if ((r && isRollover()) || (!r && !isRollover()))
if (r == isRollover())
  public void setRollover(boolean r)  {    // if this call does not represent a CHANGE in state, then return    if ((r && isRollover()) || (!r && !isRollover()))      return;        // cannot set ROLLOVER property unless button is enabled    if (!isEnabled())      return;    // make the change    if (r)      stateMask = stateMask | ROLLOVER;    else      stateMask = stateMask & (~ROLLOVER);    // notify interested ChangeListeners    fireStateChanged();  }