monifu.reactive.internals.operators.delaySubscription.scala Maven / Gradle / Ivy

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/*
 * Copyright (c) 2014-2016 by its authors. Some rights reserved.
 * See the project homepage at: https://monix.io
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package monifu.reactive.internals.operators

import monifu.reactive.Ack.Cancel
import monifu.reactive.{Ack, Observable, Observer}
import scala.concurrent.duration.FiniteDuration
import scala.concurrent.{Future, Promise}

private[reactive] object delaySubscription {
  /**
   * Implementation for [[Observable.delaySubscription]].
   */
  def onTrigger[T,U](source: Observable[T], trigger: Observable[U]): Observable[T] =
      Observable.create[T] { subscriber =>
        import subscriber.{scheduler => s}

        trigger.onSubscribe(new Observer[U] {
          def onNext(elem: U): Future[Ack] = {
            source.onSubscribe(subscriber)
            Cancel
          }

          def onError(ex: Throwable): Unit = {
            subscriber.onError(ex)
          }

          def onComplete(): Unit = {
            source.onSubscribe(subscriber)
          }
        })
      }

  /**
   * Implementation for [[Observable.delaySubscription]].
   */
  def onTimespan[T](source: Observable[T], timespan: FiniteDuration): Observable[T] =
    Observable.create { subscriber =>
      import subscriber.{scheduler => s}
      val underlying = source.delaySubscription {
        val p = Promise[Unit]()
        s.scheduleOnce(timespan)(p.success(()))
        p.future
      }

      underlying.onSubscribe(subscriber)
    }
}