// MusicApp.java
// Swing application to read the Music Collection Database
// using the Music EJB stateless session bean
// Puts recording titles into a Swing JList component
// so that user can select the title
// Upon selection (ListSelectionEvent),
// displays additional information about the recording
// When user clicks "View Tracks" JButton (ActionEvent),
// displays track list for the selected recording title.

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.rmi.PortableRemoteObject;

public class MusicApp extends JFrame implements
  ActionListener, ListSelectionListener {

  private MusicHome musicHome; // Music EJB home interface
  private Music mymusic;       // Music EJB remote interface

  // Swing components
  private JList musicTitle;    // Display music titles
  private JTextArea data;      // Display data/track titles
  private JPanel statusbar;    // Hold status text field
  private JPanel display;      // Hold music/track titles
  private JLabel helpline;     // How to use the program
  private JPanel helpPanel;    // Panel to hold helpline
  private JTextField status;   // Status/error messages
  private JButton goButton;    // Button to view tracks

  // Keep track of various lists
  private ArrayList albums;    // RecordingVO objects
  private ArrayList tracks;    // TrackVO objects
  private Vector titles;       // Recording titles
  // Given a RecordingVO, get the tracklist
  private void getTracks(RecordingVO rec) {
    try {
      // access MusicEJB
      tracks = mymusic.getTrackList(rec);
      TrackVO t;
      Iterator i = tracks.iterator();
      while (i.hasNext()) {
        t = (TrackVO)i.next();
        // put track info into data JTextArea
        data.append("
" + t.getTrackNumber() + "	" +
          t.getTrackLength() + "	" + t.getTitle());
      }

    // Check separately for NoTrackListException
    } catch (NoTrackListException ex) {
      status.setText("NoTrackListException Exception: " +
          ex.getMessage());
    } catch (Exception ex) {
      status.setText("Unexpected Exception: " +
          ex.getMessage());
      ex.printStackTrace();
    }
  }

  // Get recording information
  private void getRecordings() {
    try {
      // access MusicEJB
      albums = mymusic.getMusicList();
    } catch (Exception ex) {
      status.setText("Unexpected Exception: " +
          ex.getMessage());
      ex.printStackTrace();
    }
    RecordingVO r;
    Iterator i = albums.iterator();
    while (i.hasNext()) {
      r = (RecordingVO)i.next();
      // put Recording titles into titles Vector,
      // which is displayed in the JList Swing component
      titles.add(r.getTitle());
    }
  }

  public MusicApp() {
    // Set up Swing components
    getContentPane().setLayout(new BorderLayout());
    getContentPane().setBackground(Color.lightGray);
    setSize(800, 200);

    helpPanel = new JPanel();
    helpPanel.setLayout(new FlowLayout(
             FlowLayout.CENTER,5,5));

    // Put the help panel at the top
    getContentPane().add("North", helpPanel);
    helpline = new JLabel(
      "Select recording & click button to View Tracks");
    helpPanel.add(helpline);

    display = new JPanel();
    display.setLayout(new GridLayout(1,2,15,15));

    // Set up the musicTitle JList
    // Initialize it with titles vector
    // Make 7 rows visible and add a scrollbar
    // Add the ListSelectionListener
    // to allow user to select titles
    titles = new Vector();
    musicTitle = new JList(titles);
    musicTitle.setBackground(Color.white);
    musicTitle.setVisibleRowCount(7);
    musicTitle.addListSelectionListener(this);
    display.add( new JScrollPane( musicTitle ));
    // Set up the data JTextArea
    // Turn off editing and add a scrollbar
    data = new JTextArea(12,40);
    data.setBackground(Color.white);
    data.setEditable(false);
    display.add( new JScrollPane( data ));
    // Put the display JPanel in the Center
    getContentPane().add("Center", display);

    // Set up the statusbar JPanel
    // Put the statusbar JPanel at the bottom
    // Give it a flow layout
    // Add the goButton JButton and the status JTextField
    // Add the Action Listener to goButton
    statusbar = new JPanel();
    statusbar.setLayout(new FlowLayout(
               FlowLayout.LEFT,5,5));
    goButton = new JButton("View Tracks");
    goButton.addActionListener(this);
    statusbar.add(goButton);

    status = new JTextField(60);
    status.setEditable(false);
    statusbar.add(status);
    getContentPane().add("South", statusbar);
    setTitle("Music Collection - Using EJB with JDBC");

    try {
      // Create Music EJB
      Context initial = new InitialContext();
      Object objref = initial.lookup(
               "java:comp/env/ejb/MyMusic");
      musicHome = (MusicHome)PortableRemoteObject.narrow(
                 objref, MusicHome.class);
      mymusic = musicHome.create();
    } catch (Exception ex) {
         System.out.println("Unexpected Exception: " +
               ex.getMessage());
         ex.printStackTrace();
    }
    // Access the EJB to read the Music Collection database
    // and put the title names in the JList swing component
    getRecordings();
    status.setText("There are " + albums.size() +
          " recordings");
    pack();
    show();

    // Set up the WindowListener object
    this.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e)
        { dispose(); }
      public void windowClosed(WindowEvent e)
        { System.exit(0); }
    });
  }

  public MusicApp(String title) {
      this();
      setTitle(title);
    }

    public void actionPerformed(ActionEvent e) {

      // Event handler for ActionEvent
      // (user clicks "View Tracks" button)

      if (e.getSource() instanceof JButton) {

      // make sure the user has selected a music title
      if (musicTitle.getSelectedValue() == null) {
        status.setText(
            "You must select a recording title first.");
      }

      else {
        // Tell the user what title
        // we're getting track info for
        status.setText("Displaying track list for " +
          musicTitle.getSelectedValue());
        // Using setText() wipes out any text previously
        // written to JTextArea
        data.setText("Track information for " +
          musicTitle.getSelectedValue());
        // getTracks() calls Music EJB
        // business method getTrackList()
        // getTracks() puts track info into the
        // JTextArea component
        getTracks(
          (RecordingVO)albums.get(
            musicTitle.getSelectedIndex()));

        // In case there are more tracks than visible
        // lines, position caret to top of component
        data.setCaretPosition(0);
      }
    }
  }

  public void valueChanged(ListSelectionEvent e) {

    // Event handler for ListSelectionEvent
    // (user changes selection in musicTitle
    // JList component)

    if (!e.getValueIsAdjusting()) {
      // Tell user which title was selected
      // Method getSelectedValue() returns a String
      status.setText("You selected " +
        musicTitle.getSelectedValue());

      // Access the RecordingVO object at the index
      // of the selected music title.
      // Method getSelectedIndex() returns the index of
      // the selected list item,
      // which corresponds to the same
      // index value in the albums ArrayList collection.
      RecordingVO r =
          (RecordingVO)albums.get(
                musicTitle.getSelectedIndex());

      // Display information from the RecordingVO object
      // in the JTextArea.
      // Use method setText() to clear previously written
      // text, then use method append().
      // Set caret position to top in case text causes
      // JTextArea to scroll.
        data.setText("RecordingID = " +
               r.getRecordID() + ",
");
        data.append("Title = " + r.getTitle() + ",
");
        data.append("Artist is " +
               r.getArtistName() + ",
");
        data.append("Music Category is " +
               r.getMusicCategory() + ",
");
        data.append("Label is " + r.getLabel() + ",
");
        data.append("Number of Tracks = " +
               r.getNumberOfTracks());
        data.setCaretPosition(0);
      }
    }

  static public void main(String args[]) {
      MusicApp acs = new MusicApp();
    }
  } // MusicApp