/**
* 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.observables;
import rx.*;
import rx.functions.*;
import rx.internal.operators.*;
/**
* A {@code ConnectableObservable} resembles an ordinary {@link Observable}, except that it does not begin
* emitting items when it is subscribed to, but only when its {@link #connect} method is called. In this way you
* can wait for all intended {@link Subscriber}s to {@link Observable#subscribe} to the {@code Observable}
* before the {@code Observable} begins emitting items.
* <p>
* <img width="640" height="510" src="https://github.com/ReactiveX/RxJava/wiki/images/rx-operators/publishConnect.png" alt="">
*
* @see <a href="https://github.com/ReactiveX/RxJava/wiki/Connectable-Observable-Operators">RxJava Wiki:
* Connectable Observable Operators</a>
* @param <T>
* the type of items emitted by the {@code ConnectableObservable}
*/
public abstract class
ConnectableObservable<T> extends
Observable<T> {
protected
ConnectableObservable(
OnSubscribe<T>
onSubscribe) {
super(
onSubscribe);
}
/**
* Instructs the {@code ConnectableObservable} to begin emitting the items from its underlying
* {@link Observable} to its {@link Subscriber}s.
* <p>
* To disconnect from a synchronous source, use the {@link #connect(rx.functions.Action1)} method.
*
* @return the subscription representing the connection
* @see <a href="http://reactivex.io/documentation/operators/connect.html">ReactiveX documentation: Connect</a>
*/
public final
Subscription connect() {
final
Subscription[]
out = new
Subscription[1];
connect(new
Action1<
Subscription>() {
@
Override
public void
call(
Subscription t1) {
out[0] =
t1;
}
});
return
out[0];
}
/**
* Instructs the {@code ConnectableObservable} to begin emitting the items from its underlying
* {@link Observable} to its {@link Subscriber}s.
*
* @param connection
* the action that receives the connection subscription before the subscription to source happens
* allowing the caller to synchronously disconnect a synchronous source
* @see <a href="http://reactivex.io/documentation/operators/connect.html">ReactiveX documentation: Connect</a>
*/
public abstract void
connect(
Action1<? super
Subscription>
connection);
/**
* Returns an {@code Observable} that stays connected to this {@code ConnectableObservable} as long as there
* is at least one subscription to this {@code ConnectableObservable}.
*
* @return a {@link Observable}
* @see <a href="http://reactivex.io/documentation/operators/refcount.html">ReactiveX documentation: RefCount</a>
*/
public
Observable<T>
refCount() {
return
unsafeCreate(new
OnSubscribeRefCount<T>(this));
}
/**
* Returns an Observable that automatically connects to this ConnectableObservable
* when the first Subscriber subscribes.
*
* @return an Observable that automatically connects to this ConnectableObservable
* when the first Subscriber subscribes
* @since 1.2
*/
public
Observable<T>
autoConnect() {
return
autoConnect(1);
}
/**
* Returns an Observable that automatically connects to this ConnectableObservable
* when the specified number of Subscribers subscribe to it.
*
* @param numberOfSubscribers the number of subscribers to await before calling connect
* on the ConnectableObservable. A non-positive value indicates
* an immediate connection.
* @return an Observable that automatically connects to this ConnectableObservable
* when the specified number of Subscribers subscribe to it
* @since 1.2
*/
public
Observable<T>
autoConnect(int
numberOfSubscribers) {
return
autoConnect(
numberOfSubscribers,
Actions.
empty());
}
/**
* Returns an Observable that automatically connects to this ConnectableObservable
* when the specified number of Subscribers subscribe to it and calls the
* specified callback with the Subscription associated with the established connection.
*
* @param numberOfSubscribers the number of subscribers to await before calling connect
* on the ConnectableObservable. A non-positive value indicates
* an immediate connection.
* @param connection the callback Action1 that will receive the Subscription representing the
* established connection
* @return an Observable that automatically connects to this ConnectableObservable
* when the specified number of Subscribers subscribe to it and calls the
* specified callback with the Subscription associated with the established connection
* @since 1.2
*/
public
Observable<T>
autoConnect(int
numberOfSubscribers,
Action1<? super
Subscription>
connection) {
if (
numberOfSubscribers <= 0) {
this.
connect(
connection);
return this;
}
return
unsafeCreate(new
OnSubscribeAutoConnect<T>(this,
numberOfSubscribers,
connection));
}
}