EKOALA3.CPP

/* 
* EKOALA3.CPP
* Koala Object EXE Server Chapter 6
*
* Example object implemented in an EXE.
*
* Copyright (c)1993-1995 Microsoft Corporation, All Rights Reserved
*
* Kraig Brockschmidt, Microsoft
* Internet : kraigb@microsoft.com
* Compuserve: >INTERNET:kraigb@microsoft.com
*/


#define INITGUIDS
#include "ekoala3.h"


//Count number of objects and number of locks.
ULONG g_cObj=0;
ULONG g_cLock=0;

//Make window handle global so other code can cause a shutdown
HWND g_hWnd=NULL;


/*
* WinMain
*
* Purpose:
* Main entry point of application.
*/

int PASCAL WinMain(HINSTANCE hInst, HINSTANCE hInstPrev
, LPSTR pszCmdLine, int nCmdShow)
{
MSG msg;
PAPP pApp;

SETMESSAGEQUEUE;

pApp=new CApp(hInst, hInstPrev, pszCmdLine, nCmdShow);

if (NULL==pApp)
return -1;

if (pApp->Init())
{
while (GetMessage(&msg, NULL, 0,0 ))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}

delete pApp;
return msg.wParam;
}



/*
* KoalaWndProc
*
* Purpose:
* Standard window class procedure.
*/

LRESULT APIENTRY KoalaWndProc(HWND hWnd, UINT iMsg
, WPARAM wParam, LPARAM lParam)
{
PAPP pApp;

pApp=(PAPP)GetWindowLong(hWnd, KOALAWL_STRUCTURE);

switch (iMsg)
{
case WM_NCCREATE:
pApp=(PAPP)(((LPCREATESTRUCT)lParam)->lpCreateParams);
SetWindowLong(hWnd, KOALAWL_STRUCTURE, (LONG)pApp);
return (DefWindowProc(hWnd, iMsg, wParam, lParam));

//CHAPTER6MOD
case WM_COMMAND:
switch (LOWORD(wParam))
{
case IDM_CALLBLOCK:
pApp->m_fBlock=!pApp->m_fBlock;
CheckMenuItem(GetMenu(hWnd), IDM_CALLBLOCK
, pApp->m_fBlock ? MF_CHECKED : MF_UNCHECKED);
break;

case IDM_CALLDELAY:
pApp->m_fDelay=!pApp->m_fDelay;
CheckMenuItem(GetMenu(hWnd), IDM_CALLDELAY
, pApp->m_fDelay ? MF_CHECKED : MF_UNCHECKED);
break;
}
break;


case WM_CLOSE:
//Don't close with object's active
if (0==g_cObj && 0==g_cLock)
return (DefWindowProc(hWnd, iMsg, wParam, lParam));

break;
//End CHAPTER6MOD

case WM_DESTROY:
PostQuitMessage(0);
break;

default:
return (DefWindowProc(hWnd, iMsg, wParam, lParam));
}

return 0L;
}




/*
* ObjectDestroyed
*
* Purpose:
* Function for the Koala object to call when it gets destroyed.
* We destroy the main window if the proper conditions are met
* for shutdown.
*/

void ObjectDestroyed(void)
{
g_cObj--;

//No more objects and no locks, shut the app down.
if (0L==g_cObj && 0L==g_cLock && IsWindow(g_hWnd))
PostMessage(g_hWnd, WM_CLOSE, 0, 0L);

return;
}




/*
* CApp::CApp
* CApp::~CApp
*
* Constructor Parameters:
* hInst HINSTANCE of the Application from WinMain
* hInstPrev HINSTANCE of a previous instance from WinMain
* pszCmdLine LPSTR of the command line.
* nCmdShow UINT specifying how to show the app window,
* from WinMain.
*/

CApp::CApp(HINSTANCE hInst, HINSTANCE hInstPrev
, LPSTR pszCmdLine, UINT nCmdShow)
{
//Initialize WinMain parameter holders.
m_hInst =hInst;
m_hInstPrev =hInstPrev;
m_pszCmdLine=pszCmdLine;
m_nCmdShow =nCmdShow;

m_hWnd=NULL;
m_dwRegCO=0;
m_pIClassFactory=NULL;
m_fInitialized=FALSE;

