Swing Basics

References

java.sun.com/docs/books/tutorial/uiswing/

http://java.sun.com/products/jfc/tsc/articles/architecture/

A basic application frame

import javax.swing.*;

public class AppFrame extends JFrame implements Runnable {

�� private static final long serialVersionUID = 1L;

�� public AppFrame() {
����� setDefaultCloseOperation(EXIT_ON_CLOSE);
����� setDefaultLookAndFeelDecorated(true);
�� }

�� public void run() {
����� pack();
����� setVisible(true);
�� }

�� public void display() {
����� SwingUtilities.invokeLater(this);
�� }

�� public static void main(String[] args) {
����� AppFrame app = new AppFrame();
����� app.setTitle("Test AppFrame");
����� app.display();
�� }
}

A basic content panel

�

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

public class GUI1 extends JPanel implements ActionListener {

�� private static final long serialVersionUID = 1L;
�� private Color color = Color.RED;
�� private Color nextColor = Color.GREEN;

�� public GUI1() {
����� Button b = new Button("Change");
����� b.addActionListener(this);
����� add(b);
�� }

�� public void actionPerformed(ActionEvent ae) {
����� Color temp = nextColor;
����� nextColor = color;
����� color = temp;
����� repaint();
�� }

�� public void paintComponent(Graphics gc) {
����� super.paintComponent(gc);
����� Graphics2D gc2d = (Graphics2D) gc;
����� gc2d.setColor(color);
�� �� gc2d.fillOval(20, 20, 50, 50);

�� }

�� public static void main(String[] args) {
����� AppFrame app = new AppFrame();
����� app.setTitle("GUI 1");
����� GUI1 gui = new GUI1();
����� app.setContentPane(gui);
����� app.display();
�� }
}

Menus

public class GUI2 extends JPanel implements ActionListener {

�� private static final long serialVersionUID = 1L;
�� private Color color = Color.RED;
�� private Color nextColor = Color.GREEN;

�� public GUI2() {
����� Button b = new Button("Change");
����� b.addActionListener(this);
����� add(b);
�� }

�� private JMenu makeMenu() {
����� JMenu result = new JMenu("Commands");
����� result.setMnemonic('c');
����� JMenuItem item = new JMenuItem("Change", 'h');
����� item.addActionListener(this);
����� result.add(item);
����� item = new JMenuItem("Exit", 'x');
����� item.addActionListener(this);
����� result.add(item);
����� return result;
�� }

�� public void actionPerformed(ActionEvent ae) {
����� String cmmd = ae.getActionCommand();
����� if (cmmd.equals("Change")) {
�������� Color temp = nextColor;
�������� nextColor = color;
�������� color = temp;
�������� repaint();
����� } else if (cmmd.equals("Exit")) {
�������� System.exit(0);
����� }
�� }

�� public void paintComponent(Graphics gc) {
����� super.paintComponent(gc);
����� Graphics2D gc2d = (Graphics2D) gc;
����� gc2d.setColor(color);
����� gc2d.fillOval(20, 20, 50, 50);

�� }

�� public static void main(String[] args) {
�� �� AppFrame app = new AppFrame();
����� app.setTitle("GUI 2");
����� GUI2 gui = new GUI2();
����� JMenuBar menuBar = new JMenuBar();
����� menuBar.add(gui.makeMenu());
����� app.setJMenuBar(menuBar);
����� app.setContentPane(gui);
����� app.display();
�� }
}