1 /*
   2  * Copyright (c) 1998, 1999, 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.event;
  27 
  28 import java.util.EventListener;
  29 import javax.swing.tree.ExpandVetoException;
  30 
  31 /**
  32   * The listener that's notified when a tree expands or collapses
  33   * a node.
  34   * For further information and examples see
  35   * <a href="http://docs.oracle.com/javase/tutorial/uiswing/events/treewillexpandlistener.html">How to Write a Tree-Will-Expand Listener</a>,
  36   * a section in <em>The Java Tutorial.</em>
  37   *
  38   * @author Scott Violet
  39   */
  40 
  41 public interface TreeWillExpandListener extends EventListener {
  42     /**
  43      * Invoked whenever a node in the tree is about to be expanded.
  44      */
  45     public void treeWillExpand(TreeExpansionEvent event) throws ExpandVetoException;
  46 
  47     /**
  48      * Invoked whenever a node in the tree is about to be collapsed.
  49      */
  50     public void treeWillCollapse(TreeExpansionEvent event) throws ExpandVetoException;
  51 }