ReactEventDispatcher.kt

@Singleton
class ReactEventDispatcher @Inject constructor(val reactInstanceManager: ReactInstanceManager) {

  private val callResults = PublishSubject<ReadableMap>()
  private var currentKey: Long = 0L

  private fun nextKey(): Long {
    currentKey += 1
    return currentKey
  }

  fun route(callResult: ReadableMap) {
    callResults.onNext(callResult)
  }

  fun resultObservable(key: Long): Observable<ReadableMap> {
    return callResults.filter { it.getString("key").toLong() == key }
  }

  fun dispatchEvent(event: String, data: WritableMap): Observable<ReadableMap> {
    val key = nextKey()
    val eventData = WritableNativeMap()
    eventData.putString("key", key.toString())
    eventData.putMap("data", data)
    reactInstanceManager.currentReactContext
        ?.getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter::class.java)
        ?.emit(event, eventData)
    return resultObservable(key)
        .serialize()
        .observeOn(AndroidSchedulers.mainThread())
        .map { it.getMap("data") }
  }
}