/*
* 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 allows the user to experiment with the two's-complement
* format.
*
* @author Bill Venners
*/
public class InnerInt extends Applet {
private Label binaryField;
private Label hexField;
private Label decimalField;
private int value;
private GrayButton maximumButton = new GrayButton(StringTable.max);
private GrayButton minimumButton = new GrayButton(StringTable.min);
private GrayButton zeroButton = new GrayButton(StringTable.zero);
public void init() {
Panel buttonPanel = new PanelWithInsets(0, 0, 0, 0);
buttonPanel.setLayout(new GridLayout(3, 2, 5, 5));
buttonPanel.add(new GrayButton(StringTable.increment));
buttonPanel.add(new GrayButton(StringTable.decrement));
buttonPanel.add(minimumButton);
buttonPanel.add(maximumButton);
buttonPanel.add(zeroButton);
buttonPanel.add(new GrayButton(StringTable.negate));
zeroButton.disable();
binaryField = new Label("00000000000000000000000000000000");
hexField = new Label("00000000");
decimalField = new Label("0");
Font fieldFont = new Font("TimesRoman", Font.PLAIN, 12);
binaryField.setFont(fieldFont);
hexField.setFont(fieldFont);
decimalField.setFont(fieldFont);
Panel numberPanel = new Panel();
numberPanel.setBackground(Color.white);
numberPanel.setLayout(new GridLayout(3, 1));
Panel binaryPanel = new Panel();
binaryPanel.setLayout(new BorderLayout());
binaryPanel.add("Center", binaryField);
numberPanel.add(binaryPanel);
Panel hexPanel = new Panel();
hexPanel.setLayout(new BorderLayout());
hexPanel.add("Center", hexField);
numberPanel.add(hexPanel);
numberPanel.add(decimalField);
Panel labelPanel = new Panel();
labelPanel.setBackground(Color.white);
labelPanel.setLayout(new GridLayout(3, 1));
Label label = new Label(StringTable.binary, Label.CENTER);
Font labelFont = new Font("Helvetica", Font.ITALIC, 11);
label.setFont(labelFont);
labelPanel.add(label);
label = new Label(StringTable.hex, Label.CENTER);
label.setFont(labelFont);
labelPanel.add(label);
label = new Label(StringTable.decimal, Label.CENTER);
label.setFont(labelFont);
labelPanel.add(label);
Panel dataPanel = new Panel();
dataPanel.setLayout(new BorderLayout());
dataPanel.add("West", labelPanel);
dataPanel.add("Center", numberPanel);
ColoredLabel title = new ColoredLabel(StringTable.title, Label.CENTER, Color.yellow);
title.setFont(new Font("Helvetica", Font.BOLD, 12));
setBackground(Color.blue);
setLayout(new BorderLayout(5, 5));
add("North", title);
add("West", buttonPanel);
add("Center", dataPanel);
}
public boolean action(Event evt, Object arg) {
if (evt.target instanceof Button) {
String bname = (String) arg;
if (bname.equals(StringTable.increment)) {
++value;
}
else if (bname.equals(StringTable.decrement)) {
--value;
}
else if (bname.equals(StringTable.min)) {
value = 0x80000000;
}
else if (bname.equals(StringTable.max)) {
value = 0x7fffffff;
}
else if (bname.equals(StringTable.zero)) {
value = 0;
}
else if (bname.equals(StringTable.negate)) {
value *= -1;
}
UpdateNumberFields();
enableDisableButton(maximumButton, Integer.MAX_VALUE);
enableDisableButton(minimumButton, Integer.MIN_VALUE);
enableDisableButton(zeroButton, 0);
}
return true;
}
void enableDisableButton(Button b, int val) {
if (!b.isEnabled()) {
if (value != val) {
b.enable();
}
} else if (value == val) {
b.disable();
}
}
void UpdateNumberFields() {
decimalField.setText(Integer.toString(value));
int v = value;
StringBuffer buf = new StringBuffer();
for (int i = 0; i < 8; ++i) {
// Get lowest bit
int remainder = v & 0xf;
// Convert bit to a character and insert it into the beginning of the string
switch (remainder) {
case 0:
buf.insert(0, "0");
break;
case 1:
buf.insert(0, "1");
break;
case 2:
buf.insert(0, "2");
break;
case 3:
buf.insert(0, "3");
break;
case 4:
buf.insert(0, "4");
break;
case 5:
buf.insert(0, "5");
break;
case 6:
buf.insert(0, "6");
break;
case 7:
buf.insert(0, "7");
break;
case 8:
buf.insert(0, "8");
break;
case 9:
buf.insert(0, "9");
break;
case 10:
buf.insert(0, "a");
break;
case 11:
buf.insert(0, "b");
break;
case 12:
buf.insert(0, "c");
break;
case 13:
buf.insert(0, "d");
break;
case 14:
buf.insert(0, "e");
break;
case 15:
buf.insert(0, "f");
break;
}
// Shift the int to the right one bit
v >>>= 4;
}
hexField.setText(buf.toString());
v = value;
buf.setLength(0);
for (int i = 0; i < 32; ++i) {
// Get lowest bit
int remainder = v & 0x1;
// Convert bit to a character and insert it into the beginning of the string
if (remainder == 0) {
buf.insert(0, "0");
}
else {
buf.insert(0, "1");
}
// Shift the int to the right one bit
v >>>= 1;
}
binaryField.setText(buf.toString());
}
public Insets insets() {
return new Insets(5, 5, 5, 5);
}
}