import javax.swing.*;
import java.net.URL;
import java.awt.Color;
import java.awt.Dimension;
// for dealing with the start stop button
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
// for dealing with the delay slider
import javax.swing.event.ChangeListener;
import javax.swing.event.ChangeEvent;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
public class DiningPhilosophers extends javax.swing.JApplet
implements ActionListener, ChangeListener {
private JButton stopStartButton = new JButton("start");
// delays can go from 0 to 10,000 milliseconds, initial value is 500
int grabDelay = 500;
private JSlider grabDelaySlider = new JSlider(JSlider.HORIZONTAL, 0, 100, 5);
private JLabel label = new JLabel(" 500 milliseconds");
private JPanel philosopherArea;
public ImageIcon[] imgs = new ImageIcon[3];
Chopstick[] chopsticks = new Chopstick[NUMPHILS];
String[] names = { "Arisduktle" ,
"Dukrates",
"Pythagoduke",
"Duko",
"Dukimedes" };
static final int NUMPHILS = 5;
static final int HUNGRYDUKE = 0;
static final int RIGHTSPOONDUKE = 1;
static final int BOTHSPOONSDUKE = 2;
private int width = 0;
private int height = 0;
private double spacing;
private static final double MARGIN = 10.0f;
private Philosopher[] philosophers = new Philosopher[NUMPHILS];
public void init() {
imgs[HUNGRYDUKE] = new ImageIcon(getURL("images/hungryduke.gif"));
imgs[RIGHTSPOONDUKE] = new ImageIcon(getURL("images/rightspoonduke.gif"));
imgs[BOTHSPOONSDUKE] = new ImageIcon(getURL("images/bothspoonsduke.gif"));
width = imgs[HUNGRYDUKE].getIconWidth() + (int)(MARGIN*2.0);
height = imgs[HUNGRYDUKE].getIconHeight() + (int)(MARGIN*2.0);
spacing = width + MARGIN;
GridBagLayout gridBag = new GridBagLayout();
GridBagConstraints c = new GridBagConstraints();
JPanel contentPane = new JPanel();
contentPane.setLayout(gridBag);
philosopherArea = new JPanel(null);
philosopherArea.setBackground(Color.white);
Dimension preferredSize = createPhilosophersAndChopsticks();
philosopherArea.setBorder(BorderFactory.createCompoundBorder(
BorderFactory.createLoweredBevelBorder(),
BorderFactory.createEmptyBorder(5, 5, 5, 5)
));
philosopherArea.setPreferredSize(preferredSize);
c.fill = GridBagConstraints.BOTH;
c.weighty = 1.0;
c.gridwidth = GridBagConstraints.REMAINDER; //end row
gridBag.setConstraints(philosopherArea, c);
contentPane.add(philosopherArea);
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx = 1.0;
c.weighty = 0.0;
gridBag.setConstraints(stopStartButton, c);
contentPane.add(stopStartButton);
c.gridwidth = GridBagConstraints.RELATIVE; //don't end row
c.weightx = 1.0;
c.weighty = 0.0;
gridBag.setConstraints(grabDelaySlider, c);
contentPane.add(grabDelaySlider);
c.weightx = 0.0;
c.gridwidth = GridBagConstraints.REMAINDER; //end row
gridBag.setConstraints(label, c);
contentPane.add(label);
contentPane.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
setContentPane(contentPane);
stopStartButton.addActionListener(this);
grabDelaySlider.addChangeListener(this);
}
public void actionPerformed(ActionEvent e) {
if (stopStartButton.getText().equals("stop/reset")) {
stopPhilosophers();
stopStartButton.setText("start");
} else if (stopStartButton.getText().equals("start")) {
startPhilosophers();
stopStartButton.setText("stop/reset");
}
}
public void stateChanged(ChangeEvent e) {
JSlider source = (JSlider)e.getSource();
grabDelay = source.getValue()*100;
label.setText(String.valueOf(grabDelay + " milliseconds"));
}
public void startPhilosophers() {
for (int i = 0; i < NUMPHILS; i++)
philosophers[i].philThread.start();
}
public void stopPhilosophers() {
for (int i = 0; i < NUMPHILS; i++)
philosophers[i].philThread.interrupt();
}
public Dimension createPhilosophersAndChopsticks() {
double x, y;
double radius = 80.0;
double centerAdj = 85.0;
double radians;
Dimension preferredSize = new Dimension(0, 0);
/* for a straight line
y = MARGIN;
*/
for (int i = 0; i < NUMPHILS; i++)
chopsticks[i] = new Chopstick();
for (int i = 0; i < NUMPHILS; i++) {
/* for a straight line
x = i * spacing;
*/
radians = i*(2.0 * Math.PI /(double)NUMPHILS);
x = Math.sin(radians) * radius + centerAdj;
y = Math.cos(radians) * radius + centerAdj;
philosophers[i] = new Philosopher(this, i, imgs[HUNGRYDUKE]);
philosophers[i].setBounds((int)x, (int)y, width, height);
philosopherArea.add(philosophers[i]);
if ((int)x > preferredSize.width)
preferredSize.width = (int)x;
if ((int)y > preferredSize.height)
preferredSize.height = (int)y;
}
preferredSize.width += width;
preferredSize.height += height;
return preferredSize;
}
protected URL getURL(String filename) {
URL codeBase = getCodeBase();
URL url = null;
try {
url = new URL(codeBase, filename);
} catch (java.net.MalformedURLException e) {
System.out.println("Couldn't create image: "
+ "badly specified URL");
return null;
}
return url;
}
}
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