1 /*
   2  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.swing.tree;
  27 
  28 import java.util.Enumeration;
  29 
  30 /**
  31  * Defines the requirements for an object that can be used as a
  32  * tree node in a JTree.
  33  * <p>
  34  * Implementations of <code>TreeNode</code> that override <code>equals</code>
  35  * will typically need to override <code>hashCode</code> as well.  Refer
  36  * to {@link javax.swing.tree.TreeModel} for more information.
  37  *
  38  * For further information and examples of using tree nodes,
  39  * see <a
  40  href="http://docs.oracle.com/javase/tutorial/uiswing/components/tree.html">How to Use Tree Nodes</a>
  41  * in <em>The Java Tutorial.</em>
  42  *
  43  * @author Rob Davis
  44  * @author Scott Violet
  45  */
  46 
  47 public interface TreeNode
  48 {
  49     /**
  50      * Returns the child <code>TreeNode</code> at index
  51      * <code>childIndex</code>.
  52      *
  53      * @param   childIndex  index of child
  54      * @return              the child node at given index
  55      */
  56     TreeNode getChildAt(int childIndex);
  57 
  58     /**
  59      * Returns the number of children <code>TreeNode</code>s the receiver
  60      * contains.
  61      *
  62      * @return              the number of children the receiver contains
  63      */
  64     int getChildCount();
  65 
  66     /**
  67      * Returns the parent <code>TreeNode</code> of the receiver.
  68      *
  69      * @return              the parent of the receiver
  70      */
  71     TreeNode getParent();
  72 
  73     /**
  74      * Returns the index of <code>node</code> in the receivers children.
  75      * If the receiver does not contain <code>node</code>, -1 will be
  76      * returned.
  77      *
  78      * @param   node        node to be loked for
  79      * @return              index of specified node
  80      */
  81     int getIndex(TreeNode node);
  82 
  83     /**
  84      * Returns true if the receiver allows children.
  85      *
  86      * @return              whether the receiver allows children
  87      */
  88     boolean getAllowsChildren();
  89 
  90     /**
  91      * Returns true if the receiver is a leaf.
  92      *
  93      * @return              whether the receiver is a leaf
  94      */
  95     boolean isLeaf();
  96 
  97     /**
  98      * Returns the children of the receiver as an <code>Enumeration</code>.
  99      *
 100      * @return              the children of the receiver as an {@code Enumeration}
 101      */
 102     Enumeration<? extends TreeNode> children();
 103 }