import java.awt.BorderLayout;
import java.awt.Container;
import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

public class CSciClasses implements ListSelectionListener {
    private JList terms;
    private JTextField defn;

    public CSciClasses() {
        // The JList's model specifies the items appearing in the JList
        DefaultListModel model = new DefaultListModel();
        model.addElement("CSci 150");
        model.addElement("CSci 151");
        model.addElement("CSci 230");
        model.addElement("CSci 250");
        model.addElement("CSci 280");

        // Now we create the JList, specifying the model we are using
        terms = new JList(model);
        terms.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        terms.addListSelectionListener(this);

        defn = new JTextField(30);
        defn.setEditable(false);
    }

    public void valueChanged(ListSelectionEvent e) {
        // As a ListSelectionListener, this method is invoked each time
        // the user selects something in the list.
        Object value = terms.getSelectedValue();
        if(value != null) {
            // Removing from the model deletes what appears in the JList
            DefaultListModel model = (DefaultListModel) terms.getModel();
            model.removeElement(value);

            String result = "???";
            if(value.equals("CSci 150")) result = "Foundations I";
            else if(value.equals("CSci 151")) result = "Foundations II";
            else if(value.equals("CSci 230")) result = "Comp Sys Org";
            else if(value.equals("CSci 250")) result = "Practicum";
            else if(value.equals("CSci 280")) result = "Algorithms";
            defn.setText(value + " - " + result);
        }
    }

    public static void main(String[] args) {
        JFrame main = new JFrame("CSci classes");
        main.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        CSciClasses manager = new CSciClasses();

        Container contents = main.getContentPane();
        contents.add(new JScrollPane(manager.terms), BorderLayout.CENTER);
            // (Note the use of a JScrollPane, so that scroll bars will
            // appear if the JList is too large for the window.)
        contents.add(manager.defn, BorderLayout.SOUTH);

        main.pack();
        main.setVisible(true);
    }
}