Implementing the KeybdPdd_GetEventEx2 Function (Windows CE 5.0)

Article
09/14/2012

In your Windows CE .NET 4.2 or later keyboard driver, replace the implementation of the KeybdPdd_GetEventEx function with an implementation of the KeybdPdd_GetEventEx2 function.

Perform the following steps in the files that contain the declaration and the implementation of the Windows CE .NET 4.1 or earlier KeybdPdd_GetEventEx function. Usually, these files are named Ps2keybd.hpp and Ps2keybd.cpp.

To implement the KeybdPdd_GetEventEx2 function

In the source file, replace the KeybdPdd_GetEventEx function implementation with the KeybdPdd_GetEventEx2 function implementation.

The following code example shows an implementation of KeybdPdd_GetEventEx2.

static
UINT
KeybdPdd_GetEventEx2(
  UINT uiPddId,
  UINT32 rguiScanCode[16],
  BOOL rgfKeyUp[16]
)
{
  SETFNAME(_T("KeybdPdd_GetEventEx2"));

  UINT8 ui8ScanCode;
  UINT cEvents = 0;

  static UINT32 scInProgress;
  static UINT32 scPrevious;
  static BOOL fKeyUp;

  DEBUGCHK(rguiScanCode != NULL);
  DEBUGCHK(rgfKeyUp != NULL);

  v_pp2k->m_pp2p->KeybdDataRead(&ui8ScanCode);

  DEBUGMSG(ZONE_SCANCODES, (_T("%s: scan code 0x%08x, code in progress 0x%08x, previous 0x%08x\r\n"), pszFname, ui8ScanCode, scInProgress, scPrevious));

  if (ui8ScanCode == 0xf0) {
    fKeyUp = TRUE;
  }
  else if (ui8ScanCode == scE0Extended) {
      scInProgress = 0xe000;
  } else if (ui8ScanCode == scE1Extended) {
      scInProgress = 0xe10000;
  } else if (scInProgress == 0xe10000) {
      scInProgress |= ui8ScanCode << 8;
  } else {
      scInProgress |= ui8ScanCode;
      if ((scInProgress == scPrevious) && (fKeyUp == FALSE)) {
          // mdd handles auto-repeat so ignore auto-repeats from keybd
      } 
      else {
          // Not a repeated key.  This is the real thing.
          // The Korean keyboard has two keys which generate a single
          // scan code when pressed.  The keys do not auto-repeat or
          // generate a scan code on release.  The scan codes are 0xf1
          // and 0xf2.  It does notlook like any other driver uses
          // the 0x71 or 0x72 scan code so it should be safe.

          // If it is one of the Korean keys, drop the previous scan code.
          // If we did not, the earlier check to ignore auto-repeating keys
          // would prevent this key from working twice in a row because the
          // key does not generate a scan code on release.
          if ( ( fKeyUp == TRUE ) ||
              ( scInProgress == 0xf1 ) ||
              ( scInProgress == 0xf2 ) )
          {
              scPrevious = 0;
          }
          else {
              scPrevious = scInProgress;
          }

          rguiScanCode[cEvents] = scInProgress;
          rgfKeyUp[cEvents] = fKeyUp;
          ++cEvents;
      }

      scInProgress = 0;
      fKeyUp = FALSE;
  }

  return cEvents;
}

In the header file, replace the declaration of KeybdPdd_GetEventEx with a declaration for KeybdPdd_GetEventEx2.

The following code example shows a sample declaration for KeybdPdd_GetEventEx2.
```
UINT
WINAPI
KeybdPdd_GetEventEx2(
    UINT    uiPddId,
    UINT32  rguiScanCode[16],
    BOOL    rgfKeyDown[16]
    );
```
For some hardware platforms, in the header file, you might need to add a declaration for the KeybdPdd_PowerHandler function, which is type defined as PFN_KEYBD_PDD_POWER_HANDLER.

The following code example shows a declaration for this function.
```
void
KeybdPdd_PowerHandler(
    BOOL bOff
    );
```

Implementing the KeybdPdd_GetEventEx2 Function (Windows CE 5.0)

See Also

Additional resources