1*b1cdbd2cSJim Jagielski /************************************************************** 2*b1cdbd2cSJim Jagielski * 3*b1cdbd2cSJim Jagielski * Licensed to the Apache Software Foundation (ASF) under one 4*b1cdbd2cSJim Jagielski * or more contributor license agreements. See the NOTICE file 5*b1cdbd2cSJim Jagielski * distributed with this work for additional information 6*b1cdbd2cSJim Jagielski * regarding copyright ownership. The ASF licenses this file 7*b1cdbd2cSJim Jagielski * to you under the Apache License, Version 2.0 (the 8*b1cdbd2cSJim Jagielski * "License"); you may not use this file except in compliance 9*b1cdbd2cSJim Jagielski * with the License. You may obtain a copy of the License at 10*b1cdbd2cSJim Jagielski * 11*b1cdbd2cSJim Jagielski * http://www.apache.org/licenses/LICENSE-2.0 12*b1cdbd2cSJim Jagielski * 13*b1cdbd2cSJim Jagielski * Unless required by applicable law or agreed to in writing, 14*b1cdbd2cSJim Jagielski * software distributed under the License is distributed on an 15*b1cdbd2cSJim Jagielski * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16*b1cdbd2cSJim Jagielski * KIND, either express or implied. See the License for the 17*b1cdbd2cSJim Jagielski * specific language governing permissions and limitations 18*b1cdbd2cSJim Jagielski * under the License. 19*b1cdbd2cSJim Jagielski * 20*b1cdbd2cSJim Jagielski *************************************************************/ 21*b1cdbd2cSJim Jagielski 22*b1cdbd2cSJim Jagielski 23*b1cdbd2cSJim Jagielski 24*b1cdbd2cSJim Jagielski import java.awt.Font; 25*b1cdbd2cSJim Jagielski import java.awt.Rectangle; 26*b1cdbd2cSJim Jagielski import java.awt.Color; 27*b1cdbd2cSJim Jagielski import java.awt.Graphics; 28*b1cdbd2cSJim Jagielski import javax.swing.JScrollPane; 29*b1cdbd2cSJim Jagielski import javax.swing.JTextArea; 30*b1cdbd2cSJim Jagielski import javax.swing.JScrollBar; 31*b1cdbd2cSJim Jagielski 32*b1cdbd2cSJim Jagielski 33*b1cdbd2cSJim Jagielski 34*b1cdbd2cSJim Jagielski /** A message area displays text in a scrollable text widget. It is a 35*b1cdbd2cSJim Jagielski singleton. Other objects can access it directly to display messages. 36*b1cdbd2cSJim Jagielski */ 37*b1cdbd2cSJim Jagielski public class MessageArea 38*b1cdbd2cSJim Jagielski extends JScrollPane 39*b1cdbd2cSJim Jagielski { Instance()40*b1cdbd2cSJim Jagielski public static synchronized MessageArea Instance () 41*b1cdbd2cSJim Jagielski { 42*b1cdbd2cSJim Jagielski if (saInstance == null) 43*b1cdbd2cSJim Jagielski saInstance = new MessageArea (); 44*b1cdbd2cSJim Jagielski return saInstance; 45*b1cdbd2cSJim Jagielski } 46*b1cdbd2cSJim Jagielski 47*b1cdbd2cSJim Jagielski 48*b1cdbd2cSJim Jagielski 49*b1cdbd2cSJim Jagielski 50*b1cdbd2cSJim Jagielski /** Create a new message area. This method is private because the class is 51*b1cdbd2cSJim Jagielski a singleton and may therefore not be instanciated from the outside. 