Combobox (Editor) and IP Address

Question

Hi,
I wish to display the structure of and IP address in my ComboBox (editable) and display plus forcing user to input only digits for those 4 parts of the IP address.
So display of a blank IP initially will be
[    .    .    .    ]I was thinking of creating an editor, but haven't got a clue how those methods could be implemented to achieve the above.
public interface ComboBoxEditor {
  /** Return the component that should be added to the tree hierarchy for
    * this editor
  public Component getEditorComponent();
  /** Set the item that should be edited. Cancel any editing if necessary **/
  public void setItem(Object anObject);
  /** Return the edited item **/
  public Object getItem();
  /** Ask the editor to start editing and to select everything **/
  public void selectAll();   
  /** Add an ActionListener. An action event is generated when the edited item changes **/
  public void addActionListener(ActionListener l);
  /** Remove an ActionListener **/
  public void removeActionListener(ActionListener l);
}Do you know how this could be achieve?
Thanks in advance.

Answer 1

Hi
This sample may helps you...
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
* CustomComboBoxDemo.java is a 1.4 application that uses the following files:
*   images/Bird.gif
*   images/Cat.gif
*   images/Dog.gif
*   images/Rabbit.gif
*   images/Pig.gif
public class CustomComboBoxDemo extends JPanel {
    ImageIcon[] images;
    String[] petStrings = {"Bird", "Cat", "Dog", "Rabbit", "Pig"};
     * Despite its use of EmptyBorder, this panel makes a fine content
     * pane because the empty border just increases the panel's size
     * and is "painted" on top of the panel's normal background.  In
     * other words, the JPanel fills its entire background if it's
     * opaque (which it is by default); adding a border doesn't change
     * that.
    public CustomComboBoxDemo() {
        super(new BorderLayout());
        //Load the pet images and create an array of indexes.
        images = new ImageIcon[petStrings.length];
        Integer[] intArray = new Integer[petStrings.length];
        for (int i = 0; i < petStrings.length; i++) {
            intArray[i] = new Integer(i);
            images[i] = createImageIcon("images/" + petStrings[i] + ".gif");
            if (images[i] != null) {
                images.setDescription(petStrings[i]);
//Create the combo box.
JComboBox petList = new JComboBox(intArray);
ComboBoxRenderer renderer= new ComboBoxRenderer();
renderer.setPreferredSize(new Dimension(200, 130));
petList.setRenderer(renderer);
petList.setMaximumRowCount(3);
//Lay out the demo.
add(petList, BorderLayout.PAGE_START);
setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
/** Returns an ImageIcon, or null if the path was invalid. */
protected static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = CustomComboBoxDemo.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
private static void createAndShowGUI() {
//Make sure we have nice window decorations.
JFrame.setDefaultLookAndFeelDecorated(true);
//Create and set up the window.
JFrame frame = new JFrame("CustomComboBoxDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
JComponent newContentPane = new CustomComboBoxDemo();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setVisible(true);
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
class ComboBoxRenderer extends JLabel
implements ListCellRenderer {
private Font uhOhFont;
public ComboBoxRenderer() {
setOpaque(true);
setHorizontalAlignment(CENTER);
setVerticalAlignment(CENTER);
* This method finds the image and text corresponding
* to the selected value and returns the label, set up
* to display the text and image.
public Component getListCellRendererComponent(
JList list,
Object value,
int index,
boolean isSelected,
boolean cellHasFocus) {
//Get the selected index. (The index param isn't
//always valid, so just use the value.)
int selectedIndex = ((Integer)value).intValue();
if (isSelected) {
setBackground(list.getSelectionBackground());
setForeground(list.getSelectionForeground());
} else {
setBackground(list.getBackground());
setForeground(list.getForeground());
//Set the icon and text. If icon was null, say so.
ImageIcon icon = images[selectedIndex];
String pet = petStrings[selectedIndex];
setIcon(icon);
if (icon != null) {
setText(pet);
setFont(list.getFont());
} else {
setUhOhText(pet + " (no image available)",
list.getFont());
return this;
//Set the font and text when no image was found.
protected void setUhOhText(String uhOhText, Font normalFont) {
if (uhOhFont == null) { //lazily create this font
uhOhFont = normalFont.deriveFont(Font.ITALIC);
setFont(uhOhFont);
setText(uhOhText);