An Otto event bus subclass with force UI dispatch and stick events

EventBus.java

package co.vispera.shark.miscellaneous;

import android.os.Handler;
import android.os.Looper;

import com.squareup.otto.Bus;
import com.squareup.otto.Produce;

import java.util.concurrent.ConcurrentHashMap;

import co.vispera.shark.events.BarcodeScanned;
import co.vispera.shark.events.Event;
import co.vispera.shark.events.DeletePhoto;
import co.vispera.shark.events.PhotoRetaken;
import co.vispera.shark.events.StorePhotoCaptured;
import co.vispera.shark.events.QuestionnairePhotoCaptured;
import co.vispera.shark.events.VisitSendFailed;

public class EventBus extends Bus {

  private static final Handler mainThreadHandler = new Handler(Looper.getMainLooper());
  private final ConcurrentHashMap<Class<? extends Event>, Event> eventCache = new ConcurrentHashMap<>();
  private final EventProducer producer = new EventProducer(this);

  @Override
  public void post(final Object event) {
    if (Looper.myLooper() == Looper.getMainLooper()) {
      super.post(event);
    } else {
      mainThreadHandler.post(new Runnable() {
        @Override public void run() {
          post(event);
        }
      });
    }
  }

  public void postSticky(final Event event) {
    eventCache.put(event.getClass(), event);
    post(event);
  }

  public void removeSticky(final Event event) {
    eventCache.remove(event.getClass(), event);
  }

  private Object fetchEvent(final Class<? extends Event> key) {
    return eventCache.get(key);
  }

  class EventProducer {

    public final EventBus bus;

    public EventProducer(final EventBus bus) {
      this.bus = bus;
      this.bus.register(this);
    }

    @SuppressWarnings("unchecked")
    private <T extends Event> T produce(Class<T> klazz) {
      Object event = bus.fetchEvent(klazz);
      if (event != null) {
        return (T) event;
      }
      return null;
    }

    @Produce
    public VisitSendFailed produceVisitSendFailed() {
      return produce(VisitSendFailed.class);
    }

    @Produce
    public PhotoRetaken producePhotoRetaken() {
      return produce(PhotoRetaken.class);
    }

    @Produce
    public DeletePhoto producePhotoDeleted() {
      return produce(DeletePhoto.class);
    }

    @Produce
    public StorePhotoCaptured produceStorePhotoCaptured() {
      return produce(StorePhotoCaptured.class);
    }

    @Produce
    public QuestionnairePhotoCaptured produceQuestionnairePhotoCaptured() {
      return produce(QuestionnairePhotoCaptured.class);
    }

    @Produce
    public BarcodeScanned barcodeScanned() {
      return produce(BarcodeScanned.class);
    }
  }
}