1 /*
   2  * Copyright (c) 2016, 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 /* @test
  25  * @bug 8160246
  26  * @summary Regression: 4410243 reproducible with GTK LaF
  27  * @run main ScrollFlickerTest
  28  */
  29 
  30 import javax.swing.*;
  31 import java.awt.*;
  32 
  33 public class ScrollFlickerTest {
  34 
  35     private static JFrame frame;
  36     private static JScrollPane scroll;
  37     private static int cnt = 0;
  38 
  39     public static void main(String[] args) throws Exception {
  40         SwingUtilities.invokeAndWait(() -> {
  41             frame = new JFrame();
  42             frame.setSize(300, 200);
  43             frame.getContentPane().setLayout(null);
  44             JTextArea text = new JTextArea("Test test test test");
  45             text.setLineWrap(true);
  46             scroll = new JScrollPane(text);
  47             frame.getContentPane().add(scroll);
  48             scroll.setBounds(1, 1, 100, 50);
  49             frame.setVisible(true);
  50         });
  51 
  52         Robot robot = new Robot();
  53         robot.waitForIdle();
  54         robot.delay(200);
  55 
  56         SwingUtilities.invokeAndWait(() -> {
  57             Insets insets = scroll.getInsets();
  58             scroll.setSize(insets.left + insets.right +
  59                     scroll.getVerticalScrollBar().getPreferredSize().width, 50);
  60             scroll.revalidate();
  61         });
  62         robot.delay(200);
  63         SwingUtilities.invokeAndWait(() ->
  64                           scroll.getViewport().addChangeListener((e) -> cnt++));
  65         robot.delay(1000);
  66 
  67         SwingUtilities.invokeLater(frame::dispose);
  68 
  69         if (cnt > 0) {
  70             throw new RuntimeException("Scroll bar flickers");
  71         }
  72     }
  73 }