/**
* 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.Operator;
import rx.Subscriber;
import rx.exceptions.OnErrorThrowable;
import rx.functions.Func1;
/**
* Filters an Observable by discarding any items it emits that do not meet some test.
* <p>
* <img width="640" src="https://github.com/Netflix/RxJava/wiki/images/rx-operators/filter.png" alt="">
*/
public final class OperatorFilter<T> implements Operator<T, T> {
private final Func1<? super T, Boolean> predicate;
public OperatorFilter(Func1<? super T, Boolean> predicate) {
this.predicate = predicate;
}
@Override
public Subscriber<? super T> call(final Subscriber<? super T> child) {
return new Subscriber<T>(child) {
@Override
public void onCompleted() {
child.onCompleted();
}
@Override
public void onError(Throwable e) {
child.onError(e);
}
@Override
public void onNext(T t) {
try {
if (predicate.call(t)) {
child.onNext(t);
} else {
// TODO consider a more complicated version that batches these
request(1);
}
} catch (Throwable e) {
child.onError(OnErrorThrowable.addValueAsLastCause(e, t));
}
}
};
}
}