/**
* 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.*;
import rx.
Observable.
OnSubscribe;
import rx.exceptions.*;
import rx.functions.
Func1;
import rx.plugins.
RxJavaHooks;
/**
* Filters an Observable by discarding any items it emits that do not meet some test.
* <p>
* <img width="640" src="https://github.com/ReactiveX/RxJava/wiki/images/rx-operators/filter.png" alt="">
* @param <T> the value type
*/
public final class
OnSubscribeFilter<T> implements
OnSubscribe<T> {
final
Observable<T>
source;
final
Func1<? super T,
Boolean>
predicate;
public
OnSubscribeFilter(
Observable<T>
source,
Func1<? super T,
Boolean>
predicate) {
this.
source =
source;
this.
predicate =
predicate;
}
@
Override
public void
call(final
Subscriber<? super T>
child) {
FilterSubscriber<T>
parent = new
FilterSubscriber<T>(
child,
predicate);
child.
add(
parent);
source.
unsafeSubscribe(
parent);
}
static final class
FilterSubscriber<T> extends
Subscriber<T> {
final
Subscriber<? super T>
actual;
final
Func1<? super T,
Boolean>
predicate;
boolean
done;
public
FilterSubscriber(
Subscriber<? super T>
actual,
Func1<? super T,
Boolean>
predicate) {
this.
actual =
actual;
this.
predicate =
predicate;
request(0);
}
@
Override
public void
onNext(T
t) {
boolean
result;
try {
result =
predicate.
call(
t);
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
unsubscribe();
onError(
OnErrorThrowable.
addValueAsLastCause(
ex,
t));
return;
}
if (
result) {
actual.
onNext(
t);
} else {
request(1);
}
}
@
Override
public void
onError(
Throwable e) {
if (
done) {
RxJavaHooks.
onError(
e);
return;
}
done = true;
actual.
onError(
e);
}
@
Override
public void
onCompleted() {
if (
done) {
return;
}
actual.
onCompleted();
}
@
Override
public void
setProducer(
Producer p) {
super.setProducer(
p);
actual.
setProducer(
p);
}
}
}