considering modifier keys after gaining focus

Corinna Vinschen
Sun Aug 21 08:44:00 GMT 2011

On Aug 16 17:31, Oliver Schmidt wrote:
> Hi,
> I had the problem, that the state of the modifier keys was lost when
> a window is created (or raised).
> Example: in window A Ctrl + some key opens a window B, then in
> window B Ctrl + some other key triggers the next action. However
> after the opening of window B the Ctrl key has to be released and
> pressed again. If the user keeps the Ctrl key holding when the
> window B is opened, the next key press X will be interpreted as X
> and not as Ctrl+X.
> I send a patch to fix this problem with this email: I just extended
> the function winRestoreModeKeyStates in winkeybd.c to consider not
> only the mode switch key but also the modifiers Ctrl, Shift,
> Alt/AltGr by using the Windows function GetAsyncKeyState.
> This patch works fine for me.
> However one problem is unsolved: if the key combination for opening
> window B (in the above example) is an AltGr key combination, the
> GetAsyncKeyState will also report, that the Ctrl key is pressed,
> which is not true, since this is the well known Windows fake Ctrl_L
> :-(
> Any suggestions how to solve this?

At that time, doesn't GetAsyncKeyState (VK_RMENU) also return < 0?
So, shouldn't something along these lines do the trick:

  BOOL ctrl = (GetAsyncKeyState (VK_CONTROL) < 0);
  BOOL shift = (GetAsyncKeyState (VK_CONTROL) < 0);
  BOOL alt = (GetAsyncKeyState (VK_CONTROL) < 0);
  BOOL altlang = (GetAsyncKeyState (VK_CONTROL) < 0);
  if (ctrl & altlang)
    ctrl = FALSE;
  if (WIN_XOR (internalKeyStates & ControlMask, ctrl)
    winSendKeyEvent (KEY_LCtrl, ctrl);
  if (WIN_XOR (internalKeyStates & ShiftMask, shift))
    winSendKeyEvent (KEY_ShiftL, shift);
  if (WIN_XOR (internalKeyStates & Mod1Mask, alt))
    winSendKeyEvent (KEY_Alt, alt);
  if (WIN_XOR (internalKeyStates & Mod5Mask, altlang))
    winSendKeyEvent (KEY_AltLang, altlang);


Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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