Java tutorial
/* * Copyright (c) 1998, 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 * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing.event; import java.util.EventListener; import javax.swing.tree.ExpandVetoException; /** * The listener that's notified when a tree expands or collapses * a node. * For further information and examples see * <a href="https://docs.oracle.com/javase/tutorial/uiswing/events/treewillexpandlistener.html">How to Write a Tree-Will-Expand Listener</a>, * a section in <em>The Java Tutorial.</em> * * @author Scott Violet */ public interface TreeWillExpandListener extends EventListener { /** * Invoked whenever a node in the tree is about to be expanded. * * @param event a {@code TreeExpansionEvent} containing a {@code TreePath} * object for the node * @throws ExpandVetoException to signify expansion has been canceled */ public void treeWillExpand(TreeExpansionEvent event) throws ExpandVetoException; /** * Invoked whenever a node in the tree is about to be collapsed. * * @param event a {@code TreeExpansionEvent} containing a {@code TreePath} * object for the node * @throws ExpandVetoException to signify collapse has been canceled */ public void treeWillCollapse(TreeExpansionEvent event) throws ExpandVetoException; }