Class & int/String issues

Question

Upon compiling, I am receiving the following errors:
TeamRosterApp.java:153: cannot find symbol
symbol : class ButtonPanel
location: class TeamRosterPanel
ButtonPanel buttonPanel;
^
TeamRosterApp.java:166: cannot find symbol
symbol : class ButtonPanel
location: class TeamRosterPanel
buttonPanel = new ButtonPanel();
^
2 errors
I've included the code below, but I having difficulty understanding why it cannot find the ButtonPanel class when that class is specified in the code (Line 364).
Thanks in advance for your help!
//Modified by Doe, John 20OCT2007
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.JTextComponent;
import java.util.ArrayList;
import java.text.*;
import java.lang.*;
import java.util.*;
public class TeamRosterApp
     public static void main(String[] args)
          TeamIO.getTeam();
                JFrame frame = new TeamRosterFrame();
                frame.setVisible(true);
class Player
     String lname;
     String fname;
     int number;
     public Player()
          lname = "";
          fname = "";
          number = 0;
     public Player(String lname, String fname, int number)
          this.lname = lname;
          this.fname = fname;
          this.number = number;
     public void setLastName(String lname)
          this.lname = lname;
     public String getLastName()
          return lname;
     public void setFirstName(String fname)
          this.fname = fname;
     public String getFirstName()
          return fname;
     public void setNumber(int number)
          this.number = number;
     public int getNumber()
          return number;
class TeamIO
     private static final ArrayList<Player> team = new ArrayList<Player>();
     public static ArrayList<Player> getTeam()
          team.add(new Player("Doe", "John", 69));
          team.add(new Player("Berg", "Laura", 44));
          team.add(new Player("Bustos", "Crystl", 6));
          team.add(new Player("Clark", "Jamie", 24));
          team.add(new Player("Fernandez", "Lisa", 16));
          team.add(new Player("Finch", "Jennie", 27));
          team.add(new Player("Flowers", "Tairia", 11));
          team.add(new Player("Freed", "Amanda", 7));
          team.add(new Player("Giordano", "Nicole", 4));
          team.add(new Player("Harrigan", "Lori", 21));
          team.add(new Player("Jung", "Lovieanne", 3));
          team.add(new Player("Kretchman", "Kelly", 12));
          team.add(new Player("Lappin", "Lauren", 37));
          team.add(new Player("Mendoza", "Jessica", 2));
          team.add(new Player("O'Brien-Amico", "Lisa", 20));
          team.add(new Player("Nuveman", "Stacy", 33));
          team.add(new Player("Osterman", "Catherine", 8));
          team.add(new Player("Topping", "Jennie", 31));
          team.add(new Player("Watley", "Natasha", 29));
          System.out.println("\nOpening team list" + "\n\n" + "****************************************");
          for(int i = 0; i < team.size(); i++)
               Player p = (Player)team.get(i);
               System.out.print(p.getNumber() + "\t" + p.getLastName() + "," + p.getFirstName() + "\n");
               System.out.println("****************************************");
          return new ArrayList<Player>(team);
     public static ArrayList<Player> saveTeam()
          System.out.println("\nOpening team list" + "\n\n" + "****************************************");
          for(int i = 0; i < team.size(); i++)
          Player p = (Player)team.get(i);
          System.out.print(p.getNumber() + "\t" + p.getLastName() + "," + p.getFirstName() + "\n");
          System.out.println("****************************************");
          return new ArrayList<Player>(team);
class TeamRosterFrame extends JFrame
    public TeamRosterFrame()
        String me = "Campbell, Corey";
          String date;
          Date now = new Date();
          DateFormat longDate = DateFormat.getDateInstance(DateFormat.LONG);
          date = longDate.format(now);
          setTitle("Team Roster "+me+" "+date);
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.add(new TeamRosterPanel());
        this.pack();
        centerWindow(this);
    private void centerWindow(Window w)
        Toolkit tk = Toolkit.getDefaultToolkit();
        Dimension d = tk.getScreenSize();
        setLocation((d.width-w.getWidth())/2, (d.height-w.getHeight())/2);
class TeamRosterPanel extends JPanel
     ArrayList<Player>team;
     Player newPlayer = null;
     teamSelectorPanel selectorPanel;
     PlayerDisplayPanel playerPanel;
     ButtonPanel buttonPanel;
     public TeamRosterPanel()
          // fill the team ArrayList
          team = TeamIO.getTeam();
