Java by API/javax.swing.tree/DefaultTreeCellEditor

new DefaultTreeCellEditor(JTree tree, DefaultTreeCellRenderer renderer, TreeCellEditor editor)

import java.awt.BorderLayout;
import javax.swing.DefaultCellEditor;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultTreeCellEditor;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellEditor;
public class MainClass {
  public static void main(final String args[]) {
    JFrame frame = new JFrame("Editable Tree");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTree tree = new JTree();
    tree.setEditable(true);
    DefaultTreeCellRenderer renderer = (DefaultTreeCellRenderer) tree.getCellRenderer();
    String elements[] = { "A", "B", "C", "D" };
    JComboBox comboBox = new JComboBox(elements);
    comboBox.setEditable(true);
    TreeCellEditor comboEditor = new DefaultCellEditor(comboBox);
    TreeCellEditor editor = new DefaultTreeCellEditor(tree, renderer, comboEditor);
    tree.setCellEditor(editor);
    JScrollPane scrollPane = new JScrollPane(tree);
    frame.add(scrollPane, BorderLayout.CENTER);
    frame.setSize(300, 150);
    frame.setVisible(true);
  }
}