toolkit/test/accessibility/MessageArea.java

   1 /*
   2  * This file is part of the LibreOffice project.
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   7  *
   8  * This file incorporates work covered by the following license notice:
   9  *
  10  *   Licensed to the Apache Software Foundation (ASF) under one or more
  11  *   contributor license agreements. See the NOTICE file distributed
  12  *   with this work for additional information regarding copyright
  13  *   ownership. The ASF licenses this file to you under the Apache
  14  *   License, Version 2.0 (the "License"); you may not use this file
  15  *   except in compliance with the License. You may obtain a copy of
  16  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  17  */
  18
  19 import java.awt.Font;
  20 import java.awt.Color;
  21 import java.awt.Graphics;
  22 import javax.swing.JScrollPane;
  23 import javax.swing.JTextArea;
  24 import javax.swing.JScrollBar;
  25
  26
  27
  28 /** A message area displays text in a scrollable text widget.  It is a
  29     singleton.  Other objects can access it directly to display messages.
  30 */
  31 public class MessageArea
  32     extends JScrollPane
  33 {
  34     public static synchronized MessageArea Instance ()
  35     {
  36         if (saInstance == null)
  37             saInstance = new MessageArea ();
  38         return saInstance;
  39     }
  40
  41
  42
  43
  44     /** Create a new message area.  This method is private because the class is
  45         a singleton and may therefore not be instanciated from the outside.
  46     */
  47     private MessageArea ()
  48     {
  49         maText = new JTextArea();
  50         maText.setBackground (new Color (255,250,240));
  51         maText.setFont (new Font ("Helvetica", Font.PLAIN, 9));
  52         setViewportView (maText);
  53         setVerticalScrollBarPolicy (JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
  54         setHorizontalScrollBarPolicy (JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
  55
  56         printMessage (
  57             "class path is " + System.getProperty ("java.class.path") + "\n");
  58     }
  59
  60
  61
  62
  63     /** Show the given string at the end of the message area and scroll to make
  64         it visible.
  65     */
  66     public static synchronized void print (String aMessage)
  67     {
  68         print (0, aMessage);
  69     }
  70
  71
  72
  73
  74     /** Show the given string at the end of the message area and scroll to make
  75         it visible.  Indent the string as requested.
  76     */
  77     public static synchronized void print (int nIndentation, String aMessage)
  78     {
  79         while (nIndentation-- > 0)
  80             aMessage = " " + aMessage;
  81         Instance().printMessage(aMessage);
  82     }
  83
  84
  85
  86
  87     /** Show the given string at the end of the message area and scroll to make
  88         it visible.
  89     */
  90     public static void println (String aMessage)
  91     {
  92         println (0, aMessage);
  93     }
  94
  95
  96
  97
  98     /** Show the given string at the end of the message area and scroll to make
  99         it visible.
 100     */
 101     public static void println (int nIndentation, String aMessage)
 102     {
 103         print (nIndentation, aMessage+"\n");
 104     }
 105
 106
 107
 108
 109     public void paintComponent (Graphics g)
 110     {
 111         synchronized (g)
 112         {
 113             JScrollBar sb = getVerticalScrollBar();
 114             if (sb != null)
 115             {
 116                 int nScrollBarValue = sb.getMaximum() - sb.getVisibleAmount() - 1;
 117                 sb.setValue (nScrollBarValue);
 118             }
 119             super.paintComponent (g);
 120         }
 121     }
 122
 123
 124
 125
 126     /** Append the given string to the end of the text and scroll so that it
 127         becomes visible.  This is an internal method.  Use one of the static
 128         and public ones.
 129     */
 130     private synchronized void printMessage (String aMessage)
 131     {
 132         maText.append (aMessage);
 133     }
 134
 135
 136
 137
 138     private static MessageArea saInstance = null;
 139     private JTextArea maText;
 140 }