          // add the panels
          setLayout(new GridBagLayout());
          selectorPanel = new teamSelectorPanel();
          add(selectorPanel, getConstraints(0,0,1,1, GridBagConstraints.WEST));
          playerPanel = new PlayerDisplayPanel();
          add(playerPanel, getConstraints(0,1,1,1, GridBagConstraints.EAST));
          buttonPanel = new ButtonPanel();
          add(buttonPanel, getConstraints(0,2,1,1, GridBagConstraints.EAST));
          // set the initial player to be displayed
          playerPanel.showPlayer(team.get(0));
          selectorPanel.selectPlayer(team.get(0));
     // a method for setting grid bag constraints
     private GridBagConstraints getConstraints(int gridx, int gridy,
          int gridwidth, int gridheight, int anchor)
          GridBagConstraints c = new GridBagConstraints();
          c.insets = new Insets(5, 5, 5, 5);
          c.ipadx = 0;
          c.ipady = 0;
          c.gridx = gridx;
          c.gridy = gridy;
          c.gridwidth = gridwidth;
          c.gridheight = gridheight;
          c.anchor = anchor;
          return c;
     class teamSelectorPanel extends JPanel implements ActionListener
          public JComboBox    playerComboBox;
          private JLabel      playerLabel;
          boolean filling = false;            // used to indicate the combo box is being filled
          public teamSelectorPanel()
               // set panel layout
               setLayout(new FlowLayout(FlowLayout.LEFT));
               // Player label
               playerLabel = new JLabel("Select Player:");
               add(playerLabel);
               // Player combo box
               playerComboBox = new JComboBox();
               fillComboBox(team);
               playerComboBox.addActionListener(this);
               add(playerComboBox);
          public void actionPerformed(ActionEvent e)
               if (!filling)
                    Player p = (Player)playerComboBox.getSelectedItem();
                    playerPanel.showPlayer(p);
          public void fillComboBox(ArrayList<Player> team)
          filling = true;
          playerComboBox.removeAllItems();
          for (Player p : team)
          playerComboBox.addItem(p);
          filling = false;
          public void selectPlayer(Player p)
               playerComboBox.setSelectedItem(p);
          public Player getCurrentPlayer()
               return (Player) playerComboBox.getSelectedItem();
     class PlayerDisplayPanel extends JPanel
          public JTextField   lastNameTextField,
               firstNameTextField,
               numberTextField;
          private JLabel      lastNameLabel,
               firstNameLabel,
               numberLabel;
          public PlayerDisplayPanel()
               // set panel layout
               setLayout(new GridBagLayout());
               // last name label
               lastNameLabel = new JLabel("Last name:");
               add(lastNameLabel, getConstraints(0,0,1,1, GridBagConstraints.EAST));
               // last name text field
               lastNameTextField = new JTextField(10);
               lastNameTextField.setEditable(false);
               lastNameTextField.setFocusable(false);
               lastNameTextField.addFocusListener(new AutoSelect());
               add(lastNameTextField, getConstraints(1,0,1,1, GridBagConstraints.WEST));
               // first name label
               firstNameLabel = new JLabel("First name:");
               add(firstNameLabel, getConstraints(0,1,1,1, GridBagConstraints.EAST));
               // first name text field
               firstNameTextField = new JTextField(30);
               firstNameTextField.setEditable(false);
               firstNameTextField.setFocusable(false);
               firstNameTextField.addFocusListener(new AutoSelect());
               add(firstNameTextField, getConstraints(1,1,1,1, GridBagConstraints.WEST));
               // number label
               numberLabel = new JLabel("Number:");
               add(numberLabel, getConstraints(0,2,1,1, GridBagConstraints.EAST));
               // number text field
               numberTextField = new JTextField(10);
               numberTextField.setEditable(false);
               numberTextField.setFocusable(false);
               numberTextField.addFocusListener(new AutoSelect());
               numberTextField.addKeyListener(new IntFilter());
               add(numberTextField, getConstraints(1,2,1,1, GridBagConstraints.WEST));
          public void showPlayer(Player p)
               lastNameTextField.setText(p.getLastName());
               firstNameTextField.setText(p.getFirstName());
               numberTextField.setText(String.valueOf(p.getNumber()));
