/*-----------------------------------------
   BLOKOUT1.C -- Boutons de la souris
                 (c) Charles Petzold, 1998
  -----------------------------------------*/

#include <windows.h>

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static TCHAR szAppName[] = TEXT ("BlokOut1") ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASS     wndclass ;
     
     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (NULL, IDI_APPLICATION) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = NULL ;
     wndclass.lpszClassName = szAppName ;
          
     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("Le programme nécessite Windows NT !"), 
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
     
     hwnd = CreateWindow (szAppName, TEXT ("Boutons de la souris"),
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          NULL, NULL, hInstance, NULL) ;

     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;
     
     while (GetMessage (&msg, NULL, 0, 0))
     {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
     }
     return msg.wParam ;
}

void DrawBoxOutline (HWND hwnd, POINT ptBeg, POINT ptEnd)
{
     HDC hdc ;
     
     hdc = GetDC (hwnd) ;
     
     SetROP2 (hdc, R2_NOT) ;
     SelectObject (hdc, GetStockObject (NULL_BRUSH)) ;
     Rectangle (hdc, ptBeg.x, ptBeg.y, ptEnd.x, ptEnd.y) ;
     
     ReleaseDC (hwnd, hdc) ;
}
LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
     static BOOL  fBlocking, fValidBox ;
     static POINT ptBeg, ptEnd, ptBoxBeg, ptBoxEnd ;
     HDC          hdc ;
     PAINTSTRUCT  ps ;
     
     switch (message)
     {
     case WM_LBUTTONDOWN :
          ptBeg.x = ptEnd.x = LOWORD (lParam) ;
          ptBeg.y = ptEnd.y = HIWORD (lParam) ;
          
          DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
          
          SetCursor (LoadCursor (NULL, IDC_CROSS)) ;
          
          fBlocking = TRUE ;
          return 0 ;

     case WM_MOUSEMOVE :
          if (fBlocking)
          {
               SetCursor (LoadCursor (NULL, IDC_CROSS)) ;
               
               DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
               
               ptEnd.x = LOWORD (lParam) ;
               ptEnd.y = HIWORD (lParam) ;
               
               DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
          }
          return 0 ;
          
     case WM_LBUTTONUP :
          if (fBlocking)
          {
               DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
               
               ptBoxBeg   = ptBeg ;
               ptBoxEnd.x = LOWORD (lParam) ;
               ptBoxEnd.y = HIWORD (lParam) ;
               
               SetCursor (LoadCursor (NULL, IDC_ARROW)) ;
               fBlocking = FALSE ;
               fValidBox  = TRUE ;
               
               InvalidateRect (hwnd, NULL, TRUE) ;
          }
          return 0 ;
          
     case WM_CHAR :
          if (fBlocking & wParam == '\x1B')       // Escape
          {
               DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
               
               SetCursor (LoadCursor (NULL, IDC_ARROW)) ;
               
               fBlocking = FALSE ;
          }
          return 0 ;

     case WM_PAINT :
          hdc = BeginPaint (hwnd, &ps) ;

          if (fValidBox)
          {
               SelectObject (hdc, GetStockObject (BLACK_BRUSH)) ;
               Rectangle (hdc, ptBoxBeg.x, ptBoxBeg.y,
                    ptBoxEnd.x, ptBoxEnd.y) ;
          }
          
          if (fBlocking)
          {
               SetROP2 (hdc, R2_NOT) ;
               SelectObject (hdc, GetStockObject (NULL_BRUSH)) ;
               Rectangle (hdc, ptBeg.x, ptBeg.y, ptEnd.x, ptEnd.y) ;
          }
          
          EndPaint (hwnd, &ps) ;
          return 0 ;
          
     case WM_DESTROY :
          PostQuitMessage (0) ;
          return 0 ;
     }
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}

