shared_device_network 0.0.1 
shared_device_network: ^0.0.1 copied to clipboard
A lightweight Flutter & Dart package for local UDP hardware discovery, peripheral sharing, reliable ACK messaging, and device pairing.
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:shared_device_network/shared_device_network.dart';
import 'package:shared_device_network_example/bg_service_screen.dart';
void main() async {
WidgetsFlutterBinding.ensureInitialized();
runApp(const SharedDeviceApp());
}
class SharedDeviceApp extends StatelessWidget {
const SharedDeviceApp({super.key});
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Shared Device Network Demo',
debugShowCheckedModeBanner: false,
theme: ThemeData(
colorScheme: ColorScheme.fromSeed(seedColor: const Color(0xFF1E88E5)),
useMaterial3: true,
),
home: const HomeScreen(),
);
}
}
class HomeScreen extends StatefulWidget {
const HomeScreen({super.key});
@override
State<HomeScreen> createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen>
with SingleTickerProviderStateMixin {
late final TabController _tabController;
late final SharedDeviceNetworkClient _client;
final SharedDeviceNetworkServer server = SharedDeviceNetworkServer();
final List<String> _logs = [];
List<SharedDevice> _discoveredDevices = [];
bool _isDiscovering = false;
final Map<String, String> _devicePairKeys = {};
@override
void initState() {
super.initState();
_tabController = TabController(length: 2, vsync: this);
server.onMessageReceived((deviceId, message) async {
_log('π₯ Host received for "$deviceId": $message');
return SharedDeviceResponse.success(
message: 'Processed by $deviceId',
data: {'echo': message, 'time': DateTime.now().toIso8601String()},
);
});
server.start(port: 8888, discoveryPort: 8889);
// 3. Initialize client for testing discovery and dispatch
_client = SharedDeviceNetworkClient(
deviceId: 'client-app-01',
deviceName: 'Waiter Tablet',
discoveryPort: 8889,
defaultTimeout: const Duration(seconds: 3),
);
}
void _log(String text) {
if (!mounted) return;
final time = DateTime.now().toIso8601String().substring(11, 19);
setState(() {
_logs.insert(0, '[$time] $text');
if (_logs.length > 50) _logs.removeLast();
});
}
@override
void dispose() {
_tabController.dispose();
_client.dispose();
server.dispose();
super.dispose();
}
// --- Server Actions ---
int _sampleCounter = 1;
Future<void> _addDevice({
required String id,
required String name,
String? description,
String? pairKey,
}) async {
await server.addDevice(
id,
name,
deviceDescription: description,
pairKey: pairKey,
);
_log('β
Shared device added: $name ($id)');
setState(() {});
}
Future<void> _removeDevice(String deviceId) async {
await server.removeDevice(deviceId);
_log('ποΈ Removed device: $deviceId');
setState(() {});
}
void _showAddDeviceDialog({bool autoFillSample = false}) {
final idController = TextEditingController();
final nameController = TextEditingController();
final descController = TextEditingController();
final keyController = TextEditingController();
final samples = [
{
'id': 'printer-bt',
'name': 'Kitchen ESC/POS Printer',
'desc': 'Bluetooth 80mm Thermal Receipt Printer',
'key': '1234',
},
{
'id': 'scanner-usb',
'name': 'Counter 2D Barcode Scanner',
'desc': 'USB Handheld QR / Barcode Scanner',
'key': 'pass456',
},
{
'id': 'drawer-pos',
'name': 'Automated Cash Drawer',
'desc': 'RJ11 24V Heavy Duty Cash Drawer',
'key': '',
},
{
'id': 'scale-deli',
'name': 'Deli Digital Weighing Scale',
'desc': 'Serial RS232 Accurate Weight Scale',
'key': '7788',
},
{
'id': 'screen-cust',
'name': 'Secondary Customer Display',
'desc': 'HDMI Pole Display 2x20 Lines',
'key': '',
},
];
void fillRandom() {
final sample = samples[Random().nextInt(samples.length)];
final num = _sampleCounter++;
idController.text = '${sample['id']}-$num';
nameController.text = '${sample['name']} #$num';
descController.text = sample['desc']!;
keyController.text = sample['key']!;
}
if (autoFillSample) {
fillRandom();
}
showDialog(
context: context,
builder: (ctx) => StatefulBuilder(
builder: (ctx, setDialogState) => AlertDialog(
title: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