          public void clearFields()
               lastNameTextField.setText("");
               firstNameTextField.setText("");
               numberTextField.setText("");
          // return a new Player object with the data in the text fields
          public Player getPlayer()
               Player p = new Player();
               p.setLastName(lastNameTextField.getText());
               p.setFirstName(firstNameTextField.getText());
               int n = Integer.parseInt(numberTextField.getText());
               p.setNumber(n);
               return p;
          public void setAddEditMode(boolean e)
               lastNameTextField.setEditable(e);
               lastNameTextField.setFocusable(e);
               lastNameTextField.requestFocusInWindow();
               firstNameTextField.setEditable(e);
               firstNameTextField.setFocusable(e);
               numberTextField.setEditable(e);
               numberTextField.setFocusable(e);
          class AutoSelect implements FocusListener
               public void focusGained(FocusEvent e)
                    if(e.getComponent() instanceof JTextField)
                         JTextField t = (JTextField) e.getComponent();
                         t.selectAll();
               public void focusLost(FocusEvent e){}
          class IntFilter implements KeyListener
               public void keyTyped(KeyEvent e)
                    char c = e.getKeyChar();
                    if ( c !='0' && c !='1' && c !='2' && c !='3' && c !='4' && c !='5'
                         && c !='6' && c !='7' && c !='8' && c !='9')
                         e.consume();
               public void keyPressed(KeyEvent e){}
               public void keyReleased(KeyEvent e){}
          class ButtonPanel extends JPanel
               public JButton addButton,
                    editButton,
                    deleteButton,
                    acceptButton,
                    cancelButton,
                    exitButton;
               public ButtonPanel()
                    // create maintenance button panel
                    JPanel maintPanel = new JPanel();
                    maintPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
                    // add button
                    addButton = new JButton("Add");
                    addButton.addActionListener(new AddListener());
                    maintPanel.add(addButton);
                    // edit button
                    editButton = new JButton("Edit");
                    editButton.addActionListener(new EditListener());
                    maintPanel.add(editButton);
                    // delete button
                    deleteButton = new JButton("Delete");
                    deleteButton.addActionListener(new DeleteListener());
                    maintPanel.add(deleteButton);
                    // accept button
                    acceptButton = new JButton("Accept");
                    acceptButton.setEnabled(false);
                    acceptButton.addActionListener(new AcceptListener());
                    maintPanel.add(acceptButton);
                    // cancel button
                    cancelButton = new JButton("Cancel");
                    cancelButton.setEnabled(false);
                    cancelButton.addActionListener(new CancelListener());
                    maintPanel.add(cancelButton);
                    // create exit button panel
                    JPanel exitPanel = new JPanel();
                    exitPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
                    // exit button
                    exitButton = new JButton("Exit");
                    exitButton.addActionListener(new ExitListener());
                    exitPanel.add(exitButton);
                    // add panels to the ButtonPanel
                    setLayout(new BorderLayout());
                    add(maintPanel, BorderLayout.CENTER);
                    add(exitPanel, BorderLayout.SOUTH);
               public void setAddEditMode(boolean e)
                    addButton.setEnabled(!e);
                    editButton.setEnabled(!e);
                    deleteButton.setEnabled(!e);
                    acceptButton.setEnabled(e);
                    cancelButton.setEnabled(e);
          class AddListener implements ActionListener
               public void actionPerformed(ActionEvent e)
                    newPlayer = new Player();
                    playerPanel.clearFields();
                    buttonPanel.setAddEditMode(true);
                    playerPanel.setAddEditMode(true);
          class EditListener implements ActionListener
