/* * Copyright (c) 1997, 2003, 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 * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing.event; import java.util.EventObject;import javax.swing.tree.TreePath;  /** * Encapsulates information describing changes to a tree model, and * used to notify tree model listeners of the change. * For more information and examples see * <a href="http://java.sun.com/docs/books/tutorial/uiswing/events/treemodellistener.html">How to Write a Tree Model Listener</a>, * a section in <em>The Java Tutorial.</em> * <p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing.  As of 1.4, support for long term storage * of all JavaBeans<sup><font size="-2">TM</font></sup> * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. * * @author Rob Davis * @author Ray Ryan * @author Scott Violet */public class TreeModelEvent extends EventObject {    /** Path to the parent of the nodes that have changed. */    protected TreePath  path;    /** Indices identifying the position of where the children were. */    protected int[]     childIndices;    /** Children that have been removed. */    protected Object[]  children;     /**     * Used to create an event when nodes have been changed, inserted, or     * removed, identifying the path to the parent of the modified items as     * an array of Objects. All of the modified objects are siblings which are     * direct descendents (not grandchildren) of the specified parent.     * The positions at which the inserts, deletes, or changes occurred are     * specified by an array of <code>int</code>. The indexes in that array     * must be in order, from lowest to highest.     * <p>     * For changes, the indexes in the model correspond exactly to the indexes     * of items currently displayed in the UI. As a result, it is not really     * critical if the indexes are not in their exact order. But after multiple     * inserts or deletes, the items currently in the UI no longer correspond     * to the items in the model. It is therefore critical to specify the     * indexes properly for inserts and deletes.     * <p>     * For inserts, the indexes represent the <i>final</i> state of the tree,     * after the inserts have occurred. Since the indexes must be specified in     * order, the most natural processing methodology is to do the inserts     * starting at the lowest index and working towards the highest. Accumulate     * a Vector of <code>Integer</code> objects that specify the     * insert-locations as you go, then convert the Vector to an     * array of <code>int</code> to create the event. When the postition-index     * equals zero, the node is inserted at the beginning of the list. When the     * position index equals the size of the list, the node is "inserted" at     * (appended to) the end of the list.     * <p>     * For deletes, the indexes represent the <i>initial</i> state of the tree,     * before the deletes have occurred. Since the indexes must be specified in     * order, the most natural processing methodology is to use a delete-counter.     * Start by initializing the counter to zero and start work through the     * list from lowest to higest. Every time you do a delete, add the current     * value of the delete-counter to the index-position where the delete occurred,     * and append the result to a Vector of delete-locations, using     * <code>addElement()</code>. Then increment the delete-counter. The index     * positions stored in the Vector therefore reflect the effects of all previous     * deletes, so they represent each object's position in the initial tree.     * (You could also start at the highest index and working back towards the     * lowest, accumulating a Vector of delete-locations as you go using the     * <code>insertElementAt(Integer, 0)</code>.) However you produce the Vector     * of initial-positions, you then need to convert the Vector of <code>Integer</code>     * objects to an array of <code>int</code> to create the event.     * <p>     * <b>Notes:</b><ul>     * <li>Like the <code>insertNodeInto</code> method in the     *    <code>DefaultTreeModel</code> class, <code>insertElementAt</code>     *    appends to the <code>Vector</code> when the index matches the size     *    of the vector. So you can use <code>insertElementAt(Integer, 0)</code>     *    even when the vector is empty.     * <ul>To create a node changed event for the root node, specify the parent     *     and the child indices as <code>null</code>.     * </ul>     *     * @param source the Object responsible for generating the event (typically     *               the creator of the event object passes <code>this</code>     *               for its value)     * @param path   an array of Object identifying the path to the     *               parent of the modified item(s), where the first element     *               of the array is the Object stored at the root node and     *               the last element is the Object stored at the parent node     * @param childIndices an array of <code>int</code> that specifies the     *               index values of the removed items. The indices must be     *               in sorted order, from lowest to highest     * @param children an array of Object containing the inserted, removed, or     *                 changed objects     * @see TreePath     */    public TreeModelEvent(Object source, Object[] path, int[] childIndices,                          Object[] children)    {        this(source, new TreePath(path), childIndices, children);    }     /**     * Used to create an event when nodes have been changed, inserted, or     * removed, identifying the path to the parent of the modified items as     * a TreePath object. For more information on how to specify the indexes     * and objects, see     * <code>TreeModelEvent(Object,Object[],int[],Object[])</code>.     *     * @param source the Object responsible for generating the event (typically     *               the creator of the event object passes <code>this</code>     *               for its value)     * @param path   a TreePath object that identifies the path to the     *               parent of the modified item(s)     * @param childIndices an array of <code>int</code> that specifies the     *               index values of the modified items     * @param children an array of Object containing the inserted, removed, or     *                 changed objects     *     * @see #TreeModelEvent(Object,Object[],int[],Object[])     */    public TreeModelEvent(Object source, TreePath path, int[] childIndices,                          Object[] children)    {        super(source);        this.path = path;        this.childIndices = childIndices;        this.children = children;    }     /**     * Used to create an event when the node structure has changed in some way,     * identifying the path to the root of a modified subtree as an array of     * Objects. A structure change event might involve nodes swapping position,     * for example, or it might encapsulate multiple inserts and deletes in the     * subtree stemming from the node, where the changes may have taken place at     * different levels of the subtree.     * <blockquote>     *   <b>Note:</b><br>     *   JTree collapses all nodes under the specified node, so that only its     *   immediate children are visible.     * </blockquote>     *     * @param source the Object responsible for generating the event (typically     *               the creator of the event object passes <code>this</code>     *               for its value)     * @param path   an array of Object identifying the path to the root of the     *               modified subtree, where the first element of the array is     *               the object stored at the root node and the last element     *               is the object stored at the changed node     * @see TreePath     */    public TreeModelEvent(Object source, Object[] path)    {        this(source, new TreePath(path));    }     /**     * Used to create an event when the node structure has changed in some way,     * identifying the path to the root of the modified subtree as a TreePath     * object. For more information on this event specification, see     * <code>TreeModelEvent(Object,Object[])</code>.     *     * @param source the Object responsible for generating the event (typically     *               the creator of the event object passes <code>this</code>     *               for its value)     * @param path   a TreePath object that identifies the path to the     *               change. In the DefaultTreeModel,     *               this object contains an array of user-data objects,     *               but a subclass of TreePath could use some totally     *               different mechanism -- for example, a node ID number     *     * @see #TreeModelEvent(Object,Object[])     */    public TreeModelEvent(Object source, TreePath path)    {        super(source);        this.path = path;        this.childIndices = new int[0];    }     /**     * For all events, except treeStructureChanged,     * returns the parent of the changed nodes.     * For treeStructureChanged events, returns the ancestor of the     * structure that has changed. This and     * <code>getChildIndices</code> are used to get a list of the effected     * nodes.     * <p>     * The one exception to this is a treeNodesChanged event that is to     * identify the root, in which case this will return the root     * and <code>getChildIndices</code> will return null.     *     * @return the TreePath used in identifying the changed nodes.     * @see TreePath#getLastPathComponent     */    public TreePath getTreePath() { return path; }     /**     * Convenience method to get the array of objects from the TreePath     * instance that this event wraps.     *     * @return an array of Objects, where the first Object is the one     *         stored at the root and the last object is the one     *         stored at the node identified by the path     */    public Object[] getPath() {        if(path != null)            return path.getPath();        return null;    }     /**     * Returns the objects that are children of the node identified by     * <code>getPath</code> at the locations specified by     * <code>getChildIndices</code>. If this is a removal event the     * returned objects are no longer children of the parent node.     *     * @return an array of Object containing the children specified by     *         the event     * @see #getPath     * @see #getChildIndices     */    public Object[] getChildren() {        if(children != null) {            int            cCount = children.length;            Object[]       retChildren = new Object[cCount];             System.arraycopy(children, 0, retChildren, 0, cCount);            return retChildren;        }        return null;    }     /**     * Returns the values of the child indexes. If this is a removal event     * the indexes point to locations in the initial list where items     * were removed. If it is an insert, the indices point to locations     * in the final list where the items were added. For node changes,     * the indices point to the locations of the modified nodes.     *     * @return an array of <code>int</code> containing index locations for     *         the children specified by the event     */    public int[] getChildIndices() {        if(childIndices != null) {            int            cCount = childIndices.length;            int[]          retArray = new int[cCount];             System.arraycopy(childIndices, 0, retArray, 0, cCount);            return retArray;        }        return null;    }     /**     * Returns a string that displays and identifies this object's     * properties.     *     * @return a String representation of this object     */    public String toString() {        StringBuffer   retBuffer = new StringBuffer();         retBuffer.append(getClass().getName() + " " +                         Integer.toString(hashCode()));        if(path != null)            retBuffer.append(" path " + path);        if(childIndices != null) {            retBuffer.append(" indices [ ");            for(int counter = 0; counter < childIndices.length; counter++)                retBuffer.append(Integer.toString(childIndices[counter])+ " ");            retBuffer.append("]");        }        if(children != null) {            retBuffer.append(" children [ ");            for(int counter = 0; counter < children.length; counter++)                retBuffer.append(children[counter] + " ");            retBuffer.append("]");        }        return retBuffer.toString();    }}