MainActivity.java

public class MainActivity extends LifecycleActivity implements Observer<List<StarWarsMovie>> {

  @BindView(R.id.lv_am_movie_list) ListView listView;
  @BindView(R.id.pb_am_loading) ProgressBar progressBar;
  private MainViewModel mainViewModel;

  @Override protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mainViewModel = ViewModelProviders.of(this).get(MainViewModel.class);

    ButterKnife.bind(this);
    listView.setVisibility(View.GONE);
    progressBar.setVisibility(View.VISIBLE);

    subscribeUiUpdates();
  }

  private void subscribeUiUpdates() {
    mainViewModel.getMoviesLiveData().observe(this, this);
  }

  @Override public void onChanged(@Nullable List<StarWarsMovie> starWarsMovies) {
    Log.d("XXX","Data changed");
    MovieAdapter movieAdapter = new MovieAdapter(this, starWarsMovies);
    listView.setAdapter(movieAdapter);

    progressBar.setVisibility(View.GONE);
    listView.setVisibility(View.VISIBLE);
  }

  static class ViewHolder {
    @BindView(R.id.tv_im_movie_name) TextView tvName;
    @BindView(R.id.tv_im_movie_description) TextView tvDescription;
    @BindView(R.id.tv_im_movie_date) TextView tvDate;
    @BindView(R.id.iv_im_movie_poster) ImageView ivPoster;

    ViewHolder(View view) {
      ButterKnife.bind(this, view);
    }
  }

  private class MovieAdapter extends ArrayAdapter<StarWarsMovie> {
    public MovieAdapter(Context context, List<StarWarsMovie> users) {
      super(context, 0, users);
    }

    @NonNull @Override public View getView(int position, View convertView, ViewGroup parent) {
      StarWarsMovie starWarsMovie = getItem(position);
      ViewHolder holder;
      if (convertView == null) {
        convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_movie, parent, false);
        holder = new ViewHolder(convertView);
        convertView.setTag(holder);
      }

      holder = (ViewHolder) convertView.getTag();
      holder.tvName.setText(starWarsMovie.getName());
      holder.tvDescription.setText(starWarsMovie.getDescription());
      holder.tvDate.setText(starWarsMovie.getReleaseDate());

      Glide.with(getContext())
          .load(starWarsMovie.getImageUrl())
          .placeholder(R.drawable.placeholder)
          .into(holder.ivPoster);

      return convertView;
    }
  }
}