LibraryUI.java

/*
 * LibraryUI.java former Comp302.java
 *
 * Created on March 6, 2003, 2:52 PM with netbeans
 * 
 * Updated on March 25 2005 by Jerome Dolman
 */

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.text.Document;
import javax.swing.text.BadLocationException;

import static java.awt.event.KeyEvent.VK_E;
import static java.awt.event.KeyEvent.VK_T;
import static javax.swing.BoxLayout.X_AXIS;
import static javax.swing.JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT;
import static javax.swing.JOptionPane.ERROR_MESSAGE;
import static javax.swing.JOptionPane.QUESTION_MESSAGE;
import static javax.swing.JOptionPane.showInputDialog;
import static javax.swing.JOptionPane.showMessageDialog;
import static javax.swing.JScrollPane.VERTICAL_SCROLLBAR_ALWAYS;
import static javax.swing.KeyStroke.getKeyStroke;

import java.util.Calendar;
import java.util.HashMap;
import java.util.Map;
import java.sql.*;

import static java.util.Calendar.DAY_OF_MONTH;
import static java.util.Calendar.MONTH;
import static java.util.Calendar.YEAR;

public class LibraryUI extends JFrame {
    // Actions
    private Action exitAction;
    private Action clearTextAction;
    private Action borrowAction;
    private Action returnAction;

    // The main output area
    private JTextArea outputArea;

    // Return fields
    private JTextField retISBN;
    private JTextField retCustID;

    // Borrow fields
    private JTextField borISBN;
    private JTextField borCustID;
    private JComboBox borDay;
    private JComboBox borMonth;
    private JComboBox borYear;

    // Buttons and tabbed pane - keep them for focus order
    private JButton returnButton;
    private JButton borrowButton;
    private JTabbedPane tabbedPane;

    // The data model
    private LibraryModel model;

    // A parent for modal dialogs
    private JFrame dialogParent = this;

    /**
     * Create a new LibraryUI object - showing an authentication dialog
     * then bringing up the main window.
     */
    public LibraryUI() {
	super("JDBC Library");
	// Uncomment the following if you'd rather not see everything in bold
	//UIManager.put("swing.boldMetal", Boolean.FALSE);

	// Initialise everything
	initActions();
        initUI();
	initFocusTraversalPolicy();
        setSize(600, 600);

	// Show Authentication dialog
	AuthDialog ad = new AuthDialog(this, "Authentication");
	ad.setVisible(true);
	String userName = ad.getUserName();
	String password = ad.getDatabasePassword();

	// Create data model
        model = new LibraryModel(this, userName, password);

	// Center window on screen
	GraphicsEnvironment ge =
	    GraphicsEnvironment.getLocalGraphicsEnvironment();
        Point center = ge.getCenterPoint();
        setLocation(center.x - getSize().width/2,
                    center.y - getSize().height/2);

	// Show ourselves
        setVisible(true);
    }

    private void initActions() {
	exitAction = new ExitAction();
	clearTextAction = new ClearTextAction();
	borrowAction = new BorrowAction();
	returnAction = new ReturnAction();

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent evt) {
                doExit();
            }
        });
    }

    private void initUI() {
	// Create tabbed pane with commands in it
        tabbedPane = new JTabbedPane();
        getContentPane().add(tabbedPane, BorderLayout.NORTH);

        tabbedPane.addTab("Book", null, createBookPane(),
			  "View book information");
        tabbedPane.addTab("Author", null, createAuthorPane(),
			  "View author information");
        tabbedPane.addTab("Customer", null, createCustomerPane(),
			  "View customer information");
        tabbedPane.addTab("Borrow Book", null, createBorrowPane(),
			  "Borrow books for a customer");
        tabbedPane.addTab("Return Book", null, createReturnPane(),
			  "Return books for a customer");

	// Create output area with scrollpane
        outputArea = new JTextArea();
	outputArea.setEditable(false);
	outputArea.setFocusable(false);
	outputArea.setTabSize(2);
	JScrollPane sp = new JScrollPane(outputArea);
	sp.setVerticalScrollBarPolicy(VERTICAL_SCROLLBAR_ALWAYS);

	getContentPane().add(sp, BorderLayout.CENTER);

	// Create menus
        JMenu fileMenu = new JMenu("File");
	fileMenu.setMnemonic('F');

	JMenuItem clearTextMenuItem = new JMenuItem(clearTextAction);
	JMenuItem exitMenuItem = new JMenuItem(exitAction);

        fileMenu.add(clearTextMenuItem);
	fileMenu.addSeparator();
        fileMenu.add(exitMenuItem);

        JMenuBar menuBar = new JMenuBar();
        menuBar.add(fileMenu);
        setJMenuBar(menuBar);

