scanBluetoothDevices static method

Future<void> scanBluetoothDevices(
  1. {Duration? timeout}
)

Starts a scan for Bluetooth devices and returns a stream of the results.

  • timeout: Optionally specifies a duration after which the scan will be stopped.

Example of how to use the scanBluetoothDevices() function.

This example starts a scan for Bluetooth devices and prints the results to the console. To use the scanBluetoothDevices() function, you can do the following:

  1. Call the scanBluetoothDevices() function with the desired timeout.
  2. Listen to the scanResults stream to receive the results of the scan.
  3. Print the results of the scan to the console. The following example shows how to use the scanBluetoothDevices() function:

Implementation

static Future<void> scanBluetoothDevices({
  Duration? timeout,
}) async {
  // Stops any existing scan
  final isScanning = _isScanning.latestValue;
  if (isScanning == true) {
    await stopScan();
  }

  // Sets the scanning flag to true
  _isScanning.add(true);

  final responseStream = FlutterNewposSdk._methodStream.stream
      .where((m) => m.method == 'OnScanResponse')
      .map((m) {
    final arguments = m.arguments as Map<Object?, Object?>;
    final convertedMap = <dynamic, dynamic>{};
    arguments.forEach((key, value) {
      if (key is String) {
        convertedMap[key] = value;
      }
    });
    return convertedMap;
  }).map(
    BluetoothDevice.fromMap,
  );

  // Starts buffering the scan results
  final scanBuffer = _BufferStream.listen(responseStream);

  // Invokes the platform method to start the scan
  await _invokeMethod('scanBlueDevice') as bool;

  // Creates a stream of the scan results, filtered for devices that are still present
  final outputStream = scanBuffer.stream;

  // Creates a list to store the scan results
  final output = <DeviceScanned>[];

  // Listens to the stream of scan results and pushes them to the `scanResults` stream
  _scanSubscription = outputStream.listen((BluetoothDevice? response) {
    if (response != null) {
      // Converts the BluetoothDevice object to a DeviceScanned object
      final sr = DeviceScanned.fromDevice(response);

      // Adds or updates the DeviceScanned object in the output list
      output.addOrUpdate(sr);

      // Pushes the output list to the `scanResults` stream
      _scanResultsList.add(List.from(output));
    }
  });

  // Starts a timer to stop the scan after the specified timeout
  if (timeout != null) {
    _scanTimeout = Timer(_defaultTimeOut, stopScan);
  }
}