HideOnScrollExample - MainActivity class

MainActivity.java

public class MainActivity extends ActionBarActivity {
  private Toolbar mToolbar;
  private ImageButton mFabButton;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    initToolbar();
    mFabButton = (ImageButton) findViewById(R.id.fabButton);
    initRecyclerView();
  }

  private void initToolbar() {
    mToolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(mToolbar);
    setTitle(getString(R.string.app_name));
    mToolbar.setTitleTextColor(getResources().getColor(android.R.color.white));
  }

  private void initRecyclerView() {
    RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    RecyclerAdapter recyclerAdapter = new RecyclerAdapter(createItemList());
    recyclerView.setAdapter(recyclerAdapter);
  }

}

where is creatItemList() method?