content: /*
   * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
   *
   * 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 org.activiti.engine.debug;
  
  import java.util.Iterator;
  import java.util.LinkedList;
  
  /**
   * Iterates over an {@link ExecutionTree} using breadth-first search
   *
  
   */
  public class ExecutionTreeBfsIterator implements Iterator<ExecutionTreeNode> {
  
      protected ExecutionTreeNode rootNode;
      protected boolean reverseOrder;
  
      protected LinkedList<ExecutionTreeNode> flattenedList;
      protected Iterator<ExecutionTreeNode> flattenedListIterator;
  
      public ExecutionTreeBfsIterator(ExecutionTreeNode executionTree) {
          this(executionTree, false);
      }
  
      public ExecutionTreeBfsIterator(ExecutionTreeNode rootNode, boolean reverseOrder) {
          this.rootNode = rootNode;
          this.reverseOrder = reverseOrder;
      }
  
      protected void flattenTree() {
          flattenedList = new LinkedList<ExecutionTreeNode>();
  
          LinkedList<ExecutionTreeNode> nodesToHandle = new LinkedList<ExecutionTreeNode>();
          nodesToHandle.add(rootNode);
          while (!nodesToHandle.isEmpty()) {
              ExecutionTreeNode currentNode = nodesToHandle.pop();
              if (reverseOrder) {
                  flattenedList.addFirst(currentNode);
              } else {
                  flattenedList.add(currentNode);
              }
  
              if (currentNode.getChildren() != null && currentNode.getChildren().size() > 0) {
                  for (ExecutionTreeNode childNode : currentNode.getChildren()) {
                      nodesToHandle.add(childNode);
                  }
              }
          }
  
          flattenedListIterator = flattenedList.iterator();
      }
  
      @Override
      public boolean hasNext() {
          if (flattenedList == null) {
              flattenTree();
          }
          return flattenedListIterator.hasNext();
      }
  
      @Override
      public ExecutionTreeNode next() {
          if (flattenedList == null) {
              flattenTree();
          }
          return flattenedListIterator.next();
      }
  
      @Override
      public void remove() {
          if (flattenedList == null) {
              flattenTree();
          }
          flattenedListIterator.remove();
      }
  }
  