How to detect a call in a background and make a bridge between native and dart code

user_13228118 0
Viewed 1139

I'm trying to send a notification from dart code, when incoming call is being received. I couldn't manage to make a bridge between android native code and flutter code. The thing is that I need this feature to work in the background. I would describe the cycle like this:

  1. Flutter android native code has to detect call in a background
  2. Native code has to call a certain class from Flutter dart code
  3. This class finds certain information in database about the caller
  4. after finding it, it has to pop up a notification with certain details.

I managed to do part 3 and 4 but I need help with part 1 and 2.

I tried to figure out this given example, but it was to complicated

I found this method to detect the incoming call, but I couldn't attach it to mainActivity class and how do part 2

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) {

// I think this is the part, where I should call my dart class.

            }
        },PhoneStateListener.LISTEN_CALL_STATE);
    }
}

The question is how to properly detect a call and how to call a dart class from android native code?

dart flutter background-process android
1 Answers

You can create MethodChannel between native and dart. Here's sample code :

    String channel = "my.data";
    MethodChannel methodChannel = new MethodChannel(Objects.requireNonNull(getFlutterEngine()).getDartExecutor().getBinaryMessenger(), channel);
    final HashMap<String, String> map = new HashMap<>();
    map.put("yourvar", "myvar");

    methodChannel.setMethodCallHandler(
            new MethodChannel.MethodCallHandler() {
                @Override
                public void onMethodCall(MethodCall call, MethodChannel.Result result) {
                    if (call.method.equals("onFinish")) {
                        finish();
                    }
                }
            });
    methodChannel.invokeMethod("callMyFunction", map);

In your dart file write this code,

static const platform = const MethodChannel('my.data"');

  _MyPageState() {
    platform.setMethodCallHandler(_receiveFromNative);
  }

  Future<void> _receiveFromNative(MethodCall call) async {
    try {
      print(call.method);
      if (call.method == "callMyFunction") {
        print(call.arguments['yourvar']);
        //write your code here
       }
      } on PlatformException catch (e) {}
   }

You can refer to this document as well

user_20204440
Related