const Text(
'Add Device',
style: TextStyle(fontWeight: FontWeight.bold),
),
IconButton.filledTonal(
tooltip: 'Randomly fill form',
icon: const Icon(Icons.refresh),
onPressed: () {
fillRandom();
setDialogState(() {});
},
),
],
),
content: SingleChildScrollView(
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
TextField(
controller: idController,
decoration: const InputDecoration(
labelText: 'Device ID',
hintText: 'e.g. printer-bt-01',
border: OutlineInputBorder(),
isDense: true,
),
),
const SizedBox(height: 12),
TextField(
controller: nameController,
decoration: const InputDecoration(
labelText: 'Device Name',
hintText: 'e.g. Kitchen Printer',
border: OutlineInputBorder(),
isDense: true,
),
),
const SizedBox(height: 12),
TextField(
controller: descController,
decoration: const InputDecoration(
labelText: 'Description (Optional)',
hintText: 'e.g. Thermal 80mm ESC/POS',
border: OutlineInputBorder(),
isDense: true,
),
),
const SizedBox(height: 12),
TextField(
controller: keyController,
decoration: const InputDecoration(
labelText: 'Pair Key (Optional)',
hintText: 'Password for this device',
border: OutlineInputBorder(),
isDense: true,
),
),
],
),
),
actions: [
TextButton(
onPressed: () => Navigator.pop(ctx),
child: const Text('Cancel'),
),
FilledButton.icon(
onPressed: () async {
final id = idController.text.trim();
final name = nameController.text.trim();
final desc = descController.text.trim();
final key = keyController.text.trim();
if (id.isNotEmpty && name.isNotEmpty) {
Navigator.pop(ctx);
await _addDevice(
id: id,
name: name,
description: desc.isNotEmpty ? desc : null,
pairKey: key.isNotEmpty ? key : null,
);
}
},
icon: const Icon(Icons.add, size: 18),
label: const Text('Add Device'),
),
],
),
),
);
}
// --- Client Actions ---
Future<void> _discoverDevices() async {
setState(() => _isDiscovering = true);
_log('π Client broadcasting discovery request...');
try {
final found = await _client.discoverDevicesOnce(
timeout: const Duration(seconds: 2),
);
setState(() {
_discoveredDevices = found;
_isDiscovering = false;
});
_log('π Found ${found.length} shared device(s) on LAN');
} catch (e) {
setState(() => _isDiscovering = false);
_log('β Discovery error: $e');
}
}
void _showSetPairKeyDialog(SharedDevice dev) {
final currentKey = _devicePairKeys[dev.deviceId] ?? '';
final keyController = TextEditingController(text: currentKey);
showDialog(
context: context,
builder: (ctx) => AlertDialog(
title: Row(
children: [
const Icon(Icons.key, color: Colors.amber),
const SizedBox(width: 8),
Expanded(
child: Text(
'Pair Key: ${dev.deviceName}',
style: const TextStyle(fontSize: 17),
),
),
],
),
content: Column(
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
'Set the authorization key for "${dev.deviceId}". If this device is protected with a pair key on the server, requests without matching key will return 401 Unauthorized.',
style: const TextStyle(fontSize: 12.5, color: Colors.black87),
),
const SizedBox(height: 16),
TextField(
controller: keyController,
autofocus: true,
decoration: const InputDecoration(
labelText: 'Pair Key',
hintText: 'Enter pair key...',
border: OutlineInputBorder(),
isDense: true,
prefixIcon: Icon(Icons.password, size: 20),
),
),
],
),
actions: [
if (currentKey.isNotEmpty)
TextButton(
onPressed: () {
setState(() {
_devicePairKeys.remove(dev.deviceId);
});
Navigator.pop(ctx);
_log('π Cleared pair key for "${dev.deviceId}"');
},
child: const Text('Clear', style: TextStyle(color: Colors.red)),
),
TextButton(
onPressed: () => Navigator.pop(ctx),
child: const Text('Cancel'),
),
FilledButton(
onPressed: () {
final key = keyController.text.trim();
setState(() {
if (key.isNotEmpty) {
_devicePairKeys[dev.deviceId] = key;
} else {
_devicePairKeys.remove(dev.deviceId);
}
});
Navigator.pop(ctx);
if (key.isNotEmpty) {
_log('π Pair key saved for "${dev.deviceId}": "$key"');
} else {
_log('π Cleared pair key for "${dev.deviceId}"');
}
},
child: const Text('Save'),
),
],
),
);
}
Future<void> _sendMessage(SharedDevice dev) async {
final pairKey = _devicePairKeys[dev.deviceId];
_log(
'π€ Client sending to "${dev.deviceName}" (${dev.deviceId})'
