1 /************************************************************** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * 20 *************************************************************/ 21 22 package org.openoffice.accessibility.misc; 23 24 import java.awt.Font; 25 import java.awt.Rectangle; 26 import java.awt.Color; 27 import java.awt.Graphics; 28 import javax.swing.JScrollPane; 29 import javax.swing.JTextArea; 30 import javax.swing.JScrollBar; 31 32 33 34 /** A message area displays text in a scrollable text widget. It is a 35 singleton. Other objects can access it directly to display messages. 36 */ 37 public class MessageArea 38 extends JScrollPane 39 { Instance()40 public static synchronized MessageArea Instance () 41 { 42 if (saInstance == null) 43 saInstance = new MessageArea (); 44 return saInstance; 45 } 46 47 48 49 50 /** Create a new message area. This method is private because the class is 51 a singleton and may therefore not be instanciated from the outside. 52 */ MessageArea()53 private MessageArea () 54 { 55 maText = new JTextArea(); 56 maText.setBackground (new Color (255,250,240)); 57 maText.setFont (new Font ("Helvetica", Font.PLAIN, 9)); 58 setViewportView (maText); 59 setVerticalScrollBarPolicy (JScrollPane.VERTICAL_SCROLLBAR_ALWAYS); 60 setHorizontalScrollBarPolicy (JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS); 61 62 printMessage ( 63 "class path is " + System.getProperty ("java.class.path") + "\n"); 64 } 65 66 67 68 69 /** Show the given string at the end of the message area and scroll to make 70 it visible. 71 */ print(String aMessage)72 public static synchronized void print (String aMessage) 73 { 74 print (0, aMessage); 75 } 76 77 78 79 80 /** Show the given string at the end of the message area and scroll to make 81 it visible. Indent the string as requested. 82 */ print(int nIndentation, String aMessage)83 public static synchronized void print (int nIndentation, String aMessage) 84 { 85 while (nIndentation-- > 0) 86 aMessage = " " + aMessage; 87 Instance().printMessage(aMessage); 88 } 89 90 91 92 93 /** Show the given string at the end of the message area and scroll to make 94 it visible. 95 */ println(String aMessage)96 public static void println (String aMessage) 97 { 98 println (0, aMessage); 99 } 100 101 102 103 104 /** Show the given string at the end of the message area and scroll to make 105 it visible. 106 */ println(int nIndentation, String aMessage)107 public static void println (int nIndentation, String aMessage) 108 { 109 print (nIndentation, aMessage+"\n"); 110 } 111 112 113 114 paintComponent(Graphics g)115 public void paintComponent (Graphics g) 116 { 117 synchronized (g) 118 { 119 JScrollBar sb = getVerticalScrollBar(); 120 if (sb != null) 121 { 122 int nScrollBarValue = sb.getMaximum() - sb.getVisibleAmount() - 1; 123 sb.setValue (nScrollBarValue); 124 } 125 super.paintComponent (g); 126 } 127 } 128 129 130 131 132 /** Append the given string to the end of the text and scroll so that it 133 becomes visible. This is an internal method. Use one of the static 134 and public ones. 135 */ printMessage(String aMessage)136 private synchronized void printMessage (String aMessage) 137 { 138 maText.append (aMessage); 139 } 140 141 142 143 144 private static MessageArea saInstance = null; 145 private JTextArea maText; 146 } 147