import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
public class PropertyChangeListenerDemo {
public static void main(String args[]) {
Runnable runner = new Runnable() {
public void run() {
JFrame frame = new JFrame("Button Sample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JButton button1 = new JButton("Select Me");
final JButton button2 = new JButton("No Select Me");
final Random random = new Random();
// Define ActionListener
ActionListener actionListener = new ActionListener() {
public void actionPerformed(ActionEvent actionEvent) {
JButton button = (JButton) actionEvent.getSource();
int red = random.nextInt(255);
int green = random.nextInt(255);
int blue = random.nextInt(255);
button.setBackground(new Color(red, green, blue));
}
};
// Define PropertyChangeListener
PropertyChangeListener propertyChangeListener = new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent propertyChangeEvent) {
String property = propertyChangeEvent.getPropertyName();
if ("background".equals(property)) {
button2.setBackground((Color) propertyChangeEvent.getNewValue());
}
}
};
button1.addActionListener(actionListener);
button1.addPropertyChangeListener(propertyChangeListener);
button2.addActionListener(actionListener);
frame.add(button1, BorderLayout.NORTH);
frame.add(button2, BorderLayout.SOUTH);
frame.setSize(300, 100);
frame.setVisible(true);
}
};
EventQueue.invokeLater(runner);
}
}
15.34.Property Event |
| 15.34.1. | Using Property Change Listeners as Observers | |