Icons in JList (Applet)

Question

is it possible to display icons next to text data in a JList? (For use from with in an un-signed Applet)
do I have to jar it? or can I have it grab the images from the webserver it loaded from?
thanx.

Answer 1

Yep, you can customise your lists (and other components) to use icons alongside the text.
Take a look at:
http://java.sun.com/developer/technicalArticles/InnerWorkings/customjlist/
and
http://java.sun.com/j2se/1.4.2/docs/api/javax/swing/JList.html
for a few examples.
Basically, you create a ListCellRenderer and attach it to your JList. This is used as a kind of "rubber stamp", that's reconfigured for every line of the list and then stamped down to draw it.
You can build up quite complex renderers, but here's an example of a very simple one, just to get you going:
     class IconListCellRenderer extends DefaultListCellRenderer {
          private ImageIcon defaultImageIcon;
           * A constructor - gives us a chance to load and cache the images.
          public IconListCellRenderer() {
               super();
               // We load our default image.  here we load it as if it's in a JAR with the code,
               // in a directory in the root of the JAR called "images".                    
               defaultImageIcon = new ImageIcon(getClass().getResource("/images/myIcon.gif"));
               // An alternative is to directly pass the URL of the image on your website,
               // for example:
               //defaultImageIcon = new ImageIcon(new URL("http://yourUrl.com/AppletImages/myIcon.gif"));
           * @see javax.swing.ListCellRenderer#getListCellRendererComponent(javax.swing.JList, java.lang.Object, int, boolean, boolean)
          public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
               Component defaultRenderer = super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
               ((JLabel)defaultRenderer).setIcon( defaultImageIcon );
               return defaultRenderer;
     }You'd attach this to your list like this:
myList.setCellRenderer( new IconListCellRenderer() );If you're not already JARing up your Applet and you don't want to, then you can have your ImageIcons load from your site. If your Applet is deployed in a JAR, then you can just create an images directory, put your icons in that and add it to your JAR file (using Winzip or summat).
Hope this helps,