Event bus subscription issue (Otto - Guava event bus)

Question

Why the event is not subscribed, and onMyEvent not called. Relavent code is below. Otto is working normally in my uses, but below scenario involves posting the event from a callback handler (this is a simplification of code involving http calls). Not sure this has to do anything with it.

I use Otto (Guava event bus based) and Dagger (Guice). Hope Java experts may also be able to see any issue on how I inject and use the bus below.

Application (Module registration)

package com.example.ottocb;

import android.app.Application;
import android.content.Context;
import com.squareup.otto.Bus;
import dagger.Module;
import dagger.ObjectGraph;
import dagger.Provides;

import javax.inject.Singleton;

public class MyApplication extends Application {
    private ObjectGraph objectGraph;

    @Override
    public void onCreate() {
        super.onCreate();
        objectGraph = ObjectGraph.create(new MyModule(this));
    }

    public ObjectGraph objectGraph() {
        return objectGraph;
    }

    public void inject(Object object) {
        objectGraph.inject(object);
    }

    @Module(entryPoints = {Bus.class, MyActivity.class,
            MyFragment.class
    })
    static class MyModule {
        private final Context appContext;

        MyModule(Context appContext) {
            this.appContext = appContext;
        }

        @Provides
        @Singleton
        Bus provideBus() {
            return new Bus();
        }
    }
}

BaseFragment

package com.example.ottocb;

import android.app.Fragment;
import android.os.Bundle;

public class BaseFragment  extends Fragment {
    @Override
    public void onCreate(Bundle state) {
        super.onCreate(state);

        ((MyApplication) getActivity()
                .getApplication())
                .inject(this);
    }

}

MyFragment

package com.example.ottocb;

import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.Toast;
import com.squareup.otto.Bus;
import com.squareup.otto.Subscribe;

import javax.inject.Inject;

public class MyFragment extends BaseFragment  {
    private static final String TAG = MyFragment.class.getName();

    @Inject
    Bus bus;

    Button btn;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.myfragment, container,
                false);
        btn = (Button) view.findViewById(R.id.btn);
        btn.setOnClickListener(btnOnClick);

        return view;
    }

    Button.OnClickListener btnOnClick = new Button.OnClickListener() {

        @Override
        public void onClick(View v) {
            Log.i(TAG, "onClick");
            MyCB cb = new MyCB();
            cb.success();
        }
    };

    private class MyCB  {
        public void success() {
            Log.i(TAG, "SUCCESS " );

                bus.post(new MyEvent());

        }

        public void failure() {
            Log.e(TAG, "Error");

        }
    }

    @Subscribe
    public void onMyEvent(MyEvent event) {
        Log.i(TAG, "***** onMyEvent ********");
        Toast.makeText(getActivity(), "***** RECEIVED EVENT *****", Toast.LENGTH_SHORT).show();
    }
}

MyActivity

package com.example.ottocb;

import android.app.Activity;
import android.os.Bundle;

public class MyActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

MyEvent

package com.example.ottocb;

public class MyEvent {
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
             android:layout_width="match_parent" android:layout_height="match_parent">
    <fragment class="com.example.ottocb.MyFragment"
              android:id="@+id/myfragment"
              android:layout_width="match_parent" android:layout_height="match_parent" />
</FrameLayout>

myfragment.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">

    <Button
            android:id="@+id/btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Post" />


</LinearLayout>

Answer 1

In order to receive events, a class instance needs to register with the bus.

 bus.register(this);