static void swingAndWait(Runnable r) ctex {
  if (isAWTThread())
    r.run();
  else
    EventQueue.invokeAndWait(r);
}

static O swingAndWait(final O f) {
  if (isAWTThread())
    ret callF(f);
  else {
    final new Var result;
    swingAndWait(r {
      result.set(callF(f));
    });
    ret result.get();
  }
}