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.maybe;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.Disposable;
  import io.reactivex.rxjava3.internal.disposables.DisposableHelper;
  import io.reactivex.rxjava3.internal.fuseable.HasUpstreamMaybeSource;
  import java.util.Objects;
  
  /**
   * Signals true if the source signals a value that is object-equals with the provided
   * value, false otherwise or for empty sources.
   *
   * @param <T> the value type
   */
  public final class MaybeContains<T> extends Single<Boolean> implements HasUpstreamMaybeSource<T> {
  
      final MaybeSource<T> source;
  
      final Object value;
  
      public MaybeContains(MaybeSource<T> source, Object value) {
          this.source = source;
          this.value = value;
      }
  
      @Override
      public MaybeSource<T> source() {
          return source;
      }
  
      @Override
      protected void subscribeActual(SingleObserver<? super Boolean> observer) {
          source.subscribe(new ContainsMaybeObserver(observer, value));
      }
  
      static final class ContainsMaybeObserver implements MaybeObserver<Object>, Disposable {
  
          final SingleObserver<? super Boolean> downstream;
  
          final Object value;
  
          Disposable upstream;
  
          ContainsMaybeObserver(SingleObserver<? super Boolean> actual, Object value) {
              this.downstream = actual;
              this.value = value;
          }
  
          @Override
          public void dispose() {
              upstream.dispose();
              upstream = DisposableHelper.DISPOSED;
          }
  
          @Override
          public boolean isDisposed() {
              return upstream.isDisposed();
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              if (DisposableHelper.validate(this.upstream, d)) {
                  this.upstream = d;
                  downstream.onSubscribe(this);
              }
          }
  
          @Override
          public void onSuccess(Object value) {
              upstream = DisposableHelper.DISPOSED;
              downstream.onSuccess(Objects.equals(value, this.value));
          }
  
          @Override
          public void onError(Throwable e) {
              upstream = DisposableHelper.DISPOSED;
              downstream.onError(e);
          }
  
          @Override
          public void onComplete() {
              upstream = DisposableHelper.DISPOSED;
              downstream.onSuccess(false);
          }
      }
  }
  