Java by API/java.awt.event/ItemEvent

ItemEvent: getItem()

import java.awt.Color;
import java.awt.ruponent;
import java.awt.Graphics;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.Icon;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainClass extends JPanel implements ItemListener {
  public MainClass() {
    // Add check boxes to the content pane.
    Icon normal = new MyIcon(Color.red);
    Icon rollover = new MyIcon(Color.YELLOW);
    Icon selected = new MyIcon(Color.BLUE);
    JCheckBox cb = new JCheckBox("www.jexp.ru", normal);
    cb.setRolloverIcon(rollover);
    cb.setSelectedIcon(selected);
    cb.addItemListener(this);
    add(cb);
  }
  public void itemStateChanged(ItemEvent ie) {
    JCheckBox cb = (JCheckBox) ie.getItem();
    int state = ie.getStateChange();
    if (state == ItemEvent.SELECTED)
      System.out.println(cb.getText() + " selected");
    else
      System.out.println(cb.getText() + " cleared");
  }
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.getContentPane().add(new MainClass());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}
class MyIcon implements Icon {
  Color cl;
  public MyIcon(Color c) {
    cl = c;
  }
  public int getIconWidth() {
    return 32;
  }
  public int getIconHeight() {
    return 32;
  }
  public void paintIcon(Component c, Graphics g, int x, int y) {
    g.setColor(cl);
    g.drawString("jexp.ru", 0, 20);
  }
}

ItemEvent: getItemSelectable()

import java.awt.BorderLayout;
import java.awt.ItemSelectable;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.JComboBox;
import javax.swing.JFrame;
public class MainClass {
  public static void main(final String args[]) {
    final String labels[] = { "A", "B", "C", "D", "E" };
    JFrame frame = new JFrame("Selecting JComboBox");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JComboBox comboBox = new JComboBox(labels);
    frame.add(comboBox, BorderLayout.SOUTH);
    ItemListener itemListener = new ItemListener() {
      public void itemStateChanged(ItemEvent itemEvent) {
        int state = itemEvent.getStateChange();
        String stateString = 
          ((state == ItemEvent.SELECTED) ? "Selected" : "Deselected");
        System.out.println("Item: " + itemEvent.getItem());
        System.out.println(", State: " + stateString);
        ItemSelectable is = itemEvent.getItemSelectable();
        System.out.println(", Selected: " + selectedString(is));
      }
    };
    comboBox.addItemListener(itemListener);
    frame.setSize(400, 200);
    frame.setVisible(true);
  }
  static private String selectedString(ItemSelectable is) {
    Object selected[] = is.getSelectedObjects();
    return ((selected.length == 0) ? "null" : (String)selected[0]);
  }  
}

ItemEvent: getStateChange()

import java.awt.Color;
import java.awt.ruponent;
import java.awt.Graphics;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.Icon;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainClass extends JPanel implements ItemListener {
  public MainClass() {
    // Add check boxes to the content pane.
    Icon normal = new MyIcon(Color.red);
    Icon rollover = new MyIcon(Color.YELLOW);
    Icon selected = new MyIcon(Color.BLUE);
    JCheckBox cb = new JCheckBox("www.jexp.ru", normal);
    cb.setRolloverIcon(rollover);
    cb.setSelectedIcon(selected);
    cb.addItemListener(this);
    add(cb);
  }
  public void itemStateChanged(ItemEvent ie) {
    JCheckBox cb = (JCheckBox) ie.getItem();
    int state = ie.getStateChange();
    if (state == ItemEvent.SELECTED)
      System.out.println(cb.getText() + " selected");
    else
      System.out.println(cb.getText() + " cleared");
  }
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.getContentPane().add(new MainClass());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}
class MyIcon implements Icon {
  Color cl;
  public MyIcon(Color c) {
    cl = c;
  }
  public int getIconWidth() {
    return 32;
  }
  public int getIconHeight() {
    return 32;
  }
  public void paintIcon(Component c, Graphics g, int x, int y) {
    g.setColor(cl);
    g.drawString("jexp.ru", 0, 20);
  }
}

ItemEvent.SELECTED

import java.awt.Color;
import java.awt.ruponent;
import java.awt.Graphics;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.Icon;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainClass extends JPanel implements ItemListener {
  public MainClass() {
    // Add check boxes to the content pane.
    Icon normal = new MyIcon(Color.red);
    Icon rollover = new MyIcon(Color.YELLOW);
    Icon selected = new MyIcon(Color.BLUE);
    JCheckBox cb = new JCheckBox("www.jexp.ru", normal);
    cb.setRolloverIcon(rollover);
    cb.setSelectedIcon(selected);
    cb.addItemListener(this);
    add(cb);
  }
  public void itemStateChanged(ItemEvent ie) {
    JCheckBox cb = (JCheckBox) ie.getItem();
    int state = ie.getStateChange();
    if (state == ItemEvent.SELECTED)
      System.out.println(cb.getText() + " selected");
    else
      System.out.println(cb.getText() + " cleared");
  }
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.getContentPane().add(new MainClass());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(200, 200);
    frame.setVisible(true);
  }
}
class MyIcon implements Icon {
  Color cl;
  public MyIcon(Color c) {
    cl = c;
  }
  public int getIconWidth() {
    return 32;
  }
  public int getIconHeight() {
    return 32;
  }
  public void paintIcon(Component c, Graphics g, int x, int y) {
    g.setColor(cl);
    g.drawString("jexp.ru", 0, 20);
  }
}