MainPanel.java

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

package example;

import java.awt.*;
import java.util.stream.Stream;
import javax.swing.*;

public final class MainPanel extends JPanel {
  private MainPanel() {
    super(new BorderLayout());
    JTextField field = new JTextField(20);
    field.setToolTipText("setColumns(20)");

    JPasswordField passwd = new JPasswordField(20);
    passwd.setToolTipText("setColumns(20)");

    JSpinner spinner = new JSpinner();
    spinner.setToolTipText("setColumns(20)");
    ((JSpinner.DefaultEditor) spinner.getEditor()).getTextField().setColumns(20);

    JComboBox<String> combo1 = new JComboBox<>();
    combo1.setEditable(true);
    combo1.setToolTipText("setEditable(true), setColumns(20)");
    ((JTextField) combo1.getEditor().getEditorComponent()).setColumns(20);

    JComboBox<String> combo2 = new JComboBox<>();
    combo2.setToolTipText("setEditable(true), default");
    combo2.setEditable(true);

    JComboBox<String> combo3 = new JComboBox<>();
    combo3.setToolTipText("setEditable(false), default");

    SpringLayout layout = new SpringLayout();
    JPanel p = new JPanel(layout);
    layout.putConstraint(SpringLayout.WEST, field, 10, SpringLayout.WEST, p);
    layout.putConstraint(SpringLayout.WEST, passwd, 10, SpringLayout.WEST, p);
    layout.putConstraint(SpringLayout.WEST, spinner, 10, SpringLayout.WEST, p);
    layout.putConstraint(SpringLayout.WEST, combo1, 10, SpringLayout.WEST, p);
    layout.putConstraint(SpringLayout.WEST, combo2, 10, SpringLayout.WEST, p);
    layout.putConstraint(SpringLayout.WEST, combo3, 10, SpringLayout.WEST, p);
    layout.putConstraint(SpringLayout.NORTH, field, 10, SpringLayout.NORTH, p);
    layout.putConstraint(SpringLayout.NORTH, passwd, 10, SpringLayout.SOUTH, field);
    layout.putConstraint(SpringLayout.NORTH, spinner, 10, SpringLayout.SOUTH, passwd);
    layout.putConstraint(SpringLayout.NORTH, combo1, 10, SpringLayout.SOUTH, spinner);
    layout.putConstraint(SpringLayout.NORTH, combo2, 10, SpringLayout.SOUTH, combo1);
    layout.putConstraint(SpringLayout.NORTH, combo3, 10, SpringLayout.SOUTH, combo2);

    Stream.of(field, passwd, spinner, combo1, combo2, combo3).forEach(p::add);
    add(p);
    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.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    frame.getContentPane().add(new MainPanel());
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
  }
}