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
   *
   *      https://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 org.apache.tools.ant.types.resources;
  
  import java.util.Collection;
  import java.util.Stack;
  import java.util.stream.Collectors;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.Project;
  import org.apache.tools.ant.types.DataType;
  import org.apache.tools.ant.types.Resource;
  import org.apache.tools.ant.types.resources.comparators.DelegatedResourceComparator;
  import org.apache.tools.ant.types.resources.comparators.ResourceComparator;
  
  /**
   * ResourceCollection that sorts another ResourceCollection.
   *
   * Note that Sort must not be used in cases where the ordering of the objects
   * being sorted might change during the sorting process.
   *
   * @since Ant 1.7
   */
  public class Sort extends BaseResourceCollectionWrapper {
  
      private DelegatedResourceComparator comp = new DelegatedResourceComparator();
  
      /**
       * Sort the contained elements.
       * @return a Collection of Resources.
       */
      @Override
      protected synchronized Collection<Resource> getCollection() {
          return getResourceCollection().stream().map(Resource.class::cast)
              .sorted(comp).collect(Collectors.toList());
      }
  
      /**
       * Add a ResourceComparator to this Sort ResourceCollection.
       * If multiple ResourceComparators are added, they will be processed in LIFO order.
       * @param c the ResourceComparator to add.
       */
      public synchronized void add(ResourceComparator c) {
          if (isReference()) {
              throw noChildrenAllowed();
          }
          comp.add(c);
          FailFast.invalidate(this);
          setChecked(false);
      }
  
      /**
       * Overrides the BaseResourceCollectionContainer version
       * to recurse on nested ResourceComparators.
       * @param stk the stack of data types to use (recursively).
       * @param p   the project to use to dereference the references.
       * @throws BuildException on error.
       */
      @Override
      protected synchronized void dieOnCircularReference(Stack<Object> stk, Project p)
          throws BuildException {
          if (isChecked()) {
              return;
          }
  
          // check nested collection
          super.dieOnCircularReference(stk, p);
  
          if (!isReference()) {
              DataType.pushAndInvokeCircularReferenceCheck(comp, stk, p);
              setChecked(true);
          }
      }
  
  }
  