flutter_blue_plus 1.14.17 
flutter_blue_plus: ^1.14.17 copied to clipboard
jamcorder.comFlutter plugin for connecting and communicationg with Bluetooth Low Energy devices, on Android, iOS, and MacOS.
// Copyright 2023, Charles Weinberger & Paul DeMarco.
// All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
import 'dart:async';
import 'dart:io';
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_blue_plus/flutter_blue_plus.dart';
import 'package:permission_handler/permission_handler.dart';
import 'widgets.dart';
final snackBarKeyA = GlobalKey<ScaffoldMessengerState>();
final snackBarKeyB = GlobalKey<ScaffoldMessengerState>();
final snackBarKeyC = GlobalKey<ScaffoldMessengerState>();
final Map<DeviceIdentifier, ValueNotifier<bool>> isConnectingOrDisconnecting = {};
void main() {
if (Platform.isAndroid) {
WidgetsFlutterBinding.ensureInitialized();
[
Permission.location,
Permission.storage,
Permission.bluetooth,
Permission.bluetoothConnect,
Permission.bluetoothScan
].request().then((status) {
runApp(const FlutterBlueApp());
});
} else {
runApp(const FlutterBlueApp());
}
}
class BluetoothAdapterStateObserver extends NavigatorObserver {
StreamSubscription<BluetoothAdapterState>? _btStateSubscription;
@override
void didPush(Route route, Route? previousRoute) {
super.didPush(route, previousRoute);
if (route.settings.name == '/deviceScreen') {
// Start listening to Bluetooth state changes when a new route is pushed
_btStateSubscription ??= FlutterBluePlus.adapterState.listen((state) {
if (state != BluetoothAdapterState.on) {
// Pop the current route if Bluetooth is off
navigator?.pop();
}
});
}
}
@override
void didPop(Route route, Route? previousRoute) {
super.didPop(route, previousRoute);
// Cancel the subscription when the route is popped
_btStateSubscription?.cancel();
_btStateSubscription = null;
}
}
class FlutterBlueApp extends StatelessWidget {
const FlutterBlueApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
color: Colors.lightBlue,
home: StreamBuilder<BluetoothAdapterState>(
stream: FlutterBluePlus.adapterState,
initialData: BluetoothAdapterState.unknown,
builder: (c, snapshot) {
final adapterState = snapshot.data;
if (adapterState == BluetoothAdapterState.on) {
return const FindDevicesScreen();
} else {
FlutterBluePlus.stopScan();
return BluetoothOffScreen(adapterState: adapterState);
}
}),
navigatorObservers: [BluetoothAdapterStateObserver()],
);
}
}
class BluetoothOffScreen extends StatelessWidget {
const BluetoothOffScreen({Key? key, this.adapterState}) : super(key: key);
final BluetoothAdapterState? adapterState;
@override
Widget build(BuildContext context) {
return ScaffoldMessenger(
key: snackBarKeyA,
child: Scaffold(
backgroundColor: Colors.lightBlue,
body: Center(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
const Icon(
Icons.bluetooth_disabled,
size: 200.0,
color: Colors.white54,
),
Text(
'Bluetooth Adapter is ${adapterState != null ? adapterState.toString().split(".").last : 'not available'}.',
style: Theme.of(context).primaryTextTheme.titleSmall?.copyWith(color: Colors.white),
),
if (Platform.isAndroid)
ElevatedButton(
child: const Text('TURN ON'),
onPressed: () async {
try {
if (Platform.isAndroid) {
await FlutterBluePlus.turnOn();
}
} catch (e) {
final snackBar = snackBarFail(prettyException("Error Turning On:", e));
snackBarKeyA.currentState?.removeCurrentSnackBar();
snackBarKeyA.currentState?.showSnackBar(snackBar);
}
},
),
],
),
),
),
);
}
}
class FindDevicesScreen extends StatefulWidget {
const FindDevicesScreen({Key? key}) : super(key: key);
@override
State<FindDevicesScreen> createState() => _FindDevicesScreenState();
}
class _FindDevicesScreenState extends State<FindDevicesScreen> {
@override
Widget build(BuildContext context) {
return ScaffoldMessenger(
key: snackBarKeyB,
child: Scaffold(
appBar: AppBar(
title: const Text('Find Devices'),
),
body: RefreshIndicator(
onRefresh: () {
setState(() {}); // force refresh of connectedSystemDevices
