ENUMRECT.CPP

/* 
 * ENUMRECT.CPP 
 * C/C++ Enumerator Demonstartion Chapter 2 
 * 
 * Copyright (c)1993-1995 Microsoft Corporation, All Rights Reserved 
 * 
 * Kraig Brockschmidt, Microsoft 
 * Internet  :  kraigb@microsoft.com 
 * Compuserve:  >INTERNET:kraigb@microsoft.com 
 */ 
 
 
#define INITGUIDS 
#include "enumrect.h" 
 
 
/* 
 * WinMain 
 * 
 * Purpose: 
 *  Main entry point of application. 
 */ 
 
int PASCAL WinMain(HINSTANCE hInst, HINSTANCE hInstPrev 
    , LPSTR pszCmdLine, int nCmdShow) 
    { 
    MSG     msg; 
    PAPP    pApp; 
 
    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; 
    } 
 
 
 
 
 
 
 
/* 
 * EnumWndProc 
 * 
 * Purpose: 
 *  Standard window class procedure. 
 */ 
 
LRESULT APIENTRY EnumWndProc(HWND hWnd, UINT iMsg, WPARAM wParam 
    , LPARAM lParam) 
    { 
    PAPP        pApp; 
    RECT        rc; 
    DWORD       cRect; 
    BOOL        fRes; 
    PENUMRECT   pClone; 
 
    COMMANDPARAMS(wID, wCode, hWndMsg); 
 
    pApp=(PAPP)GetWindowLong(hWnd, ENUMWL_STRUCTURE); 
 
    switch (iMsg) 
        { 
        case WM_NCCREATE: 
            pApp=(PAPP)(((LPCREATESTRUCT)lParam)->lpCreateParams); 
            SetWindowLong(hWnd, ENUMWL_STRUCTURE, (LONG)pApp); 
            return (DefWindowProc(hWnd, iMsg, wParam, lParam)); 
 
 
        case WM_DESTROY: 
            PostQuitMessage(0); 
            break; 
 
 
        case WM_COMMAND: 
            switch (wID) 
                { 
                case IDM_ENUMCREATEC: 
                    if (NULL!=pApp->m_pIEnumRect) 
                        pApp->m_pIEnumRect->Release(); 
 
                    fRes=CreateRECTEnumeratorC(&pApp->m_pIEnumRect); 
 
                    pApp->Message(fRes ? TEXT("C Object created") 
                        : TEXT("C Object creation failed")); 
 
                    break; 
 
                case IDM_ENUMCREATECPP: 
                    if (NULL!=pApp->m_pIEnumRect) 
                        pApp->m_pIEnumRect->Release(); 
 
                    fRes=CreateRECTEnumeratorCPP(&pApp->m_pIEnumRect); 
 
                    pApp->Message(fRes ? TEXT("C++ Object created") 
                        : TEXT("C++ Object creation failed")); 
 
                    break; 
 
 
                case IDM_ENUMRELEASE: 
                    if (NULL==pApp->m_pIEnumRect) 
                        { 
                        pApp->Message(TEXT("There is no object")); 
                        break; 
                        } 
 
                    if (0==pApp->m_pIEnumRect->Release()) 
                        { 
                        pApp->m_pIEnumRect=NULL; 
                        pApp->Message(TEXT("Object released")); 
                        } 
 
                    break; 
 
 
                case IDM_ENUMRUNTHROUGH: 
                    if (NULL==pApp->m_pIEnumRect) 
                        { 
                        pApp->Message(TEXT("There is no object")); 
                        break; 
                        } 
 
                    while (pApp->m_pIEnumRect->Next(1, &rc, &cRect)) 
                        ; 
 
                    pApp->Message(TEXT("Enumeration complete")); 
                    break; 
 
 
                case IDM_ENUMEVERYTHIRD: 
                    if (NULL==pApp->m_pIEnumRect) 
                        { 
                        pApp->Message(TEXT("There is no object")); 
                        break; 
                        } 
 
                    while (NOERROR==pApp->m_pIEnumRect->Next(1 
                        , &rc, &cRect)) 
                        { 
                        if (NOERROR!=pApp->m_pIEnumRect->Skip(2)) 
                            break; 
                        } 
 
                    pApp->Message(TEXT("Enumeration complete")); 
                    break; 
 
 
                case IDM_ENUMRESET: 
                    if (NULL==pApp->m_pIEnumRect) 
                        { 
                        pApp->Message(TEXT("There is no object")); 
                        break; 
                        } 
 
                    pApp->m_pIEnumRect->Reset(); 
                    pApp->Message(TEXT("Reset complete")); 
                    break; 
 
 
                case IDM_ENUMCLONE: 
                    if (NULL==pApp->m_pIEnumRect) 
                        { 
                        pApp->Message(TEXT("There is no object")); 
                        break; 
                        } 
 
                    pApp->m_pIEnumRect->Clone((PENUMRECT *)&pClone); 
 
                    if (NULL==pClone) 
                        pApp->Message(TEXT("Clone failed")); 
                    else 
                        { 
                        pApp->Message(TEXT("Clone succeeded")); 
                        pClone->Release(); 
                        } 
                    break; 
 
 
                case IDM_ENUMEXIT: 
                    PostMessage(hWnd, WM_CLOSE, 0, 0L); 
                    break; 
                } 
            break; 
 
        default: 
            return (DefWindowProc(hWnd, iMsg, wParam, lParam)); 
        } 
 
    return 0L; 
    } 
 
 
 
 
/* 
 * CApp::CApp 
 * CApp::~CApp 
 * 
 * Constructor Parameters: 
 *  hInst           HINSTANCE of the Application from WinMain 
 *  hInstPrev       HINSTANCE of a previous instance from WinMain 
 *  nCmdShow        UINT specifying how to show the app window, 
 *                  from WinMain. 
 */ 
 
CApp::CApp(HINSTANCE hInst, HINSTANCE hInstPrev 
    , UINT nCmdShow) 
    { 
    //Initialize WinMain parameter holders. 
    m_hInst     =hInst; 
    m_hInstPrev =hInstPrev; 
    m_nCmdShow  =nCmdShow; 
 
    m_hWnd=NULL; 
    m_pIEnumRect=NULL; 
 
    return; 
    } 
 
 
CApp::~CApp(void) 
    { 
    //Free the enumerator object if we have one. 
    if (NULL!=m_pIEnumRect) 
        m_pIEnumRect->Release(); 
 
    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; 
 
    if (!m_hInstPrev) 
        { 
        wc.style          = CS_HREDRAW | CS_VREDRAW; 
        wc.lpfnWndProc    = EnumWndProc; 
        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("ENUMRECT"); 
 
        if (!RegisterClass(&wc)) 
            return FALSE; 
        } 
 
    m_hWnd=CreateWindow(TEXT("ENUMRECT"), TEXT("RECT Enumerator") 
        , WS_MINIMIZEBOX | 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); 
 
    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; 
    }