               public void actionPerformed(ActionEvent e)
                    buttonPanel.setAddEditMode(true);
                    playerPanel.setAddEditMode(true);
          class DeleteListener implements ActionListener
               public void actionPerformed(ActionEvent e)
                    Player p = selectorPanel.getCurrentPlayer();
                    team.remove(p);
                    TeamIO.saveTeam();
                    selectorPanel.fillComboBox(team);
                    selectorPanel.selectPlayer(team.get(0));
                    playerPanel.showPlayer(team.get(0));
                    selectorPanel.playerComboBox.requestFocusInWindow();
          class AcceptListener implements ActionListener
               public void actionPerformed(ActionEvent e)
                    if (isValidData())
                         if (newPlayer != null)
                              newPlayer = playerPanel.getPlayer();
                              team.add(newPlayer);
                              TeamIO.saveTeam();
                              selectorPanel.fillComboBox(team);
                              selectorPanel.selectPlayer(newPlayer);
                              newPlayer = null;
                         else
                              Player p = selectorPanel.getCurrentPlayer();
                              Player newPlayer = playerPanel.getPlayer();
                              p.setLastName(newPlayer.getLastName());
                              p.setFirstName(newPlayer.getFirstName());
                              p.setNumber(newPlayer.getNumber());
                              TeamIO.saveTeam();
                              selectorPanel.fillComboBox(team);
                              selectorPanel.selectPlayer(p);
                              playerPanel.showPlayer(selectorPanel.getCurrentPlayer());
                         playerPanel.setAddEditMode(false);
                         buttonPanel.setAddEditMode(false);
                         selectorPanel.playerComboBox.requestFocusInWindow();
               public boolean isValidData()
                    return SwingValidator.isPresent(playerPanel.lastNameTextField, "Last Name")
                         && SwingValidator.isPresent(playerPanel.firstNameTextField, "First Name")
                         && SwingValidator.isPresent(playerPanel.numberTextField, "Number")
                         && SwingValidator.isInteger(playerPanel.numberTextField, "Number");
          class CancelListener implements ActionListener
               public void actionPerformed(ActionEvent e)
                    if (newPlayer != null)
                         newPlayer = null;
                    playerPanel.setAddEditMode(false);
                    playerPanel.showPlayer(selectorPanel.getCurrentPlayer());
                    buttonPanel.setAddEditMode(false);
                    selectorPanel.playerComboBox.requestFocusInWindow();
          class ExitListener implements ActionListener
               public void actionPerformed(ActionEvent e)
                    System.exit(0);
}Swing Validator Code:
//Programmed by Doe, John 20OCT2007
import javax.swing.*;
import javax.swing.text.JTextComponent;
public class SwingValidator
     public static boolean isPresent(JTextComponent c, String title)
          if(c.getText().length()==0)
               showMessage(c, title + " is a required field.\n" + "Please re-enter.");
               c.requestFocusInWindow();
               return false;
          return true;
     public static boolean isInteger(JTextComponent c, String title)
          try
               int i = Integer.parseInt(c.getText());
               return true;
          catch(NumberFormatException e)
               showMessage(c,title+" must be an integer.\n"+"Please re-enter.");
               c.requestFocusInWindow();
               return false;
     private static void showMessage(JTextComponent c, String message)
          JOptionPane.showMessageDialog(c, message, "Invalid Entry", JOptionPane.ERROR_MESSAGE);
}Edited by: kc0poc on Oct 21, 2007 8:17 AM

Answer 1

Ok. Got it, understand it now. Corrected all 58 errors after created the top level classes. It compiles, but I'm now encountering a NullPointerException:
Exception in thread "main" java.lang.NullPointerException
at teamSelectorPanel.fillComboBox(TeamRosterAppTest.java:233)
at teamSelectorPanel.<init>(TeamRosterAppTest.java:214)
at TeamRosterPanel.<init>(TeamRosterAppTest.java:164)
at TeamRosterFrame.<init>(TeamRosterAppTest.java:135)
at TeamRosterAppTest.main(TeamRosterAppTest.java:17)
I think I am not initializing something correctly and it involved the "team" variable. Thoughts anyone?
