Question

I haven’t used Swing components a lot so am a bit confused:
I’m trying to display a file system tree using a JTree and used Ian Darwin’s example
with a slight modification so it won’t display hidden files:

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.io.File;
import java.util.Collections;
import java.util.Vector;

import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;

/**
 * Display a file system in a JTree view
 * 
 * @version $Id: FileTree.java,v 1.9 2004/02/23 03:39:22 ian Exp $
 * @author Ian Darwin
 */
public class FileTree extends JPanel {
  /** Construct a FileTree */
  public FileTree(File dir) {
    setLayout(new BorderLayout());

    // Make a tree list with all the nodes, and make it a JTree
    JTree tree = new JTree(addNodes(null, dir));

    // Add a listener
    tree.addTreeSelectionListener(new TreeSelectionListener() {
      public void valueChanged(TreeSelectionEvent e) {
        DefaultMutableTreeNode node = (DefaultMutableTreeNode) e
            .getPath().getLastPathComponent();
        System.out.println("You selected " + node);
      }
    });

    // Lastly, put the JTree into a JScrollPane.
    JScrollPane scrollpane = new JScrollPane();
    scrollpane.getViewport().add(tree);
    add(BorderLayout.CENTER, scrollpane);
  }

  /** Add nodes from under "dir" into curTop. Highly recursive. */
  DefaultMutableTreeNode addNodes(DefaultMutableTreeNode curTop, File dir) {
    String curPath = dir.getPath();
    DefaultMutableTreeNode curDir = new DefaultMutableTreeNode(curPath);
    if (curTop != null) { // should only be null at root
      curTop.add(curDir);
    }
    Vector ol = new Vector();
    String[] tmp = dir.list();
    for (int i = 0; i < tmp.length; i++)
      ol.addElement(tmp[i]);
    Collections.sort(ol, String.CASE_INSENSITIVE_ORDER);
    File f;
    Vector files = new Vector();
    // Make two passes, one for Dirs and one for Files. This is #1.
    for (int i = 0; i < ol.size(); i++) {
      String thisObject = (String) ol.elementAt(i);
      String newPath;
      if (curPath.equals("."))
        newPath = thisObject;
      else
        newPath = curPath + File.separator + thisObject;
      if ((f = new File(newPath)).isDirectory())
        addNodes(curDir, f);
      else
        if(!new File(thisObject).isHidden()) files.addElement(thisObject);
    }
    // Pass two: for files.
    for (int fnum = 0; fnum < files.size(); fnum++)
      curDir.add(new DefaultMutableTreeNode(files.elementAt(fnum)));
    return curDir;
  }

  public Dimension getMinimumSize() {
    return new Dimension(200, 400);
  }

  public Dimension getPreferredSize() {
    return new Dimension(200, 400);
  }

  /** Main: make a Frame, add a FileTree */
  public static void main(String[] av) {

    JFrame frame = new JFrame("FileTree");
    frame.setForeground(Color.black);
    frame.setBackground(Color.lightGray);
    Container cp = frame.getContentPane();


    cp.add(new FileTree(new File("/Users/"+System.getProperty("user.name")+"/Downloads")));

    frame.pack();
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }
}

By default folder nodes display the full path, rather than the folder name.
Is it possible to display just the folder name ? If so, how ?

Answer 1

Yep.

tree.setCellRenderer( new DefaultTreeCellRenderer(){

    public Component getTreeCellRendererComponent( tree, value, selected, false,                      
                                                   false,0, hasFocus ){

        super.getTreeCellRendererComponent( tree, value, selected, false, false,0, 
                                            hasFocus );

        if( value instanceof DefaultMutableTreeNode){

            DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
            Object userValue = node.getUserObject();

            if( value instanceof File ){
                 setText( ((File) value).getName();
            }
        }

        return this;
    }
}