🚀 go-pugleaf

Hi there,

I'm trying out a sample program using a JTree and I'm trying to render 
my own icons for closed/open folders and leaf nodes.
I subclassed DefaultTreeCellRenderer and used the inherited methods
to set the appropriate icons.

When I run my sample program I don't get any error messages and I don't 
get any icons being displayed either.  I don't get it! Could someone 
please look over my code below and advise as to where I went wrong?

Alan

*********************************************

import java.awt.*;
import javax.swing.*;
import javax.swing.tree.*;
import java.net.*;

public class MyTreeCellRenderer extends DefaultTreeCellRenderer
{
   public MyTreeCellRenderer()
   {
     setFont(new Font("Monospaced", Font.PLAIN, 12));
     setHorizontalAlignment(SwingConstants.CENTER);
     ImageIcon closed = createImageIcon("images/ClosedFolder.gif", 
"ClosedFolder");
     if(closed == null)System.out.println("closed is null");
     ImageIcon open = createImageIcon("images/OpenFolder.gif", 
"OpenFolder");
     if(open == null)System.out.println("open is null");
     ImageIcon leaf = createImageIcon("images/Leaf.gif", "Leaf");
     if(leaf == null)System.out.println("leaf is null");
     setClosedIcon(closed);
     setOpenIcon(open);
     setLeafIcon(leaf);
   }

    /** Returns an ImageIcon, or null if the path was invalid. */
   protected static ImageIcon createImageIcon(String path, 
                           String description)
   {
     URL imgURL = MyTreeCellRenderer.class.getResource(path);
     if (imgURL != null) {
         return new ImageIcon(imgURL, description);
     } else {
         System.err.println("Couldn't find file: " + path);
         return null;
     }
   }
}

***************************************************

import java.awt.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;

public class TestTree extends JFrame
{
   JTree tree;

   public TestTree()
   {
     super("Tree Test Example");
     setSize(300, 250);
     addWindowListener(new WindowAdapter()
	{
	  public void windowClosing(WindowEvent e)
           {
		System.exit(0);
	  }
	});
   }

   public static void main(String args[])
   {
     TestTree tt = new TestTree();
     tt.init();
     tt.setVisible(true);
   }

   public void init()
   {
     //Build the hierarchy of containers & objects
     String[] schoolyard = {"School", "Playground", "Parking Lot", "Field"};
     String[] mainstreet = {"Grocery", "Shoe Shop", "Five & Dime", "Post 
Office"};
     String[] highway = {"Gas Station", "Convenience Store"};
     String[] housing = {"Victorian_Blue", "Faux Colonial", 
"Victorian_White"};
     String[] housing2 = {"Mission", "Ranch", "Condo"};
     Hashtable homeHash = new Hashtable();
     homeHash.put("Residential 1", housing);
     homeHash.put("Residential 2", housing2);

     Hashtable cityHash = new Hashtable();
     cityHash.put("School grounds", schoolyard);
     cityHash.put("Downtown", mainstreet);
     cityHash.put("Highway", highway);
     cityHash.put("Housing", homeHash);

     Hashtable worldHash = new Hashtable();
     worldHash.put("My First VRML World", cityHash);

     //Build our tree out of our big hashtable
     tree = new JTree(worldHash);
     tree.setCellRenderer(new MyTreeCellRenderer());
     tree.putClientProperty("JTree.lineStyle", "Angled");

     getContentPane().add(tree, BorderLayout.CENTER);
   }


}