windows-nt/Source/XPSP1/NT/enduser/stuff/hhctrl/unknown.h

// Copyright 1995-1997 Microsoft Corporation.  All Rights Reserved.

#if _MSC_VER > 1000
#pragma once
#endif

#ifndef _UNKNOWN_H_
#define _UNKNOWN_H_

//=--------------------------------------------------------------------------=
// UNKNOWNOBJECTINFO
//
// if you want a simple co-creatable object, with no other guarantees about
// it, then you need to put the following entry in the global table of objects.
// other object types that are more complex, such as automation objects, and
// controls, will also use this information...

typedef struct {

	const CLSID *rclsid;					// CLSID of your object.	  ONLY USE IF YOU'RE CoCreatable!
	LPCSTR		 pszObjectName; 			// Name of your object. 	  ONLY USE IF YOU'RE CoCreatable!
	IUnknown	*(*pfnCreate)(IUnknown *);	// pointer to creation fn.	  ONLY USE IF YOU'RE CoCreatable!

} UNKNOWNOBJECTINFO;

#define NAMEOFOBJECT(index) 	  (((UNKNOWNOBJECTINFO *)(g_ObjectInfo[(index)]).pInfo)->pszObjectName)
#define CLSIDOFOBJECT(index)	  (*(((UNKNOWNOBJECTINFO *)(g_ObjectInfo[(index)]).pInfo)->rclsid))
#define CREATEFNOFOBJECT(index)   (((UNKNOWNOBJECTINFO *)(g_ObjectInfo[(index)]).pInfo)->pfnCreate)

#ifndef INITOBJECTS

#define DEFINE_UNKNOWNOBJECT(name, clsid, objname, fn) \
extern UNKNOWNOBJECTINFO name##Object \

#else
#define DEFINE_UNKNOWNOBJECT(name, clsid, objname, fn) \
	UNKNOWNOBJECTINFO name##Object = { clsid, objname, fn } \

#endif // INITOBJECTS


//=--------------------------------------------------------------------------=
// DECLARE_STANDARD_UNKNOWN
//
// All objects that are going to inherit from CUnknown for their IUnknown
// implementation should put this in their class declaration instead of the
// three IUnknown methods.
//
#define DECLARE_STANDARD_UNKNOWN() \
	STDMETHOD(QueryInterface)(REFIID riid, void **ppvObjOut) { \
		return ExternalQueryInterface(riid, ppvObjOut); \
	} \
	STDMETHOD_(ULONG, AddRef)(void) { \
		return ExternalAddRef(); \
	} \
	STDMETHOD_(ULONG, Release)(void) { \
		return ExternalRelease(); \
	} \

// global variable where we store the current lock count on our DLL.  This resides
// in InProcServer.Cpp

extern LONG g_cLocks;

//=--------------------------------------------------------------------------=
// this class doesn't inherit from IUnknown since people inheriting from it
// are going to do so, and just delegate their IUnknown calls to the External*
// member functions on this object.  the internal private unknown object does
// need to inherit from IUnknown, since it will be used directly as an IUnknown
// object.

class CUnknownObject
{
public:
	CUnknownObject(IUnknown *pUnkOuter, void *pvInterface)
		: m_pvInterface(pvInterface),
		  m_pUnkOuter((pUnkOuter) ? pUnkOuter : &m_UnkPrivate)
		{  InterlockedIncrement(&g_cLocks); }

	CUnknownObject(IUnknown *pUnkOuter) {
		m_pUnkOuter = pUnkOuter ? pUnkOuter : &m_UnkPrivate;
		InterlockedIncrement(&g_cLocks);
	}
	virtual ~CUnknownObject() { InterlockedDecrement(&g_cLocks); }

	// these are all protected so that classes that inherit from this can
	// at get at them.

protected:
	// IUnknown methods.  these just delegate to the controlling
	// unknown.

	HRESULT ExternalQueryInterface(REFIID riid, void **ppvObjOut) {
		return m_pUnkOuter->QueryInterface(riid, ppvObjOut);
	}
	ULONG ExternalAddRef(void) {
		return m_pUnkOuter->AddRef();
	}
	ULONG ExternalRelease(void) {
		return m_pUnkOuter->Release();
	}

	// people should use this during creation to return their private
	// unknown
	//
	inline IUnknown *PrivateUnknown (void) {
		return &m_UnkPrivate;
	}

	virtual HRESULT InternalQueryInterface(REFIID riid, void **ppvObjOut);

	IUnknown *m_pUnkOuter;			  // outer controlling Unknown
	void	 *m_pvInterface;		  // the real interface we're working with.

private:
	// the inner, private unknown implementation is for the aggregator
	// to control the lifetime of this object, and for those cases where
	// this object isn't aggregated.

	class CPrivateUnknownObject : public IUnknown {
public:
		STDMETHOD(QueryInterface)(REFIID riid, void **ppvObjOut);
		STDMETHOD_(ULONG, AddRef)(void);
		STDMETHOD_(ULONG, Release)(void);

		// constructor is remarkably trivial
		//
		CPrivateUnknownObject() : m_cRef(1) {}

private:
		CUnknownObject *m_pMainUnknown();
		ULONG m_cRef;
	} m_UnkPrivate;

	// so they can reference themselves in CUnknownObject from pMainUnknown()

	friend class CPrivateUnknownObject;
};

#endif // _UNKNOWN_H_