rx.observables.ConnectableObservable Maven / Gradle / Ivy
/**
* 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.annotations.Beta;
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.
*
* 
*
* @see RxJava Wiki:
* Connectable Observable Operators
* @param
* the type of items emitted by the {@code ConnectableObservable}
*/
public abstract class ConnectableObservable extends Observable {
protected ConnectableObservable(OnSubscribe onSubscribe) {
super(onSubscribe);
}
/**
* Instructs the {@code ConnectableObservable} to begin emitting the items from its underlying
* {@link Observable} to its {@link Subscriber}s.
*
* To disconnect from a synchronous source, use the {@link #connect(rx.functions.Action1)} method.
*
* @return the subscription representing the connection
* @see ReactiveX documentation: Connect
*/
public final Subscription connect() {
final Subscription[] out = new Subscription[1];
connect(new Action1() {
@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 ReactiveX documentation: Connect
*/
public abstract void connect(Action1 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 ReactiveX documentation: RefCount
*/
public Observable refCount() {
return create(new OnSubscribeRefCount(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 (if this graduates from Experimental/Beta to supported, replace this parenthetical with the release number)
*/
@Beta
public Observable 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 (if this graduates from Experimental/Beta to supported, replace this parenthetical with the release number)
*/
@Beta
public Observable 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 (if this graduates from Experimental/Beta to supported, replace this parenthetical with the release number)
*/
@Beta
public Observable autoConnect(int numberOfSubscribers, Action1 connection) {
if (numberOfSubscribers <= 0) {
this.connect(connection);
return this;
}
return create(new OnSubscribeAutoConnect(this, numberOfSubscribers, connection));
}
}