EKOALA4.CPP
/*
* EKOALA4.CPP
* Koala Object EXE Server with Custom Interface Chapter 6
*
* Example object with a custom interface 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 "ekoala4.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));
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;
return;
}
CApp::~CApp(void)
{
//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);
wc.lpszMenuName = NULL;
wc.lpszClassName = TEXT("Koala");
if (!RegisterClass(&wc))
return FALSE;
}
m_hWnd=CreateWindow(TEXT("Koala"), TEXT("Koala")
, WS_OVERLAPPEDWINDOW, 35, 35, 350, 250
, NULL, NULL, m_hInst, this);
if (NULL==m_hWnd)
return FALSE;
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;
return TRUE;
}
/*
* CKoalaClassFactory::CKoalaClassFactory
* CKoalaClassFactory::~CKoalaClassFactory
*
* Constructor Parameters:
* None
*/
CKoalaClassFactory::CKoalaClassFactory(void)
{
m_cRef=0L;
return;
}
CKoalaClassFactory::~CKoalaClassFactory(void)
{
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;
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;
}