//CHAPTER6MOD
m_pMsgFilter=NULL;
m_fBlock=FALSE;
m_fDelay=FALSE;
//End CHAPTER6MOD
return;
}


CApp::~CApp(void)
{
//CHAPTER6MOD
if (NULL!=m_pMsgFilter)
{
CoRegisterMessageFilter(NULL, NULL);
ReleaseInterface(m_pMsgFilter);
}
//End CHAPTER6MOD

//Opposite of CoRegisterClassObject; class factory ref is now 1
if (0L!=m_dwRegCO)
CoRevokeClassObject(m_dwRegCO);

//The last Release, which frees the class factory.
if (NULL!=m_pIClassFactory)
m_pIClassFactory->Release();

if (m_fInitialized)
CoUninitialize();

return;
}




/*
* CApp::Init
*
* Purpose:
* Initializes an CApp object by registering window classes,
* creating the main window, and doing anything else prone to
* failure. If this function fails the caller should guarantee
* that the destructor is called.
*
* Parameters:
* None
*
* Return Value:
* BOOL TRUE if successful, FALSE otherwise.
*/

BOOL CApp::Init(void)
{
WNDCLASS wc;
HRESULT hr;
#ifndef WIN32
DWORD dwVer;
#endif

//Fail if we're run outside of CoGetClassObject
if (lstrcmpiA(m_pszCmdLine, "-Embedding")
&& lstrcmpiA(m_pszCmdLine, "/Embedding"))
return FALSE;

#ifndef WIN32
dwVer=CoBuildVersion();

if (rmm!=HIWORD(dwVer))
return FALSE;

//No need to check minor versions.
#endif

//Call CoInitialize so we can call other Co* functions
if (FAILED(CoInitialize(NULL)))
return FALSE;

m_fInitialized=TRUE;

if (!m_hInstPrev)
{
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = KoalaWndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = CBWNDEXTRA;
wc.hInstance = m_hInst;
wc.hIcon = NULL;
wc.hCursor = NULL;
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
//CHAPTER6MOD
wc.lpszMenuName = MAKEINTRESOURCE(IDR_MENU);
//End CHAPTER6MOD
wc.lpszClassName = TEXT("Koala");

if (!RegisterClass(&wc))
return FALSE;
}

//CHAPTER6MOD
m_hWnd=CreateWindow(TEXT("Koala"), TEXT("Koala Object")
, WS_OVERLAPPEDWINDOW, 400, 35, 350, 250
, NULL, NULL, m_hInst, this);

if (NULL==m_hWnd)
return FALSE;

ShowWindow(m_hWnd, SW_SHOW);
UpdateWindow(m_hWnd);
//End CHAPTER6MOD

g_hWnd=m_hWnd;

/*
* Create our class factory and register it for this application
* using CoRegisterClassObject. We are able to service more than
* one object at a time so we use REGCLS_MULTIPLEUSE.
*/
m_pIClassFactory=new CKoalaClassFactory();

if (NULL==m_pIClassFactory)
return FALSE;

//Since we hold on to this, we should AddRef it.
m_pIClassFactory->AddRef();

hr=CoRegisterClassObject(CLSID_Koala, m_pIClassFactory
, CLSCTX_LOCAL_SERVER, REGCLS_MULTIPLEUSE, &m_dwRegCO);

if (FAILED(hr))
return FALSE;

//CHAPTER6MOD
/*
* Call CoLockObjectExternal to lock and unlock to show
* its strong lock effect through IExternalConnection.
*/
CoLockObjectExternal(m_pIClassFactory, TRUE, FALSE);
CoLockObjectExternal(m_pIClassFactory, FALSE, FALSE);

//Create and register the message filter
m_pMsgFilter=new CMessageFilter(this);

if (NULL!=m_pMsgFilter)
{
m_pMsgFilter->AddRef();

if (FAILED(CoRegisterMessageFilter(m_pMsgFilter, NULL)))
ReleaseInterface(m_pMsgFilter);
}
//End CHAPTER6MOD

return TRUE;
}






/*
* CKoalaClassFactory::CKoalaClassFactory
* CKoalaClassFactory::~CKoalaClassFactory
*
* Constructor Parameters:
* None
*/

