Here you can find the source of makeTreeAutoExpandable(JTree tree)
| Parameter | Description |
|---|---|
| tree | The tree to make auto-expandable |
public static void makeTreeAutoExpandable(JTree tree)
//package com.java2s; /*//from w w w. ja v a2s. com * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 1997-2010 Oracle and/or its affiliates. All rights reserved. * * Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2 only ("GPL") or the Common * Development and Distribution License("CDDL") (collectively, the * "License"). You may not use this file except in compliance with the * License. You can obtain a copy of the License at * http://www.netbeans.org/cddl-gplv2.html * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the * specific language governing permissions and limitations under the * License. When distributing the software, include this License Header * Notice in each file and include the License file at * nbbuild/licenses/CDDL-GPL-2-CP. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the GPL Version 2 section of the License file that * accompanied this code. If applicable, add the following below the * License Header, with the fields enclosed by brackets [] replaced by * your own identifying information: * "Portions Copyrighted [year] [name of copyright owner]" * * Contributor(s): * The Original Software is NetBeans. The Initial Developer of the Original * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun * Microsystems, Inc. All Rights Reserved. * * If you wish your version of this file to be governed by only the CDDL * or only the GPL Version 2, indicate your decision by adding * "[Contributor] elects to include this software in this distribution * under the [CDDL or GPL Version 2] license." If you do not indicate a * single choice of license, a recipient has the option to distribute * your version of this file under either the CDDL, the GPL Version 2 or * to extend the choice of license to its licensees as provided above. * However, if you add GPL Version 2 code and therefore, elected the GPL * Version 2 license, then the option applies only if the new code is * made subject to such option by the copyright holder. */ import javax.swing.*; import javax.swing.event.TreeExpansionEvent; import javax.swing.event.TreeExpansionListener; import javax.swing.tree.TreeModel; import javax.swing.tree.TreePath; public class Main { public static final String PROP_AUTO_EXPANDING = "auto_expanding"; public static final String PROP_EXPANSION_TRANSACTION = "expansion_transaction"; private static final int MAX_TREE_AUTOEXPAND_LINES = 50; /** By calling this method, the provided tree will become auto-expandable, i.e. * When a node is expanded, if it has only one child, that child gets expanded, and so on. * This is very useful for trees that have a deep node hierarchy with typical paths from * root to leaves containing only one node along the whole path. * * @param tree The tree to make auto-expandable */ public static void makeTreeAutoExpandable(JTree tree) { makeTreeAutoExpandable(tree, 1, false); } public static void makeTreeAutoExpandable(JTree tree, final boolean dontExpandToLeafs) { makeTreeAutoExpandable(tree, 1, dontExpandToLeafs); } /** By calling this method, the provided tree will become auto-expandable, i.e. * When a node is expanded, if it has only one child, that child gets expanded, and so on. * This is very useful for trees that have a deep node hierarchy with typical paths from * root to leaves containing only one node along the whole path. * * @param tree The tree to make auto-expandable */ public static void makeTreeAutoExpandable(JTree tree, final int maxChildToExpand) { makeTreeAutoExpandable(tree, maxChildToExpand, false); } public static void makeTreeAutoExpandable(final JTree tree, final int maxChildToExpand, final boolean dontExpandToLeafs) { tree.addTreeExpansionListener(new TreeExpansionListener() { boolean internalChange = false; public void treeCollapsed(TreeExpansionEvent event) { } public void treeExpanded(TreeExpansionEvent event) { if (internalChange || Boolean.TRUE.equals(tree.getClientProperty(PROP_EXPANSION_TRANSACTION))) { // NOI18N return; } // Auto expand more if the just expanded child has only one child TreePath path = event.getPath(); JTree tree = (JTree) event.getSource(); internalChange = true; tree.putClientProperty(PROP_AUTO_EXPANDING, Boolean.TRUE); try { autoExpand(tree, path, MAX_TREE_AUTOEXPAND_LINES, maxChildToExpand, dontExpandToLeafs); } finally { tree.putClientProperty(PROP_AUTO_EXPANDING, null); internalChange = false; } } }); } /** Checks give TreePath for the last node, and if it ends with a node with just one child, * it keeps expanding further. * Current implementation expands through the first child that is not leaf. To more correctly * fulfil expected semantics in case maxChildToExpand is > 1, it should expand all paths through * all children. * * @param tree * @param path * @param maxChildToExpand */ public static void autoExpand(JTree tree, TreePath path, int maxLines, int maxChildToExpand, boolean dontExpandToLeafs) { TreeModel model = tree.getModel(); Object node = path.getLastPathComponent(); TreePath newPath = path; int currentLines = 0; while (currentLines++ < maxLines && !model.isLeaf(node) && (model.getChildCount(node) > 0) && (model.getChildCount(node) <= maxChildToExpand)) { for (int i = 0; i < model.getChildCount(node); i++) { node = tree.getModel().getChild(node, i); if (!model.isLeaf(node)) { if (dontExpandToLeafs && hasOnlyLeafs(tree, node)) { break; } newPath = newPath.pathByAddingChild(node); // if the leaf is added the path will not expand break; // from for } } } tree.expandPath(newPath); } public static boolean hasOnlyLeafs(JTree tree, Object node) { TreeModel model = tree.getModel(); for (int i = 0; i < model.getChildCount(node); i++) { if (!model.isLeaf(model.getChild(node, i))) { return false; } } return true; } }