'${pairKey != null && pairKey.isNotEmpty ? " [PairKey: $pairKey]" : ""}...',
);
final status = await _client.sendToDevice(
dev.deviceId,
{'action': 'PRINT_TEST', 'item': 'Coffee x2', 'total': 9.50},
targetDevice: dev,
pairKey: pairKey != null && pairKey.isNotEmpty ? pairKey : null,
);
if (status.isSuccess) {
_log('β
ACK from ${dev.deviceId}: ${status.message}');
} else {
_log('β Failed [${status.statusCode}]: ${status.message}');
}
}
@override
Widget build(BuildContext context) {
final isRunning = server.isRunning;
final deviceCount = server.deviceCount;
return Scaffold(
appBar: AppBar(
title: const Text('Shared Device Network'),
actions: [
ElevatedButton(
onPressed: () {
Navigator.of(context).push(
MaterialPageRoute(builder: (context) => BgServiceScreen()),
);
},
child: Text('In Background'),
),
],
bottom: TabBar(
controller: _tabController,
tabs: [
Tab(
icon: const Icon(Icons.router),
text: 'Host Server ($deviceCount)',
),
Tab(
icon: const Icon(Icons.devices),
text: 'Client (${_discoveredDevices.length})',
),
],
),
),
body: Column(
children: [
// Status banner
Container(
padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
color: isRunning ? Colors.green.shade50 : Colors.amber.shade50,
child: Row(
children: [
Icon(
isRunning ? Icons.check_circle : Icons.pause_circle_outline,
color: isRunning
? Colors.green.shade700
: Colors.amber.shade800,
size: 20,
),
const SizedBox(width: 8),
Expanded(
child: Text(
isRunning
? 'Server Active β’ Sharing $deviceCount device(s)'
: 'Server Inactive (add a device below to start)',
style: TextStyle(
fontSize: 12,
fontWeight: FontWeight.w600,
color: isRunning
? Colors.green.shade900
: Colors.amber.shade900,
),
),
),
],
),
),
// Main Tabs
Expanded(
child: TabBarView(
controller: _tabController,
children: [_buildHostServerTab(), _buildClientTab()],
),
),
// Collapsible Activity Logs
_buildLogsPanel(),
],
),
);
}
Widget _buildHostServerTab() {
final devices = server.devices;
return ListView(
padding: const EdgeInsets.all(16),
children: [
// Centered Big Add Device Button with Sample Refresh Button
Padding(
padding: const EdgeInsets.symmetric(vertical: 12),
child: Center(
child: Row(
mainAxisSize: MainAxisSize.min,
children: [
FilledButton.icon(
onPressed: () => _showAddDeviceDialog(),
icon: const Icon(Icons.add, size: 24),
label: const Text(
'Add Device',
style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
),
style: FilledButton.styleFrom(
padding: const EdgeInsets.symmetric(
horizontal: 32,
vertical: 16,
),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(14),
),
),
),
const SizedBox(width: 10),
IconButton.filledTonal(
tooltip: 'Sample (randomly fills form)',
icon: const Icon(Icons.refresh),
iconSize: 22,
style: IconButton.styleFrom(
padding: const EdgeInsets.all(14),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(14),
),
),
onPressed: () => _showAddDeviceDialog(autoFillSample: true),
),
],
),
),
),
const SizedBox(height: 12),
// Shared devices list
Text(
'Currently Shared on LAN (${devices.length})',
style: Theme.of(context).textTheme.titleSmall,
),
const SizedBox(height: 8),
if (devices.isEmpty)
Card(
elevation: 0,
color: Theme.of(context).colorScheme.surfaceContainerHighest,
child: const Padding(
padding: EdgeInsets.all(24),
child: Center(
child: Text(
'No peripherals shared yet.\nTap a button above to add a device and auto-start the server.',
textAlign: TextAlign.center,
style: TextStyle(fontSize: 13),
),
),
),
)
else
...devices.map(
(dev) => Card(
margin: const EdgeInsets.only(bottom: 8),
child: ListTile(
leading: CircleAvatar(
child: Icon(
dev.deviceId.contains('scanner')
? Icons.qr_code_scanner
: Icons.print,
),
),
title: Text(
dev.deviceName,
style: const TextStyle(fontWeight: FontWeight.bold),
),
subtitle: Text(
'${dev.deviceId} β’ ${dev.deviceDescription ?? "No description"}',
),
trailing: IconButton(
icon: const Icon(Icons.delete_outline, color: Colors.red),
tooltip: 'Remove device',
onPressed: () => _removeDevice(dev.deviceId),
),
),
),
),
],
);
}
Widget _buildClientTab() {
return ListView(
padding: const EdgeInsets.all(16),
children: [
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Text(