52*b1cdbd2cSJim Jagielski */ MessageArea()53*b1cdbd2cSJim Jagielski private MessageArea () 54*b1cdbd2cSJim Jagielski { 55*b1cdbd2cSJim Jagielski maText = new JTextArea(); 56*b1cdbd2cSJim Jagielski maText.setBackground (new Color (255,250,240)); 57*b1cdbd2cSJim Jagielski maText.setFont (new Font ("Helvetica", Font.PLAIN, 9)); 58*b1cdbd2cSJim Jagielski setViewportView (maText); 59*b1cdbd2cSJim Jagielski setVerticalScrollBarPolicy (JScrollPane.VERTICAL_SCROLLBAR_ALWAYS); 60*b1cdbd2cSJim Jagielski setHorizontalScrollBarPolicy (JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS); 61*b1cdbd2cSJim Jagielski 62*b1cdbd2cSJim Jagielski printMessage ( 63*b1cdbd2cSJim Jagielski "class path is " + System.getProperty ("java.class.path") + "\n"); 64*b1cdbd2cSJim Jagielski } 65*b1cdbd2cSJim Jagielski 66*b1cdbd2cSJim Jagielski 67*b1cdbd2cSJim Jagielski 68*b1cdbd2cSJim Jagielski 69*b1cdbd2cSJim Jagielski /** Show the given string at the end of the message area and scroll to make 70*b1cdbd2cSJim Jagielski it visible. 71*b1cdbd2cSJim Jagielski */ print(String aMessage)72*b1cdbd2cSJim Jagielski public static synchronized void print (String aMessage) 73*b1cdbd2cSJim Jagielski { 74*b1cdbd2cSJim Jagielski Instance().printMessage(aMessage); 75*b1cdbd2cSJim Jagielski } 76*b1cdbd2cSJim Jagielski 77*b1cdbd2cSJim Jagielski 78*b1cdbd2cSJim Jagielski 79*b1cdbd2cSJim Jagielski 80*b1cdbd2cSJim Jagielski /** Show the given string at the end of the message area and scroll to make 81*b1cdbd2cSJim Jagielski it visible. 82*b1cdbd2cSJim Jagielski */ println(String aMessage)83*b1cdbd2cSJim Jagielski public static void println (String aMessage) 84*b1cdbd2cSJim Jagielski { 85*b1cdbd2cSJim Jagielski Instance().printMessage (aMessage+"\n"); 86*b1cdbd2cSJim Jagielski } 87*b1cdbd2cSJim Jagielski 88*b1cdbd2cSJim Jagielski paintComponent(Graphics g)89*b1cdbd2cSJim Jagielski public void paintComponent (Graphics g) 90*b1cdbd2cSJim Jagielski { 91*b1cdbd2cSJim Jagielski // Synchronize with the graphics object to prevent paint problems. 92*b1cdbd2cSJim Jagielski // Remember that this is not done by Swing itself. 93*b1cdbd2cSJim Jagielski synchronized (g) 94*b1cdbd2cSJim Jagielski { 95*b1cdbd2cSJim Jagielski JScrollBar sb = getVerticalScrollBar(); 96*b1cdbd2cSJim Jagielski if (sb != null) 97*b1cdbd2cSJim Jagielski { 98*b1cdbd2cSJim Jagielski int nScrollBarValue = sb.getMaximum() - sb.getVisibleAmount() - 1; 99*b1cdbd2cSJim Jagielski sb.setValue (nScrollBarValue); 100*b1cdbd2cSJim Jagielski } 101*b1cdbd2cSJim Jagielski super.paintComponent (g); 102*b1cdbd2cSJim Jagielski } 103*b1cdbd2cSJim Jagielski } 104*b1cdbd2cSJim Jagielski 105*b1cdbd2cSJim Jagielski 106*b1cdbd2cSJim Jagielski 107*b1cdbd2cSJim Jagielski 108*b1cdbd2cSJim Jagielski /** Append the given string to the end of the text and scroll so that it 109*b1cdbd2cSJim Jagielski becomes visible. This is an internal method. Use one of the static 110*b1cdbd2cSJim Jagielski and public ones. 111*b1cdbd2cSJim Jagielski */ printMessage(String aMessage)112*b1cdbd2cSJim Jagielski private synchronized void printMessage (String aMessage) 113*b1cdbd2cSJim Jagielski { 114*b1cdbd2cSJim Jagielski maText.append (aMessage); 115*b1cdbd2cSJim Jagielski } 116*b1cdbd2cSJim Jagielski 117*b1cdbd2cSJim Jagielski 118*b1cdbd2cSJim Jagielski 119*b1cdbd2cSJim Jagielski 120*b1cdbd2cSJim Jagielski private static MessageArea saInstance = null; 121*b1cdbd2cSJim Jagielski private JTextArea maText; 122*b1cdbd2cSJim Jagielski } 123