content: /*
   * Copyright (C) 2016 Airbnb, Inc.
   *
   * 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 com.airbnb.rxgroups;
  
  
  import io.reactivex.Observable;
  import io.reactivex.ObservableEmitter;
  import io.reactivex.ObservableOnSubscribe;
  import io.reactivex.ObservableSource;
  import io.reactivex.ObservableTransformer;
  import io.reactivex.annotations.NonNull;
  import io.reactivex.disposables.Disposable;
  
  /**
   * Transforms an existing {@link Observable} by returning a new {@link Observable} that is
   * automatically added to the provided {@link ObservableGroup} with the specified {@code
   * observableTag} when subscribed to.
   */
  class GroupSubscriptionTransformer<T> implements ObservableTransformer<T, T> {
    private final ObservableGroup group;
    private final String observableTag;
    private final String observerTag;
  
    GroupSubscriptionTransformer(ObservableGroup group, String observerTag, String observableTag) {
      this.group = group;
      this.observableTag = observableTag;
      this.observerTag = observerTag;
    }
  
    @Override public ObservableSource<T> apply(@NonNull final Observable<T> sourceObservable) {
      return Observable.create(new ObservableOnSubscribe<T>() {
        @Override
        public void subscribe(@NonNull final ObservableEmitter<T> emitter) throws Exception {
          group.add(observerTag, observableTag, sourceObservable, emitter);
          emitter.setDisposable(managedObservableDisposable);
        }
      });
    }
  
    private Disposable managedObservableDisposable = new Disposable() {
      @Override public void dispose() {
        ManagedObservable managedObservable =
            group.getObservablesForObserver(observerTag).get(observableTag);
        if (managedObservable != null) {
          managedObservable.dispose();
        }
      }
  
      @Override public boolean isDisposed() {
        ManagedObservable managedObservable =
            group.getObservablesForObserver(observerTag).get(observableTag);
        return managedObservable == null || managedObservable.isDisposed();
      }
    };
  
  }
  