/// <summary>
///
/// </summary>
public Boolean IsFunctionalKeyUp(FunctionalKey key)
{
return !PressedFunctionalKeys.Contains (key);
}
/// <summary>
///
/// </summary>
public KeyState this[FunctionalKey key]
{
get {return PressedFunctionalKeys.Contains (key) ? KeyState.Down : KeyState.Up; }
}