Java Code:
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

/**
 * This class demonstrates TreeEditor
 */
public class TextTreeEditor {
  // Constant for how many items to create at each level
  private static final int NUM = 3;

  /**
   * Runs the //Send questions, comments, bug reports, etc. to the authors:

//Rob Warner (rwarner@interspatial.com)
//Robert Harris (rbrt_harris@yahoo.com)application
   */
  public void run() {
    Display display = new Display();
    Shell shell = new Shell(display);
    shell.setText("Text Tree Editor");
    createContents(shell);
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        display.sleep();
      }
    }
    display.dispose();
  }

  /**
   * Creates the contents of the main window
   * 
   * @param shell the main window
   */
  public void createContents(Shell shell) {
    shell.setLayout(new FillLayout());

    // Create the tree
    final Tree tree = new Tree(shell, SWT.SINGLE);

    // Fill the tree with data
    for (int i = 0; i < NUM; i++) {
      TreeItem iItem = new TreeItem(tree, SWT.NONE);
      iItem.setText("Item " + (i + 1));
      for (int j = 0; j < NUM; j++) {
        TreeItem jItem = new TreeItem(iItem, SWT.NONE);
        jItem.setText("Sub Item " + (j + 1));
        for (int k = 0; k < NUM; k++) {
          new TreeItem(jItem, SWT.NONE).setText("Sub Sub Item " + (k + 1));
        }
        jItem.setExpanded(true);
      }
      iItem.setExpanded(true);
    }

    // Create the editor and set its attributes
    final TreeEditor editor = new TreeEditor(tree);
    editor.horizontalAlignment = SWT.LEFT;
    editor.grabHorizontal = true;

    // Add a key listener to the tree that listens for F2.
    // If F2 is pressed, we do the editing
    tree.addKeyListener(new KeyAdapter() {
      public void keyPressed(KeyEvent event) {
        // Make sure one and only one item is selected when F2 is pressed
        if (event.keyCode == SWT.F2 && tree.getSelectionCount() == 1) {
          // Determine the item to edit
          final TreeItem item = tree.getSelection()[0];

          // Create a text field to do the editing
          final Text text = new Text(tree, SWT.NONE);
          text.setText(item.getText());
          text.selectAll();
          text.setFocus();

          // If the text field loses focus, set its text into the tree
          // and end the editing session
          text.addFocusListener(new FocusAdapter() {
            public void focusLost(FocusEvent event) {
              item.setText(text.getText());
              text.dispose();
            }
          });

          // If they hit Enter, set the text into the tree and end the editing
          // session. If they hit Escape, ignore the text and end the editing
          // session
          text.addKeyListener(new KeyAdapter() {
            public void keyPressed(KeyEvent event) {
              switch (event.keyCode) {
              case SWT.CR:
                // Enter hit--set the text into the tree and drop through
                item.setText(text.getText());
              case SWT.ESC:
                // End editing session
                text.dispose();
                break;
              }
            }
          });

          // Set the text field into the editor
          editor.setEditor(text, item);
        }
      }
    });
  }

  /**
   * The application entry point
   * 
   * @param args the command line arguments
   */
  public static void main(String[] args) {
    new TextTreeEditor().run();
  }
}