handleStringResponsePart method

Stream<String> handleStringResponsePart(Stream<OnCharacteristicReceivedEvent> source)

Handles string response parts from the device.

Implementation

Stream<String> handleStringResponsePart(
    Stream<OnCharacteristicReceivedEvent> source) async* {
  Uint8List? ongoingPrintResponse;
  int? ongoingPrintResponseChunkCount;
  await for (final event in source) {
    if (event.value[0] == FrameDataTypePrefixes.longText.value) {
      // ongoing long text
      if (ongoingPrintResponse == null ||
          ongoingPrintResponseChunkCount == null) {
        ongoingPrintResponse = Uint8List(0);
        ongoingPrintResponseChunkCount = 0;
        _log.fine("Starting receiving new long printed string");
      }
      ongoingPrintResponse =
          Uint8List.fromList(ongoingPrintResponse + event.value.sublist(1));

      ongoingPrintResponseChunkCount++;
      final receivedString = utf8.decode(event.value.sublist(1));
      _log.finer(
          "Received long text chunk #$ongoingPrintResponseChunkCount: $receivedString");

      if (ongoingPrintResponse.length > maxReceiveBuffer) {
        _log.severe(
            "Buffered received long printed string is more than $maxReceiveBuffer bytes: ${ongoingPrintResponse.lengthInBytes} bytes received");
        throw BrilliantBluetoothException(
            "Buffered received long printed string is more than $maxReceiveBuffer bytes: ${ongoingPrintResponse.lengthInBytes} bytes received");
      }
    } else if (event.value[0] == FrameDataTypePrefixes.longTextEnd.value) {
      final totalExpectedChunkCount =
          int.parse(utf8.decode(event.value.sublist(1)));
      _log.finer(
          "Received final string chunk count: $totalExpectedChunkCount");
      if (ongoingPrintResponseChunkCount != totalExpectedChunkCount) {
        _log.warning(
            "Chunk count mismatch in long received string (expected $totalExpectedChunkCount, got $ongoingPrintResponseChunkCount)");
        throw BrilliantBluetoothException(
            "Chunk count mismatch in long received string (expected $totalExpectedChunkCount, got $ongoingPrintResponseChunkCount)");
      }
      final completePrintResponse = utf8.decode(ongoingPrintResponse!);
      ongoingPrintResponse = null;
      ongoingPrintResponseChunkCount = null;
      _log.info("Finished receiving long string: $completePrintResponse");
      yield completePrintResponse;
    } else {
      final receivedString = utf8.decode(event.value);
      if (receivedString.startsWith("+") || receivedString.startsWith(">")) {
        _log.fine("Received check string: $receivedString");
      } else {
        _log.info("Received string: $receivedString");
      }
      yield receivedString;
    }
  }
}