CKoalaClassFactory::CKoalaClassFactory(void)
{
m_cRef=0L;
//CHAPTER6MOD
m_pImpIExtConn=new CImpIExternalConnection(this, this);
//End CHAPTER6MOD
return;
}

CKoalaClassFactory::~CKoalaClassFactory(void)
{
//CHAPTER6MOD
DeleteInterfaceImp(m_pImpIExtConn);
//End CHAPTER6MOD
return;
}




/*
* CKoalaClassFactory::QueryInterface
* CKoalaClassFactory::AddRef
* CKoalaClassFactory::Release
*/

STDMETHODIMP CKoalaClassFactory::QueryInterface(REFIID riid
, PPVOID ppv)
{
*ppv=NULL;

if (IID_IUnknown==riid || IID_IClassFactory==riid)
*ppv=this;

//CHAPTER6MOD
if (IID_IExternalConnection==riid && NULL!=m_pImpIExtConn)
*ppv=m_pImpIExtConn;
//End CHAPTER6MOD

if (NULL!=*ppv)
{
((LPUNKNOWN)*ppv)->AddRef();
return NOERROR;
}

return ResultFromScode(E_NOINTERFACE);
}


STDMETHODIMP_(ULONG) CKoalaClassFactory::AddRef(void)
{
return ++m_cRef;
}


STDMETHODIMP_(ULONG) CKoalaClassFactory::Release(void)
{
if (0L!=--m_cRef)
return m_cRef;

delete this;
return 0;
}






/*
* CKoalaClassFactory::CreateInstance
*
* Purpose:
* Instantiates a Koala object returning an interface pointer.
*
* Parameters:
* pUnkOuter LPUNKNOWN to the controlling IUnknown if we are
* being used in an aggregation.
* riid REFIID identifying the interface the caller
* desires to have for the new object.
* ppvObj PPVOID in which to store the desired
* interface pointer for the new object.
*
* Return Value:
* HRESULT NOERROR if successful, otherwise E_NOINTERFACE
* if we cannot support the requested interface.
*/

STDMETHODIMP CKoalaClassFactory::CreateInstance(LPUNKNOWN pUnkOuter
, REFIID riid, PPVOID ppvObj)
{
PCKoala pObj;
HRESULT hr;

*ppvObj=NULL;
hr=ResultFromScode(E_OUTOFMEMORY);

//Verify that a controlling unknown asks for IUnknown
if (NULL!=pUnkOuter && IID_IUnknown!=riid)
return ResultFromScode(CLASS_E_NOAGGREGATION);

//Create the object telling us to notify us when it's gone.
pObj=new CKoala(pUnkOuter, ObjectDestroyed);

if (NULL==pObj)
{
//This starts shutdown if there are no other objects.
g_cObj++;
ObjectDestroyed();
return hr;
}

if (pObj->Init())
hr=pObj->QueryInterface(riid, ppvObj);

g_cObj++;

/*
* Kill the object if initial creation or Init failed. If
* the object failed, we handle the g_cObj increment above
* in ObjectDestroyed.
*/
if (FAILED(hr))
{
delete pObj;
ObjectDestroyed(); //Handle shutdown cases.
}

return hr;
}






/*
* CKoalaClassFactory::LockServer
*
* Purpose:
* Increments or decrements the lock count of the serving
* IClassFactory object. When the number of locks goes to
* zero and the number of objects is zero, we shut down the
* application.
*
* Parameters:
* fLock BOOL specifying whether to increment or
* decrement the lock count.
*
* Return Value:
* HRESULT NOERROR always.
*/

STDMETHODIMP CKoalaClassFactory::LockServer(BOOL fLock)
{
if (fLock)
g_cLock++;
else
{
g_cLock--;

/*
* Fake an object destruction: this centralizes
* all the shutdown code in the ObjectDestroyed
* function, eliminating duplicate code here.
*/
g_cObj++;
ObjectDestroyed();
}

return NOERROR;
}




//CHAPTER6MOD
//Class factory implementation of IExternalConnection

/*
* CImpIExternalConnection::CImpIExternalConnection
* CImpIExternalConnection::~CImpIExternalConnection
*
* Parameters (Constructor):
* pObj PCKoalaClassFactory of the object we're in.
* pUnkOuter LPUNKNOWN to which we delegate.
*/