if (FlutterBluePlus.isScanningNow == false) {
FlutterBluePlus.startScan(timeout: const Duration(seconds: 15), androidUsesFineLocation: false);
}
return Future.delayed(Duration(milliseconds: 500)); // show refresh icon breifly
},
child: SingleChildScrollView(
child: Column(
children: <Widget>[
StreamBuilder<List<BluetoothDevice>>(
stream: Stream.fromFuture(FlutterBluePlus.connectedSystemDevices),
initialData: const [],
builder: (c, snapshot) => Column(
children: (snapshot.data ?? [])
.map((d) => ListTile(
title: Text(d.localName),
subtitle: Text(d.remoteId.toString()),
trailing: StreamBuilder<BluetoothConnectionState>(
stream: d.connectionState,
initialData: BluetoothConnectionState.disconnected,
builder: (c, snapshot) {
if (snapshot.data == BluetoothConnectionState.connected) {
return ElevatedButton(
child: const Text('OPEN'),
onPressed: () => Navigator.of(context).push(MaterialPageRoute(
builder: (context) => DeviceScreen(device: d),
settings: RouteSettings(name: '/deviceScreen'))),
);
}
if (snapshot.data == BluetoothConnectionState.disconnected) {
return ElevatedButton(
child: const Text('CONNECT'),
onPressed: () {
Navigator.of(context).push(MaterialPageRoute(
builder: (context) {
isConnectingOrDisconnecting[d.remoteId] ??= ValueNotifier(true);
isConnectingOrDisconnecting[d.remoteId]!.value = true;
d.connect(timeout: Duration(seconds: 35)).catchError((e) {
final snackBar = snackBarFail(prettyException("Connect Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}).then((v) {
isConnectingOrDisconnecting[d.remoteId] ??= ValueNotifier(false);
isConnectingOrDisconnecting[d.remoteId]!.value = false;
});
return DeviceScreen(device: d);
},
settings: RouteSettings(name: '/deviceScreen')));
});
}
return Text(snapshot.data.toString().toUpperCase().split('.')[1]);
},
),
))
.toList(),
),
),
StreamBuilder<List<ScanResult>>(
stream: FlutterBluePlus.scanResults,
initialData: const [],
builder: (c, snapshot) => Column(
children: (snapshot.data ?? [])
.map(
(r) => ScanResultTile(
result: r,
onTap: () => Navigator.of(context).push(MaterialPageRoute(
builder: (context) {
isConnectingOrDisconnecting[r.device.remoteId] ??= ValueNotifier(true);
isConnectingOrDisconnecting[r.device.remoteId]!.value = true;
r.device.connect(timeout: Duration(seconds: 35)).catchError((e) {
final snackBar = snackBarFail(prettyException("Connect Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}).then((v) {
isConnectingOrDisconnecting[r.device.remoteId] ??= ValueNotifier(false);
isConnectingOrDisconnecting[r.device.remoteId]!.value = false;
});
return DeviceScreen(device: r.device);
},
settings: RouteSettings(name: '/deviceScreen'))),
),
)
.toList(),
),
),
],
),
),
),
floatingActionButton: StreamBuilder<bool>(
stream: FlutterBluePlus.isScanning,
initialData: false,
builder: (c, snapshot) {
if (snapshot.data ?? false) {
return FloatingActionButton(
child: const Icon(Icons.stop),
onPressed: () async {
try {
FlutterBluePlus.stopScan();
} catch (e) {
final snackBar = snackBarFail(prettyException("Stop Scan Error:", e));
snackBarKeyB.currentState?.removeCurrentSnackBar();
snackBarKeyB.currentState?.showSnackBar(snackBar);
}
},
backgroundColor: Colors.red,
);
} else {
return FloatingActionButton(
child: const Text("SCAN"),
onPressed: () async {
try {
if (FlutterBluePlus.isScanningNow == false) {
FlutterBluePlus.startScan(timeout: const Duration(seconds: 15), androidUsesFineLocation: false);
}
} catch (e) {
final snackBar = snackBarFail(prettyException("Start Scan Error:", e));
snackBarKeyB.currentState?.removeCurrentSnackBar();
snackBarKeyB.currentState?.showSnackBar(snackBar);
}
setState(() {}); // force refresh of connectedSystemDevices
});
}
},
),
),
);
}
}
class DeviceScreen extends StatelessWidget {
final BluetoothDevice device;
const DeviceScreen({Key? key, required this.device}) : super(key: key);
List<int> _getRandomBytes() {
final math = Random();
return [math.nextInt(255), math.nextInt(255), math.nextInt(255), math.nextInt(255)];
}
