Pass information to a paused activity to call a method (Not UI update)

Question

Scenerio:

Activity A opens Activity B. Activity B has some filters based on which the content of Activity A will change. To reduce waiting time for the users, I want to notify Activity A to start fetching the content as soon as there is a change on Activity B.

What would be the best way to achieve this without changing activity's structure ?

You can use interfaces. Just curious why are you using filters on another activity ? — Umair, Aug 11 '20 at 05:22
@Umair That's a separate discussion and not an option at the moment. I thought about interfaces but do you have an idea how to use them in a good way ? — Sayed Jalil Hassan, Aug 11 '20 at 06:00
@AbhayKoradiya eventbus will require an architectural change. How do you propose RXJava be used ? — Sayed Jalil Hassan, Aug 11 '20 at 06:01
@SayedJalilHassan what do you mean by using them in good way? :) .Interfaces are pretty easy to use or you can use local broadcast receivers. — Umair, Aug 11 '20 at 06:22
@Umair I am talking about communication between 2 activities using interfaces. — Sayed Jalil Hassan, Aug 11 '20 at 06:34
@SayedJalilHassan please take a look at the second answer it's the cleanest way to do using interfaces: https://stackoverflow.com/questions/19026515/how-to-use-interface-to-communicate-between-two-activities — Umair, Aug 11 '20 at 06:40
@Umair Yes, it will work but it uses a static object that will be attached to Activities. — Sayed Jalil Hassan, Aug 11 '20 at 08:50
Try using BroadcastReciever that listen on changes in Activity B then onReceive() will be called in Activity A and do what you want on it . I hope I understood your Q correctly and answered it as well . — Ahmed Elsayed, Aug 13 '20 at 09:41

score 0 · Accepted Answer · answered Aug 13 '20 at 09:53

Ended up using a LocalBroadcastManager. Register a LocalBroadCastManager in Activity A and send a message from Activity B. Unregister it upon exiting Activity A.

In Activity A:

LocalBroadcastManager.getInstance(this).registerReceiver(
  mMessageReceiver, new IntentFilter("CUSTOM-EVENT_NAME"));

private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
      // process the message here
      String data = intent.getStringExtra("intent-key")
    }
};

In Activity B:

Intent intent = new Intent("CUSTOM-EVENT_NAME");
intent.putExtra("intent-key","data");
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);

Pass information to a paused activity to call a method (Not UI update)

1 Answers1