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TreeNode.java

package gov.nasa.arc.ase.util;

//#ifdef JDK11



//#else JDK11
import java.util.Collection;
import java.util.ArrayList;
import java.util.Iterator;
//#endif JDK11

/**
 * This is a node in a tree.
 */
public class TreeNode {
  /**
   * The tree the node belongs to.
   */
  private Tree tree;

  /**
   * The parent of this node.
   */
  private TreeNode parent;

  /**
   * The children of this node.
   */
  private Collection children;

  /**
   * Creates a new node as the root of a tree.
   */
  public TreeNode(Tree t) {
    tree = t;
    parent = null;
    children = new ArrayList();

    t.setRoot(this);
  }  
  /**
   * Creates a new node under a given node.
   */
  public TreeNode(TreeNode p) {
    tree = p.tree;
    parent = p;
    children = new ArrayList();

    p.addChild(this);
  }  
  /**
   * Returns the set of nodes above this one.
   */
  public Collection above() {
    Collection a = new ArrayList();

    if(parent != null) {
      a.add(parent);
      a.addAll(parent.above());
    }

    return a;
  }  
  /**
   * Adds a children.
   */
  private void addChild(TreeNode n) {
    children.add(n);
  }  
  /**
   * Returns the set of nodes below this one.
   */
  public Collection below() {
    Collection b = new ArrayList();

    for(Iterator i = children.iterator(); i.hasNext(); ) {
      TreeNode n = (TreeNode)i.next();

      b.add(n);
      b.addAll(n.below());
    }

    return b;
  }  
  /**
   * Returns the children of a node.
   */
  public Collection children() {
    return children;
  }  
  /**
   * Gets all the node under this one that are
   * equal to a given one.
   */
  public Collection get(TreeNode n) {
    Collection nodes = new ArrayList();

    if(equals(n)) nodes.add(this);

    for(Iterator i = children.iterator(); i.hasNext(); ) {
      TreeNode child = (TreeNode)i.next();

      nodes.addAll(child.get(n));
    }

    return nodes;
  }  
  /**
   * Returns the parent of this node.
   */
  public TreeNode getParent() {
    return parent;
  }  
  /**
   * Returns the tree the node belongs to.
   */
  public Tree getTree() {
    return tree;
  }  
  /**
   * Returns a string rapresentation of the node and the nodes below.
   */
  public String toString(String prefix) {
    StringBuffer sb = new StringBuffer();

    sb.append(' ');
    sb.append(this);
    sb.append('\n');

    for(Iterator i = children.iterator(); i.hasNext(); ) {
      TreeNode child = (TreeNode)i.next();

      sb.append(prefix);
      if(i.hasNext()) {
    sb.append('+');
    sb.append(child.toString(prefix + "|  "));
      } else {
    sb.append('\\');
    sb.append(child.toString(prefix + "   "));
      }
    }

    return sb.toString();
  }  
}

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