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  * @key headful
  27  * @bug 6505523
  28  * @summary NullPointerException in BasicTreeUI when a node is removed by expansion listener
  29  * @author Alexandr Scherbatiy
  30  * @run main bug6505523
  31  */
  32 import java.awt.Point;
  33 import java.awt.Rectangle;
  34 import java.awt.Robot;
  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 
  46 public class bug6505523 {
  47 
  48     private static JTree tree;
  49 
  50     public static void main(String[] args) throws Exception {
  51         Robot robot = new Robot();
  52         robot.setAutoDelay(50);
  53 
  54         SwingUtilities.invokeAndWait(new Runnable() {
  55 
  56             @Override
  57             public void run() {
  58                 createAndShowGUI();
  59             }
  60         });
  61 
  62         robot.waitForIdle();
  63 
  64         Point point = getRowPointToClick(2);
  65         robot.mouseMove(point.x, point.y);
  66         robot.mousePress(InputEvent.BUTTON1_MASK);
  67         robot.mouseRelease(InputEvent.BUTTON1_MASK);
  68 
  69         robot.waitForIdle();
  70 
  71     }
  72 
  73     private static Point getRowPointToClick(final int row) throws Exception {
  74 
  75         final Point[] result = new Point[1];
  76 
  77         SwingUtilities.invokeAndWait(new Runnable() {
  78 
  79             @Override
  80             public void run() {
  81                 Rectangle rect = tree.getRowBounds(row);
  82                 Point point = new Point(rect.x - 5, rect.y + rect.height / 2);
  83                 SwingUtilities.convertPointToScreen(point, tree);
  84                 result[0] = point;
  85             }
  86         });
  87 
  88         return result[0];
  89     }
  90 
  91     private static void createAndShowGUI() {
  92         final DefaultMutableTreeNode root = new DefaultMutableTreeNode("Problem with NPE under JDK 1.6");
  93         final DefaultMutableTreeNode problematic = new DefaultMutableTreeNode("Expand me and behold a NPE in stderr");
  94         problematic.add(new DefaultMutableTreeNode("some content"));
  95         root.add(new DefaultMutableTreeNode("irrelevant..."));
  96         root.add(problematic);
  97 
  98         final DefaultTreeModel model = new DefaultTreeModel(root);
  99         tree = new JTree(model);
 100         tree.setRootVisible(true);
 101         tree.setShowsRootHandles(true);
 102         tree.expandRow(0);
 103         tree.collapseRow(2);
 104 
 105         // this is critical - without dragEnabled everything works
 106         tree.setDragEnabled(true);
 107 
 108         tree.addTreeExpansionListener(new TreeExpansionListener() {
 109 
 110             @Override
 111             public void treeExpanded(TreeExpansionEvent event) {
 112                 TreeNode parent = problematic.getParent();
 113                 if (parent instanceof DefaultMutableTreeNode) {
 114                     model.removeNodeFromParent(problematic);
 115                 }
 116             }
 117 
 118             @Override
 119             public void treeCollapsed(TreeExpansionEvent event) {
 120             }
 121         });
 122 
 123         JFrame frame = new JFrame("JTree Problem");
 124         frame.add(new JScrollPane(tree));
 125         frame.setSize(500, 300);
 126         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 127         frame.setLocationRelativeTo(null);
 128         frame.setVisible(true);
 129     }
 130 }