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	/*
	* Copyright (c) 1997, 2013, 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="https://docs.oracle.com/javase/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™
	* 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 highest. 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 style="list-style-type:none">
	* <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.</li>
	* <li>To create a node changed event for the root node, specify the parent
	* and the child indices as <code>null</code>.</li>
	* </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, (path == null) ? null : 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, (path == null) ? null : 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();
	}
	}

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