Android InstanceState and createIntent() examples

gistfile1.txt

public class MovieDetailActivity extends AppCompatActivity {

    private static final String EXTRA_INSTANCE_STATE = "extra:instanceState";

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

        InstanceState is = InstanceState.from(getIntent().getExtras());
        displayMovieDetail(is.id, is.rank);
    }
    
    private void displayMovieDetail(String id, int rank) {
      ...
    }

    public static Intent createIntent(Context context, String id, int rank) {
        Intent intent = new Intent(context, MovieDetailActivity.class);
        intent.putExtras(new InstanceState(id, rank).toBundle(new Bundle()));
        return intent;
    }

    private static class InstanceState implements Serializable {
        private final String id;
        private final int rank;

        private InstanceState(String id, int rank) {
            this.id = id;
            this.rank = rank;
        }

        Bundle toBundle(Bundle bundle) {
            bundle.putSerializable(EXTRA_INSTANCE_STATE, this);
            return bundle;
        }

        private static InstanceState from(Bundle bundle) {
            return (InstanceState) bundle.getSerializable(EXTRA_INSTANCE_STATE);
        }
    }
}