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

/*
Demo modified from Walrath and Campione's ListDemo.java in
The JFC Swing Tutorial:  Java 2 Platform, Addison Wesley 1999
that has an initially empty list.

mike barnes
*/

public class ListDemo extends JFrame 
                      implements ListSelectionListener {
  private JList list;
  private DefaultListModel listModel;

  private JPanel panel;
  private JButton one, two, three, four;

  private static final String todoString = "To do ";
  private static final String doneString = "Done";
  private static final String editString = "Edit";
  private JButton todoButton, doneButton, editButton;
  private JTextField textValue;

  public ListDemo() {
    super("To Do Demo");

    listModel = new DefaultListModel();

    //Create the list and put it in a scroll pane
    list = new JList(listModel);
    list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    list.addListSelectionListener(this);
    JScrollPane listScrollPane = new JScrollPane(list);
  


    todoButton = new JButton(todoString);
    todoButton.setActionCommand(todoString);
    todoButton.addActionListener(new ToDoListener());

    doneButton = new JButton("Done");
    doneButton.setActionCommand(doneString);
    doneButton.setEnabled(false);
    doneButton.addActionListener(new DoneListener());

    editButton = new JButton("Edit");
    editButton.setActionCommand(editString);
    editButton.setEnabled(false);
    editButton.addActionListener(new EditListener());

    textValue = new JTextField(10);
    textValue.addActionListener(new ToDoListener());
    //        String name = listModel.getElementAt(
    //                    list.getSelectedIndex()).toString();
    textValue.setText("");

    //Create a panel that uses FlowLayout (the default).
    JPanel buttonPane = new JPanel();
    buttonPane.add(textValue);
    buttonPane.add(todoButton);
    buttonPane.add(doneButton);
    buttonPane.add(editButton);

    Container contentPane = getContentPane();
    contentPane.setLayout(new BorderLayout());
    listScrollPane.setPreferredSize(new Dimension(300, 200));
    contentPane.add(listScrollPane, BorderLayout.CENTER);
    contentPane.add(buttonPane, BorderLayout.SOUTH);
    System.out.println("selected position is" +
      Integer.toString(list.getSelectedIndex()));
    }

  class EditListener implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      int index = list.getSelectedIndex();
      listModel.insertElementAt(textValue.getText(), index);
      listModel.remove(index +1);
      list.setSelectedIndex(index);
      }
    }

  class DoneListener implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      //This method can be called only if
      //there's a valid selection
      //so go ahead and remove whatever's selected.
      int index = list.getSelectedIndex();
      System.out.println("remove position is" +
      Integer.toString(list.getSelectedIndex()));
      listModel.remove(index);

      int size = listModel.getSize();

      if (size == 0) {
          //Nobody's left, disable firing.
          doneButton.setEnabled(false);
          editButton.setEnabled(false); } 
        else {
          //Adjust the selection.
          if (index == listModel.getSize())//removed item in last position
          index--;
         list.setSelectedIndex(index); }   //otherwise select same index
        }
    }

  //This listener is shared by the text field and the ToDo button
  class ToDoListener implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      //User didn't type in a name...
      if (textValue.getText().equals("")) {
        Toolkit.getDefaultToolkit().beep();
        return;
        }

      int index = list.getSelectedIndex();
      int size = listModel.getSize();

      //If no selection or if item in last position is selected,
      //add the new hire to end of list, and select new hire.
      if (index == -1 || (index+1 == size)) {
          listModel.addElement(textValue.getText());
          list.setSelectedIndex(size); }
        //Otherwise insert the new hire after the current selection,
        //and select new hire.
        else {
          listModel.insertElementAt(textValue.getText(), index+1);
          list.setSelectedIndex(index+1);
          }
      System.out.println("added position is" +
         Integer.toString(list.getSelectedIndex()));
      }
    }

  public void valueChanged(ListSelectionEvent e) {
    if (e.getValueIsAdjusting() == false) {
      if (list.getSelectedIndex() == -1) {
          //No selection, disable fire button.
          doneButton.setEnabled(false);
          editButton.setEnabled(false);
          textValue.setText(""); } 
        else {
          //Selection, update text field.
          editButton.setEnabled(true);
          doneButton.setEnabled(true);
          String name = list.getSelectedValue().toString();
          textValue.setText(name); }
        }
    }

  public static void main(String s[]) {
    JFrame frame = new ListDemo();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0); }
        });
    frame.pack();
    frame.setVisible(true);
    }
  }