public class Action {

  private final String type;
  private final HashMap<String, Object> data;

  public Action(String type, HashMap<String, Object> data) {
    this.type = type;
    this.data = data;
  }

  public static Builder type(String type) {
    return new Builder().with(type);
  }

  public String getType() {
    return type;
  }

  public HashMap getData() {
    return data;
  }

  public static class Builder {
    private String type;
    private HashMap<String, Object> data;

    Builder with(String type) {
      if(type == null) {
        throw new IllegalArgumentException("Type may not be null.");
      }
      this.type = type;
      this.data = new HashMap<>();
      return this;
    }

    public Builder bundle(String key, Object value) {
      if (key == null) {
        throw new IllegalArgumentException("Key may not be null.");
      }
      if(value == null) {
        throw new IllegalArgumentException("Value may not be null.");
      }
      data.put(key, value);
      return this;
    }

    public Action build() {
      if (TextUtils.isEmpty(type)) {
        throw new IllegalArgumentException("At least one key is required.");
      }
      return new Action(type, data);
    }
  }
}

public interface ShowActions {
  String TODO_SHOW = "todo-show";
  String GET_TEXT = "get-text";
}

public class ActionsCreator {

  private static ActionsCreator instance;

  final Dispatcher mDispatcher;

  ActionsCreator(Dispatcher dispatcher){
    mDispatcher = dispatcher;
  }

  public static ActionsCreator get(Dispatcher dispatcher) {
    if (instance == null) {
      instance = new ActionsCreator(dispatcher);
    }
    return instance;
  }

  public void create(String text) {
    mDispatcher.dispatch(ShowActions.TODO_SHOW, ShowActions.GET_TEXT, text);
  }

public class Dispatcher {

  private final Bus bus;
  private static Dispatcher instance;

  Dispatcher(Bus bus){
    this.bus = bus;
  }

  public static Dispatcher get(Bus bus) {
    if (instance == null) {
      instance = new Dispatcher(bus);
    }
    return instance;
  }

  public void register(final Object cls) {
    bus.register(cls);
  }

  public void unRegister(final Object cls) {
    bus.unregister(cls);
  }

  public void emitChange(Store.StoreChangeEvent o) {post(o);}

  public void dispatch(String type, Object... data) {
    if(TextUtils.isEmpty(type)) {
      throw new IllegalArgumentException("Type must not be empty");
    }

    if (data.length % 2 != 0) {
      throw new IllegalArgumentException("Data must be a valid list of key");
    }

    Action.Builder actionBuilder = Action.type(type);
    for (int i = 0; i < data.length; i++) {
      String key = (String) data[i++];
      Object value = data[i++];
      actionBuilder.bundle(key, value);
    }
    post(actionBuilder.build());
  }

  private boolean isEmpty(String type) {
    return TextUtils.isEmpty(type);
  }

  private void post(final Object event) {
    bus.post(event);
  }
}

public abstract class Store {
  final Dispatcher mDispatcher;

  protected Store(Dispatcher dispatcher) {
    this.mDispatcher = dispatcher;
  }

  void emitStoreChange() {
    mDispatcher.emitChange(changeEvent());
  }

  abstract StoreChangeEvent changeEvent();

  public abstract void onAction(Action action);

  public interface StoreChangeEvent {}

}

public class ShowStore extends Store {

  private static ShowStore instance;
  private String showText;

  public ShowStore(Dispatcher dispatcher){
    super(dispatcher);
  }

  public static ShowStore get(Dispatcher dispatcher) {
    if (instance == null) {
      instance = new ShowStore(dispatcher);
    }
    return instance;
  }

  @Subscribe
  public void onAction(Action action) {
    switch (action.getType()) {
      case ShowActions.TODO_SHOW :
        showText = ((String)action.getData().get(ShowActions.GET_TEXT));
        Log.i("showText", showText);
        emitStoreChange();
        break;
      default:
        break;
    }
  }

  public String getShowText(){
    return showText;
  }

  @Override
  StoreChangeEvent changeEvent() {
    return new ShowChangeEvent();
  }

  public class ShowChangeEvent implements StoreChangeEvent {

  }
}

 @Subscribe
  public void showText (ShowStore.ShowChangeEvent event){
    mTextView.setText(mShowStore.getShowText());
   }