RxJava Refreshable

Refreshable.kt

import io.reactivex.Observable
import io.reactivex.Single
import io.reactivex.subjects.BehaviorSubject

class RefreshTrigger {
    private val _refreshEvents = BehaviorSubject.createDefault(Unit).toSerialized()

    val refreshEvents: Observable<Unit> = _refreshEvents
    fun refresh() = _refreshEvents.onNext(Unit)
}

/**
 * Implementing Refreshable on companion objects provides access to refresh functions and a `RefreshTrigger`,
 */
abstract class Refreshable {
    val refreshTrigger = RefreshTrigger()
    val refreshEvents: Observable<Unit> = refreshTrigger.refreshEvents
    fun refresh() = refreshTrigger.refresh()
}

fun <T> Single<T>.toRefreshable(triggerSource: RefreshTrigger) = triggerSource.refreshEvents.toRefreshable { this }