monorepo/dialer/lib/main.dart

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

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

class IcingDialerApp extends StatefulWidget {
  const IcingDialerApp({Key? key}) : super(key: key);

  @override
  State<IcingDialerApp> createState() => _IcingDialerAppState();
}

class _IcingDialerAppState extends State<IcingDialerApp> {
  // This channel must match the one in MainActivity.kt.
  static const platform = MethodChannel('com.example.dialer/call_events');
  bool isDefaultDialer = false;

  @override
  void initState() {
    super.initState();
    // Listen for method calls from the Android side.
    platform.setMethodCallHandler(handleMethodCalls);
  }



  Future<void> handleMethodCalls(MethodCall call) async {
    switch (call.method) {
      case 'onDefaultDialerSet':
      // Update our UI to show that we are now the default dialer.
        setState(() {
          isDefaultDialer = true;
        });
        break;
      case 'onDefaultDialerDenied':
      // Show a message to the user when they deny the request.
        _showDefaultDialerDeniedDialog();
        break;
      case 'onIncomingCall':
        final phoneNumber = call.arguments as String? ?? "Unknown";
        _showIncomingCallDialog(phoneNumber);
        break;
      default:
        print("Unhandled method: ${call.method}");
    }
  }

  // Show a dialog when the user denies the default dialer request.
  void _showDefaultDialerDeniedDialog() {
    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Permission Denied'),
        content: const Text(
            'To use this app as your default dialer, please grant the permission when prompted.'),
        actions: [
          TextButton(
            onPressed: () {
              Navigator.of(context).pop();
            },
            child: const Text('OK'),
          ),
        ],
      ),
    );
  }

  // Show a dialog when an incoming call is intercepted.
  void _showIncomingCallDialog(String phoneNumber) {
    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (_) => AlertDialog(
        title: const Text('Incoming Call'),
        content: Text('Call from: $phoneNumber'),
        actions: [
          TextButton(
            onPressed: () {
              // (Here you could add code to reject the call.)
              Navigator.of(context).pop();
            },
            child: const Text('Reject'),
          ),
          ElevatedButton(
            onPressed: () {
              // (Here you could add code to accept the call.)
              Navigator.of(context).pop();
            },
            child: const Text('Accept'),
          ),
        ],
      ),
    );
  }

  // Invoke the native method to request to be the default dialer.
  Future<void> requestDefaultDialer() async {
    try {
      await platform.invokeMethod('requestDefaultDialer');
    } catch (e) {
      print('Error requesting default dialer: $e');
      // Show an error message if the request fails.
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Error requesting default dialer: $e')),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Icing Dialer',
      theme: ThemeData.dark(),
      home: isDefaultDialer
          ? const CallScreen()
          : DefaultDialerSetupScreen(onRequestDefaultDialer: requestDefaultDialer),
    );
  }
}

/// Shown when the app is not yet the default dialer.
class DefaultDialerSetupScreen extends StatelessWidget {
  final VoidCallback onRequestDefaultDialer;
  const DefaultDialerSetupScreen({Key? key, required this.onRequestDefaultDialer})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Set as Default Dialer')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text(
              'This app is not set as your default dialer.',
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 20),
            ElevatedButton(
              onPressed: onRequestDefaultDialer,
              child: const Text('Set as Default Dialer'),
            ),
          ],
        ),
      ),
    );
  }
}

/// Shown when the app is the default dialer.
class CallScreen extends StatelessWidget {
  const CallScreen({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    // A simple UI indicating that the app is waiting for incoming calls.
    return Scaffold(
      appBar: AppBar(title: const Text('Icing Dialer')),
      body: const Center(
        child: Text('Waiting for incoming calls...'),
      ),
    );
  }
}