io.reactivex.observable.internal.operators.MaybeCount Maven / Gradle / Ivy

Go to download
/**
 * 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.observable.internal.operators;

import io.reactivex.common.Disposable;
import io.reactivex.common.internal.disposables.DisposableHelper;
import io.reactivex.observable.*;
import io.reactivex.observable.extensions.HasUpstreamMaybeSource;

/**
 * Signals 1L if the source signalled an item or 0L if the source is empty.
 *
 * @param  the source value type
 */
public final class MaybeCount extends Single implements HasUpstreamMaybeSource {

    final MaybeSource source;

    public MaybeCount(MaybeSource source) {
        this.source = source;
    }

    @Override
    public MaybeSource source() {
        return source;
    }

    @Override
    protected void subscribeActual(SingleObserver observer) {
        source.subscribe(new CountMaybeObserver(observer));
    }

    static final class CountMaybeObserver implements MaybeObserver