/*	File: D:\wacker\ext\defclsf.c (Created: 02-Mar-1994)
 *
 *	Copyright 1994 by Hilgraeve Inc. -- Monroe, MI
 *	All rights reserved
 *
 *	$Revision: 2 $
 *	$Date: 2/05/99 3:20p $
 */

//
// This file contains the implementation of SHCreateDefClassObject
//

#define _INC_OLE		// WIN32, get ole2 from windows.h
#define CONST_VTABLE

#include <windows.h>
#pragma hdrstop

#include <windowsx.h>
#include <shellapi.h>
#include <shlobj.h>
#include "pageext.hh"

// Helper macro for C programmers

#define _IOffset(class, itf)         ((UINT_PTR)&(((class *)0)->itf))
#define IToClass(class, itf, pitf)   ((class  *)(((LPSTR)pitf)-_IOffset(class, itf)))
#define IToClassN(class, itf, pitf)  IToClass(class, itf, pitf)

#if 0
/*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
 * FUNCTION:
 *	IsEqualGUID
 *
 * DESCRIPTION:
 *	By using this function, we keep from linking into OLE32.DLL.
 *
 */
STDAPI_(BOOL) IsEqualGUID(REFGUID guid1, REFGUID guid2)
	{
        return !memcmp(guid1, guid2, sizeof(GUID));
	}
#endif

//=========================================================================
// CDefClassFactory class
//=========================================================================

STDMETHODIMP CDefClassFactory_QueryInterface(IClassFactory FAR * pcf, REFIID riid, LPVOID FAR* ppvObj);
ULONG STDMETHODCALLTYPE CDefClassFactory_AddRef(IClassFactory FAR * pcf);
ULONG STDMETHODCALLTYPE CDefClassFactory_Release(IClassFactory FAR * pcf);
STDMETHODIMP CDefClassFactory_CreateInstance(IClassFactory FAR * pcf, LPUNKNOWN pUnkOuter,
                              REFIID riid,
                              LPVOID FAR* ppvObject);
STDMETHODIMP CDefClassFactory_LockServer(IClassFactory FAR * pcf, BOOL fLock);

//
// CDefClassFactory: Class definition
//
//#pragma data_seg(DATASEG_READONLY)
static IClassFactoryVtbl c_vtblAppUIClassFactory =
	{
	CDefClassFactory_QueryInterface,
	CDefClassFactory_AddRef,
	CDefClassFactory_Release,
	CDefClassFactory_CreateInstance,
	CDefClassFactory_LockServer
	};

typedef struct
	{
    IClassFactory      cf;		
    UINT               cRef;		// Reference count
	LPFNCREATEINSTANCE lpfnCI;		// CreateInstance callback entry
    UINT FAR *         pcRefDll;	// Reference count of the DLL
	const IID FAR *    riidInst;	// Optional interface for instance
	} CDefClassFactory;

//
// CDefClassFactory::QueryInterface
//
STDMETHODIMP CDefClassFactory_QueryInterface(IClassFactory FAR * pcf, REFIID riid, LPVOID FAR* ppvObj)
	{
	register CDefClassFactory * this=IToClass(CDefClassFactory, cf, pcf);

    if (IsEqualIID(riid, &IID_IClassFactory)
			|| IsEqualIID(riid, &IID_IUnknown))
		{
		(LPCLASSFACTORY)*ppvObj = &this->cf;
		this->cRef++;
        return NOERROR;
		}

    return ResultFromScode(E_NOINTERFACE);
	}

//
// CDefClassFactory::AddRef
//
ULONG STDMETHODCALLTYPE CDefClassFactory_AddRef(IClassFactory FAR * pcf)
	{
	register CDefClassFactory * this=IToClass(CDefClassFactory, cf, pcf);
    return (++this->cRef);
	}

//
// CDefClassFactory::Release
//
ULONG STDMETHODCALLTYPE CDefClassFactory_Release(IClassFactory FAR * pcf)
	{
	register CDefClassFactory * this=IToClass(CDefClassFactory, cf, pcf);

    if (--this->cRef > 0)
		return this->cRef;

	if (this->pcRefDll)
		{
		(*this->pcRefDll)--;
		}

	LocalFree((HLOCAL)this);
    return 0;
	}

//
// CDefClassFactory::CDefClassFactory
//
STDMETHODIMP CDefClassFactory_CreateInstance(IClassFactory FAR * pcf, LPUNKNOWN pUnkOuter,
							  REFIID riid,
                              LPVOID FAR* ppvObject)
	{
	register CDefClassFactory * this=IToClass(CDefClassFactory, cf, pcf);

    //
    // We don't support aggregation at all.
	//
    if (pUnkOuter)
		return ResultFromScode(CLASS_E_NOAGGREGATION);

    //
    // if this->riidInst is specified, they should match.
    //
	if (this->riidInst==NULL || IsEqualIID(riid, this->riidInst)
			|| IsEqualIID(riid, &IID_IUnknown))
		{
		return this->lpfnCI(pUnkOuter, riid, ppvObject);
		}

    return ResultFromScode(E_NOINTERFACE);
	}

//
// CDefClassFactory::LockServer
//
STDMETHODIMP CDefClassFactory_LockServer(IClassFactory FAR * pcf, BOOL fLock)
	{
    // REVIEW: Is this appropriate?
    return ResultFromScode(E_NOTIMPL);
	}


//
// CDefClassFactory constructor
//
CDefClassFactory * NEAR PASCAL CDefClassFactory_Create(
		LPFNCREATEINSTANCE lpfnCI, UINT FAR * pcRefDll, REFIID riidInst)
	{
	register CDefClassFactory * pacf;

	pacf = (CDefClassFactory *)LocalAlloc(LPTR, sizeof(CDefClassFactory));
    if (pacf)
		{
		pacf->cf.lpVtbl = &c_vtblAppUIClassFactory;
		pacf->cRef++;  // pacf->cRef=0; (generates smaller code)
		pacf->pcRefDll = pcRefDll;
		pacf->lpfnCI = lpfnCI;
		pacf->riidInst = riidInst;

		if (pcRefDll)
			(*pcRefDll)++;

		}
    return pacf;
	}

//
// creates a simple default implementation of IClassFactory
//
// Parameters:
//  riid     -- Specifies the interface to the class object
//  ppv      -- Specifies the pointer to LPVOID where the class object pointer
//               will be returned.
//  lpfnCI   -- Specifies the callback entry for instanciation.
//  pcRefDll -- Specifies the address to the DLL reference count (optional)
//  riidInst -- Specifies the interface to the instance (optional).
//
// Notes:
//   The riidInst will be specified only if the instance of the class
//  support only one interface.
//
STDAPI SHCreateDefClassObject(REFIID riid, LPVOID FAR* ppv,
			 LPFNCREATEINSTANCE lpfnCI, UINT FAR * pcRefDll,
			 REFIID riidInst)
	{
	// The default class factory supports only IClassFactory interface

    if (IsEqualIID(riid, &IID_IClassFactory))
		{
		CDefClassFactory *pacf =
			CDefClassFactory_Create(lpfnCI, pcRefDll, riidInst);

		if (pacf)
			{
			(IClassFactory FAR *)*ppv = &pacf->cf;
			return NOERROR;
			}

		return ResultFromScode(E_OUTOFMEMORY);
		}

    return ResultFromScode(E_NOINTERFACE);
	}