@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        application = (RandomWebmApplication) getApplicationContext();

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

        // Default fragment
        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction().replace(R.id.container, new RandomFragment()).commit();
        }
        loadTags();
    }

    private ApolloCall.Callback<TagsQuery.Data> tagsDataCallback = new ApolloCallback<>(new ApolloCall.Callback<TagsQuery.Data>() {
        @Override
        public void onResponse(@Nonnull Response<TagsQuery.Data> response) {

        }

        @Override
        public void onFailure(@Nonnull ApolloException e) {
            Log.e(TAG, e.getMessage(), e);
        }
    }, uiHandler);

    private List<TagsQuery.GetTag> responseTag(Response<TagsQuery.Data> response) {
        List<TagsQuery.GetTag> tagList = new ArrayList<>();
        final TagsQuery.Data responseData = response.data();
        if (responseData == null) {
            return Collections.emptyList();
        }
        final List<TagsQuery.GetTag> tags = responseData.getTags();
        if (tags != null) {
            if (tags.size() > 0) {
                tagList.addAll(tags);
            }
        }
        return tagList;
    }

    private void loadTags() {
        final TagsQuery tagsQuery = TagsQuery.builder()
                .build();
        tagsCall = application.apolloClient()
                .query(tagsQuery);
        tagsCall.enqueue(tagsDataCallback);
    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            if (backPressed + 2000 > System.currentTimeMillis()) {
                super.onBackPressed();
            } else {
                Toast.makeText(getBaseContext(), R.string.exit, Toast.LENGTH_SHORT).show();
            }
            backPressed = System.currentTimeMillis();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
        SearchView searchView = (SearchView) menu.findItem(R.id.action_search).getActionView();
        if (searchManager != null) {
            searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
        }
        final SearchView.SearchAutoComplete searchAutoComplete = (SearchView.SearchAutoComplete) searchView
                .findViewById(android.support.v7.appcompat.R.id.search_src_text);

        /*String dataArr[] = {"Apple" , "Amazon" , "Amd", "Microsoft", "Microwave", "MicroNews", "Intel", "Intelligence"};
        ArrayAdapter<String> newsAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, dataArr);
        searchAutoComplete.setAdapter();*/

        searchAutoComplete.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                String queryString=(String)adapterView.getItemAtPosition(i);
                searchAutoComplete.setText("" + queryString);
                Toast.makeText(MainActivity.this, "you clicked " + queryString, Toast.LENGTH_LONG).show();
            }
        });

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create();
                alertDialog.setMessage("Search keyword is " + query);
                alertDialog.show();
                return true;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                return true;
            }
        });

        return true;
    }