MainPanel.java

// -*- mode:java; encoding:utf-8 -*-
// vim:set fileencoding=utf-8:
// @homepage@

package example;

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

public final class MainPanel extends JPanel {
  private MainPanel() {
    super(new BorderLayout());
    int tgtIndex = 1;
    JTabbedPane tabs = new JTabbedPane();

    JCheckBox check = new JCheckBox("Enable Advanced");
    check.addActionListener(e -> tabs.setEnabledAt(tgtIndex, check.isSelected()));

    tabs.addTab("Preferences", check);
    tabs.addTab("Advanced", new JScrollPane(new JTree()));
    tabs.setEnabledAt(tgtIndex, false);

    add(tabs);
    setPreferredSize(new Dimension(320, 240));
  }

  public static void main(String[] args) {
    EventQueue.invokeLater(MainPanel::createAndShowGui);
  }

  private static void createAndShowGui() {
    try {
      UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
    } catch (UnsupportedLookAndFeelException ignored) {
      Toolkit.getDefaultToolkit().beep();
    } catch (ClassNotFoundException | InstantiationException | IllegalAccessException ex) {
      ex.printStackTrace();
      return;
    }
    JFrame frame = new JFrame("@title@");
    frame.setMinimumSize(new Dimension(256, 100));
    frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    frame.getContentPane().add(new MainPanel());
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }
}