test.java

《Java2图形设计卷II：Swing》配套光盘源码

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

public class Test extends JFrame {
	JDesktopPane desktopPane = new JDesktopPane();

	public Test() {
		Container contentPane = getContentPane();

		contentPane.add(desktopPane, BorderLayout.CENTER);
		desktopPane.setLayout(new FlowLayout());

		JInternalFrame jif = new JInternalFrame(
									"Some Editor", // title
				  					false,  // resizable
				  					true);  // closable

		jif.setPreferredSize(new Dimension(300, 250));
		jif.addVetoableChangeListener(new CloseListener());

		desktopPane.add(jif);
	}
	public static void main(String args[]) {
		GJApp.launch(new Test(), 
					"Vetoing Internal Frame Closing",
					300,300,450,300);
	}
}
class CloseListener implements VetoableChangeListener { 
	private Test applet;

	public void vetoableChange(PropertyChangeEvent e) 
									throws PropertyVetoException {
		String name = e.getPropertyName();

		if(name.equals(JInternalFrame.IS_CLOSED_PROPERTY)) {
			Component internalFrame = (Component)e.getSource();
			Boolean oldValue = (Boolean)e.getOldValue(),
			  		newValue = (Boolean)e.getNewValue();

			if(oldValue == Boolean.FALSE && 
									newValue == Boolean.TRUE) {
				int answer = JOptionPane.showConfirmDialog(
						internalFrame,		// parentComponent
						"Save Changes?", 	// message
						"Unsaved Changes", 	// title
						JOptionPane.YES_NO_CANCEL_OPTION); 

				if(answer == JOptionPane.CANCEL_OPTION) {
					throw new PropertyVetoException(
											"close cancelled", e);
				}
			}
		}
	}
}
class GJApp extends WindowAdapter {
	static private JPanel statusArea = new JPanel();
	static private JLabel status = new JLabel(" ");
	static private ResourceBundle resources;

	public static void launch(final JFrame f, String title,
							  final int x, final int y, 
							  final int w, int h) {
		launch(f,title,x,y,w,h,null);	
	}
	public static void launch(final JFrame f, String title,
							  final int x, final int y, 
							  final int w, int h,
							  String propertiesFilename) {
		f.setTitle(title);
		f.setBounds(x,y,w,h);
		f.setVisible(true);

		statusArea.setBorder(BorderFactory.createEtchedBorder());
		statusArea.setLayout(new FlowLayout(FlowLayout.LEFT,0,0));
		statusArea.add(status);
		status.setHorizontalAlignment(JLabel.LEFT);

		f.setDefaultCloseOperation(
							WindowConstants.DISPOSE_ON_CLOSE);

		if(propertiesFilename != null) {
			resources = ResourceBundle.getBundle(
						propertiesFilename, Locale.getDefault());
		}

		f.addWindowListener(new WindowAdapter() {
			public void windowClosed(WindowEvent e) {
				System.exit(0);
			}
		});
	}
	static public JPanel getStatusArea() {
		return statusArea;
	}
	static public void showStatus(String s) {
		status.setText(s);
	}
	static Object getResource(String key) {
		if(resources != null) {
			return resources.getString(key);
		}
		return null;
	}
}