OBJUSER.CPP
/*
* OBJUSER.CPP
* Koala Object User/Client Chapter 5
*
* Copyright (c)1993-1995 Microsoft Corporation, All Rights Reserved
*
* Kraig Brockschmidt, Microsoft
* Internet : kraigb@microsoft.com
* Compuserve: >INTERNET:kraigb@microsoft.com
*/
#define INITGUIDS
#include "objuser.h"
/*
* 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, nCmdShow);
if (NULL==pApp)
return -1;
if (pApp->Init())
{
while (GetMessage(&msg, NULL, 0,0 ))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
delete pApp;
return msg.wParam;
}
/*
* ObjectUserWndProc
*
* Purpose:
* Window class procedure. Standard callback.
*/
LRESULT APIENTRY ObjectUserWndProc(HWND hWnd, UINT iMsg
, WPARAM wParam, LPARAM lParam)
{
HRESULT hr;
PAPP pApp;
LPCLASSFACTORY pIClassFactory;
DWORD dwClsCtx;
ULONG cRef;
TCHAR szTemp[80];
pApp=(PAPP)GetWindowLong(hWnd, OBJUSERWL_STRUCTURE);
switch (iMsg)
{
case WM_NCCREATE:
pApp=(PAPP)(((LPCREATESTRUCT)lParam)->lpCreateParams);
SetWindowLong(hWnd, OBJUSERWL_STRUCTURE, (LONG)pApp);
return (DefWindowProc(hWnd, iMsg, wParam, lParam));
case WM_DESTROY:
PostQuitMessage(0);
break;
case WM_COMMAND:
switch (LOWORD(wParam))
{
case IDM_OBJECTUSEDLL:
pApp->m_fEXE=FALSE;
CheckMenuItem(GetMenu(hWnd), IDM_OBJECTUSEDLL
, MF_CHECKED);
CheckMenuItem(GetMenu(hWnd), IDM_OBJECTUSEEXE
, MF_UNCHECKED);
break;
case IDM_OBJECTUSEEXE:
pApp->m_fEXE=TRUE;
CheckMenuItem(GetMenu(hWnd), IDM_OBJECTUSEDLL
, MF_UNCHECKED);
CheckMenuItem(GetMenu(hWnd), IDM_OBJECTUSEEXE
, MF_CHECKED);
break;
case IDM_OBJECTCREATECOGCO:
if (NULL!=pApp->m_pIUnknown)
{
while (pApp->m_cRefOurs--)
ReleaseInterface(pApp->m_pIUnknown);
CoFreeUnusedLibraries();
}
dwClsCtx=(pApp->m_fEXE) ? CLSCTX_LOCAL_SERVER
: CLSCTX_INPROC_SERVER;
hr=CoGetClassObject(CLSID_Koala, dwClsCtx, NULL
, IID_IClassFactory, (PPVOID)&pIClassFactory);
if (SUCCEEDED(hr))
{
hr=pIClassFactory->CreateInstance(NULL
, IID_IUnknown
, (PPVOID)&pApp->m_pIUnknown);
//Release the class factory when done.
pIClassFactory->Release();
if (SUCCEEDED(hr))
{
pApp->Message(TEXT("Creation succeeded"));
pApp->m_cRefOurs=1;
}
else
pApp->Message(TEXT("Creation failed"));
}
else
pApp->Message(TEXT("CoGetClassObject failed"));
break;
case IDM_OBJECTCREATECOCI:
if (NULL!=pApp->m_pIUnknown)
{
while (pApp->m_cRefOurs--)
ReleaseInterface(pApp->m_pIUnknown);
CoFreeUnusedLibraries();
}
//Simpler creation: use CoCreateInstance
dwClsCtx=(pApp->m_fEXE) ? CLSCTX_LOCAL_SERVER
: CLSCTX_INPROC_SERVER;
hr=CoCreateInstance(CLSID_Koala, NULL, dwClsCtx
, IID_IUnknown, (PPVOID)&pApp->m_pIUnknown);
if (SUCCEEDED(hr))
{
pApp->Message(TEXT("Creation succeeded"));
pApp->m_cRefOurs=1;
}
else
pApp->Message(TEXT("Creation failed"));
break;
case IDM_OBJECTADDREF:
if (NULL==pApp->m_pIUnknown)
{
pApp->Message(TEXT("There is no object"));
break;
}
/*
* We maintain our own usage count so we
* know later when to NULL our pointer.