Thank you as always!
Below is my code:
//Modified by Campbell, Corey 20OCT2007
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.JTextComponent;
import java.util.ArrayList;
import java.text.*;
import java.lang.*;
import java.util.*;
public class TeamRosterAppTest
     public static void main(String[] args)
          TeamIO.getTeam();
          JFrame frame = new TeamRosterFrame();
          frame.setVisible(true);
class Player
     String lname;
     String fname;
     int number;
     public Player()
          lname = "";
          fname = "";
          number = 0;
     public Player(String lname, String fname, int number)
          this.lname = lname;
          this.fname = fname;
          this.number = number;
     public void setLastName(String lname)
          this.lname = lname;
     public String getLastName()
          return lname;
     public void setFirstName(String fname)
          this.fname = fname;
     public String getFirstName()
          return fname;
     public void setNumber(int number)
          this.number = number;
     public int getNumber()
          return number;
class TeamIO
     private static final ArrayList<Player> team = new ArrayList<Player>();
     public static ArrayList<Player> getTeam()
          team.add(new Player("Campbell", "Corey", 69));
          team.add(new Player("Berg", "Laura", 44));
          team.add(new Player("Bustos", "Crystl", 6));
          team.add(new Player("Clark", "Jamie", 24));
          team.add(new Player("Fernandez", "Lisa", 16));
          team.add(new Player("Finch", "Jennie", 27));
          team.add(new Player("Flowers", "Tairia", 11));
          team.add(new Player("Freed", "Amanda", 7));
          team.add(new Player("Giordano", "Nicole", 4));
          team.add(new Player("Harrigan", "Lori", 21));
          team.add(new Player("Jung", "Lovieanne", 3));
          team.add(new Player("Kretchman", "Kelly", 12));
          team.add(new Player("Lappin", "Lauren", 37));
          team.add(new Player("Mendoza", "Jessica", 2));
          team.add(new Player("O'Brien-Amico", "Lisa", 20));
          team.add(new Player("Nuveman", "Stacy", 33));
          team.add(new Player("Osterman", "Catherine", 8));
          team.add(new Player("Topping", "Jennie", 31));
          team.add(new Player("Watley", "Natasha", 29));
          //System.out.println("\nOpening team list" + "\n\n" + "****************************************");
          //for(int i = 0; i < team.size(); i++)
          //          Player p = (Player)team.get(i);
          //          System.out.print(p.getNumber() + "\t" + p.getLastName() + "," + p.getFirstName() + "\n");
          //System.out.println("****************************************");
          return new ArrayList<Player>(team);
     public static ArrayList<Player> saveTeam()
          System.out.println("\nOpening team list" + "\n\n" + "****************************************");
          for(int i = 0; i < team.size(); i++)
               Player p = (Player)team.get(i);
               System.out.print(p.getNumber() + "\t" + p.getLastName() + "," + p.getFirstName() + "\n");
          System.out.println("****************************************");
          return new ArrayList<Player>(team);
class TeamRosterFrame extends JFrame
     public TeamRosterFrame()
          String me = "Campbell, Corey";
          String date;
          Date now = new Date();
          DateFormat longDate = DateFormat.getDateInstance(DateFormat.LONG);
          date = longDate.format(now);
          setTitle("Team Roster "+me+" "+date);
          setResizable(false);
          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          this.add(new TeamRosterPanel());
          this.pack();
          centerWindow(this);
     private void centerWindow(Window w)
          Toolkit tk = Toolkit.getDefaultToolkit();
          Dimension d = tk.getScreenSize();
          setLocation((d.width-w.getWidth())/2, (d.height-w.getHeight())/2);
class TeamRosterPanel extends JPanel
     ArrayList<Player>team;
     Player newPlayer = null;
     teamSelectorPanel selectorPanel;
     PlayerDisplayPanel playerPanel;
     ButtonPanel buttonPanel;
     public TeamRosterPanel()
          // fill the team ArrayList
