/*
 * Copyright (C) 2009 The Guava Authors
 *
 * 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 com.google.common.util.concurrent;

import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import org.checkerframework.checker.nullness.qual.Nullable;

A ListenableFuture whose result can be set by a set(Object), setException(Throwable) or setFuture(ListenableFuture) call. It can also, like any other Future, be cancelled. 
SettableFuture is the recommended ListenableFuture implementation when your task cannot be implemented with ListeningExecutorService, the various Futures utility methods, or ListenableFutureTask. Those APIs have less opportunity for developer error. If your needs are more complex than SettableFuture supports, use AbstractFuture, which offers an extensible version of the API. 
Author:
Sven Mawson
Since:
9.0 (in 1.0 as ValueFuture)/**
 * A {@link ListenableFuture} whose result can be set by a {@link #set(Object)}, {@link
 * #setException(Throwable)} or {@link #setFuture(ListenableFuture)} call. It can also, like any
 * other {@code Future}, be {@linkplain #cancel cancelled}.
 *
 * <p>{@code SettableFuture} is the recommended {@code ListenableFuture} implementation when your
 * task cannot be implemented with {@link ListeningExecutorService}, the various {@link Futures}
 * utility methods, or {@link ListenableFutureTask}. Those APIs have less opportunity for developer
 * error. If your needs are more complex than {@code SettableFuture} supports, use {@link
 * AbstractFuture}, which offers an extensible version of the API.
 *
 * @author Sven Mawson
 * @since 9.0 (in 1.0 as {@code ValueFuture})
 */
@GwtCompatible
public final class SettableFuture<V> extends AbstractFuture.TrustedFuture<V> {
  
Creates a new SettableFuture that can be completed or cancelled by a later method call. /**
   * Creates a new {@code SettableFuture} that can be completed or cancelled by a later method call.
   */
  public static <V> SettableFuture<V> create() {
    return new SettableFuture<V>();
  }

  @CanIgnoreReturnValue
  @Override
  public boolean set(@Nullable V value) {
    return super.set(value);
  }

  @CanIgnoreReturnValue
  @Override
  public boolean setException(Throwable throwable) {
    return super.setException(throwable);
  }

  @Beta
  @CanIgnoreReturnValue
  @Override
  public boolean setFuture(ListenableFuture<? extends V> future) {
    return super.setFuture(future);
  }

  private SettableFuture() {}
}