int java.awt.event.WindowEvent.WINDOW_OPENED : Window Event « Swing Event « Java Tutorial

1. Java Tutorial
2. Swing Event
3. Window Event

import java.awt.AWTEvent;
import java.awt.Toolkit;
import java.awt.event.AWTEventListener;
import java.awt.event.ActionEvent;
import java.awt.event.ComponentEvent;
import java.awt.event.WindowEvent;

import javax.swing.AbstractAction;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;

public class Main implements AWTEventListener {
  public void eventDispatched(AWTEvent evt) {
    if (evt.getID() == WindowEvent.WINDOW_OPENED) {
      ComponentEvent cev = (ComponentEvent) evt;
      if (cev.getComponent() instanceof JFrame) {
        System.out.println("event: " + evt);
        JFrame frame = (JFrame) cev.getComponent();
        loadSettings(frame);
      }
    }
  }

  public static void loadSettings(JFrame frame) {
    System.out.println("loading");
  }

  public static void saveSettings() {
    System.out.println("saving");
  }

  public static void main(String[] args) throws Exception {
    Toolkit tk = Toolkit.getDefaultToolkit();
    final Main main = new Main();

    tk.addAWTEventListener(main, AWTEvent.WINDOW_EVENT_MASK);

    final JFrame frame = new JFrame("");
    frame.setName("your frame");
    JMenuBar mb = new JMenuBar();
    JMenu menu = new JMenu("File");
    menu.add(new AbstractAction("Quit") {
      public void actionPerformed(ActionEvent evt) {
        try {
          main.saveSettings();
          System.exit(0);
        } catch (Exception ex) {
          System.out.println(ex);
        }
      }
    });
    mb.add(menu);
    frame.setJMenuBar(mb);
    frame.pack();
    frame.setVisible(true);
  }

}

15.41.Window Event
	15.41.1.	The event IDs for the WindowEvent class
	15.41.2.	Making a Window Handle its Own Events
	15.41.3.	The WindowListener Interface: events reflecting changes in the state of a window
	15.41.4.	Using WindowListener
	15.41.5.	Using Adapter Classes
	15.41.6.	Listens for window iconify and deiconify events, so that it can stop the animation when the window isn't visible.
	15.41.7.	WindowListener, WindowFocusListener, WindowStateListener
	15.41.8.	extends WindowAdapter
	15.41.9.	Handle a window closing event
	15.41.10.	Setting the Initial Focused Component in a Window
	15.41.11.	int java.awt.event.WindowEvent.WINDOW_OPENED