'Discovered LAN Peripherals',
style: Theme.of(context).textTheme.titleSmall,
),
FilledButton.tonalIcon(
onPressed: _isDiscovering ? null : _discoverDevices,
icon: _isDiscovering
? const SizedBox(
width: 14,
height: 14,
child: CircularProgressIndicator(strokeWidth: 2),
)
: const Icon(Icons.refresh, size: 16),
label: const Text('Discover'),
),
],
),
const SizedBox(height: 10),
if (_discoveredDevices.isEmpty)
Card(
elevation: 0,
color: Theme.of(context).colorScheme.surfaceContainerHighest,
child: const Padding(
padding: EdgeInsets.all(24),
child: Center(
child: Text(
'No devices discovered yet.\nTap "Discover" to scan for shared peripherals on this WiFi.',
textAlign: TextAlign.center,
style: TextStyle(fontSize: 13),
),
),
),
)
else
..._discoveredDevices.map((dev) {
final pairKey = _devicePairKeys[dev.deviceId];
final hasKey = pairKey != null && pairKey.isNotEmpty;
return Card(
margin: const EdgeInsets.only(bottom: 8),
child: Padding(
padding: const EdgeInsets.symmetric(
horizontal: 14,
vertical: 12,
),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
// Top Row: Device Avatar & Info
Row(
children: [
CircleAvatar(
backgroundColor: hasKey
? Colors.amber.shade100
: Theme.of(context).colorScheme.primaryContainer,
child: Icon(
hasKey ? Icons.lock : Icons.devices,
color: hasKey
? Colors.amber.shade900
: Theme.of(
context,
).colorScheme.onPrimaryContainer,
),
),
const SizedBox(width: 12),
Expanded(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
dev.deviceName,
style: const TextStyle(
fontWeight: FontWeight.bold,
fontSize: 15,
),
),
const SizedBox(height: 2),
Text(
'${dev.deviceId} β’ ${dev.deviceIp}:${dev.devicePort}',
style: TextStyle(
fontSize: 12,
color: Colors.grey.shade700,
),
),
],
),
),
],
),
const SizedBox(height: 10),
const Divider(height: 1),
const SizedBox(height: 8),
// Below Row: Pair Key button & Send button
Row(
children: [
OutlinedButton.icon(
onPressed: () => _showSetPairKeyDialog(dev),
icon: Icon(
hasKey ? Icons.key : Icons.key_outlined,
size: 15,
color: hasKey
? Colors.amber.shade900
: Colors.grey.shade700,
),
label: Text(
hasKey ? 'Key: $pairKey' : 'Set Pair Key',
style: TextStyle(
fontSize: 12,
color: hasKey
? Colors.amber.shade900
: Colors.grey.shade800,
fontWeight: hasKey
? FontWeight.bold
: FontWeight.normal,
),
),
style: OutlinedButton.styleFrom(
backgroundColor: hasKey
? Colors.amber.shade50
: null,
side: BorderSide(
color: hasKey
? Colors.amber.shade400
: Colors.grey.shade400,
),
padding: const EdgeInsets.symmetric(
horizontal: 10,
vertical: 6,
),
minimumSize: Size.zero,
tapTargetSize: MaterialTapTargetSize.shrinkWrap,
),
),
const Spacer(),
FilledButton.icon(
icon: const Icon(Icons.send, size: 14),
label: const Text('Send'),
onPressed: () => _sendMessage(dev),
),
],
),
],
),
),
);
}),
],
);
}
Widget _buildLogsPanel() {
return Container(
height: 140,
decoration: BoxDecoration(
color: Theme.of(
context,
).colorScheme.surfaceContainerHighest.withValues(alpha: 0.6),
border: Border(top: BorderSide(color: Colors.grey.shade300)),
),
child: Column(
children: [
Padding(
padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
const Text(
'Activity Logs',
style: TextStyle(fontSize: 11, fontWeight: FontWeight.bold),
),
if (_logs.isNotEmpty)
InkWell(
onTap: () => setState(() => _logs.clear()),
child: const Text(
'Clear',
style: TextStyle(fontSize: 11, color: Colors.blue),
),
),
],
),
),
const Divider(height: 1),
Expanded(
child: _logs.isEmpty
? const Center(
child: Text(
'No activity yet',
style: TextStyle(fontSize: 11, color: Colors.grey),
),
)
: ListView.builder(
padding: const EdgeInsets.symmetric(
horizontal: 12,
vertical: 4,
),
itemCount: _logs.length,
itemBuilder: (ctx, i) => Text(
_logs[i],
style: const TextStyle(
fontFamily: 'monospace',
fontSize: 11,
),
),
),
),
],
),
);
}
}Metadata
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Metadata
A lightweight Flutter & Dart package for local UDP hardware discovery, peripheral sharing, reliable ACK messaging, and device pairing.
Repository (GitHub)
View/report issues
Topics
#networking #udp #discovery #hardware #pos
License
MIT (license)