Tech Arsenal 1/Tech Arsenal (Arsenal Computer).ISO/tek-01/msoftapp.zip/GENERIC.C

C/C++ Source or Header | 1993-06-01 | 6KB | 186 lines

// Global variables at the beginning of GENERIC.C

static  HINSTANCE hInst;            // current instance
static  FARPROC lpProcHorzList;     // ptr to the HorzList procedure
static  FARPROC lpProcAbout;        // ptr to the About procedure
static  FARPROC lpProcOrgProc;      // ptr to the original list box proc
static  FARPROC lpProcSubClassProc; // ptr to the subclass list box proc

static  UINT    uScrollMessage;     // custom notification message

/////////////////////////////////////////////////////////////////
// Added to the instance-initialization routine

uScrollMessage = RegisterWindowMessage( "MyScrollNotificationMsg" );

/////////////////////////////////////////////////////////////////
// Replacement for the WM_COMMAND case

case WM_COMMAND:    // message: command from application menu
    {
    switch (wParam)
        {
        case IDM_HORZLIST:
            {
            lpProcHorzList = MakeProcInstance(
                    (FARPROC)HorzListProc, hInst );
            lpProcSubClassProc = MakeProcInstance(
                    (FARPROC)WndListBoxProc, hInst );

            DialogBox( hInst, "HorzListBox",
                    hWnd, lpProcHorzList );

            FreeProcInstance( lpProcSubClassProc );
            FreeProcInstance( lpProcHorzList );
            return 0;
            }

        case IDM_ABOUT:
            {
            lpProcAbout = MakeProcInstance( About, hInst );

            DialogBox( hInst, "AboutBox", hWnd, lpProcAbout );

            FreeProcInstance( lpProcAbout );
            return 0;
            }

        default:
            // Let Windows process it
            return DefWindowProc( hWnd, message, wParam, lParam );
        } // End of switch (wParam)
    } // End of case WM_COMMAND:

/////////////////////////////////////////////////////////////////
//  Horizontal-Scrolling List Box Dialog Procedure

extern  BOOL FAR PASCAL HorzListProc
(
        HWND            hDlg,
        unsigned        message,
        WORD            wParam,
        LONG            lParam
)
{
auto    HWND            hWndListBox;
auto    char            buf[256];

if (message == uScrollMessage)
    {
    int     iMinPos,
            iMaxPos,
            iCurPos;

    hWndListBox = GetDlgItem( hDlg, ID_LIST );
    GetScrollRange( hWndListBox, SB_HORZ, &iMinPos, &iMaxPos );
    iCurPos = GetScrollPos( hWndListBox, SB_HORZ );
    wsprintf( buf, "Min: %d, Cur: %d, Max: %d",
            iMinPos, iCurPos, iMaxPos );
    SetDlgItemText( hDlg, ID_TEXT, buf );
    return 0;
    }

switch (message)
    {
    case WM_INITDIALOG:
        {
        char    c;

        // Get the window handle of the list box
        hWndListBox = GetDlgItem( hDlg, ID_LIST );

        // Grab the original list box window procedure
        lpProcOrgProc = (FARPROC)GetWindowLong(
                hWndListBox, GWL_WNDPROC );

        // ... and replace it with our own!
        SetWindowLong( hWndListBox, GWL_WNDPROC,
                (LONG)lpProcSubClassProc );

        // Initialize the list box with some sample data
        for (c = 'A';  c <= 'Z';  c++)
            {
            // format a string
            wsprintf( buf, "%c\tThis is a very long string "
                    "to test the horizontal scrolling\t%c",
                    c, c );

            // stick the string into the list box
            SendMessage( hWndListBox, LB_ADDSTRING, 0,
                    (LPARAM)(LPSTR)buf );
            }

        // Enable the horizontal scroll bar
        SendMessage( hWndListBox,
                LB_SETHORIZONTALEXTENT, 500, 0L );

        // Set the horizontal scroll bar range and position
        SetScrollRange( hWndListBox, SB_HORZ, 0, 100, FALSE );
        SetScrollPos( hWndListBox, SB_HORZ, 0, FALSE );

        // Force the display to initialize the display
        PostMessage( hDlg, uScrollMessage, wParam, lParam );

        return TRUE;
        }

    case WM_COMMAND:
        if (wParam == IDOK
        ||  wParam == IDCANCEL)
            {
            // Get the window handle to the list box
            hWndListBox = GetDlgItem( hDlg, ID_LIST );

            // Reinstall the original list box procedure
            SetWindowLong( hWndListBox, GWL_WNDPROC,
                    (LONG)lpProcOrgProc );

            // ... and end the dialog
            EndDialog( hDlg, TRUE );
            return TRUE;
            }
        break;
    }
return FALSE;
}


/////////////////////////////////////////////////////////////////
//  List Box Subclassing Window Procedure.
//  This subclass procedure will notify the parent window
//  whenever the Horizontal Scroll Bar is scrolled.

extern  long FAR PASCAL WndListBoxProc
(
        HWND            hWnd,
        unsigned        wMsg,
        WORD            wParam,
        LONG            lParam
)
{
switch (wMsg)
    {
    // When the scroll bar notifies the parent window
    // (in this case the list box) of a horizontal
    // scroll message, notify the parent of the list
    // box, also.
    case WM_HSCROLL:
        {
        HWND hParentWnd;

        // Get the handle to the parent of the list box
        hParentWnd = GetWindowWord( hWnd, GWW_HWNDPARENT );

        // Post a special notification message to it.
        PostMessage( hParentWnd, uScrollMessage,
                wParam, lParam );
        }
    }

// Allow all messages to be processed normally by the original
// list box window procedure
return CallWindowProc( lpProcOrgProc, hWnd, wMsg, wParam, lParam );
}