Custom TreeCellRenderer

Question

I've written a custom TreeCellRenderer that extends DefaultTreeCellRenderer. Each node in the tree has an object associated with it, and depending on that object, a different icon is used by the renderer (its not a file system, but similar).
The problem is that when you edit a node, the default icons are used. The custom renderer is being used by the TreeCellEditor (also custom), but I think it is using the getXXXXIcon() methods rather than the getTreeCellRendererComponent method.
The solution seems to be to override the getTreeCellEditorComponent() method in the TreeCellEditor class, but apart from the icon this is doint exactly what I want it to do.
Is there an easy way to change the icon it will use without causing too much carnage?

Answer 1

I wanted to make sure I was correct, but I wasn't.import java.awt.*;
import javax.swing.*;
import javax.swing.tree.*;
import java.util.Random;
public class Test2 extends JFrame {
  static final ImageIcon[] icons = { new ImageIcon("icon1.gif"),
                                     new ImageIcon("icon2.gif") };
  public Test2() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = getContentPane();
    DefaultMutableTreeNode root = new DefaultMutableTreeNode(
                                              new MyObject("root", icons[0]));
    JTree jt = new JTree(root);
    jt.setCellRenderer(new MyRenderer());
    Random r = new Random();
    for (int i=0; i<5; i++) {
      DefaultMutableTreeNode child = new DefaultMutableTreeNode(
                  new MyObject("Child-"+i,icons[r.nextInt(icons.length)]));
      root.add(child);
      for (int j=0; j<5; j++) {
        DefaultMutableTreeNode gchild = new DefaultMutableTreeNode(
                    new MyObject("Grandchild-"+j,icons[r.nextInt(icons.length)]));
        child.add(gchild);
      content.add(new JScrollPane(jt), BorderLayout.CENTER);
    setSize(300,300);
  public static void main(String[] args) { new Test2().setVisible(true); }
class MyObject {
  String text;
  Icon icon;
  public MyObject(String text, Icon icon) { this.text=text; this.icon=icon; }
  public String toString() { return text; }
  public Icon getIcon() { return icon; }
class MyRenderer extends DefaultTreeCellRenderer {
  public Component getTreeCellRendererComponent(JTree tree, Object value,
                                                boolean sel, boolean exp,
                                                boolean leaf, int row,
                                                boolean focus) {
    Component c = super.getTreeCellRendererComponent(tree, value, sel, exp, leaf,
                                                row, focus);
    if (value instanceof DefaultMutableTreeNode) {
      Object val = ( (DefaultMutableTreeNode) value).getUserObject();
      if (val instanceof MyObject) {
        System.out.println("Yes");
        setIcon( ( (MyObject) val).getIcon());
      } else System.out.println("No: " + val.getClass());
    return c;
}