rx.internal.operators.OperatorTakeWhile Maven / Gradle / Ivy
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/**
* 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.functions.Func1;
import rx.functions.Func2;
/**
* Returns an Observable that emits items emitted by the source Observable as long as a specified
* condition is true.
*
* 
*/
public final class OperatorTakeWhile implements Operator {
private final Func2 predicate;
public OperatorTakeWhile(final Func1 underlying) {
this(new Func2() {
@Override
public Boolean call(T input, Integer index) {
return underlying.call(input);
}
});
}
public OperatorTakeWhile(Func2 predicate) {
this.predicate = predicate;
}
@Override
public Subscriber call(final Subscriber subscriber) {
return new Subscriber(subscriber) {
private int counter = 0;
private boolean done = false;
@Override
public void onNext(T args) {
boolean isSelected;
try {
isSelected = predicate.call(args, counter++);
} catch (Throwable e) {
done = true;
subscriber.onError(e);
unsubscribe();
return;
}
if (isSelected) {
subscriber.onNext(args);
} else {
done = true;
subscriber.onCompleted();
unsubscribe();
}
}
@Override
public void onCompleted() {
if (!done) {
subscriber.onCompleted();
}
}
@Override
public void onError(Throwable e) {
if (!done) {
subscriber.onError(e);
}
}
};
}
}