1*1b0aaa91SAndrew Rist /************************************************************** 2*1b0aaa91SAndrew Rist * 3*1b0aaa91SAndrew Rist * Licensed to the Apache Software Foundation (ASF) under one 4*1b0aaa91SAndrew Rist * or more contributor license agreements. See the NOTICE file 5*1b0aaa91SAndrew Rist * distributed with this work for additional information 6*1b0aaa91SAndrew Rist * regarding copyright ownership. The ASF licenses this file 7*1b0aaa91SAndrew Rist * to you under the Apache License, Version 2.0 (the 8*1b0aaa91SAndrew Rist * "License"); you may not use this file except in compliance 9*1b0aaa91SAndrew Rist * with the License. You may obtain a copy of the License at 10*1b0aaa91SAndrew Rist * 11*1b0aaa91SAndrew Rist * http://www.apache.org/licenses/LICENSE-2.0 12*1b0aaa91SAndrew Rist * 13*1b0aaa91SAndrew Rist * Unless required by applicable law or agreed to in writing, 14*1b0aaa91SAndrew Rist * software distributed under the License is distributed on an 15*1b0aaa91SAndrew Rist * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16*1b0aaa91SAndrew Rist * KIND, either express or implied. See the License for the 17*1b0aaa91SAndrew Rist * specific language governing permissions and limitations 18*1b0aaa91SAndrew Rist * under the License. 19*1b0aaa91SAndrew Rist * 20*1b0aaa91SAndrew Rist *************************************************************/ 21*1b0aaa91SAndrew Rist 22cdf0e10cSrcweir import java.awt.Font; 23cdf0e10cSrcweir import java.awt.Rectangle; 24cdf0e10cSrcweir import java.awt.Color; 25cdf0e10cSrcweir import java.awt.Graphics; 26cdf0e10cSrcweir import javax.swing.JScrollPane; 27cdf0e10cSrcweir import javax.swing.JTextArea; 28cdf0e10cSrcweir import javax.swing.JScrollBar; 29cdf0e10cSrcweir 30cdf0e10cSrcweir 31cdf0e10cSrcweir 32cdf0e10cSrcweir /** A message area displays text in a scrollable text widget. It is a 33cdf0e10cSrcweir singleton. Other objects can access it directly to display messages. 34cdf0e10cSrcweir */ 35cdf0e10cSrcweir public class MessageArea 36cdf0e10cSrcweir extends JScrollPane 37cdf0e10cSrcweir { Instance()38cdf0e10cSrcweir public static synchronized MessageArea Instance () 39cdf0e10cSrcweir { 40cdf0e10cSrcweir if (saInstance == null) 41cdf0e10cSrcweir saInstance = new MessageArea (); 42cdf0e10cSrcweir return saInstance; 43cdf0e10cSrcweir } 44cdf0e10cSrcweir 45cdf0e10cSrcweir 46cdf0e10cSrcweir 47cdf0e10cSrcweir 48cdf0e10cSrcweir /** Create a new message area. This method is private because the class is 49cdf0e10cSrcweir a singleton and may therefore not be instanciated from the outside. 50cdf0e10cSrcweir */ MessageArea()51cdf0e10cSrcweir private MessageArea () 52cdf0e10cSrcweir { 53cdf0e10cSrcweir maText = new JTextArea(); 54cdf0e10cSrcweir maText.setBackground (new Color (255,250,240)); 55cdf0e10cSrcweir maText.setFont (new Font ("Helvetica", Font.PLAIN, 9)); 56cdf0e10cSrcweir setViewportView (maText); 57cdf0e10cSrcweir setVerticalScrollBarPolicy (JScrollPane.VERTICAL_SCROLLBAR_ALWAYS); 58cdf0e10cSrcweir setHorizontalScrollBarPolicy (JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS); 59cdf0e10cSrcweir 60cdf0e10cSrcweir printMessage ( 61cdf0e10cSrcweir "class path is " + System.getProperty ("java.class.path") + "\n"); 62cdf0e10cSrcweir } 63cdf0e10cSrcweir 64cdf0e10cSrcweir 65cdf0e10cSrcweir 66cdf0e10cSrcweir 67cdf0e10cSrcweir /** Show the given string at the end of the message area and scroll to make 68cdf0e10cSrcweir it visible. 