scan method
Starts a scan for Bluetooth Low Energy devices Timeout closes the stream after a specified Duration
Implementation
Stream<BluetoothDevice> scan({
Duration? timeout,
}) async* {
if (_isScanning.value == true) {
throw Exception('Another scan is already in progress.');
}
// Emit to isScanning
_isScanning.add(true);
final killStreams = <Stream>[];
killStreams.add(_stopScanPill);
if (timeout != null) {
killStreams.add(Rx.timer(null, timeout));
}
// Clear scan results list
_scanResults.add(<BluetoothDevice>[]);
try {
await _channel.invokeMethod('startScan');
} catch (e) {
print('Error starting scan.');
_stopScanPill.add(null);
_isScanning.add(false);
throw e;
}
yield* BluetoothPrint.instance._methodStream
.where((m) => m.method == "ScanResult")
.map((m) => m.arguments)
.takeUntil(Rx.merge(killStreams))
.doOnDone(stopScan)
.map((map) {
final device = BluetoothDevice.fromJson(Map<String, dynamic>.from(map));
final List<BluetoothDevice> list = _scanResults.value;
int newIndex = -1;
list.asMap().forEach((index, e) {
if (e.address == device.address) {
newIndex = index;
}
});
if (newIndex != -1) {
list[newIndex] = device;
} else {
list.add(device);
}
_scanResults.add(list);
return device;
});
}