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import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class WidgetDemo {
public static void main(String[] args) {
WidgetDemo demo = new WidgetDemo();
}
JLabel label;
WidgetDemo()
{
JFrame f = new JFrame("WidgetDemo.java");
f.setSize(500, 200);
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
// create a button and add a listener for events
JButton button = new JButton("My Button");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
label.setText("button");
}
});
// create a slider
JSlider slider = new JSlider(0, 100, 50);
slider.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent e) {
JSlider s = (JSlider)e.getSource();
label.setText("slider " + s.getValue());
}
});
// create a radio button group
ButtonGroup radiobuttons = new ButtonGroup();
JPanel radioPanel = new JPanel(new GridLayout(1, 0));
for (String s: new String[] {"A", "B", "C"})
{
JRadioButton rb = new JRadioButton(s);
rb.addActionListener(radioButtonListener);
radiobuttons.add(rb);
radioPanel.add(rb);
}
// create a menu
JMenu menu = new JMenu("Choices");
// create some menu choices
for (String s: new String[] {"apple", "orange", "banana", "pear" })
{
// add this menu item to the menu
JMenuItem mi = new JMenuItem(s);
// set the listener when events occur
mi.addActionListener(menuItemListener);
// add this menu item to the menu
menu.add(mi);
}
JMenuBar menubar = new JMenuBar();
menubar.add(menu);
// create a label
// (we'll use this to display messages)
label = new JLabel("message");
// set some properties to customize how it looks
label.setPreferredSize(new Dimension(500, 60));
label.setHorizontalAlignment( SwingConstants.CENTER );
label.setBackground(Color.WHITE);
label.setBorder(BorderFactory.createLineBorder(Color.black));
label.setFont(new Font("SansSerif", Font.PLAIN, 30));
// define the layout
// http://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html
// add the widgets
f.add(button);
f.add(slider);
f.add(menubar);
f.add(radioPanel);
f.add(label);
f.setLayout(new FlowLayout());
f.setVisible(true);
}
// create a menu item listener
MenuItemListener menuItemListener = new MenuItemListener();
class MenuItemListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
JMenuItem mi = (JMenuItem)e.getSource();
label.setText(mi.getText());
}
}
// create a radio button listener
RadioButtonListener radioButtonListener = new RadioButtonListener();
class RadioButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
JRadioButton rb = (JRadioButton)e.getSource();
label.setText(rb.getText());
}
}
}