/****************************************************************************\
*
*     PROGRAM: head.c
*
*     PURPOSE: head template for Windows applications
*
*     FUNCTIONS:
*
*         WinMain() - calls initialization function, processes message loop
*         InitApplication() - initializes window data and registers window
*         InitInstance() - saves instance handle and creates main window
*         MainWndProc() - processes messages
*         About() - processes messages for "About" dialog box
*
*     COMMENTS:
*
*         Windows can have several copies of your application running at the
*         same time.  The variable hInst keeps track of which instance this
*         application is so that processing will be to the correct window.
*
\****************************************************************************/

#include <windows.h>
#include <commctrl.h>
#include "head.h"

HINSTANCE hInst;
HWND ghwndHead;

BOOL DoCommand( HWND hWnd, UINT wParam, LONG lParam );
int DoInsertItem(HWND hwndHeader, int iInsertAfter, int nWidth, LPSTR lpsz);
HWND DoCreateHeader(HWND hwndParent);
void ErrorBox( HWND hwnd, LPTSTR pszText );

/****************************************************************************
*
*     FUNCTION: WinMain(HANDLE, HANDLE, LPSTR, int)
*
*     PURPOSE: calls initialization function, processes message loop
*
*     COMMENTS:
*
*         Windows recognizes this function by name as the initial entry point
*         for the program.  This function calls the application initialization
*         routine, if no other instance of the program is running, and always
*         calls the instance initialization routine.  It then executes a message
*         retrieval and dispatch loop that is the top-level control structure
*         for the remainder of execution.  The loop is terminated when a WM_QUIT
*         message is received, at which time this function exits the application
*         instance by returning the value passed by PostQuitMessage().
*
*         If this function must abort before entering the message loop, it
*         returns the conventional value NULL.
*
\****************************************************************************/

int APIENTRY WinMain(
    HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    LPSTR lpCmdLine,
    int nCmdShow
    )
{

    MSG msg;                                 /* message                      */

    UNREFERENCED_PARAMETER( lpCmdLine );

    if (!hPrevInstance)                  /* Other instances of app running? */
        if (!InitApplication(hInstance)) /* Initialize shared things        */
            return (FALSE);              /* Exits if unable to initialize   */

    /* Perform initializations that apply to a specific instance */

    if (!InitInstance(hInstance, nCmdShow))
        return (FALSE);

    /* Acquire and dispatch messages until a WM_QUIT message is received. */

    while (GetMessage(&msg,        /* message structure                      */
            NULL,                  /* handle of window receiving the message */
            0L,                    /* lowest message to examine              */
            0L))                   /* highest message to examine             */
        {
        TranslateMessage(&msg);    /* Translates virtual key codes           */
        DispatchMessage(&msg);     /* Dispatches message to window           */
    }
    return (msg.wParam);           /* Returns the value from PostQuitMessage */
}


/****************************************************************************
*
*     FUNCTION: InitApplication(HANDLE)
*
*     PURPOSE: Initializes window data and registers window class
*
*     COMMENTS:
*
*         This function is called at initialization time only if no other
*         instances of the application are running.  This function performs
*         initialization tasks that can be done once for any number of running
*         instances.
*
*         In this case, we initialize a window class by filling out a data
*         structure of type WNDCLASS and calling the Windows RegisterClass()
*         function.  Since all instances of this application use the same window
*         class, we only need to do this when the first instance is initialized.
*
*
\****************************************************************************/

BOOL InitApplication(HANDLE hInstance)       /* current instance             */
{
    WNDCLASS  wc;

    /* Fill in window class structure with parameters that describe the       */
    /* main window.                                                           */

    wc.style = 0L;
    wc.lpfnWndProc = (WNDPROC)MainWndProc;

    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;           /* Application that owns the class.   */
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = GetStockObject(WHITE_BRUSH); 
    wc.lpszMenuName =  "headMenu";
    wc.lpszClassName = "headWClass";

    /* Register the window class and return success/failure code. */

    return (RegisterClass(&wc));

