// OFWIN.CPP   Native windows program to display text in a window
#include <windows.h>


long WINAPI WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);


void OnPaint( HWND );
void OnLButtonDown( void );
void OnRButtonDown( void );
void OnChar( void );

// Listing OFWIN_1
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine, int nCmdShow)
{
   WNDCLASS WindowClass;                 // Structure to hold our window's attributes

   static char szAppName[] = "OFWin";    // Define window class name
   HWND hWnd;                            // Window handle
   MSG msg;                              // Windows message structure

   // Redraws the entire window if a movement or size 
   // adjustment changes the height/width of the client area.
   WindowClass.style   = CS_HREDRAW | CS_VREDRAW;

   // *** Define our procedure for message handling ***
   WindowClass.lpfnWndProc = WindowProc;

   WindowClass.cbClsExtra = 0;  // No extra bytes after the window class
   WindowClass.cbWndExtra = 0;  // structure or the window instance

   WindowClass.hInstance = hInstance;   // Application instance handle

   // Set default application icon
   WindowClass.hIcon = LoadIcon(0, IDI_APPLICATION );

   // Set window cursor to be the standard arrow
   WindowClass.hCursor = LoadCursor(0, IDC_ARROW);

   // Set gray brush for background color
   WindowClass.hbrBackground = static_cast<HBRUSH>(GetStockObject(GRAY_BRUSH));

   WindowClass.lpszMenuName = 0;           // No menu, so no menu resource name

   WindowClass.lpszClassName = szAppName;  // Set class name



   // The RegisterClass function registers a window class 
   // for subsequent use in calls to the CreateWindow or 
   // CreateWindowEx function
   RegisterClass(&WindowClass);

   //  Now we can create the window
   hWnd = CreateWindow(
          szAppName,                       // the window class name
          "A Basic Window the Hard Way",   // The window title
          WS_OVERLAPPEDWINDOW,             // Window style as overlapped
          0, // CW_USEDEFAULT,         // Default screen position of upper left
          0, //CW_USEDEFAULT,         // corner of our window as x,y...
          700, //CW_USEDEFAULT,         // Default window size
          400, //CW_USEDEFAULT,         // .... 
          0,                     // No parent window
          0,                     // No menu
          hInstance,             // Program Instance handle
          0                      // No window creation data
        );

   ShowWindow( hWnd, nCmdShow );   // Display the window

   // Cause window client area to be drawn
   // by posting a WM_PAINT message to the message queue
   UpdateWindow( hWnd );

   // The GetMessage function retrieves a message 
   // from the calling thread's message queue and places 
   // it in the specified structure. 
   // Exits loop on WM_CLOSE event!
   while( GetMessage(&msg, 0, 0, 0) == TRUE)   // Get any messages
   {
      // Translates virtual-key messages into character 
      // messages. The character messages are posted to the 
      // calling thread's message queue, to be read the next 
      // time the thread calls the GetMessage or 
      // PeekMessage function. 
      TranslateMessage(&msg);

      // The DispatchMessage function dispatches a message 
      // to a window procedure. It is typically used to 
      // dispatch a message retrieved by the GetMessage function
      DispatchMessage(&msg);
   }

   return msg.wParam;                         // End so return to Windows
}


// This is your function that handles messages that windows
// routes to this application. Only write code for the messages
// that you want to handle.
long WINAPI WindowProc(HWND hWnd, UINT message, WPARAM wParam,
                       LPARAM lParam)
{                     // Display context handle

   switch( message )                // Process selected messages
   {
      case WM_PAINT:                       // Message is to redraw the window
         OnPaint( hWnd );
         return 0;

      case WM_DESTROY:             // Window is being destroyed
         // The PostQuitMessage function posts a 
         // WM_QUIT message to the thread's message 
         // queue and returns immediately; the function 
         // simply indicates to the system that the 
         // thread is requesting to quit at some time in the future. 
         PostQuitMessage(0);
         return 0;

      case WM_LBUTTONDOWN:
         OnLButtonDown();
         return 0;

      case WM_RBUTTONDOWN:
         OnRButtonDown();
         return 0;

      case WM_CHAR:
         OnChar();
         return 0;

      default:             
         // Any other message - we don't want to know,
         // so call default message processing
         return DefWindowProc(hWnd, message, wParam, lParam);
   }
}

void OnPaint( HWND hWnd )
{
    RECT aRect;
    PAINTSTRUCT PaintSt;           // Structure defining area to be drawn
    HDC hDC;

    hDC = BeginPaint( hWnd, &PaintSt ); // Prepare to draw the window

    // Get upper left and lower right of client area
    GetClientRect( hWnd, &aRect );

    SetBkMode(hDC, TRANSPARENT);      // Set text background mode

    // Now draw the text in the window client area
    DrawText( hDC,                  // Device context handle
              "But, soft! What light through yonder window breaks?",
              -1,                   // Indicate null terminated string
              &aRect,               // Rectangle in which text is to be drawn
              DT_SINGLELINE|        // Text format - single line
              DT_CENTER|            //             - centered in the line
              DT_VCENTER );         //             - line centered in aRect

    EndPaint(hWnd, &PaintSt); // Terminate window redraw operation
}

void OnLButtonDown( void )
{
    MessageBox( NULL, "You just pressed the left mouse button", 
                "OnLButtonDown()", MB_OK );
}

void OnRButtonDown( void )
{
    for( int i=0; i<5; i++)
    {
       MessageBeep( (DWORD)-1 );
       Sleep( 100 );
    }
}

void OnChar( void )
{
   MessageBox( NULL, "You just pressed a Key!", 
                "OnChar()", MB_OK );
}