Java Foundation Classes in a Nutshell

Example 2−1: Cr eating a Simple GUI with Swing (continued)

msgLabel.setBorder(new EmptyBorder(10,10,10,10)); // A 10-pixel margin

yesButton.setText((args.length >= 2)?args[1]:"Yes"); // Text for yes button

noButton.setText((args.length >= 3)?args[2]:"No"); // Text for no button

/*

* Step 3: Create containers to hold the components

*/

JFrame win = new JFrame("Message"); // The main application window

JPanel buttonbox = new JPanel(); // A container for the two buttons

/*

* Step 4: Specify LayoutManagers to arrange components in the containers

*/

win.getContentPane().setLayout(new BorderLayout()); // Layout on borders

buttonbox.setLayout(new FlowLayout()); // Layout left-to-right

/*

* Step 5: Add components to containers, with optional layout constraints

*/

buttonbox.add(yesButton); // Add yes button to the panel

buttonbox.add(noButton); // Add no button to the panel

// add JLabel to window, telling the BorderLayout to put it in the middle

win.getContentPane().add(msgLabel, "Center");

// add panel to window, telling the BorderLayout to put it at the bottom

win.getContentPane().add(buttonbox, "South");

/*

* Step 6: Arrange to handle events in the user interface

*/

yesButton.addActionListener(new ActionListener() { // Note: inner class

// This method is called when the Yes button is clicked

public void actionPerformed(ActionEvent e) { System.exit(0); }

});

noButton.addActionListener(new ActionListener() { // ...