preferred_upi_launcher 0.0.2

A Flutter plugin to discover installed UPI apps and launch them with pre-filled payment details. No payment gateway required.

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:preferred_upi_launcher/preferred_upi_launcher.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(title: 'UPI Launcher Demo', theme: ThemeData(colorSchemeSeed: Colors.indigo, useMaterial3: true), home: const UpiDemoPage());
  }
}

class UpiDemoPage extends StatefulWidget {
  const UpiDemoPage({super.key});

  @override
  State<UpiDemoPage> createState() => _UpiDemoPageState();
}

class _UpiDemoPageState extends State<UpiDemoPage> {
  List<UpiAppInfo> _apps = [];
  bool _loading = false;
  String? _error;

  // Replace payeeVpa and transactionRef with real values before live testing
  static const _config = UpiPaymentConfig(payeeVpa: 'ashankartri****@oksbi', payeeName: 'Aditya', amount: '1', transactionRef: 'DEMO_TX_001', transactionNote: 'Demo payment');

  @override
  void initState() {
    super.initState();
    _fetchApps();
  }

  Future<void> _fetchApps() async {
    setState(() {
      _loading = true;
      _error = null;
    });
    try {
      final apps = await PreferredUpiLauncher.getInstalledApps();
      setState(() => _apps = apps);
    } catch (e) {
      setState(() => _error = e.toString());
    } finally {
      setState(() => _loading = false);
    }
  }

  Future<void> _launch(UpiAppInfo app) async {
    try {
      await PreferredUpiLauncher.launchApp(app: app, config: _config);
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Failed to launch ${app.name}: $e')));
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('UPI Launcher Demo'), actions: [IconButton(icon: const Icon(Icons.refresh), tooltip: 'Refresh', onPressed: _fetchApps)]),
      body: Column(crossAxisAlignment: CrossAxisAlignment.stretch, children: [_PaymentInfoCard(config: _config), Expanded(child: _buildBody())]),
    );
  }

  Widget _buildBody() {
    if (_loading) return const Center(child: CircularProgressIndicator());
    if (_error != null) {
      return Center(child: Padding(padding: const EdgeInsets.all(24), child: Text('Error: $_error', style: const TextStyle(color: Colors.red))));
    }
    if (_apps.isEmpty) {
      return const Center(child: Padding(padding: EdgeInsets.all(24), child: Text('No UPI apps found.\nTest on a physical device with UPI apps installed.', textAlign: TextAlign.center)));
    }
    return ListView.separated(
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
      itemCount: _apps.length,
      separatorBuilder: (_, __) => const Divider(height: 1),
      itemBuilder: (context, index) {
        final app = _apps[index];
        return ListTile(
          leading: const CircleAvatar(child: Icon(Icons.account_balance_wallet_outlined)),
          title: Text(app.name, style: const TextStyle(fontWeight: FontWeight.w600)),
          subtitle: Text(app.packageName, style: Theme.of(context).textTheme.bodySmall),
          trailing: const Icon(Icons.arrow_forward_ios, size: 14),
          onTap: () => _launch(app),
        );
      },
    );
  }
}

class _PaymentInfoCard extends StatelessWidget {
  final UpiPaymentConfig config;
  const _PaymentInfoCard({required this.config});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Card(
      margin: const EdgeInsets.all(16),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('Payment Details', style: theme.textTheme.titleMedium),
            const SizedBox(height: 8),
            _row('Payee', '${config.payeeName} (${config.payeeVpa})'),
            _row('Amount', '₹${config.amount}'),
            _row('Ref', config.transactionRef),
          ],
        ),
      ),
    );
  }

  Widget _row(String label, String value) => Padding(
    padding: const EdgeInsets.symmetric(vertical: 2),
    child: Row(children: [SizedBox(width: 56, child: Text('$label:', style: const TextStyle(color: Colors.grey))), Expanded(child: Text(value))]),
  );
}