69cdf0e10cSrcweir */ print(String aMessage)70cdf0e10cSrcweir public static synchronized void print (String aMessage) 71cdf0e10cSrcweir { 72cdf0e10cSrcweir print (0, aMessage); 73cdf0e10cSrcweir } 74cdf0e10cSrcweir 75cdf0e10cSrcweir 76cdf0e10cSrcweir 77cdf0e10cSrcweir 78cdf0e10cSrcweir /** Show the given string at the end of the message area and scroll to make 79cdf0e10cSrcweir it visible. Indent the string as requested. 80cdf0e10cSrcweir */ print(int nIndentation, String aMessage)81cdf0e10cSrcweir public static synchronized void print (int nIndentation, String aMessage) 82cdf0e10cSrcweir { 83cdf0e10cSrcweir while (nIndentation-- > 0) 84cdf0e10cSrcweir aMessage = " " + aMessage; 85cdf0e10cSrcweir Instance().printMessage(aMessage); 86cdf0e10cSrcweir } 87cdf0e10cSrcweir 88cdf0e10cSrcweir 89cdf0e10cSrcweir 90cdf0e10cSrcweir 91cdf0e10cSrcweir /** Show the given string at the end of the message area and scroll to make 92cdf0e10cSrcweir it visible. 93cdf0e10cSrcweir */ println(String aMessage)94cdf0e10cSrcweir public static void println (String aMessage) 95cdf0e10cSrcweir { 96cdf0e10cSrcweir println (0, aMessage); 97cdf0e10cSrcweir } 98cdf0e10cSrcweir 99cdf0e10cSrcweir 100cdf0e10cSrcweir 101cdf0e10cSrcweir 102cdf0e10cSrcweir /** Show the given string at the end of the message area and scroll to make 103cdf0e10cSrcweir it visible. 104cdf0e10cSrcweir */ println(int nIndentation, String aMessage)105cdf0e10cSrcweir public static void println (int nIndentation, String aMessage) 106cdf0e10cSrcweir { 107cdf0e10cSrcweir print (nIndentation, aMessage+"\n"); 108cdf0e10cSrcweir } 109cdf0e10cSrcweir 110cdf0e10cSrcweir 111cdf0e10cSrcweir 112cdf0e10cSrcweir paintComponent(Graphics g)113cdf0e10cSrcweir public void paintComponent (Graphics g) 114cdf0e10cSrcweir { 115cdf0e10cSrcweir synchronized (g) 116cdf0e10cSrcweir { 117cdf0e10cSrcweir JScrollBar sb = getVerticalScrollBar(); 118cdf0e10cSrcweir if (sb != null) 119cdf0e10cSrcweir { 120cdf0e10cSrcweir int nScrollBarValue = sb.getMaximum() - sb.getVisibleAmount() - 1; 121cdf0e10cSrcweir sb.setValue (nScrollBarValue); 122cdf0e10cSrcweir } 123cdf0e10cSrcweir super.paintComponent (g); 124cdf0e10cSrcweir } 125cdf0e10cSrcweir } 126cdf0e10cSrcweir 127cdf0e10cSrcweir 128cdf0e10cSrcweir 129cdf0e10cSrcweir 130cdf0e10cSrcweir /** Append the given string to the end of the text and scroll so that it 131cdf0e10cSrcweir becomes visible. This is an internal method. Use one of the static 132cdf0e10cSrcweir and public ones. 133cdf0e10cSrcweir */ printMessage(String aMessage)134cdf0e10cSrcweir private synchronized void printMessage (String aMessage) 135cdf0e10cSrcweir { 136cdf0e10cSrcweir maText.append (aMessage); 137cdf0e10cSrcweir } 138cdf0e10cSrcweir 139cdf0e10cSrcweir 140cdf0e10cSrcweir 141cdf0e10cSrcweir 142cdf0e10cSrcweir private static MessageArea saInstance = null; 143cdf0e10cSrcweir private JTextArea maText; 144cdf0e10cSrcweir } 145