code: /*
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * 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 io.reactivex.rxjava3.internal.operators.observable;
  
  import java.util.concurrent.TimeUnit;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.core.Scheduler.Worker;
  import io.reactivex.rxjava3.disposables.Disposable;
  import io.reactivex.rxjava3.internal.disposables.DisposableHelper;
  import io.reactivex.rxjava3.observers.SerializedObserver;
  
  public final class ObservableDelay<T> extends AbstractObservableWithUpstream<T, T> {
      final long delay;
      final TimeUnit unit;
      final Scheduler scheduler;
      final boolean delayError;
  
      public ObservableDelay(ObservableSource<T> source, long delay, TimeUnit unit, Scheduler scheduler, boolean delayError) {
          super(source);
          this.delay = delay;
          this.unit = unit;
          this.scheduler = scheduler;
          this.delayError = delayError;
      }
  
      @Override
      @SuppressWarnings("unchecked")
      public void subscribeActual(Observer<? super T> t) {
          Observer<T> observer;
          if (delayError) {
              observer = (Observer<T>)t;
          } else {
              observer = new SerializedObserver<>(t);
          }
  
          Scheduler.Worker w = scheduler.createWorker();
  
          source.subscribe(new DelayObserver<>(observer, delay, unit, w, delayError));
      }
  
      static final class DelayObserver<T> implements Observer<T>, Disposable {
          final Observer<? super T> downstream;
          final long delay;
          final TimeUnit unit;
          final Scheduler.Worker w;
          final boolean delayError;
  
          Disposable upstream;
  
          DelayObserver(Observer<? super T> actual, long delay, TimeUnit unit, Worker w, boolean delayError) {
              super();
              this.downstream = actual;
              this.delay = delay;
              this.unit = unit;
              this.w = w;
              this.delayError = delayError;
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              if (DisposableHelper.validate(this.upstream, d)) {
                  this.upstream = d;
                  downstream.onSubscribe(this);
              }
          }
  
          @Override
          public void onNext(final T t) {
              w.schedule(new OnNext(t), delay, unit);
          }
  
          @Override
          public void onError(final Throwable t) {
              w.schedule(new OnError(t), delayError ? delay : 0, unit);
          }
  
          @Override
          public void onComplete() {
              w.schedule(new OnComplete(), delay, unit);
          }
  
          @Override
          public void dispose() {
              upstream.dispose();
              w.dispose();
          }
  
          @Override
          public boolean isDisposed() {
              return w.isDisposed();
          }
  
          final class OnNext implements Runnable {
              private final T t;
  
              OnNext(T t) {
                  this.t = t;
              }
  
              @Override
              public void run() {
                  downstream.onNext(t);
              }
          }
  
          final class OnError implements Runnable {
              private final Throwable throwable;
  
              OnError(Throwable throwable) {
                  this.throwable = throwable;
              }
  
              @Override
              public void run() {
                  try {
                      downstream.onError(throwable);
                  } finally {
                      w.dispose();
                  }
              }
          }
  
          final class OnComplete implements Runnable {
              @Override
              public void run() {
                  try {
                      downstream.onComplete();
                  } finally {
                      w.dispose();
                  }
              }
          }
      }
  }
  