reactos/lib/sdk/crt/conio/kbhit.c

   1 /*
   2  * COPYRIGHT:   See COPYING in the top level directory
   3  * PROJECT:     ReactOS system libraries
   4  * FILE:        lib/msvcrt/conio/kbhit.c
   5  * PURPOSE:     Checks for keyboard hits
   6  * PROGRAMERS:  Ariadne, Russell
   7  * UPDATE HISTORY:
   8  *              28/12/98: Created
   9  *              27/9/08: An almost 100% working version of _kbhit()
  10  */
  11
  12 #include <precomp.h>
  13
  14 static CRITICAL_SECTION CriticalSection;
  15 volatile BOOL CriticalSectionInitialized=FALSE;
  16
  17 /*
  18  * FIXME Initial keyboard char not detected on first punch
  19  *
  20  * @implemented
  21  */
  22
  23 int _kbhit(void)
  24 {
  25     PINPUT_RECORD InputRecord = NULL;
  26     DWORD NumberRead = 0;
  27     DWORD EventsRead = 0;
  28     DWORD RecordIndex = 0;
  29     DWORD BufferIndex = 0;
  30     HANDLE StdInputHandle = 0;
  31     DWORD ConsoleInputMode = 0;
  32
  33     /* Attempt some thread safety */
  34     if (!CriticalSectionInitialized)
  35     {
  36         InitializeCriticalSectionAndSpinCount(&CriticalSection, 0x80000400);
  37         CriticalSectionInitialized = TRUE;
  38     }
  39
  40     EnterCriticalSection(&CriticalSection);
  41
  42     if (char_avail)
  43     {
  44         LeaveCriticalSection(&CriticalSection);
  45         return 1;
  46     }
  47
  48     StdInputHandle = GetStdHandle(STD_INPUT_HANDLE);
  49
  50     /* Turn off processed input so we get key modifiers as well */
  51     GetConsoleMode(StdInputHandle, &ConsoleInputMode);
  52
  53     SetConsoleMode(StdInputHandle, ConsoleInputMode & ~ENABLE_PROCESSED_INPUT);
  54
  55     /* Start the process */
  56     if (!GetNumberOfConsoleInputEvents(StdInputHandle, &EventsRead))
  57     {
  58         LeaveCriticalSection(&CriticalSection);
  59         return 0;
  60     }
  61
  62     if (!EventsRead)
  63     {
  64         LeaveCriticalSection(&CriticalSection);
  65         return 0;
  66     }
  67
  68     if (!(InputRecord = (PINPUT_RECORD)malloc(EventsRead * sizeof(INPUT_RECORD))))
  69     {
  70         LeaveCriticalSection(&CriticalSection);
  71         return 0;
  72     }
  73
  74     if (!ReadConsoleInput(StdInputHandle, InputRecord, EventsRead, &NumberRead))
  75     {
  76         free(InputRecord);
  77         LeaveCriticalSection(&CriticalSection);
  78         return 0;
  79     }
  80
  81     for (RecordIndex = 0; RecordIndex < NumberRead; RecordIndex++)
  82     {
  83         if (InputRecord[RecordIndex].EventType == KEY_EVENT &&
  84             InputRecord[RecordIndex].Event.KeyEvent.bKeyDown)
  85         {
  86             BufferIndex = 1;
  87             break;
  88         }
  89     }
  90
  91     free(InputRecord);
  92
  93     /* Restore console input mode */
  94     SetConsoleMode(StdInputHandle, ConsoleInputMode);
  95
  96     LeaveCriticalSection(&CriticalSection);
  97
  98     return BufferIndex;
  99 }
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