currency_sdk 1.0.1

Free, open-source currency conversion SDK for Flutter with 160+ currencies and offline-first architecture. No API keys required.

example/lib/main.dart

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

void main() {
  runApp(const MyApp());
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Currency SDK Example',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const CurrencyConverterExample(),
    );
  }
}

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

  @override
  State<CurrencyConverterExample> createState() =>
      _CurrencyConverterExampleState();
}

class _CurrencyConverterExampleState extends State<CurrencyConverterExample> {
  final CurrencyClient _client = CurrencyClient();
  final TextEditingController _amountController = TextEditingController();

  String _fromCurrency = 'USD';
  String _toCurrency = 'EUR';
  double? _convertedAmount;
  bool _isLoading = false;
  bool _isInitialized = false;
  bool _isOnline = false;
  String? _error;

  List<String> _currencies = [];

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

  Future<void> _initializeSDK() async {
    setState(() {
      _isLoading = true;
      _error = null;
    });

    try {
      // Initialize SDK (free tier - no API key needed)
      await _client.initialize();

      // Listen to connectivity changes
      _client.connectivityStream.listen((isOnline) {
        setState(() {
          _isOnline = isOnline;
        });
      });

      // Get initial connectivity status
      _isOnline = _client.isOnline;

      // Load available currencies
      final currencies = await _client.getSupportedCurrencies();

      setState(() {
        _isInitialized = true;
        _currencies = currencies;
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _error = 'Failed to initialize: ${e.toString()}';
        _isLoading = false;
      });
    }
  }

  Future<void> _convertCurrency() async {
    if (_amountController.text.isEmpty) return;

    setState(() {
      _isLoading = true;
      _error = null;
      _convertedAmount = null;
    });

    try {
      final amount = double.parse(_amountController.text);

      // Use SDK to convert
      final result = await _client.convert(
        amount: amount,
        from: _fromCurrency,
        to: _toCurrency,
      );

      setState(() {
        _convertedAmount = result;
        _isLoading = false;
      });
    } on FormatException {
      setState(() {
        _error = 'Please enter a valid number';
        _isLoading = false;
      });
    } on CurrencySDKException catch (e) {
      setState(() {
        _error = e.message;
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _error = e.toString();
        _isLoading = false;
      });
    }
  }

  @override
  void dispose() {
    _client.dispose();
    _amountController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    if (!_isInitialized) {
      return Scaffold(
        appBar: AppBar(title: const Text('Currency SDK Example')),
        body: Center(
          child: _error != null
              ? Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    const Icon(
                      Icons.error_outline,
                      size: 64,
                      color: Colors.red,
                    ),
                    const SizedBox(height: 16),
                    Text(_error!, textAlign: TextAlign.center),
                    const SizedBox(height: 16),
                    ElevatedButton(
                      onPressed: _initializeSDK,
                      child: const Text('Retry'),
                    ),
                  ],
                )
              : const CircularProgressIndicator(),
        ),
      );
    }

    return Scaffold(
      appBar: AppBar(
        title: const Text('Currency SDK Example'),
        actions: [
          Padding(
            padding: const EdgeInsets.all(16.0),
            child: Row(
              children: [
                Icon(
                  _isOnline ? Icons.wifi : Icons.wifi_off,
                  color: _isOnline ? Colors.green : Colors.red,
                ),
                const SizedBox(width: 4),
                Text(_isOnline ? 'Online' : 'Offline'),
              ],
            ),
          ),
        ],
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            // Amount input
            TextField(
              controller: _amountController,
              keyboardType: TextInputType.number,
              decoration: const InputDecoration(
                labelText: 'Amount',
                border: OutlineInputBorder(),
                prefixIcon: Icon(Icons.attach_money),
              ),
            ),
            const SizedBox(height: 16),

            // From currency dropdown
            DropdownButtonFormField<String>(
              value: _fromCurrency,
              decoration: const InputDecoration(
                labelText: 'From',
                border: OutlineInputBorder(),
              ),
              items: _currencies
                  .map(
                    (code) => DropdownMenuItem(value: code, child: Text(code)),
                  )
                  .toList(),
              onChanged: (value) {
                setState(() {
                  _fromCurrency = value!;
                });
              },
            ),
            const SizedBox(height: 16),

            // To currency dropdown
            DropdownButtonFormField<String>(
              value: _toCurrency,
              decoration: const InputDecoration(
                labelText: 'To',
                border: OutlineInputBorder(),
              ),
              items: _currencies
                  .map(
                    (code) => DropdownMenuItem(value: code, child: Text(code)),
                  )
                  .toList(),
              onChanged: (value) {
                setState(() {
                  _toCurrency = value!;
                });
              },
            ),
            const SizedBox(height: 24),

            // Convert button
            ElevatedButton(
              onPressed: _isLoading ? null : _convertCurrency,
              child: _isLoading
                  ? const SizedBox(
                      height: 20,
                      width: 20,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    )
                  : const Text('Convert'),
            ),
            const SizedBox(height: 24),

            // Result
            if (_convertedAmount != null)
              Card(
                child: Padding(
                  padding: const EdgeInsets.all(16.0),
                  child: Column(
                    children: [
                      const Text(
                        'Result',
                        style: TextStyle(
                          fontSize: 16,
                          fontWeight: FontWeight.bold,
                        ),
                      ),
                      const SizedBox(height: 8),
                      Text(
                        '${_amountController.text} $_fromCurrency = ${_convertedAmount!.toStringAsFixed(2)} $_toCurrency',
                        style: const TextStyle(fontSize: 20),
                        textAlign: TextAlign.center,
                      ),
                    ],
                  ),
                ),
              ),

            // Error
            if (_error != null)
              Card(
                color: Colors.red.shade50,
                child: Padding(
                  padding: const EdgeInsets.all(16.0),
                  child: Text(
                    _error!,
                    style: const TextStyle(color: Colors.red),
                    textAlign: TextAlign.center,
                  ),
                ),
              ),

            const Spacer(),

            // Info card
            Card(
              color: Colors.blue.shade50,
              child: Padding(
                padding: const EdgeInsets.all(16.0),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    const Text(
                      'SDK Features:',
                      style: TextStyle(fontWeight: FontWeight.bold),
                    ),
                    const SizedBox(height: 8),
                    const Text('✅ 160+ currencies'),
                    const Text('✅ Offline-first caching'),
                    const Text('✅ Real-time updates every 2 hours'),
                    const Text('✅ Free tier - no API key needed'),
                    const SizedBox(height: 8),
                    Text(
                      'Status: ${_isOnline ? 'Using live data' : 'Using cached data'}',
                      style: TextStyle(
                        color: _isOnline ? Colors.green : Colors.orange,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}