content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.github.jobson.utils;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.TimeoutException;
  import java.util.function.Consumer;
  
  public final class SimpleCancelablePromise<T> implements CancelablePromise<T> {
  
      private CompletableFuture<T> internalPromise = new CompletableFuture<>();
      private List<Runnable> onCancelCallbacks = new ArrayList<>();
      private boolean isCancelled = false;
  
  
      public boolean completeExceptionally(Throwable ex) {
          return internalPromise.completeExceptionally(ex);
      }
  
      public boolean complete(T value) {
          return internalPromise.complete(value);
      }
  
      public void onCancel(Runnable f) {
          if (!isCancelled)
              onCancelCallbacks.add(f);
      }
  
      public boolean cancel(boolean mayInterrupt) {
          if (!isCancelled) {
              isCancelled = true;
              onCancelCallbacks.forEach(Runnable::run);
              return true;
          } else return false;
      }
  
      public CompletableFuture<Void> thenAccept(Consumer<? super T> action) {
          return internalPromise.thenAccept(action);
      }
  
      @Override
      public T get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
          return internalPromise.get(timeout, unit);
      }
  
      @Override
      public T get() throws InterruptedException, ExecutionException, TimeoutException {
          return internalPromise.get();
      }
  }
  