/* 
 * Code largely lifted and modified from Java Tutorials Code Sample – ComboBoxDemo.java 
 */ 
package brokenscrollbar; 

import java.awt.BorderLayout; 
import java.awt.Dimension; 
import java.awt.Font; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import javax.swing.BorderFactory; 
import javax.swing.ImageIcon; 
import javax.swing.JComboBox; 
import javax.swing.JComponent; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JPanel; 

/** 
 * 
 * @author smm 
 */ 
public class BrokenScrollBar extends JPanel implements ActionListener { 
    JLabel picture; 
  
    public BrokenScrollBar() { 
        super(new BorderLayout()); 
  
        String[] petStrings = { "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", 
        "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig", "Bird", "Cat", "Dog", "Rabbit", "Pig"}; 
  
        //Create the combo box, select the item at index 4. 
        //Indices start at 0, so 4 specifies the pig. 
        JComboBox petList = new JComboBox(petStrings); 
        petList.setSelectedIndex(4); 
        petList.addActionListener(this); 
        petList.setMaximumRowCount(Integer.MAX_VALUE); 
  
        //Set up the picture. 
        picture = new JLabel(); 
        picture.setFont(picture.getFont().deriveFont(Font.ITALIC)); 
        picture.setHorizontalAlignment(JLabel.CENTER); 
        updateLabel(petStrings[petList.getSelectedIndex()]); 
        picture.setBorder(BorderFactory.createEmptyBorder(10,0,0,0)); 
  
        //The preferred size is hard-coded to be the width of the 
        //widest image and the height of the tallest image + the border. 
        //A real program would compute this. 
        picture.setPreferredSize(new Dimension(177, 122+10)); 
  
        //Lay out the demo. 
        add(petList, BorderLayout.PAGE_START); 
        add(picture, BorderLayout.PAGE_END); 
        setBorder(BorderFactory.createEmptyBorder(20,20,20,20)); 
    } 
  
    /** Listens to the combo box. */ 
    public void actionPerformed(ActionEvent e) { 
        JComboBox cb = (JComboBox)e.getSource(); 
        String petName = (String)cb.getSelectedItem(); 
        updateLabel(petName); 
    } 
  
    protected void updateLabel(String name) { 
        ImageIcon icon = createImageIcon("images/" + name + ".gif"); 
        picture.setIcon(icon); 
        picture.setToolTipText("A drawing of a " + name.toLowerCase()); 
        if (icon != null) { 
            picture.setText(null); 
        } else { 
            picture.setText("Image not found"); 
        } 
    } 
  
    /** Returns an ImageIcon, or null if the path was invalid. */ 
    protected static ImageIcon createImageIcon(String path) { 
        java.net.URL imgURL = BrokenScrollBar.class.getResource(path); 
        if (imgURL != null) { 
            return new ImageIcon(imgURL); 
        } else { 
            System.err.println("Couldn't find file: " + path); 
            return null; 
        } 
    } 
  
    /** 
     * Create the GUI and show it. For thread safety, 
     * this method should be invoked from the 
     * event-dispatching thread. 
     */ 
    private static void createAndShowGUI() { 
        //Create and set up the window. 
        JFrame frame = new JFrame("ComboBoxDemo"); 
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
  
        //Create and set up the content pane. 
        JComponent newContentPane = new BrokenScrollBar(); 
        newContentPane.setOpaque(true); //content panes must be opaque 
        frame.setContentPane(newContentPane); 
  
        //Display the window. 
        frame.pack(); 
        frame.setVisible(true); 
    } 
  
    public static void main(String[] args) { 
        //Schedule a job for the event-dispatching thread: 
        //creating and showing this application's GUI. 
        javax.swing.SwingUtilities.invokeLater(new Runnable() { 
            public void run() { 
                createAndShowGUI(); 
            } 
        }); 
    } 
     
}