ICLASSF.CPP

////////////////////////////////////////////////////////////////////////////// 
// 
//  FILE:           ICLASSF.CPP 
// 
//  DESCRIPTION:    Sample form's class factory 
// 
// 
//  Copyright (c) 1994, Microsoft Corporation. 
//  All rights reserved. 
// 
//-- 
 
#include "precomp.h" 
 
CClassFactory           ClassFactory; 
 
HWND  CClassFactory::ms_hWndMain; 
ULONG CClassFactory::ms_cLocks= 0; 
ULONG CClassFactory::ms_cObjs = 0; 
 
 
/////////////////////////////////////////////////////////////////////////////// 
// 
//  Constructor and destructor 
 
CClassFactory::CClassFactory() 
{ 
    m_cRef   = 1; 
} 
 
CClassFactory::~CClassFactory (void) 
{ 
    ASSERT(m_cRef == 1); 
} 
 
 
/////////////////////////////////////////////////////////////////////////////// 
// 
//  IUnknown methods 
 
STDMETHODIMP CClassFactory::QueryInterface(REFIID riid, void ** ppvObj) 
{ 
 
    if ((IID_IClassFactory == riid) || (IID_IUnknown == riid)) 
    { 
        *ppvObj = (IClassFactory*) this; 
        AddRef (); 
        return NOERROR; 
    } 
 
    *ppvObj = 0; 
 
    return ResultFromScode (E_NOINTERFACE); 
} 
 
 
STDMETHODIMP_ (ULONG)CClassFactory::AddRef() 
{ 
    return ++ m_cRef; 
} 
 
STDMETHODIMP_(ULONG) CClassFactory::Release() 
{ 
    ULONG cRef = -- m_cRef; 
 
    //We quit when cRef == 1 (as oppossed to == 0) because OLE 
    //will not release its reference until after we call 
    // CoRevokeClassObject(). So if cRef==1 we know that only 
    //OLE has a reference to as, and it's time to go... 
    if ((cRef == 1) && (ms_cLocks == 0) && (ms_cObjs == 0)) 
    { 
        if (ms_hWndMain) 
        { 
            PostMessage (ms_hWndMain, WM_CLOSE, 0, 0L); 
        } 
    } 
 
    return cRef; 
} 
 
 
/////////////////////////////////////////////////////////////////////////////// 
// 
 
STDMETHODIMP CClassFactory::CreateInstance(LPUNKNOWN pUnkOuter, REFIID riid, 
                                           LPVOID FAR* ppvObject) 
{ 
    HRESULT     hr  = ResultFromScode (E_NOINTERFACE); 
    CBaseForm * pbf = NULL; 
 
    if (!ppvObject) 
        return ResultFromScode (E_INVALIDARG); 
     
    *ppvObject = 0; 
 
    // 
    //  We don't support aggregation. 
 
    if (pUnkOuter != NULL) 
        return  ResultFromScode (CLASS_E_NOAGGREGATION); 
 
    pbf = new CBaseForm (this); 
 
    if(NULL == pbf) 
        return ResultFromScode(E_OUTOFMEMORY); 
 
    hr = pbf -> QueryInterface (riid, ppvObject); 
    if (HR_FAILED(hr)) 
        goto err; 
 
    ms_cObjs ++; 
 
    hr = hrSuccess; 
 
err: 
    if (pbf) 
    { 
        pbf -> Release (); 
    } 
    return hr; 
} 
 
 
/////////////////////////////////////////////////////////////////////////////// 
// 
 
STDMETHODIMP CClassFactory::LockServer(BOOL fLock) 
{ 
    if (fLock) 
    { 
        ++ ms_cLocks; 
    } 
    else 
    { 
        ASSERT (ms_cLocks > 0); 
        -- ms_cLocks; 
 
        if ((ms_cLocks == 0) && (ms_cObjs == 0)) 
        { 
            if (ms_hWndMain) 
            { 
                PostMessage (ms_hWndMain, WM_CLOSE, 0, 0L); 
            } 
        } 
    } 
    return NOERROR; 
} 
 
 
void FAR PASCAL CClassFactory::ObjDestroyedCallback (void) 
{ 
    ASSERT (ms_cObjs > 0); 
    ms_cObjs --; 
 
    if ((ms_cLocks == 0) && (ms_cObjs == 0)) 
    { 
        if (ms_hWndMain) 
        { 
            PostMessage (ms_hWndMain, WM_CLOSE, 0, 0L); 
        } 
    } 
}