/**

* 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.operators;

import rx.Observable;

import rx.Observable.Operator;

import rx.Subscriber;

import rx.functions.Func1;

/**

* Returns an {@link Observable} that emits <code>true</code> if any element of

* an observable sequence satisfies a condition, otherwise <code>false</code>.

*/

public final class OperatorAny<T> implements Operator<Boolean, T> {

private final Func1<? super T, Boolean> predicate;

private final boolean returnOnEmpty;

public OperatorAny(Func1<? super T, Boolean> predicate, boolean returnOnEmpty) {

this.predicate = predicate;

this.returnOnEmpty = returnOnEmpty;

}

@Override

public Subscriber<? super T> call(final Subscriber<? super Boolean> child) {

return new Subscriber<T>(child) {

boolean hasElements;

boolean done;

@Override

public void onNext(T t) {

hasElements = true;

boolean result = predicate.call(t);

if (result && !done) {

done = true;

child.onNext(!returnOnEmpty);

child.onCompleted();

unsubscribe();

}

}

@Override

public void onError(Throwable e) {

child.onError(e);

}

@Override

public void onCompleted() {

if (!done) {

done = true;

if (hasElements) {

child.onNext(false);

} else {

child.onNext(returnOnEmpty);

}

child.onCompleted();

}

}

};

}

}