CImpIExternalConnection::CImpIExternalConnection
(PCKoalaClassFactory pObj, LPUNKNOWN pUnkOuter)
{
m_cRef=0;
m_pObj=pObj;
m_pUnkOuter=pUnkOuter;

m_cStrong=0;
m_cWeak=0;
return;
}

CImpIExternalConnection::~CImpIExternalConnection(void)
{
return;
}



/*
* CImpIExternalConnection::QueryInterface
* CImpIExternalConnection::AddRef
* CImpIExternalConnection::Release
*
* Purpose:
* Delegating IUnknown members for CImpIExternalConnection.
*/

STDMETHODIMP CImpIExternalConnection::QueryInterface(REFIID riid
, LPVOID *ppv)
{
return m_pUnkOuter->QueryInterface(riid, ppv);
}

STDMETHODIMP_(ULONG) CImpIExternalConnection::AddRef(void)
{
++m_cRef;
return m_pUnkOuter->AddRef();
}

STDMETHODIMP_(ULONG) CImpIExternalConnection::Release(void)
{
--m_cRef;
return m_pUnkOuter->Release();
}





/*
* CImpIExternalConnection::AddConnection
*
* Purpose:
* Informs the object that a strong connection has been made to it.
*
* Parameters:
* dwConn DWORD identifying the type of connection, taken
* from the EXTCONN enumeration.
* dwReserved DWORD reserved. This is used inside OLE and
* should not be validated.
*
* Return Value:
* DWORD The number of connection counts on the
* object, used for debugging purposes only.
*/

STDMETHODIMP_(DWORD) CImpIExternalConnection::AddConnection
(DWORD dwConn, DWORD dwReserved)
{
DWORD dwRet;
TCHAR szTemp[80];

if (EXTCONN_STRONG & dwConn)
{
dwRet=++m_cStrong;
wsprintf(szTemp
, TEXT("AddConnection cStrong=%lu"), m_cStrong);
}

#ifdef WIN32
if (EXTCONN_WEAK & dwConn)
{
dwRet=++m_cWeak;
wsprintf(szTemp
, TEXT("ReleaseConnection cWeak=%lu"), m_cWeak);
}
#endif

#ifndef WIN32
ODS(szTemp);
#else
MessageBox(NULL, szTemp
, TEXT("EKoala3: CKoalaClassFactory::IExternalConnection")
, MB_OK);
#endif

return dwRet;
}



/*
* CImpIExternalConnection::ReleaseConnection
*
* Purpose:
* Informs an object that a connection has been taken away from
* it in which case the object may need to shut down.
*
* Parameters:
* dwConn DWORD identifying the type of connection,
* taken from the EXTCONN enumeration.
* dwReserved DWORD reserved. This is used inside OLE and
* should not be validated.
* dwRerved DWORD reserved
* fLastReleaseCloses BOOL indicating if the last call to this
* function should close the object.
*
* Return Value:
* DWORD The number of remaining connection counts on
* the object, used for debugging purposes only.
*/

STDMETHODIMP_(DWORD) CImpIExternalConnection::ReleaseConnection
(DWORD dwConn, DWORD dwReserved, BOOL fLastReleaseCloses)
{
DWORD dwRet;
TCHAR szTemp[80];

if (EXTCONN_STRONG & dwConn)
{
/*
* Note: We don't need to close ourselves when the last
* strong lock is removed; we're just implementing this
* interface for demonstration.
*/

dwRet=--m_cStrong;
wsprintf(szTemp
, TEXT("ReleaseConnection cStrong=%lu"), m_cStrong);
}

#ifdef WIN32
if (EXTCONN_WEAK & dwConn)
{
dwRet=--m_cWeak;
wsprintf(szTemp
, TEXT("ReleaseConnection cWeak=%lu"), m_cWeak);
}
#endif

#ifndef WIN32
ODS(szTemp);
#else
MessageBox(NULL, szTemp
, TEXT("EKoala3: CKoalaClassFactory::IExternalConnection")
, MB_OK);
#endif

return dwRet;
}

//End CHAPTER6MOD