Event bus implementation with RxJava and RxRelay (https://github.com/JakeWharton/RxRelay) with API similar to https://github.com/greenrobot/EventBus

RxBus.kt

/**
 * Created with Android Studio
 * User: electrolobzik electrolobzik@gmail.com
 * Date: 27/03/2017
 * Time: 22:05
 *
 * Event bus implementation with RxJava and RxRelay (https://github.com/JakeWharton/RxRelay) with API similar to https://github.com/greenrobot/EventBus
 */
class RxBus<T> {
    var stickyEvent: T? = null

    private val publishRelay: PublishRelay<T> = PublishRelay.create<T>()

    fun <E : T> post(event: E) {
        publishRelay.call(event)
    }

    fun <E : T> postSticky(event: E) {
        post(event)
        stickyEvent = event
    }

    fun observeEvents(): Observable<T> {
        return publishRelay
    }

    fun observeEventsSticky(): Observable<T> {
        val result: Observable<T>
        val stickyEvent = stickyEvent
        if (stickyEvent != null) {
            result = Observable.just(stickyEvent).mergeWith(publishRelay)
        } else {
            result = publishRelay
        }

        return result
    }

    fun <E : T> observeEvents(eventClass: Class<E>): Observable<E> {
        return observeEvents().ofType(eventClass)  //pass only events of specified type, filter all other
    }

    fun <E : T> observeEventsSticky(eventClass: Class<E>): Observable<E> {
        return observeEventsSticky().ofType(eventClass)
    }
}