/**
* Copyright 2014 Netflix, 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 rx.internal.operators;
import rx.Observable;
import rx.Observable.Operator;
import rx.Subscriber;
import rx.functions.Func1;
import rx.observers.SerializedSubscriber;
import rx.subjects.PublishSubject;
/**
* Delay the subscription and emission of the source items by a per-item observable that fires its first element.
*
* @param <T>
* the item type
* @param <V>
* the value type of the item-delaying observable
*/
public final class OperatorDelayWithSelector<T, V> implements Operator<T, T> {
final Observable<? extends T> source;
final Func1<? super T, ? extends Observable<V>> itemDelay;
public OperatorDelayWithSelector(Observable<? extends T> source, Func1<? super T, ? extends Observable<V>> itemDelay) {
this.source = source;
this.itemDelay = itemDelay;
}
@Override
public Subscriber<? super T> call(final Subscriber<? super T> _child) {
final SerializedSubscriber<T> child = new SerializedSubscriber<T>(_child);
final PublishSubject<Observable<T>> delayedEmissions = PublishSubject.create();
_child.add(Observable.merge(delayedEmissions).unsafeSubscribe(new Subscriber<T>() {
@Override
public void onCompleted() {
child.onCompleted();
}
@Override
public void onError(Throwable e) {
child.onError(e);
}
@Override
public void onNext(T t) {
child.onNext(t);
}
}));
return new Subscriber<T>(_child) {
@Override
public void onCompleted() {
delayedEmissions.onCompleted();
}
@Override
public void onError(Throwable e) {
child.onError(e);
}
@Override
public void onNext(final T t) {
try {
delayedEmissions.onNext(itemDelay.call(t).take(1).defaultIfEmpty(null).map(new Func1<V, T>() {
@Override
public T call(V v) {
return t;
}
}));
} catch (Throwable e) {
onError(e);
}
}
};
}
}