/// <summary>
/// Convert wParam and lParam to a key.
/// </summary>
private Key TranslateKey(ulong wParam, ulong lParam)
{
switch (wParam)
{
// Control keys require special handling.
case (uint)VirtualKey.CONTROL when(lParam& 0x01000000) != 0:
return(Key.RightControl);
case (uint)VirtualKey.CONTROL:
{
uint time = User32.GetMessageTime();
// HACK: Alt Gr sends Left Ctrl and then Right Alt in close sequence
// We only want the Right Alt message, so if the next message is
// Right Alt we ignore this (synthetic) Left Ctrl message
if (!User32.PeekMessage(out Message next, IntPtr.Zero, 0, 0, PeekMessageFlags.PM_NOREMOVE))
{
return(Key.LeftControl);
}
if (next.Value != WM.KEYDOWN && next.Value != WM.SYSKEYDOWN && next.Value != WM.KEYUP && next.Value != WM.SYSKEYUP)
{
return(Key.LeftControl);
}
if ((uint)next.WParam == (uint)VirtualKey.MENU && ((uint)next.LParam & 0x01000000) != 0 && next.Time == time)
{
// Next message is Right Alt down so discard this
return(Key.Unknown);
}
return(Key.LeftControl);
}
// IME notifies that keys have been filtered by setting the virtual
// key-code to VK_PROCESSKEY
case (uint)VirtualKey.PROCESSKEY:
return(Key.Unknown);
}
int index = NativeHelpers.HiWord(lParam) & 0x1FF;
if (index < 0 || index >= _keyCodes.Length)
{
return(Key.Unknown);
}
return(_keyCodes[index]);
}
