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) ;
ReleaseCapture () ;
SetCursor (LoadCursor (NULL, IDC_ARROW)) ;
fBlocking = FALSE ;
fValidBox = TRUE ;
InvalidateRect (hwnd, NULL, TRUE) ;
}
return 0 ;
case WM_CHAR :
if (fBlocking & wParam == '\x1B') // i.e., Escape
{
DrawBoxOutline (hwnd, ptBeg, ptEnd) ;
ReleaseCapture () ;
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 ;
}
retur