Thread: implement mouse listener class

I can't figure out how to implement this class:

public class ViewController extends CircleView {
public ViewController() {
// Register mouse listener
addMouseListener(new java.awt.event.MouseAdapter() {
public void mousePressed(java.awt.event.MouseEvent e) {
CircleModel model = getModel(); // Get model

if (model == null) return;

if (e.isMetaDown())
model.setRadius(model.getRadius() - 5); // Right button
else
model.setRadius(model.getRadius() + 5); // Left button
}
});
}
}


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To this program:



import java.awt.event.*;
import java.awt.*;
import javax.swing.*;

public class CircleController extends JPanel {
private CircleModel model;
private JTextField jtfRadius = new JTextField();
private JButton jbtSend = new JButton("SEND");
private JComboBox jcboFilled = new JComboBox(new Boolean[]{
new Boolean(false), new Boolean(true)});

/** Creates new form CircleController */
public CircleController() {
// Panel to group labels
JPanel panel1 = new JPanel();
panel1.setLayout(new GridLayout(3, 1));
panel1.add(new JLabel("Radius"));
panel1.add(new JLabel(""));
panel1.add(new JLabel("Filled"));

// Panel to group text field, combo box, and another panel
JPanel panel2 = new JPanel();
panel2.setLayout(new GridLayout(3, 1));
panel2.add(jtfRadius);
panel2.add(jbtSend);
panel2.add(jcboFilled);

setLayout(new BorderLayout());
add(panel1, BorderLayout.WEST);
add(panel2, BorderLayout.CENTER);

// Register listeners

jbtSend.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (model == null) return; // No model associated yet. Do nothing
model.setRadius(new Double(jtfRadius.getText()).doubleValue());
}
});

jcboFilled.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (model == null) return; // No model associated yet. Do nothing
model.setFilled(
((Boolean)jcboFilled.getSelectedItem()).booleanVal ue());
}
});
}

public void setModel(CircleModel newModel) {
model = newModel;
}

public CircleModel getModel() {
return model;
}
}


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import java.awt.event.*;
import java.util.*;

public class CircleModel {
/** Property radius. */
private double radius = 20;

/** Property filled. */
private boolean filled;

/** Property color. */
private java.awt.Color color;

/** Utility field used by event firing mechanism. */
private ArrayList<ActionListener> actionListenerList;

public double getRadius() {
return radius;
}

public void setRadius(double radius) {
this.radius = radius;

// Notify the listener for the change on radius
processEvent(
new ActionEvent(this, ActionEvent.ACTION_PERFORMED,"radius"));
}

public boolean isFilled() {
return filled;
}

public void setFilled(boolean filled) {
this.filled = filled;

// Notify the listener for the change on filled
processEvent(
new ActionEvent(this, ActionEvent.ACTION_PERFORMED, "filled"));
}

public java.awt.Color getColor() {
return color;
}

public void setColor(java.awt.Color color) {
this.color = color;

// Notify the listener for the change on color
processEvent(
new ActionEvent(this, ActionEvent.ACTION_PERFORMED, "color"));
}

/** Register an action event listener */
public synchronized void addActionListener(ActionListener l) {
if (actionListenerList == null)
actionListenerList = new ArrayList<ActionListener>();

actionListenerList.add(l);
}

/** Remove an action event listener */
public synchronized void removeActionListener(ActionListener l) {
if (actionListenerList != null && actionListenerList.contains(l))
actionListenerList.remove(l);
}

/** Fire TickEvent */
private void processEvent(ActionEvent e) {
ArrayList list;

synchronized (this) {
if (actionListenerList == null) return;
list = (ArrayList)actionListenerList.clone();
}

for (int i = 0; i < list.size(); i++) {
ActionListener listener = (ActionListener)list.get(i);
listener.actionPerformed(e);
}
}
}


*********************

import java.awt.*;
import java.awt.event.*;

public class CircleView extends javax.swing.JPanel
implements ActionListener {
private CircleModel model;

public void actionPerformed(ActionEvent actionEvent) {
repaint();
}

/** Set a model */
public void setModel(CircleModel newModel) {
model = newModel;

if (model != null)
// Register the view as listener for the model
model.addActionListener(this);

repaint();
}

public CircleModel getModel() {
return model;
}

public void paintComponent(Graphics g) {
super.paintComponent(g);

if (model == null) return;

g.setColor(model.getColor());

int xCenter = getWidth() / 2;
int yCenter = getHeight() / 2;
int radius = (int)model.getRadius();

if (model.isFilled()) {
g.fillOval(xCenter - radius, yCenter - radius,
2 * radius, 2 * radius);
}
else {
g.drawOval(xCenter - radius, yCenter - radius,
2 * radius, 2 * radius);
}
}
}

**********

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MVCDemo extends JApplet {
private JButton jbtController = new JButton("Show Controller");
private JButton jbtView = new JButton("Show View");
private CircleModel model = new CircleModel();

public MVCDemo() {
setLayout(new FlowLayout());
add(jbtController);
add(jbtView);

jbtController.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JFrame frame = new JFrame("Controller");
CircleController controller = new CircleController();
controller.setModel(model);
frame.add(controller);
frame.setSize(200, 200);
frame.setLocation(200, 200);
frame.setVisible(true);
}
});

jbtView.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JFrame frame = new JFrame("View");
CircleView view = new CircleView();
view.setModel(model);
frame.add(view);
frame.setSize(500, 200);
frame.setLocation(200, 200);
frame.setVisible(true);
}
});
}

public static void main(String[] args) {
MVCDemo applet = new MVCDemo();
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOS E);
frame.setTitle("MVCDemo");
frame.getContentPane().add(applet, BorderLayout.CENTER);
frame.setSize(400, 320);
frame.setVisible(true);
}
}

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Thanks for helping!