          team = TeamIO.getTeam();
          // add the panels
          setLayout(new GridBagLayout());
          selectorPanel = new teamSelectorPanel();
          add(selectorPanel, getConstraints(0,0,1,1, GridBagConstraints.WEST));
          playerPanel = new PlayerDisplayPanel();
          add(playerPanel, getConstraints(0,1,1,1, GridBagConstraints.EAST));
          buttonPanel = new ButtonPanel();
          add(buttonPanel, getConstraints(0,2,1,1, GridBagConstraints.EAST));
          // set the initial player to be displayed
          playerPanel.showPlayer(team.get(0));
          selectorPanel.selectPlayer(team.get(0));
     // a method for setting grid bag constraints
     private GridBagConstraints getConstraints(int gridx, int gridy,
          int gridwidth, int gridheight, int anchor)
          GridBagConstraints c = new GridBagConstraints();
          c.insets = new Insets(5, 5, 5, 5);
          c.ipadx = 0;
          c.ipady = 0;
          c.gridx = gridx;
          c.gridy = gridy;
          c.gridwidth = gridwidth;
          c.gridheight = gridheight;
          c.anchor = anchor;
          return c;
class teamSelectorPanel extends JPanel implements ActionListener
     public JComboBox playerComboBox;
     private JLabel playerLabel;
     boolean filling = false;            // used to indicate the combo box is being filled
     ArrayList<Player>team;
     PlayerDisplayPanel playerPanel;
     public teamSelectorPanel()
          // set panel layout
          setLayout(new FlowLayout(FlowLayout.LEFT));
          // Player label
          playerLabel = new JLabel("Select Player:");
          add(playerLabel);
          // Player combo box
          playerComboBox = new JComboBox();
          fillComboBox(team);
          playerComboBox.addActionListener(this);
          add(playerComboBox);
     public void actionPerformed(ActionEvent e)
          if (!filling)
               Player p = (Player)playerComboBox.getSelectedItem();
               playerPanel.showPlayer(p);
     public void fillComboBox(ArrayList<Player> team)
          filling = true;
          playerComboBox.removeAllItems();
          for (Player p : team)
          playerComboBox.addItem(p);
          filling = false;
     public void selectPlayer(Player p)
          playerComboBox.setSelectedItem(p);
     public Player getCurrentPlayer()
          return (Player) playerComboBox.getSelectedItem();
class PlayerDisplayPanel extends JPanel
     public JTextField lastNameTextField,
          firstNameTextField,
          numberTextField;
     private JLabel lastNameLabel,
          firstNameLabel,
          numberLabel;
     public PlayerDisplayPanel()
          // set panel layout
          setLayout(new GridBagLayout());
          // last name label
          lastNameLabel = new JLabel("Last name:");
          add(lastNameLabel, getConstraints(0,0,1,1, GridBagConstraints.EAST));
          // last name text field
          lastNameTextField = new JTextField(10);
          lastNameTextField.setEditable(false);
          lastNameTextField.setFocusable(false);
          lastNameTextField.addFocusListener(new AutoSelect());
          add(lastNameTextField, getConstraints(1,0,1,1, GridBagConstraints.WEST));
          // first name label
          firstNameLabel = new JLabel("First name:");
          add(firstNameLabel, getConstraints(0,1,1,1, GridBagConstraints.EAST));
          // first name text field
          firstNameTextField = new JTextField(30);
          firstNameTextField.setEditable(false);
          firstNameTextField.setFocusable(false);
          firstNameTextField.addFocusListener(new AutoSelect());
          add(firstNameTextField, getConstraints(1,1,1,1, GridBagConstraints.WEST));
          // number label
          numberLabel = new JLabel("Number:");
          add(numberLabel, getConstraints(0,2,1,1, GridBagConstraints.EAST));
          // number text field
          numberTextField = new JTextField(10);
          numberTextField.setEditable(false);
          numberTextField.setFocusable(false);
          numberTextField.addFocusListener(new AutoSelect());
          numberTextField.addKeyListener(new IntFilter());
          add(numberTextField, getConstraints(1,2,1,1, GridBagConstraints.WEST));
