Separator pada JComboBox

frameComboSeparator.java

import java.awt.EventQueue;
import java.util.Vector;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSeparator;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.ImageIcon;

public class frameComboSeparator extends JFrame {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private JPanel contentPane;
	@SuppressWarnings("rawtypes")
	private JComboBox comboBox;
	private JLabel lblWall;
	private JLabel lblIcon;

	/**
	 * Create the frame.
	 */
	@SuppressWarnings({ "rawtypes", "unchecked" })
	public frameComboSeparator()
	{
		setTitle("ComboBox Separator");
		setResizable(false);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setBounds(100, 100, 593, 394);
		contentPane = new JPanel();
		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
		setContentPane(contentPane);
		contentPane.setLayout(null);
		
		Vector v = new Vector();
		v.addElement("Nasi Goreng");
		v.addElement("Mie Goreng");
		v.addElement("Pecel Lele");
		v.addElement("Gudeg");
		v.addElement(new JSeparator());
		v.addElement("Es Teh Manis");
		v.addElement("Es Jeruk");
		v.addElement("Susu Coklat");
		v.addElement(new JSeparator());
		v.addElement("Ice Cream");
		comboBox = new SeparatorComboBox(v);
		comboBox.setBounds(86, 128, 220, 33);
		contentPane.add(comboBox);
		
		lblIcon = new JLabel("");
		lblIcon.setIcon(new ImageIcon(frameComboSeparator.class.getResource("/comboBoxSeparator/pencil.png")));
		lblIcon.setBounds(407, 68, 152, 141);
		contentPane.add(lblIcon);
		
		lblWall = new JLabel("");
		lblWall.setIcon(new ImageIcon(frameComboSeparator.class.getResource("/comboBoxSeparator/wall.jpg")));
		lblWall.setBounds(0, -12, 591, 374);
		contentPane.add(lblWall);
		setLocationRelativeTo(null);
	}
	
	/**
	 * Launch the application.
	 */
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				try {
					//Nimbus Look and Feel
					UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
					//GTK Look and Feel
					/*for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) 
					{
					    if ("com.sun.java.swing.plaf.gtk.GTKLookAndFeel".equals(info.getClassName())) 
					    {   
					       try 
					       {
							javax.swing.UIManager.setLookAndFeel(info.getClassName());
					       } 
					       catch (ClassNotFoundException e) 
					       {
							// TODO Auto-generated catch block
							e.printStackTrace();
					       } 
					       catch (InstantiationException e) 
					       {
							// TODO Auto-generated catch block
							e.printStackTrace();
					       } 
					       catch (IllegalAccessException e) 
					       {
							// TODO Auto-generated catch block
							e.printStackTrace();
					       } 
					       catch (UnsupportedLookAndFeelException e)
					       {
							// TODO Auto-generated catch block
							e.printStackTrace();
					       }
					       break;
					     } 
					}*/
					frameComboSeparator frame = new frameComboSeparator();
					frame.setVisible(true);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
	}
}

SeparatorComboBox.java

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.plaf.basic.*;

@SuppressWarnings({ "serial", "rawtypes" })
public class SeparatorComboBox extends JComboBox implements KeyListener
{

	private boolean released = true;
	private boolean separatorSelected = false;

	public SeparatorComboBox()
	{
		super();
		init();
	}
	@SuppressWarnings("unchecked")
	public SeparatorComboBox(ComboBoxModel model)
	{
		super(model);
		init();
	}

	@SuppressWarnings("unchecked")
	public SeparatorComboBox(Object[] items)
	{
		super(items);
		init();
	}

	@SuppressWarnings("unchecked")
	public SeparatorComboBox(Vector<?> items)
	{
		super(items);
		init();
	}

	@SuppressWarnings("unchecked")
	private void init()
	{
		setRenderer( new SeparatorRenderer() );
		addKeyListener(this);
	}
	@Override
	public void setSelectedIndex(int index)
	{
		Object value = getItemAt(index);
		if (value instanceof JSeparator)
		{
			if (released)
			{
				separatorSelected = true;
				return;
			}

			int current = getSelectedIndex();
			index += (index > current) ? 1 : -1;

			if (index == -1 || index >= dataModel.getSize())
				return;
		}

		super.setSelectedIndex(index);
	}
	@Override
	public void setPopupVisible(boolean visible)
	{
		if (separatorSelected)
		{
			separatorSelected = false;
			return;
		}

		super.setPopupVisible(visible);
	}
	public void keyPressed(KeyEvent e)
	{
		released = false;
	}

	public void keyReleased(KeyEvent e)
	{
		released = true;
	}

	public void keyTyped(KeyEvent e) {}

	class SeparatorRenderer extends BasicComboBoxRenderer
	{
		public Component getListCellRendererComponent(JList list, Object value,
			int index, boolean isSelected, boolean cellHasFocus)
		{
			super.getListCellRendererComponent(
				list, value, index, isSelected, cellHasFocus);

			if (value instanceof JSeparator)
				return (JSeparator)value;

			return this;
		}
	}
}