在JTree节点中动态调整JTextField的大小

import javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreePath;
import java.awt.*;
import java.awt.event.TreeExpansionEvent;
import java.awt.event.TreeWillExpandListener;

public class JTreeTextFieldDemo {
    public static void main(String[] args) {
        JFrame frame = new JFrame("JTree TextField Demo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 400);

        DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
        DefaultMutableTreeNode child1 = new DefaultMutableTreeNode("Child 1");
        DefaultMutableTreeNode child2 = new DefaultMutableTreeNode("Child 2");
        DefaultMutableTreeNode child3 = new DefaultMutableTreeNode("Child 3");
        DefaultMutableTreeNode child4 = new DefaultMutableTreeNode("Child 4");
        DefaultMutableTreeNode child5 = new DefaultMutableTreeNode("Child 5");

        root.add(child1);
        root.add(child2);
        root.add(child3);
        root.add(child4);
        root.add(child5);

        DefaultTreeModel model = new DefaultTreeModel(root);
        JTree tree = new JTree(model);

        tree.addTreeWillExpandListener(new TreeWillExpandListener() {
            @Override
            public void treeWillExpand(TreeExpansionEvent event) {
                TreePath path = event.getPath();
                DefaultMutableTreeNode node = (DefaultMutableTreeNode) path.getLastPathComponent();
                node.add(new DefaultMutableTreeNode(new JTextField("New TextField")));
                model.nodeStructureChanged(node);
            }

            @Override
            public void treeWillCollapse(TreeExpansionEvent event) {
                // Do nothing
            }
        });

        JScrollPane scrollPane = new JScrollPane(tree);
        frame.getContentPane().add(scrollPane, BorderLayout.CENTER);

        frame.setVisible(true);
    }
}