     public void showPlayer(Player p)
          lastNameTextField.setText(p.getLastName());
          firstNameTextField.setText(p.getFirstName());
          numberTextField.setText(String.valueOf(p.getNumber()));
     public void clearFields()
          lastNameTextField.setText("");
          firstNameTextField.setText("");
          numberTextField.setText("");
     // return a new Player object with the data in the text fields
     public Player getPlayer()
          Player p = new Player();
          p.setLastName(lastNameTextField.getText());
          p.setFirstName(firstNameTextField.getText());
          int n = Integer.parseInt(numberTextField.getText());
          p.setNumber(n);
          return p;
     public void setAddEditMode(boolean e)
          lastNameTextField.setEditable(e);
          lastNameTextField.setFocusable(e);
          lastNameTextField.requestFocusInWindow();
          firstNameTextField.setEditable(e);
          firstNameTextField.setFocusable(e);
          numberTextField.setEditable(e);
          numberTextField.setFocusable(e);
     // a method for setting grid bag constraints
     private GridBagConstraints getConstraints(int gridx, int gridy,
          int gridwidth, int gridheight, int anchor)
          GridBagConstraints c = new GridBagConstraints();
          c.insets = new Insets(5, 5, 5, 5);
          c.ipadx = 0;
          c.ipady = 0;
          c.gridx = gridx;
          c.gridy = gridy;
          c.gridwidth = gridwidth;
          c.gridheight = gridheight;
          c.anchor = anchor;
          return c;
class AutoSelect implements FocusListener
     public void focusGained(FocusEvent e)
          if(e.getComponent() instanceof JTextField)
               JTextField t = (JTextField) e.getComponent();
               t.selectAll();
     public void focusLost(FocusEvent e){}
class IntFilter implements KeyListener
     public void keyTyped(KeyEvent e)
          char c = e.getKeyChar();
          if ( c !='0' && c !='1' && c !='2' && c !='3' && c !='4' && c !='5'
               && c !='6' && c !='7' && c !='8' && c !='9')
               e.consume();
     public void keyPressed(KeyEvent e){}
     public void keyReleased(KeyEvent e){}
class ButtonPanel extends JPanel
     public JButton addButton,
          editButton,
          deleteButton,
          acceptButton,
          cancelButton,
          exitButton;
     public ButtonPanel()
          // create maintenance button panel
          JPanel maintPanel = new JPanel();
          maintPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
          // add button
          addButton = new JButton("Add");
          addButton.addActionListener(new AddListener());
          maintPanel.add(addButton);
          // edit button
          editButton = new JButton("Edit");
          editButton.addActionListener(new EditListener());
          maintPanel.add(editButton);
          // delete button
          deleteButton = new JButton("Delete");
          deleteButton.addActionListener(new DeleteListener());
          maintPanel.add(deleteButton);
          // accept button
          acceptButton = new JButton("Accept");
          acceptButton.setEnabled(false);
          acceptButton.addActionListener(new AcceptListener());
          maintPanel.add(acceptButton);
          // cancel button
          cancelButton = new JButton("Cancel");
          cancelButton.setEnabled(false);
          cancelButton.addActionListener(new CancelListener());
          maintPanel.add(cancelButton);
          // create exit button panel
          JPanel exitPanel = new JPanel();
          exitPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
          // exit button
          exitButton = new JButton("Exit");
          exitButton.addActionListener(new ExitListener());
          exitPanel.add(exitButton);
          // add panels to the ButtonPanel
          setLayout(new BorderLayout());
          add(maintPanel, BorderLayout.CENTER);
          add(exitPanel, BorderLayout.SOUTH);
     public void setAddEditMode(boolean e)
          addButton.setEnabled(!e);
          editButton.setEnabled(!e);
          deleteButton.setEnabled(!e);
          acceptButton.setEnabled(e);
          cancelButton.setEnabled(e);
