/*
 * 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
 *
 *   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.apache.myfaces.custom.tree.model;


/**
 * @author <a href="mailto:oliver@rossmueller.com">Oliver Rossmueller</a>
 * @version $Revision: 472638 $ $Date: 2006-11-08 15:54:13 -0500 (Wed, 08 Nov 2006) $
 */
public interface TreeModelListener
{
    /**
     * <p>Invoked after a node (or a set of siblings) has changed in some
     * way. The node(s) have not changed locations in the tree or
     * altered their children arrays, but other attributes have
     * changed and may affect presentation. Example: the name of a
     * file has changed, but it is in the same location in the file
     * system.</p>
     * <p>To indicate the root has changed, childIndices and children
     * will be null. </p>
     * <p/>
     * <p>Use <code>e.getPath()</code>
     * to get the parent of the changed node(s).
     * <code>e.getChildIndices()</code>
     * returns the index(es) of the changed node(s).</p>
     */
    void treeNodesChanged(TreeModelEvent e);

    /**
     * <p>Invoked after nodes have been inserted into the tree.</p>
     * <p/>
     * <p>Use <code>e.getPath()</code>
     * to get the parent of the new node(s).
     * <code>e.getChildIndices()</code>
     * returns the index(es) of the new node(s)
     * in ascending order.</p>
     */
    void treeNodesInserted(TreeModelEvent e);

    /**
     * <p>Invoked after nodes have been removed from the tree.  Note that
     * if a subtree is removed from the tree, this method may only be
     * invoked once for the root of the removed subtree, not once for
     * each individual set of siblings removed.</p>
     * <p/>
     * <p>Use <code>e.getPath()</code>
     * to get the former parent of the deleted node(s).
     * <code>e.getChildIndices()</code>
     * returns, in ascending order, the index(es)
     * the node(s) had before being deleted.</p>
     */
    void treeNodesRemoved(TreeModelEvent e);

    /**
     * <p>Invoked after the tree has drastically changed structure from a
     * given node down.  If the path returned by e.getPath() is of length
     * one and the first element does not identify the current root node
     * the first element should become the new root of the tree.<p>
     * <p/>
     * <p>Use <code>e.getPath()</code>
     * to get the path to the node.
     * <code>e.getChildIndices()</code>
     * returns null.</p>
     */
    void treeStructureChanged(TreeModelEvent e);

}
