/**
* 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.exceptions.
Exceptions;
import io.reactivex.internal.functions.
ObjectHelper;
import io.reactivex.plugins.
RxJavaPlugins;
/**
* Allows lifting operators into a chain of Observables.
*
* <p>By having a concrete ObservableSource as lift, operator fusing can now identify
* both the source and the operation inside it via casting, unlike the lambda version of this.
*
* @param <T> the upstream value type
* @param <R> the downstream parameter type
*/
public final class
ObservableLift<R, T> extends
AbstractObservableWithUpstream<T, R> {
/** The actual operator. */
final
ObservableOperator<? extends R, ? super T>
operator;
public
ObservableLift(
ObservableSource<T>
source,
ObservableOperator<? extends R, ? super T>
operator) {
super(
source);
this.
operator =
operator;
}
@
Override
public void
subscribeActual(
Observer<? super R>
observer) {
Observer<? super T>
liftedObserver;
try {
liftedObserver =
ObjectHelper.
requireNonNull(
operator.
apply(
observer), "Operator " +
operator + " returned a null Observer");
} catch (
NullPointerException e) { // NOPMD
throw
e;
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
// can't call onError because no way to know if a Disposable has been set or not
// can't call onSubscribe because the call might have set a Disposable already
RxJavaPlugins.
onError(
e);
NullPointerException npe = new
NullPointerException("Actually not, but can't throw other exceptions due to RS");
npe.
initCause(
e);
throw
npe;
}
source.
subscribe(
liftedObserver);
}
}