class AddListener implements ActionListener
     PlayerDisplayPanel playerPanel;
     ButtonPanel buttonPanel;
     Player newPlayer;
     public void actionPerformed(ActionEvent e)
          newPlayer = new Player();
          playerPanel.clearFields();
          buttonPanel.setAddEditMode(true);
          playerPanel.setAddEditMode(true);
class EditListener implements ActionListener
     ButtonPanel buttonPanel;
     PlayerDisplayPanel playerPanel;
     public void actionPerformed(ActionEvent e)
          buttonPanel.setAddEditMode(true);
          playerPanel.setAddEditMode(true);
class DeleteListener implements ActionListener
     teamSelectorPanel selectorPanel;
     PlayerDisplayPanel playerPanel;
     ArrayList<Player>team;
     public void actionPerformed(ActionEvent e)
          Player p = selectorPanel.getCurrentPlayer();
          team.remove(p);
          TeamIO.saveTeam();
          selectorPanel.fillComboBox(team);
          selectorPanel.selectPlayer(team.get(0));
          playerPanel.showPlayer(team.get(0));
          selectorPanel.playerComboBox.requestFocusInWindow();
class AcceptListener implements ActionListener
     teamSelectorPanel selectorPanel;
     PlayerDisplayPanel playerPanel;
     ButtonPanel buttonPanel;
     ArrayList<Player>team;
     Player newPlayer;
     public void actionPerformed(ActionEvent e)
          if (isValidData())
               if (newPlayer != null)
                    newPlayer = playerPanel.getPlayer();
                    team.add(newPlayer);
                    TeamIO.saveTeam();
                    selectorPanel.fillComboBox(team);
                    selectorPanel.selectPlayer(newPlayer);
                    newPlayer = null;
               else
                    Player p = selectorPanel.getCurrentPlayer();
                    Player newPlayer = playerPanel.getPlayer();
                    p.setLastName(newPlayer.getLastName());
                    p.setFirstName(newPlayer.getFirstName());
                    p.setNumber(newPlayer.getNumber());
                    TeamIO.saveTeam();
                    selectorPanel.fillComboBox(team);
                    selectorPanel.selectPlayer(p);
                    playerPanel.showPlayer(selectorPanel.getCurrentPlayer());
               playerPanel.setAddEditMode(false);
               buttonPanel.setAddEditMode(false);
               selectorPanel.playerComboBox.requestFocusInWindow();
     public boolean isValidData()
          return SwingValidator.isPresent(playerPanel.lastNameTextField, "Last Name")
               && SwingValidator.isPresent(playerPanel.firstNameTextField, "First Name")
               && SwingValidator.isPresent(playerPanel.numberTextField, "Number")
               && SwingValidator.isInteger(playerPanel.numberTextField, "Number");
class CancelListener implements ActionListener
     Player newPlayer;
     PlayerDisplayPanel playerPanel;
     ButtonPanel buttonPanel;
     teamSelectorPanel selectorPanel;
     public void actionPerformed(ActionEvent e)
          if (newPlayer != null)
               newPlayer = null;
          playerPanel.setAddEditMode(false);
          playerPanel.showPlayer(selectorPanel.getCurrentPlayer());
          buttonPanel.setAddEditMode(false);
          selectorPanel.playerComboBox.requestFocusInWindow();
class ExitListener implements ActionListener
     public void actionPerformed(ActionEvent e)
          System.exit(0);
class SwingValidator
     public static boolean isPresent(JTextComponent c, String title)
          if(c.getText().length()==0)
               showMessage(c, title + " is a required field.\n" + "Please re-enter.");
               c.requestFocusInWindow();
               return false;
          return true;
     public static boolean isInteger(JTextComponent c, String title)
          try
               int i = Integer.parseInt(c.getText());
               return true;
          catch(NumberFormatException e)
               showMessage(c,title+" must be an integer.\n"+"Please re-enter.");
               c.requestFocusInWindow();
               return false;
     private static void showMessage(JTextComponent c, String message)
          JOptionPane.showMessageDialog(c, message, "Invalid Entry", JOptionPane.ERROR_MESSAGE);
}