MainActivity.java

package com.tutosandroidfrance.searchviewsample;

import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.SearchView;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

import de.greenrobot.event.EventBus;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);

        final MenuItem searchItem = menu.findItem(R.id.action_search);
        final SearchView searchView = (SearchView)MenuItemCompat.getActionView(searchItem);

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                EventBus.getDefault().post(new QueryEvent(query));

                //if you want to collapse the searchview
                invalidateOptionsMenu();

                return false;
            }

            @Override
            public boolean onQueryTextChange(String s) {
                return false;
            }
        });

        return true;
    }

}