law and  may not be disclosed to third
// parties or  copied  or  duplicated,  in  whole  or in part,  without prior
// written  consent  of Alias Systems, a division of Silicon Graphics Limited
// ==========================================================================
//+
//
// CLASS:    MFnBase
//
// *****************************************************************************
//
// CLASS DESCRIPTION (MFnBase)
//
// The API provides access to Maya Objects as generic MObjects.  Under the
// C++ class scheme MObjects simply have type MObject with no base or
// derived hierarchy.  However,  MObjects may be many different types of
// model or scene objects, from Attributes to Xforms, within Maya.  This
// allows many different types of objects to be moved across or accessed
// through the API without undue concern on the part of plug-in developers
// for the type of object being manipulated.
// 
// Since it is impractical to provide every applicable method on MObjects,
// the methods applicable to Maya Objects are encapsulated in Function
// Sets.  Function Sets can be attached to compatible MObjects to provide
// an external interface to methods appropriate to that MObject.
// 
// The link between an MObject and the role it performs as a Maya scene or
// model object, as well as the compatibility between MObjects and
// Function Sets is managed by the API Run-Time Type Identification (RTTI)
// system.  The two key concepts of this system are the Maya Object type
// and the Function Set type (both are MFn::Type).  All MObjects have
// one and only one Maya Object type.  All Function Sets have one and only
// one Function Set type.  MObjects may, however, be compatible with many
// types of Function Sets.  This compatibility follows the class hierarchy
// of the Function Sets.  Thus an MObject with Maya Object type
// MFn::kNurbsSurface would be compatible with MFnNurbsSurface,
// MFnDagNode, MFnDependencyNode, MFnNamedObject and MFnBase.
// 
// Any MObject can be queried with the MObject::hasFn() method to
// determine if it is comaptible with a given Function Set.
// 
// The purpose of the Base Function Set (MFnBase) is to provide methods
// for determining whether or not a Function Set is compatible with a
// given Maya Object (MObject) type (MFn::Type) or a specific MObject.  See:
// 				MFnBase::hasObj(MFn::Type)
// 						and
// 				MFnBase::hasObj(const MObject &)
// 
// As well, this Function Set provides virtual methods for determining the
// type of a Function Set under the API RTTI system. 
//
// *****************************************************************************

#if defined __cplusplus

// *****************************************************************************

// INCLUDED HEADER FILES



#include <maya/MFn.h>
#include <maya/MStatus.h>
#include <maya/MTypes.h>

// *****************************************************************************

// DECLARATIONS

class MObject;
class MPtrBase;

// *****************************************************************************

// CLASS DECLARATION (MFnBase)

///  Function Set Base Class
/**

Defines the interface for the API RTTI and Maya Object attachment methods
common to all Function Set Classes.

Implements the Function Set compatibility test methods for all Function Sets.

*/
#ifdef _WIN32
#pragma warning(disable: 4522)
#endif // _WIN32

class OPENMAYA_EXPORT MFnBase  
{
public:
    ///
 	virtual				~MFnBase();
    ///
	virtual MFn::Type	type() const;
    ///
	bool				hasObj( MFn::Type ) const;
    ///
	bool				hasObj( const MObject & ) const;
	///
	MObject				object( MStatus* ReturnStatus = NULL ) const;
    ///
 	virtual MStatus		setObject( MObject & object );
    ///
 	virtual MStatus		setObject( const MObject & object );

protected:
	MFnBase(); 
	virtual const char*	className() const;
	void				setPtr( MPtrBase* );
	void				setPtr( const MPtrBase* );
	void				setPtrNull();
	virtual bool		objectChanged( MFn::Type, MStatus * );
 	MPtrBase* 			f_ptr;	    // initialized/set with volatile
 	const MPtrBase*		f_constptr;	// initialized/set with volatile/const

	// Specific for function sets which use internally reference counted objects!
	// Only those function sets which use these objects need to set this to true.
	// By default it is set to false.
	//
	// Classes which do not use internally reference counted objects must not
	// tamper with this boolean value. Doing so can cause crashes when dealing with
	// manually deleted objects.
	//
	bool				fIsReferenceCounted;
private:
#ifndef _WIN32
	MFnBase & operator=( const MFnBase & ) const;
#endif
	MFnBase & operator=( const MFnBase & );
	MFnBase * operator& () const;
	MFnBase * operator& ();
};

#ifdef _WIN32
#pragma warning(default: 4522)
#endif // _WIN32

// *****************************************************************************

#define declareMinimalMFn( MFnClass )							 	\
	public:														 	\
		virtual MFn::Type type() const;							 	\
		virtual ~MFnClass();									 	\
																 	\
	protected:													 	\
		virtual const char* className() const;					 	\
																 	\
	private:													 	\
		MFnClass & operator=( const MFnClass & ) const;			 	\
		MFnClass & operator=( const MFnClass & );				 	\
		MFnClass * operator& () const;							 	\
		MFnClass * operator& ()

#define declareMinimalMFnDisallowCopyConstructor( MFnClass )		\
	declareMinimalMFn( MFnClass );								 	\
	private:														\
		MFnClass( const MFnClass &rhs )

#define declareMFn( MFnClass, MFnParentClass )					 	\
	declareMinimalMFn( MFnClass );								 	\
	public:	        											 	\
		MFnClass() {};											 	\
		MFnClass( MObject & object, MStatus * ReturnStatus = NULL );\
		MFnClass( const MObject & object, MStatus * ReturnStatus = NULL )

// Standard MFn class interface *without* the class constructor. This
// is to allow derived MFn classes to optionally specify their own
// custom constructor. For example if they wanted to declare that they
// use internally reference counted objects, they could set fIsReferenceCounted
// to true inside their own custom constructor.
//
#define declareMFnNoConstructor( MFnClass, MFnParentClass )			\
	declareMinimalMFn( MFnClass );									\
	public:															\
		MFnClass( MObject & object, MStatus * ReturnStatus = NULL );\
		MFnClass( const MObject & object, MStatus * ReturnStatus = NULL )


#endif /* __cplusplus */
#endif /* _MFnBase */
