/* * Copyright (c) 1996-1999 Bill Venners. All Rights Reserved. * * This Java source file is part of the Interactive Illustrations Web * Site, which is delivered in the applets directory of the CD-ROM * that accompanies the book "Inside the Java 2 Virtual Machine" by Bill * Venners, published by McGraw-Hill, 1999, ISBN: 0-07-135093-4. This * source file is provided for evaluation purposes only, but you can * redistribute it under certain conditions, described in the full * copyright notice below. * * Full Copyright Notice: * * All the web pages and Java applets delivered in the applets * directory of the CD-ROM, consisting of ".html," ".gif," ".class," * and ".java" files, are copyrighted (c) 1996-1999 by Bill * Venners, and all rights are reserved. This material may be copied * and placed on any commercial or non-commercial web server on any * network (including the internet) provided that the following * guidelines are followed: * * a. All the web pages and Java Applets (".html," ".gif," ".class," * and ".java" files), including the source code, that are delivered * in the applets directory of the CD-ROM that * accompanies the book must be published together on the same web * site. * * b. All the web pages and Java Applets (".html," ".gif," ".class," * and ".java" files) must be published "as is" and may not be altered * in any way. * * c. All use and access to this web site must be free, and no fees * can be charged to view these materials, unless express written * permission is obtained from Bill Venners. * * d. The web pages and Java Applets may not be distributed on any * media, other than a web server on a network, and may not accompany * any book or publication. * * BILL VENNERS MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE * SUITABILITY OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING * BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, * FITNESS FOR PARTICULAR PURPOSE, OR NON-INFRINGEMENT. BILL VENNERS * SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY A LICENSEE AS A * RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS * DERIVATIVES. */ import java.awt.*; import java.applet.*; /** * This applet simulates a compacting, mark-and-sweep * garbage-collected heap inside a Java Virtual Machine. * * @author Bill Venners */ public class HeapOfFish extends Applet { private GCHeap gcHeap = new GCHeap(15, 50); private LocalVariables localVars = new LocalVariables(); private HeapOfFishControlPanel controlPanel = new HeapOfFishControlPanel(); private HeapOfFishCanvases canvases = new HeapOfFishCanvases(gcHeap, localVars, controlPanel.getTextArea()); private String currentHeapOfFishMode = HeapOfFishStrings.swim; public void init() { super.init(); setBackground(Color.cyan); setLayout(new BorderLayout(5, 5)); add("North", new ColoredLabel("HEAP OF FISH", Label.CENTER, Color.white)); add("South", controlPanel); add("Center", canvases); } public void start() { canvases.start(); } public void stop() { canvases.stop(); } public Insets insets() { return new Insets(5, 5, 5, 5); } public boolean action(Event evt, Object arg) { if (evt.target instanceof Checkbox) { Checkbox cb = (Checkbox) evt.target; String cbname = cb.getLabel(); if (cbname.equals(HeapOfFishStrings.allocateFish)) { if (!currentHeapOfFishMode.equals(HeapOfFishStrings.allocateFish)) { controlPanel.getTextArea().setText(HeapOfFishStrings.allocateFishInstructions); canvases.setMode(HeapOfFishStrings.allocateFish); } } else if (cbname.equals(HeapOfFishStrings.assignReferences)) { if (!currentHeapOfFishMode.equals(HeapOfFishStrings.assignReferences)) { canvases.setMode(HeapOfFishStrings.assignReferences); } } else if (cbname.equals(HeapOfFishStrings.garbageCollect)) { if (!currentHeapOfFishMode.equals(HeapOfFishStrings.garbageCollect)) { canvases.setMode(HeapOfFishStrings.garbageCollect); } } else if (cbname.equals(HeapOfFishStrings.compactHeap)) { if (!currentHeapOfFishMode.equals(HeapOfFishStrings.compactHeap)) { controlPanel.getTextArea().setText(HeapOfFishStrings.compactHeapInstructions); canvases.setMode(HeapOfFishStrings.compactHeap); } } else if (cbname.equals(HeapOfFishStrings.swim)) { if (!currentHeapOfFishMode.equals(HeapOfFishStrings.swim)) { controlPanel.getTextArea().setText(""); canvases.setMode(HeapOfFishStrings.swim); } } currentHeapOfFishMode = cbname; canvases.repaint(); } return true; } }