*/
cRef=pApp->m_pIUnknown->AddRef();
pApp->m_cRefOurs++;
wsprintf(szTemp, TEXT("Object Count=%lu, Usage=%lu")
, cRef, pApp->m_cRefOurs);
pApp->Message(szTemp);
break;
case IDM_OBJECTRELEASE:
if (NULL==pApp->m_pIUnknown)
{
pApp->Message(TEXT("There is no object"));
break;
}
cRef=pApp->m_pIUnknown->Release();
/*
* Our private usage count tells us when we
* believe we're done with the object. We can't
* use the ref count from Release to tell us
* if the object is really destroyed or not--so
* in this case we maintain our own count.
*/
if (0==--pApp->m_cRefOurs)
{
pApp->m_pIUnknown=NULL;
CoFreeUnusedLibraries();
}
wsprintf(szTemp, TEXT("Object Count=%lu, Usage=%lu")
, cRef, pApp->m_cRefOurs);
pApp->Message(szTemp);
break;
case IDM_OBJECTEXIT:
PostMessage(hWnd, WM_CLOSE, 0, 0L);
break;
}
break;
default:
return (DefWindowProc(hWnd, iMsg, wParam, lParam));
}
return 0L;
}
/*
* CApp::CApp
* CApp::~CApp
*
* Constructor Parameters: (from WinMain)
* hInst HINSTANCE of the application.
* hInstPrev HINSTANCE of a previous instance.
* nCmdShow UINT specifying how to show the app window.
*
*/
CApp::CApp(HINSTANCE hInst, HINSTANCE hInstPrev
, UINT nCmdShow)
{
m_hInst =hInst;
m_hInstPrev =hInstPrev;
m_nCmdShow =nCmdShow;
m_hWnd =NULL;
m_fEXE =FALSE;
m_cRefOurs =0L;
m_pIUnknown =NULL;
m_fInitialized=FALSE;
return;
}
CApp::~CApp(void)
{
while (m_cRefOurs-- > 0)
m_pIUnknown->Release();
m_pIUnknown=NULL;
if (IsWindow(m_hWnd))
DestroyWindow(m_hWnd);
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 such as calling CoInitialize. If this function fails
* the caller should insure that the destructor is called.
*
* Parameters:
* None
*
* Return Value:
* BOOL TRUE if successful, FALSE otherwise.
*/
BOOL CApp::Init(void)
{
WNDCLASS wc;
CHECKVER_COM;
if (FAILED(CoInitialize(NULL)))
return FALSE;
m_fInitialized=TRUE;
if (!m_hInstPrev)
{
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = ObjectUserWndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = CBWNDEXTRA;
wc.hInstance = m_hInst;
wc.hIcon = LoadIcon(m_hInst, TEXT("Icon"));
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wc.lpszMenuName = MAKEINTRESOURCE(IDR_MENU);
wc.lpszClassName = TEXT("OBJUSER");
if (!RegisterClass(&wc))
return FALSE;
}
m_hWnd=CreateWindow(TEXT("OBJUSER")
, TEXT("DLL and EXE Object User/Client"), WS_OVERLAPPEDWINDOW
, 35, 35, 350, 250, NULL, NULL, m_hInst, this);
if (NULL==m_hWnd)
return FALSE;
ShowWindow(m_hWnd, m_nCmdShow);
UpdateWindow(m_hWnd);
CheckMenuItem(GetMenu(m_hWnd), IDM_OBJECTUSEDLL, MF_CHECKED);
CheckMenuItem(GetMenu(m_hWnd), IDM_OBJECTUSEEXE, MF_UNCHECKED);
return TRUE;
}
/*
* CApp::Message
*
* Purpose:
* Displays a message in the client area of the window. This is
* just to centralize the call to simpify other code.
*
* Parameters:
* psz LPTSTR to the string to display.
*
* Return Value:
* None
*/
void CApp::Message(LPTSTR psz)
{
HDC hDC;
RECT rc;
hDC=GetDC(m_hWnd);
GetClientRect(m_hWnd, &rc);
SetBkColor(hDC, GetSysColor(COLOR_WINDOW));
SetTextColor(hDC, GetSysColor(COLOR_WINDOWTEXT));
/*
* We'll just be sloppy and clear the whole window as
* well as write the string with one ExtTextOut call.
* No word wrapping here...
*/
ExtTextOut(hDC, 0, 0, ETO_OPAQUE, &rc, psz, lstrlen(psz), NULL);
ReleaseDC(m_hWnd, hDC);
return;
}