}


/****************************************************************************
*
*     FUNCTION:  InitInstance(HANDLE, int)
*
*     PURPOSE:  Saves instance handle and creates main window
*
*     COMMENTS:
*
*         This function is called at initialization time for every instance of
*         this application.  This function performs initialization tasks that
*         cannot be shared by multiple instances.
*
*         In this case, we save the instance handle in a static variable and
*         create and display the main program window.
*
\****************************************************************************/

BOOL InitInstance(
    HANDLE          hInstance,          /* Current instance identifier.       */
    int             nCmdShow)           /* Param for first ShowWindow() call. */
{
    HWND            hWnd;               /* Main window handle.                */

    /* Save the instance handle in static variable, which will be used in  */
    /* many subsequence calls from this application to Windows.            */

    hInst = hInstance;

    /* Create a main window for this application instance.  */

    hWnd = CreateWindow(
        "headWClass",                /* See RegisterClass() call.          */
        "head Sample Application",   /* Text for window title bar.         */
        WS_OVERLAPPEDWINDOW,            /* Window style.                      */
        CW_USEDEFAULT,                  /* Default horizontal position.       */
        CW_USEDEFAULT,                  /* Default vertical position.         */
        CW_USEDEFAULT,                  /* Default width.                     */
        CW_USEDEFAULT,                  /* Default height.                    */
        NULL,                           /* Overlapped windows have no parent. */
        NULL,                           /* Use the window class menu.         */
        hInstance,                      /* This instance owns this window.    */
        NULL                            /* Pointer not needed.                */
    );

    /* If window could not be created, return "failure" */

    if (!hWnd)
        return (FALSE);

    /* Make the window visible; update its client area; and return "success" */

    ShowWindow(hWnd, nCmdShow);  /* Show the window                        */
    UpdateWindow(hWnd);          /* Sends WM_PAINT message                 */
    return (TRUE);               /* Returns the value from PostQuitMessage */

}

/****************************************************************************
*
*     FUNCTION: MainWndProc(HWND, unsigned, WORD, LONG)
*
*     PURPOSE:  Processes messages
*
*     MESSAGES:
*
*         WM_COMMAND    - application menu (About dialog box)
*         WM_DESTROY    - destroy window
*
*     COMMENTS:
*
*         To process the IDM_ABOUT message, call MakeProcInstance() to get the
*         current instance address of the About() function.  Then call Dialog
*         box which will create the box according to the information in your
*         head.rc file and turn control over to the About() function.  When
*         it returns, free the intance address.
*
\****************************************************************************/

LONG APIENTRY MainWndProc(
        HWND hWnd,                /* window handle                   */
        UINT message,             /* type of message                 */
        UINT wParam,              /* additional information          */
        LONG lParam)              /* additional information          */
{
    switch (message) {
        case WM_COMMAND:           /* message: command from application menu */
            if( !DoCommand( hWnd, wParam, lParam ) )
                return (DefWindowProc(hWnd, message, wParam, lParam));
            break;

        case WM_DESTROY:                  /* message: window being destroyed */
            PostQuitMessage(0);
            break;

        default:                          /* Passes it on if unproccessed    */
            return (DefWindowProc(hWnd, message, wParam, lParam));
    }
    return (0L);
}


/****************************************************************************\
*
*     FUNCTION: About(HWND, unsigned, WORD, LONG)
*
*     PURPOSE:  Processes messages for "About" dialog box
*
*     MESSAGES:
*
*         WM_INITDIALOG - initialize dialog box
*         WM_COMMAND    - Input received
*
*     COMMENTS:
*
*         No initialization is needed for this particular dialog box, but TRUE
*         must be returned to Windows.
*
*         Wait for user to click on "Ok" button, then close the dialog box.
*
\****************************************************************************/
BOOL DoCommand( HWND hwnd, UINT wParam, LONG lParam )
{
    DLGPROC lpProcAbout;          /* pointer to the "About" function */

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

        DialogBox(hInst,                 /* current instance         */
            "AboutBox",                  /* resource to use          */
                hwnd,                    /* parent handle            */
                (DLGPROC)lpProcAbout);   /* About() instance address */

