1 /*
   2  * Copyright (c) 2012, 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.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 6505523
  27  * @summary NullPointerException in BasicTreeUI when a node is removed by expansion listener
  28  * @author Alexandr Scherbatiy
  29  * @run main bug6505523
  30  */
  31 import java.awt.Point;
  32 import java.awt.Rectangle;
  33 import java.awt.Robot;
  34 import java.awt.Toolkit;
  35 import java.awt.event.InputEvent;
  36 import javax.swing.JFrame;
  37 import javax.swing.JScrollPane;
  38 import javax.swing.JTree;
  39 import javax.swing.SwingUtilities;
  40 import javax.swing.event.TreeExpansionEvent;
  41 import javax.swing.event.TreeExpansionListener;
  42 import javax.swing.tree.DefaultMutableTreeNode;
  43 import javax.swing.tree.DefaultTreeModel;
  44 import javax.swing.tree.TreeNode;
  45 import sun.awt.SunToolkit;
  46 
  47 public class bug6505523 {
  48 
  49     private static JTree tree;
  50 
  51     public static void main(String[] args) throws Exception {
  52         SunToolkit toolkit = (SunToolkit) Toolkit.getDefaultToolkit();
  53         Robot robot = new Robot();
  54         robot.setAutoDelay(50);
  55 
  56         SwingUtilities.invokeAndWait(new Runnable() {
  57 
  58             @Override
  59             public void run() {
  60                 createAndShowGUI();
  61             }
  62         });
  63 
  64         toolkit.realSync();
  65 
  66         Point point = getRowPointToClick(2);
  67         robot.mouseMove(point.x, point.y);
  68         robot.mousePress(InputEvent.BUTTON1_MASK);
  69         robot.mouseRelease(InputEvent.BUTTON1_MASK);
  70 
  71         toolkit.realSync();
  72 
  73     }
  74 
  75     private static Point getRowPointToClick(final int row) throws Exception {
  76 
  77         final Point[] result = new Point[1];
  78 
  79         SwingUtilities.invokeAndWait(new Runnable() {
  80 
  81             @Override
  82             public void run() {
  83                 Rectangle rect = tree.getRowBounds(row);
  84                 Point point = new Point(rect.x - 5, rect.y + rect.height / 2);
  85                 SwingUtilities.convertPointToScreen(point, tree);
  86                 result[0] = point;
  87             }
  88         });
  89 
  90         return result[0];
  91     }
  92 
  93     private static void createAndShowGUI() {
  94         final DefaultMutableTreeNode root = new DefaultMutableTreeNode("Problem with NPE under JDK 1.6");
  95         final DefaultMutableTreeNode problematic = new DefaultMutableTreeNode("Expand me and behold a NPE in stderr");
  96         problematic.add(new DefaultMutableTreeNode("some content"));
  97         root.add(new DefaultMutableTreeNode("irrelevant..."));
  98         root.add(problematic);
  99 
 100         final DefaultTreeModel model = new DefaultTreeModel(root);
 101         tree = new JTree(model);
 102         tree.setRootVisible(true);
 103         tree.setShowsRootHandles(true);
 104         tree.expandRow(0);
 105         tree.collapseRow(2);
 106 
 107         // this is critical - without dragEnabled everything works
 108         tree.setDragEnabled(true);
 109 
 110         tree.addTreeExpansionListener(new TreeExpansionListener() {
 111 
 112             @Override
 113             public void treeExpanded(TreeExpansionEvent event) {
 114                 TreeNode parent = problematic.getParent();
 115                 if (parent instanceof DefaultMutableTreeNode) {
 116                     model.removeNodeFromParent(problematic);
 117                 }
 118             }
 119 
 120             @Override
 121             public void treeCollapsed(TreeExpansionEvent event) {
 122             }
 123         });
 124 
 125         JFrame frame = new JFrame("JTree Problem");
 126         frame.add(new JScrollPane(tree));
 127         frame.setSize(500, 300);
 128         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 129         frame.setLocationRelativeTo(null);
 130         frame.setVisible(true);
 131     }
 132 }