/**
* 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.*;
import rx.
Observable.
Operator;
/**
* Reverses the effect of {@link OperatorMaterialize} by transforming the Notification objects
* emitted by a source Observable into the items or notifications they represent.
* <p>
* <img width="640" src="https://github.com/ReactiveX/RxJava/wiki/images/rx-operators/dematerialize.png" alt="">
* <p>
* See <a href="http://msdn.microsoft.com/en-us/library/hh229047.aspx">here</a> for the Microsoft Rx equivalent.
*
* @param <T> the wrapped value type
*/
public final class
OperatorDematerialize<T> implements
Operator<T,
Notification<T>> {
/** Lazy initialization via inner-class holder. */
static final class
Holder {
/** A singleton instance. */
static final
OperatorDematerialize<
Object>
INSTANCE = new
OperatorDematerialize<
Object>();
}
/**
* @return a singleton instance of this stateless operator.
*/
@
SuppressWarnings({ "rawtypes" })
public static
OperatorDematerialize instance() {
return
Holder.
INSTANCE; // using raw types because the type inference is not good enough
}
OperatorDematerialize() {
// singleton
}
@
Override
public
Subscriber<? super
Notification<T>>
call(final
Subscriber<? super T>
child) {
return new
Subscriber<
Notification<T>>(
child) {
/** Do not send two onCompleted events. */
boolean
terminated;
@
Override
public void
onNext(
Notification<T>
t) {
switch (
t.
getKind()) {
case
OnNext:
if (!
terminated) {
child.
onNext(
t.
getValue());
}
break;
case
OnError:
onError(
t.
getThrowable());
break;
case
OnCompleted:
onCompleted();
break;
default:
onError(new
IllegalArgumentException("Unsupported notification type: " +
t));
break;
}
}
@
Override
public void
onError(
Throwable e) {
if (!
terminated) {
terminated = true;
child.
onError(
e);
}
}
@
Override
public void
onCompleted() {
if (!
terminated) {
terminated = true;
child.
onCompleted();
}
}
};
}
}