List<Widget> _buildServiceTiles(BuildContext context, List<BluetoothService> services) {
return services
.map(
(s) => ServiceTile(
service: s,
characteristicTiles: s.characteristics
.map(
(c) => CharacteristicTile(
characteristic: c,
onReadPressed: () async {
try {
await c.read();
final snackBar = snackBarGood("Read: Success");
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
} catch (e) {
final snackBar = snackBarFail(prettyException("Read Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}
},
onWritePressed: () async {
try {
await c.write(_getRandomBytes(), withoutResponse: c.properties.writeWithoutResponse);
final snackBar = snackBarGood("Write: Success");
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
if (c.properties.read) {
await c.read();
}
} catch (e) {
final snackBar = snackBarFail(prettyException("Write Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}
},
onNotificationPressed: () async {
try {
String op = c.isNotifying == false ? "Subscribe" : "Unubscribe";
await c.setNotifyValue(c.isNotifying == false);
final snackBar = snackBarGood("$op : Success");
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
if (c.properties.read) {
await c.read();
}
} catch (e) {
final snackBar = snackBarFail(prettyException("Subscribe Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}
},
descriptorTiles: c.descriptors
.map(
(d) => DescriptorTile(
descriptor: d,
onReadPressed: () async {
try {
await d.read();
final snackBar = snackBarGood("Read: Success");
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
} catch (e) {
final snackBar = snackBarFail(prettyException("Read Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}
},
onWritePressed: () async {
try {
await d.write(_getRandomBytes());
final snackBar = snackBarGood("Write: Success");
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
} catch (e) {
final snackBar = snackBarFail(prettyException("Write Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}
},
),
)
.toList(),
),
)
.toList(),
),
)
.toList();
}
@override
Widget build(BuildContext context) {
return ScaffoldMessenger(
key: snackBarKeyC,
child: Scaffold(
appBar: AppBar(
title: Text(device.localName),
actions: <Widget>[
StreamBuilder<BluetoothConnectionState>(
stream: device.connectionState,
initialData: BluetoothConnectionState.connecting,
builder: (c, snapshot) {
VoidCallback? onPressed;
String text;
switch (snapshot.data) {
case BluetoothConnectionState.connected:
onPressed = () async {
isConnectingOrDisconnecting[device.remoteId] ??= ValueNotifier(true);
isConnectingOrDisconnecting[device.remoteId]!.value = true;
try {
await device.disconnect();
final snackBar = snackBarGood("Disconnect: Success");
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
} catch (e) {
final snackBar = snackBarFail(prettyException("Disconnect Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}
isConnectingOrDisconnecting[device.remoteId] ??= ValueNotifier(false);
isConnectingOrDisconnecting[device.remoteId]!.value = false;
};
text = 'DISCONNECT';
break;
case BluetoothConnectionState.disconnected:
onPressed = () async {
isConnectingOrDisconnecting[device.remoteId] ??= ValueNotifier(true);
isConnectingOrDisconnecting[device.remoteId]!.value = true;
try {
await device.connect(timeout: Duration(seconds: 35));
final snackBar = snackBarGood("Connect: Success");
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
} catch (e) {
final snackBar = snackBarFail(prettyException("Connect Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}
isConnectingOrDisconnecting[device.remoteId] ??= ValueNotifier(false);
isConnectingOrDisconnecting[device.remoteId]!.value = false;
};
text = 'CONNECT';
break;
default:
onPressed = null;
text = snapshot.data.toString().split(".").last.toUpperCase();
break;
}
return ValueListenableBuilder<bool>(
valueListenable: isConnectingOrDisconnecting[device.remoteId]!,
builder: (context, value, child) {
isConnectingOrDisconnecting[device.remoteId] ??= ValueNotifier(false);
