/**
* Copyright (c) 2016-present, RxJava Contributors.
*
* 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 io.reactivex.internal.operators.observable;
import io.reactivex.*;
import io.reactivex.disposables.
Disposable;
import io.reactivex.internal.disposables.
DisposableHelper;
import io.reactivex.internal.fuseable.
FuseToObservable;
import io.reactivex.plugins.
RxJavaPlugins;
public final class
ObservableElementAtMaybe<T> extends
Maybe<T> implements
FuseToObservable<T> {
final
ObservableSource<T>
source;
final long
index;
public
ObservableElementAtMaybe(
ObservableSource<T>
source, long
index) {
this.
source =
source;
this.
index =
index;
}
@
Override
public void
subscribeActual(
MaybeObserver<? super T>
t) {
source.
subscribe(new
ElementAtObserver<T>(
t,
index));
}
@
Override
public
Observable<T>
fuseToObservable() {
return
RxJavaPlugins.
onAssembly(new
ObservableElementAt<T>(
source,
index, null, false));
}
static final class
ElementAtObserver<T> implements
Observer<T>,
Disposable {
final
MaybeObserver<? super T>
downstream;
final long
index;
Disposable upstream;
long
count;
boolean
done;
ElementAtObserver(
MaybeObserver<? super T>
actual, long
index) {
this.
downstream =
actual;
this.
index =
index;
}
@
Override
public void
onSubscribe(
Disposable d) {
if (
DisposableHelper.
validate(this.
upstream,
d)) {
this.
upstream =
d;
downstream.
onSubscribe(this);
}
}
@
Override
public void
dispose() {
upstream.
dispose();
}
@
Override
public boolean
isDisposed() {
return
upstream.
isDisposed();
}
@
Override
public void
onNext(T
t) {
if (
done) {
return;
}
long
c =
count;
if (
c ==
index) {
done = true;
upstream.
dispose();
downstream.
onSuccess(
t);
return;
}
count =
c + 1;
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
RxJavaPlugins.
onError(
t);
return;
}
done = true;
downstream.
onError(
t);
}
@
Override
public void
onComplete() {
if (!
done) {
done = true;
downstream.
onComplete();
}
}
}
}