CIS 260 TestListWidgets.java

Code

/*
    TestListWidgets.java
    David Klick
    CIS 260
    2006-02-14

    Demonstrates use of JList and JComboBox.
*/

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

public class TestListWidgets extends JFrame
    implements ListSelectionListener, ActionListener {

    JList lst;
    JComboBox cbo;

    public static void main(String[] args) {
        TestListWidgets app = new TestListWidgets("List Widget Test");
    }

    public TestListWidgets() { this(""); }
    public TestListWidgets(String title) { super(title); init(); }

    private void init() {
        // make Window shut down graphics thread properly
        setDefaultCloseOperation(EXIT_ON_CLOSE);

        // get content pane and set to GridLayout
        Container c = getContentPane();
        c.setLayout(new GridLayout(1,2));
      
        // create widgets
        String[] colors = { "red", "blue", "green", "white", "yellow",
            "pink", "tan", "black", "orange", "maroon", "beige" };
        String[] shortNames = { "Bob", "Carol", "Ted", "Alice", "Dave",
            "Sue", "Sam", "Pam", "Art", "Ali", "Beth", "Cindy", "Ed", "Fred" };
        lst = new JList(colors);
        cbo = new JComboBox(shortNames);
      
        // set some properties of the list widgets
        lst.setVisibleRowCount(5);
        lst.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
        cbo.setMaximumRowCount(7);

        // add widgets
        c.add(new JScrollPane(lst));
        c.add(cbo);
      
        // add event handlers (listeners)
        lst.addListSelectionListener(this);
        cbo.addActionListener(this);

        // make it live
        setSize(200, 100);
        setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        String item = (String)(((JComboBox) (e.getSource())).getSelectedItem());
        System.out.println("You selected " + item);
    }

    public void valueChanged(ListSelectionEvent e) {
        Object[] items = (((JList) (e.getSource())).getSelectedValues());
        System.out.println("You selected");
        if (items.length == 0) System.out.println(" * nothing *");
        else for (Object s : items) System.out.println("   " + s);
    }

}