/*

 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package javax.swing.tree;

import java.util.Enumeration;

/**

 * Defines the requirements for an object that can be used as a

 * tree node in a JTree.

 * <p>

 * Implementations of <code>TreeNode</code> that override <code>equals</code>

 * will typically need to override <code>hashCode</code> as well.  Refer

 * to {@link javax.swing.tree.TreeModel} for more information.

 *

 * For further information and examples of using tree nodes,

 * see <a

 href="http://docs.oracle.com/javase/tutorial/uiswing/components/tree.html">How to Use Tree Nodes</a>

 * in <em>The Java Tutorial.</em>

 *

 * @author Rob Davis

 * @author Scott Violet

 */

public interface TreeNode

{

    /**

     * Returns the child <code>TreeNode</code> at index

     * <code>childIndex</code>.

     *

     * @param   childIndex  index of child

     * @return              the child node at given index

     */

    TreeNode getChildAt(int childIndex);

    /**

     * Returns the number of children <code>TreeNode</code>s the receiver

     * contains.

     *

     * @return              the number of children the receiver contains

     */

    int getChildCount();

    /**

     * Returns the parent <code>TreeNode</code> of the receiver.

     *

     * @return              the parent of the receiver

     */

    TreeNode getParent();

    /**

     * Returns the index of <code>node</code> in the receivers children.

     * If the receiver does not contain <code>node</code>, -1 will be

     * returned.

     *

     * @param   node        node to be loked for

     * @return              index of specified node

     */

    int getIndex(TreeNode node);

    /**

     * Returns true if the receiver allows children.

     *

     * @return              whether the receiver allows children

     */

    boolean getAllowsChildren();

    /**

     * Returns true if the receiver is a leaf.

     *

     * @return              whether the receiver is a leaf

     */

    boolean isLeaf();

    /**

     * Returns the children of the receiver as an <code>Enumeration</code>.

     *

     * @return              the children of the receiver as an {@code Enumeration}

     */

    Enumeration<? extends TreeNode> children();

}