/**
* 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.
Exceptions;
import rx.functions.*;
/**O
* Returns an Observable that emits items emitted by the source Observable as long as a specified
* condition is true.
* <p>
* <img width="640" src="https://github.com/ReactiveX/RxJava/wiki/images/rx-operators/takeWhile.png" alt="">
* @param <T> the value type
*/
public final class
OperatorTakeWhile<T> implements
Operator<T, T> {
final
Func2<? super T, ? super
Integer,
Boolean>
predicate;
public
OperatorTakeWhile(final
Func1<? super T,
Boolean>
underlying) {
this(new
Func2<T,
Integer,
Boolean>() {
@
Override
public
Boolean call(T
input,
Integer index) {
return
underlying.
call(
input);
}
});
}
public
OperatorTakeWhile(
Func2<? super T, ? super
Integer,
Boolean>
predicate) {
this.
predicate =
predicate;
}
@
Override
public
Subscriber<? super T>
call(final
Subscriber<? super T>
subscriber) {
Subscriber<T>
s = new
Subscriber<T>(
subscriber, false) {
private int
counter;
private boolean
done;
@
Override
public void
onNext(T
t) {
boolean
isSelected;
try {
isSelected =
predicate.
call(
t,
counter++);
} catch (
Throwable e) {
done = true;
Exceptions.
throwOrReport(
e,
subscriber,
t);
unsubscribe();
return;
}
if (
isSelected) {
subscriber.
onNext(
t);
} 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);
}
}
};
subscriber.
add(
s);
return
s;
}
}