Painting JLIst cell part 1

Question

Hi,
I previously post a question on the forum but I believe my question may be confused, so I would like to rephrase my problem again.
I need to come up with a program to monitor products/goods for my operation.
The program should let me enter more products or delete them, one at a time.
Once entered, a product should be highlighted or painted in “Red” or default color, indicating it needs attention.
I want to enter several products before coming to take a look at individual product though I need to enter more products during manufacture operation.
Once I finish considering a product in the list, I would like to toggle it to change the color to normal, indicating this product does not need attention.
During manufacture operation, should the problem arise with any product(s), I would like to toggle the product(s) background to Red again, indicating they needs attention again.
I found that ListDemo.java in the Sun (SDN) website is very close to my need but I need help to paint/highlight the background once I select the product.
Right now, if I leave the previous selection for the new selection, the previous one will lose the hightlight. I need them to stay permanent no matter where I click until I re-elect it.
I post part 2 of this topic, containing only java code I borrowed from Sun, just want to make myself clear. Please see part 2 next to this one.

Answer 1

Sorry for the inconvenience, but I got error message for posting message that is more than 7,500. Here is the code I borrowed from Sun website:
Part 1:
package components;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
/* ListDemo.java requires no other files. */
public class ListDemo extends JPanel
implements ListSelectionListener {
private JList list;
private DefaultListModel listModel;
private static final String hireString = "Hire";
private static final String fireString = "Fire";
private JButton fireButton;
private JTextField employeeName;
public ListDemo() {
super(new BorderLayout());
listModel = new DefaultListModel();
listModel.addElement("Debbie Scott");
listModel.addElement("Scott Hommel");
listModel.addElement("Sharon Zakhour");
//Create the list and put it in a scroll pane.
list = new JList(listModel);
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
list.setSelectedIndex(0);
list.addListSelectionListener(this);
list.setVisibleRowCount(5);
JScrollPane listScrollPane = new JScrollPane(list);
JButton hireButton = new JButton(hireString);
HireListener hireListener = new HireListener(hireButton);
hireButton.setActionCommand(hireString);
hireButton.addActionListener(hireListener);
hireButton.setEnabled(false);
fireButton = new JButton(fireString);
fireButton.setActionCommand(fireString);
fireButton.addActionListener(new FireListener());
employeeName = new JTextField(10);
employeeName.addActionListener(hireListener);
employeeName.getDocument().addDocumentListener(hireListener);
String name = listModel.getElementAt(
list.getSelectedIndex()).toString();
//Create a panel that uses BoxLayout.
JPanel buttonPane = new JPanel();
buttonPane.setLayout(new BoxLayout(buttonPane,
BoxLayout.LINE_AXIS));
buttonPane.add(fireButton);
buttonPane.add(Box.createHorizontalStrut(5));
buttonPane.add(new JSeparator(SwingConstants.VERTICAL));
buttonPane.add(Box.createHorizontalStrut(5));
buttonPane.add(employeeName);
buttonPane.add(hireButton);
buttonPane.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
add(listScrollPane, BorderLayout.CENTER);
add(buttonPane, BorderLayout.PAGE_END);
class FireListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
//This method can be called only if
//there's a valid selection
//so go ahead and remove whatever's selected.
int index = list.getSelectedIndex();
listModel.remove(index);
int size = listModel.getSize();
if (size == 0) { //Nobody's left, disable firing.
fireButton.setEnabled(false);
} else { //Select an index.
if (index == listModel.getSize()) {
//removed item in last position
index--;
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
//This listener is shared by the text field and the hire button.
class HireListener implements ActionListener, DocumentListener {
private boolean alreadyEnabled = false;
private JButton button;
public HireListener(JButton button) {
this.button = button;
//Required by ActionListener.
public void actionPerformed(ActionEvent e) {
String name = employeeName.getText();
//User didn't type in a unique name...
if (name.equals("") || alreadyInList(name)) {
Toolkit.getDefaultToolkit().beep();
employeeName.requestFocusInWindow();
employeeName.selectAll();
return;
int index = list.getSelectedIndex(); //get selected index
if (index == -1) { //no selection, so insert at beginning
index = 0;
} else {           //add after the selected item
index++;
listModel.insertElementAt(employeeName.getText(), index);
//If we just wanted to add to the end, we'd do this:
//listModel.addElement(employeeName.getText());
//Reset the text field.
employeeName.requestFocusInWindow();
employeeName.setText("");
//Select the new item and make it visible.
list.setSelectedIndex(index);
list.ensureIndexIsVisible(index);
}