12.1.2 Klasse block2.BinaerIntApplet

Das Applet

Starten des Applets als Hauptprogramm

Laden Sie die jar Datei Kurs1Applet.jar.

Die Anwendung kann von der Kommandozeile mit dem folgenden Kommando gestartet werden.

java -cp Kurs1Applet.jar block2.BinaerIntApplet

Die Datei Kurs1Applet.jar muss im gleichen Verzeichnis sein 

Der Quellcode

package block2;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.BoxLayout;
import javax.swing.ButtonGroup;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTextField;
/**
*
* @author sschneid
* @version 1.2
*
* Copyright (c) 2013, Dr. Stefan Schneider, schneider4me.de
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation are those
* of the authors and should not be interpreted as representing official policies,
* either expressed or implied, of the FreeBSD Project.
*/
public class BinaerIntApplet extends JApplet implements ActionListener {
private JTextField eingabeText;
private JButton enterButton;
private JRadioButton byteButton;
private JRadioButton charButton;
private JRadioButton shortButton;
private JRadioButton intButton;
private JRadioButton longButton;
private int[] bits;
private String eingabeWert = "0";
private String typeTxt = "int";
/**
* Konstruktor der Klasse. Hier werden alle graphischen
* Objekte angeliegt.
*/
public BinaerIntApplet() {
JPanel buttonPanel;
JFrame f;
Container co;
bits = new int[32];
// Erzeugen der Buttons und Texteingabefeld
JLabel eingabeLabel = new JLabel("Eingabewert: ");
eingabeText = new JTextField(eingabeWert);
eingabeText.setPreferredSize(new Dimension(100, 20));
enterButton = new JButton("Enter");
enterButton.addActionListener(this);
byteButton = new JRadioButton("byte");
byteButton.setMnemonic(KeyEvent.VK_B);
charButton = new JRadioButton("char");
charButton.setMnemonic(KeyEvent.VK_C);
shortButton = new JRadioButton("short");
shortButton.setMnemonic(KeyEvent.VK_S);
intButton = new JRadioButton("int");
intButton.setMnemonic(KeyEvent.VK_I);
intButton.setSelected(true);
longButton = new JRadioButton("long");
longButton.setMnemonic(KeyEvent.VK_L);
ButtonGroup intType = new ButtonGroup();
intType.add(byteButton);
intType.add(charButton);
intType.add(shortButton);
intType.add(intButton);
intType.add(longButton);
JPanel typePanel = new JPanel();
typePanel.setLayout(new BoxLayout(typePanel, BoxLayout.Y_AXIS));
typePanel.add(byteButton);
typePanel.add(charButton);
typePanel.add(shortButton);
typePanel.add(intButton);
typePanel.add(longButton);
// Einfügen der drei Komponenten in ein Panel
// Das Gridlayout führt zum Strecken der drei Komponenten
buttonPanel = new JPanel();
buttonPanel.add(eingabeLabel);
buttonPanel.add(eingabeText);
buttonPanel.add(enterButton);
JPanel centerPanel=new JPanel();
centerPanel.setSize(500, 500);
Container myPane = getContentPane();
myPane.add(buttonPanel, BorderLayout.SOUTH);
myPane.add(typePanel, BorderLayout.EAST);
myPane.add(centerPanel, BorderLayout.CENTER);
}
/**
* Dies Methode erlaubt das Malen der Vektorgraphik
* auf dem Hintergrund der graphischen Komponente
* @param g
*/
@Override
public void paint(Graphics g) {
super.paint(g);
g.setColor(Color.blue);
g.drawString(typeTxt + ", " +bits.length + " bits, "
+eingabeWert +": ", 20, 25);

int rows=0;
int cols=0;
for (int i = (bits.length - 1); i >= 0; i--) {
if (i == bits.length - 1) {
g.setColor(Color.red);
} else {
g.setColor(Color.black);
}
g.drawString(Integer.toString(bits[i]),
20 + 10 * cols,
50+ 25*rows);
if (cols!=15) cols++;
else {cols=0; rows++;}
}
}
/**
* Diese Methode wird nach einer Eingabe aufgerufen.
* Sie dekodiert die Eingabe des Benutzers
* @param e
*/
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
try {
eingabeWert = eingabeText.getText();
if (source == enterButton) { //enter Button aufgerufen
if (byteButton.isSelected()) {
typeTxt = "byte";
byte wert = Byte.parseByte(eingabeWert);
bits = decode(wert);
}
if (shortButton.isSelected()) {
typeTxt = "short";
short wert = Short.parseShort(eingabeWert);
bits = decode(wert);
}
if (charButton.isSelected()) {
typeTxt = "char";
char wert = eingabeWert.charAt(0);
bits = decode(wert);
eingabeWert = eingabeWert.substring(0, 1);
}
if (intButton.isSelected()) {
typeTxt = "int";
int wert = Integer.parseInt(eingabeWert);
bits = decode(wert);
}
if (longButton.isSelected()) {
typeTxt = "long";
long wert = Long.parseLong(eingabeWert);
bits = decode(wert);
}
}
} catch (java.lang.NumberFormatException ex) {
// Fehlerbehandlung bei fehlerhafter Eingabe
eingabeWert="Fehler";
eingabeText.setText(eingabeWert);
bits = decode((byte)0);
}
repaint();
}
public static int[] decode(short s) {
int size = 16;
int[] stellen = new int[size];
for (int i = 0; i < size; i++) {
stellen[i] = (1 & s);
s >>>= 1;
}
return stellen;
}
public static int[] decode(byte s) {
int size = 8;
int[] stellen = new int[size];
for (int i = 0; i < size; i++) {
stellen[i] = (1 & s);
s >>>= 1;
}
return stellen;
}

public static int[] decode(char s) {
return decode((short) s);
}

public static int[] decode(int s) {
int size = 32;
int[] stellen = new int[size];
for (int i = 0; i < size; i++) {
stellen[i] = (1 & s);
s >>>= 1;
}
return stellen;
}
public static int[] decode(long s) {
int size = 64;
int[] stellen = new int[size];
for (int i = 0; i < size; i++) {
stellen[i] = (int) (1 & s);
s >>>= 1;
}
return stellen;
}
/**
* Starten der Anwendung als eigenständiges Programm
*
* @param args
*/
public static void main(String[] args) {
// Es wird ein JFrame benötigt, in das das Applet als Komponente
// gesteckt wird.
JFrame f = new JFrame("BinaerIntApplet-Standalone");
f.add(new block2.BinaerIntApplet());
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.pack();
f.setVisible(true);
}
/**
* Berechnen eines neuen Tupels von Kubikwurzel
* und dazu gehöriger dritter Potenz
*/
}