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.event.InputEvent;
  35 import javax.swing.JFrame;
  36 import javax.swing.JScrollPane;
  37 import javax.swing.JTree;
  38 import javax.swing.SwingUtilities;
  39 import javax.swing.event.TreeExpansionEvent;
  40 import javax.swing.event.TreeExpansionListener;
  41 import javax.swing.tree.DefaultMutableTreeNode;
  42 import javax.swing.tree.DefaultTreeModel;
  43 import javax.swing.tree.TreeNode;
  44 
  45 public class bug6505523 {
  46 
  47     private static JTree tree;
  48 
  49     public static void main(String[] args) throws Exception {
  50         Robot robot = new Robot();
  51         robot.setAutoDelay(50);
  52 
  53         SwingUtilities.invokeAndWait(new Runnable() {
  54 
  55             @Override
  56             public void run() {
  57                 createAndShowGUI();
  58             }
  59         });
  60 
  61         robot.waitForIdle();
  62 
  63         Point point = getRowPointToClick(2);
  64         robot.mouseMove(point.x, point.y);
  65         robot.mousePress(InputEvent.BUTTON1_MASK);
  66         robot.mouseRelease(InputEvent.BUTTON1_MASK);
  67 
  68         robot.waitForIdle();
  69 
  70     }
  71 
  72     private static Point getRowPointToClick(final int row) throws Exception {
  73 
  74         final Point[] result = new Point[1];
  75 
  76         SwingUtilities.invokeAndWait(new Runnable() {
  77 
  78             @Override
  79             public void run() {
  80                 Rectangle rect = tree.getRowBounds(row);
  81                 Point point = new Point(rect.x - 5, rect.y + rect.height / 2);
  82                 SwingUtilities.convertPointToScreen(point, tree);
  83                 result[0] = point;
  84             }
  85         });
  86 
  87         return result[0];
  88     }
  89 
  90     private static void createAndShowGUI() {
  91         final DefaultMutableTreeNode root = new DefaultMutableTreeNode("Problem with NPE under JDK 1.6");
  92         final DefaultMutableTreeNode problematic = new DefaultMutableTreeNode("Expand me and behold a NPE in stderr");
  93         problematic.add(new DefaultMutableTreeNode("some content"));
  94         root.add(new DefaultMutableTreeNode("irrelevant..."));
  95         root.add(problematic);
  96 
  97         final DefaultTreeModel model = new DefaultTreeModel(root);
  98         tree = new JTree(model);
  99         tree.setRootVisible(true);
 100         tree.setShowsRootHandles(true);
 101         tree.expandRow(0);
 102         tree.collapseRow(2);
 103 
 104         // this is critical - without dragEnabled everything works
 105         tree.setDragEnabled(true);
 106 
 107         tree.addTreeExpansionListener(new TreeExpansionListener() {
 108 
 109             @Override
 110             public void treeExpanded(TreeExpansionEvent event) {
 111                 TreeNode parent = problematic.getParent();
 112                 if (parent instanceof DefaultMutableTreeNode) {
 113                     model.removeNodeFromParent(problematic);
 114                 }
 115             }
 116 
 117             @Override
 118             public void treeCollapsed(TreeExpansionEvent event) {
 119             }
 120         });
 121 
 122         JFrame frame = new JFrame("JTree Problem");
 123         frame.add(new JScrollPane(tree));
 124         frame.setSize(500, 300);
 125         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 126         frame.setLocationRelativeTo(null);
 127         frame.setVisible(true);
 128     }
 129 }