readModemStatus method

@override Future<ModemStatus> readModemStatus()

Read the current state of the four DCE→DTE modem-status lines. Production transports query the underlying driver (sp_get_signals for libserialport, GetCommModemStatus for Windows). The default throws so existing custom transports keep compiling; override to expose this capability.

Implementation

@override
Future<ModemStatus> readModemStatus() async {
  if (!isOpen) throw StateError('LibserialportSerialTransport not open');
  final bitsPtr = malloc<Int32>();
  try {
    _check(
      _bindings.spGetSignals(_port!, bitsPtr),
      'sp_get_signals',
    );
    final bits = bitsPtr.value;
    return ModemStatus(
      cts: (bits & SpSignalMask.cts) != 0,
      dsr: (bits & SpSignalMask.dsr) != 0,
      ri: (bits & SpSignalMask.ri) != 0,
      cd: (bits & SpSignalMask.dcd) != 0,
    );
  } finally {
    malloc.free(bitsPtr);
  }
}