if (isConnectingOrDisconnecting[device.remoteId]!.value == true) {
// Show spinner when connecting or disconnecting
return Padding(
padding: const EdgeInsets.all(14.0),
child: AspectRatio(
aspectRatio: 1.0,
child: CircularProgressIndicator(
backgroundColor: Colors.black12,
color: Colors.black26,
),
),
);
} else {
return TextButton(
onPressed: onPressed,
child: Text(
text,
style: Theme.of(context).primaryTextTheme.labelLarge?.copyWith(color: Colors.white),
));
}
});
},
),
],
),
body: SingleChildScrollView(
child: Column(
children: <Widget>[
StreamBuilder<BluetoothConnectionState>(
stream: device.connectionState,
initialData: BluetoothConnectionState.connecting,
builder: (c, snapshot) => Column(
children: [
Padding(
padding: const EdgeInsets.all(8.0),
child: Text('${device.remoteId}'),
),
ListTile(
leading: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
snapshot.data == BluetoothConnectionState.connected
? const Icon(Icons.bluetooth_connected)
: const Icon(Icons.bluetooth_disabled),
snapshot.data == BluetoothConnectionState.connected
? StreamBuilder<int>(
stream: rssiStream(maxItems: 1),
builder: (context, snapshot) {
return Text(snapshot.hasData ? '${snapshot.data}dBm' : '',
style: Theme.of(context).textTheme.bodySmall);
})
: Text('', style: Theme.of(context).textTheme.bodySmall),
],
),
title: Text('Device is ${snapshot.data.toString().split('.')[1]}.'),
trailing: StreamBuilder<bool>(
stream: device.isDiscoveringServices,
initialData: false,
builder: (c, snapshot) => IndexedStack(
index: (snapshot.data ?? false) ? 1 : 0,
children: <Widget>[
TextButton(
child: const Text("Get Services"),
onPressed: () async {
try {
await device.discoverServices();
final snackBar = snackBarGood("Discover Services: Success");
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
} catch (e) {
final snackBar = snackBarFail(prettyException("Discover Services Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}
},
),
const IconButton(
icon: SizedBox(
child: CircularProgressIndicator(
valueColor: AlwaysStoppedAnimation(Colors.grey),
),
width: 18.0,
height: 18.0,
),
onPressed: null,
)
],
),
),
),
],
),
),
StreamBuilder<int>(
stream: device.mtu,
initialData: 0,
builder: (c, snapshot) => ListTile(
title: const Text('MTU Size'),
subtitle: Text('${snapshot.data} bytes'),
trailing: IconButton(
icon: const Icon(Icons.edit),
onPressed: () async {
try {
await device.requestMtu(223);
final snackBar = snackBarGood("Request Mtu: Success");
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
} catch (e) {
final snackBar = snackBarFail(prettyException("Change Mtu Error:", e));
snackBarKeyC.currentState?.removeCurrentSnackBar();
snackBarKeyC.currentState?.showSnackBar(snackBar);
}
}),
),
),
StreamBuilder<List<BluetoothService>>(
stream: device.servicesStream,
initialData: const [],
builder: (c, snapshot) {
return Column(
children: _buildServiceTiles(context, snapshot.data ?? []),
);
},
),
],
),
),
),
);
}
Stream<int> rssiStream({Duration frequency = const Duration(seconds: 5), int? maxItems = null}) async* {
var isConnected = true;
final subscription = device.connectionState.listen((v) {
isConnected = v == BluetoothConnectionState.connected;
});
int i = 0;
while (isConnected && (maxItems == null || i < maxItems)) {
try {
yield await device.readRssi();
} catch (e) {
print("Error reading RSSI: $e");
break;
}
await Future.delayed(frequency);
i++;
}
// Device disconnected, stopping RSSI stream
subscription.cancel();
}
}
String prettyException(String prefix, dynamic e) {
if (e is FlutterBluePlusException) {
return "$prefix ${e.description}";
} else if (e is PlatformException) {
return "$prefix ${e.message}";
}
return prefix + e.toString();
}Metadata
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Metadata
Flutter plugin for connecting and communicationg with Bluetooth Low Energy devices, on Android, iOS, and MacOS.
Repository (GitHub)
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License
unknown (license)
