How to send event from Service to Activity with Otto event bus?

Question

Simple BusProvider.getInstance().post() bring exception not main thread. How to send event from Service to Activity with Otto event bus?

Answer 1

To post from any thread (main or background) and receive on the main thread, try something like

public class MainThreadBus extends Bus {
  private final Handler mHandler = new Handler(Looper.getMainLooper());

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

Note: credit goes to Jake Wharton and "pommedeterresaute" at https://github.com/square/otto/issues/38 for the general approach. I just implemented it with a wrapper class rather than a subclass.