Execute a dart function in background while receiving a call

Question

Is there any flutter plugin or article to do it.

what I want is: Run a method inside the dart which uses the incoming call number as a parameter, even after the app is terminated.

Is there any way to run the code even after the flutter app is terminated or closed.

Scenario: When a user gets a call. That number should be added to a flutter function which I wrote inside the flutter app. The function will check the number with my database and share that number to the API.

I need this process to work on background even the app is killed.(like Truecaller)

Main.dart

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  static const platform = const MethodChannel('samples.flutter.dev/battery');
  // Get battery level.
  String _batteryLevel = 'Unknown battery level.';

  Future<void> _getBatteryLevel() async {
    String batteryLevel;
    try {
      final int result = await platform.invokeMethod('getBatteryLevel');
      batteryLevel = 'Battery level at $result % .';
    } on PlatformException catch (e) {
      batteryLevel = "Failed to get battery level: '${e.message}'.";
    }

    setState(() {
      _batteryLevel = batteryLevel;
    });
  }

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(_batteryLevel),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _getBatteryLevel,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

MainActivity.java

package com.ashbu.flutterappbackground;

import androidx.annotation.NonNull;
import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.plugin.common.MethodChannel;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.widget.Toast;


public class MainActivity extends FlutterActivity {
    private static final String CHANNEL = "samples.flutter.dev/battery";
    AlarmManager alarmManager;
    PendingIntent pendingIntent;

    @Override
    public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
        super.configureFlutterEngine(flutterEngine);

        alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

        Intent alarmIntent = new Intent(this, MyBroadcastReceiver.class);
        pendingIntent = PendingIntent.getBroadcast(this, 0, alarmIntent, 0);

        new MethodChannel(flutterEngine.getDartExecutor().getBinaryMessenger(), CHANNEL)
                .setMethodCallHandler(
                        (call, result) -> {
                            // Note: this method is invoked on the main thread.
                            if (call.method.equals("getBatteryLevel")) {
                                startAlarm();
                            } else {
                                cancelAlarm();
                            }
                        }
                );
    }


    private void startAlarm() {

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            alarmManager.setAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, 0, pendingIntent);
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            alarmManager.setExact(AlarmManager.RTC_WAKEUP, 0, pendingIntent);
        } else {
            alarmManager.set(AlarmManager.RTC_WAKEUP, 0, pendingIntent);
        }


    }

    private void cancelAlarm() {
        alarmManager.cancel(pendingIntent);
        Toast.makeText(getApplicationContext(), "Alarm Cancelled", Toast.LENGTH_LONG).show();
    }


}

MyBroadcastReciever.java

    package com.ashbu.flutterappbackground;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class MyBroadcastReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
//        if (intent.getAction().equals("android.intent.action.BOOT_COMPLETED")) {
//
            Intent serviceIntent = new Intent(context, MyService.class);
            context.startService(serviceIntent);
//        } else {
//            Toast.makeText(context.getApplicationContext(), "Alarm Manager just ran", Toast.LENGTH_LONG).show();
//        }
        Toast.makeText(context, "TeleDuce Customer .",
                Toast.LENGTH_LONG).show();
        // Vibrate the mobile phone

    }
}

MyPhoneReciever.java

package com.ashbu.flutterappbackground;


import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.TelephonyManager;
import android.util.Log;

public class MyPhoneReciever extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        Bundle extras = intent.getExtras();
        if (extras != null) {
            String state = extras.getString(TelephonyManager.EXTRA_STATE);
            Log.w("MY_DEBUG_TAG", state);
            if (state.equals(TelephonyManager.EXTRA_STATE_RINGING)) {
                String phoneNumber = extras
                        .getString(TelephonyManager.EXTRA_INCOMING_NUMBER);
                Log.w("MY_DEBUG_TAG", phoneNumber);
            }
        }
    }
}

MyServices.java

package com.ashbu.flutterappbackground;

import android.app.AlarmManager;
import android.app.IntentService;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;

import androidx.annotation.Nullable;

public class MyService extends IntentService {


    public MyService() {
        super("MyService");
    }

    @Override
    protected void onHandleIntent(@Nullable Intent intent) {

        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

        Intent alarmIntent = new Intent(this, MyBroadcastReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, alarmIntent, 0);
        alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, 0, 10000, pendingIntent);
    }
}

Answer 1

Here MyPhoneReceiver.java is not needed...

change MyBroadcastReceiver code to this...

package com.ashbu.flutterappbackground;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.telephony.PhoneStateListener;
import android.widget.Toast;
import android.telephony.TelephonyManager;

public class MyBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(final Context context, Intent intent) {
        TelephonyManager telephony = (TelephonyManager)context.getSystemService(Service.TELEPHONY_SERVICE);
        telephony.listen(new PhoneStateListener(){
            @Override
            public void onCallStateChanged(int state, String incomingNumber) {
                super.onCallStateChanged(state, incomingNumber);
                System.out.println("incomingNumber : "+incomingNumber);
                Toast.makeText(context, "TeleDuce Customer "+ incomingNumber,
            Toast.LENGTH_LONG).show();
            }
        },PhoneStateListener.LISTEN_CALL_STATE);
    }
}

The main thing is to give phonecall access from mobile to the app...(in permission settings)