        FreeProcInstance(lpProcAbout);
        break;

    case IDM_MAKEHEAD:
        ghwndHead = DoCreateHeader(hwnd);
        DoInsertItem(ghwndHead, 0, 80, TEXT("me."));
        DoInsertItem(ghwndHead, 0, 80, TEXT("to"));
        DoInsertItem(ghwndHead, 0, 80, TEXT("comes"));
        DoInsertItem(ghwndHead, 0, 80, TEXT("Mary"));
        DoInsertItem(ghwndHead, 0, 80, TEXT("Mother"));
        break;

    case IDM_ADDITEMS:
        DoInsertItem(ghwndHead, 255, 40, TEXT("Let"));
        DoInsertItem(ghwndHead, 255, 40, TEXT("It"));
        DoInsertItem(ghwndHead, 255, 40, TEXT("Be"));
        break;

    case IDM_DELITEM:
        SendMessage(ghwndHead, HDM_DELETEITEM, 0, 0);
        InvalidateRect (ghwndHead, NULL, TRUE);
        break;

    default:
        return FALSE;
    }

    return TRUE;
}

/****************************************************************************\
*
*     FUNCTION: About(HWND, unsigned, WORD, LONG)
*
*     PURPOSE:  Processes messages for "About" dialog box
*
*     MESSAGES:
*
*         WM_INITDIALOG - initialize dialog box
*         WM_COMMAND    - Input received
*
*     COMMENTS:
*
*         No initialization is needed for this particular dialog box, but TRUE
*         must be returned to Windows.
*
*         Wait for user to click on "Ok" button, then close the dialog box.
*
\****************************************************************************/

BOOL APIENTRY About(
        HWND hDlg,                /* window handle of the dialog box */
        UINT message,             /* type of message                 */
        UINT wParam,              /* message-specific information    */
        LONG lParam)
{
    switch (message) {
        case WM_INITDIALOG:                /* message: initialize dialog box */
            return (TRUE);

        case WM_COMMAND:                      /* message: received a command */
            if (LOWORD(wParam) == IDOK        /* "OK" box selected?          */
                || LOWORD(wParam) == IDCANCEL) { /*System menu close command?*/
                EndDialog(hDlg, TRUE);        /* Exits the dialog box        */
                return (TRUE);
            }
            break;
    }
    return (FALSE);                           /* Didn't process a message    */
        UNREFERENCED_PARAMETER(lParam);
}


HWND DoCreateHeader(HWND hwndParent) {
    HWND hwndHeader;
    RECT rcParent;
    HD_LAYOUT hdl;
    WINDOWPOS wp;

    InitCommonControls();

    hwndHeader = CreateWindow(WC_HEADER, NULL, WS_CHILD | WS_BORDER |
                                HDS_BUTTONS | HDS_HORZ,
                                0, 0, 0, 0, hwndParent, (HMENU)ID_HEADER, hInst,
                                NULL);
    if (hwndHeader == NULL) {
        ErrorBox( hwndParent, "CreateWindow" );
        return NULL;
    }

    GetClientRect(hwndParent, &rcParent);

    hdl.prc = &rcParent;
    hdl.pwpos = &wp;

    if (!SendMessage(hwndHeader, HDM_LAYOUT, 0, (LPARAM)&hdl))
        return NULL;

    SetWindowPos(hwndHeader, wp.hwndInsertAfter, wp.x, wp.y, wp.cx, wp.cy,
            wp.flags | SWP_SHOWWINDOW);

    return hwndHeader;

}

int DoInsertItem(HWND hwndHeader, int iInsertAfter, int nWidth, LPSTR lpsz) {

    HD_ITEM hdi;
    int index;

    hdi.mask = HDI_TEXT | HDI_FORMAT | HDI_WIDTH;
    hdi.pszText = lpsz;
    hdi.cxy = nWidth;
    hdi.cchTextMax = lstrlen(hdi.pszText);
    hdi.fmt = HDF_LEFT | HDF_STRING;

    index = SendMessage(hwndHeader, HDM_INSERTITEM, (WPARAM)iInsertAfter,
            (LPARAM)&hdi);

    return index;
}

void ErrorBox( HWND hwnd, LPTSTR pszText ) {
    TCHAR szMsg[80];

    wsprintf(szMsg, TEXT("Error %lu from %s"), GetLastError(), pszText);
    MessageBox(hwnd, szMsg, NULL, MB_OK | MB_ICONSTOP);
}