	// Pack it all
        pack();
    }

    // By default the GridBagLayout stuffs up tab ordering for the
    // borrow book and return book panes, so I need this to ensure it's all
    // the right way round.
    private void initFocusTraversalPolicy() {
	Container nearestRoot =
	    (isFocusCycleRoot()) ? this : getFocusCycleRootAncestor();
	final FocusTraversalPolicy defaultPolicy =
	    nearestRoot.getFocusTraversalPolicy();

	MapFocusTraversalPolicy mine =
	    new MapFocusTraversalPolicy(defaultPolicy, tabbedPane);
	mine.putAfter(retISBN, retCustID);
	mine.putAfter(retCustID, returnButton);
	mine.putAfter(returnButton, tabbedPane);
	mine.putAfter(borISBN, borCustID);
	mine.putAfter(borCustID, borDay);
	mine.putAfter(borDay, borMonth);
	mine.putAfter(borMonth, borYear);
	mine.putAfter(borYear, borrowButton);
	mine.putAfter(borrowButton, tabbedPane);

	mine.putBefore(retCustID, retISBN);
	mine.putBefore(returnButton, retCustID);
	mine.putBefore(borCustID, borISBN);
	mine.putBefore(borDay, borCustID);
	mine.putBefore(borMonth, borDay);
	mine.putBefore(borYear, borMonth);
	mine.putBefore(borrowButton, borYear);

	mine.putTabBefore("Borrow Book", borrowButton);
	mine.putTabBefore("Return Book", returnButton);

	nearestRoot.setFocusTraversalPolicy(mine);
    }

    private Container createBookPane() {
	// Create buttons
        JButton bookLookup = new JButton(new BookLookupAction());
        JButton showCat = new JButton(new ShowCatalogueAction());
        JButton showLoanedBook = new JButton(new ShowLoanedBooksAction());
        JButton deleteBook = new JButton(new DeleteBookAction());

	// Create panel
	Box pane = new Box(X_AXIS);
	pane.add(Box.createHorizontalGlue());
        pane.add(bookLookup);
	pane.add(Box.createHorizontalStrut(5));
        pane.add(showCat);
	pane.add(Box.createHorizontalStrut(5));
        pane.add(showLoanedBook);
    pane.add(Box.createHorizontalStrut(5));
        pane.add(deleteBook);
	pane.add(Box.createHorizontalGlue());
	return pane;
    }

    private Container createAuthorPane() {
	// Create buttons
        JButton showAuthor = new JButton(new ShowAuthorAction());
        JButton showAllAuth = new JButton(new ShowAllAuthorsAction());
        JButton deleteAuthor = new JButton(new DeleteAuthorAction());
	// Create panel
	Box pane = new Box(X_AXIS);
	pane.add(Box.createHorizontalGlue());
        pane.add(showAuthor);
	pane.add(Box.createHorizontalStrut(5));
        pane.add(showAllAuth);
    pane.add(Box.createHorizontalStrut(5));
        pane.add(deleteAuthor);
	pane.add(Box.createHorizontalGlue());

	return pane;
    }

    private Container createCustomerPane() {
	// Create buttons
        JButton showCus = new JButton(new ShowCustomerAction());
        JButton showAllCus = new JButton(new ShowAllCustomersAction());
        JButton deleteCus = new JButton(new DeleteCustomerAction());

	// Create panel
	Box pane = new Box(X_AXIS);
	pane.add(Box.createHorizontalGlue());
        pane.add(showCus);
	pane.add(Box.createHorizontalStrut(5));
        pane.add(showAllCus);
    pane.add(Box.createHorizontalStrut(5));
        pane.add(deleteCus);
	pane.add(Box.createHorizontalGlue());

	return pane;
    }

    private Container createBorrowPane() {
	// Initialise date combo boxes
        borDay = new JComboBox();
        borMonth = new JComboBox();
        borYear = new JComboBox();
	String[] days = new String[31];
	for (int i = 0; i < 31; i++) days[i] = String.valueOf(i+1);
	String[] months = { "January", "February", "March", "April",
			    "May", "June", "July", "August",
			    "September", "October", "November", "December" };
	String[] years = { "2005", "2006", "2007", "2008", "2009", "2010", "2011","2012","2013","2014","2015"}; 
        borDay.setModel(new DefaultComboBoxModel(days));
        borMonth.setModel(new DefaultComboBoxModel(months));
        borYear.setModel(new DefaultComboBoxModel(years));
	Calendar today = Calendar.getInstance();
	borDay.setSelectedIndex(today.get(DAY_OF_MONTH)-1);
	borMonth.setSelectedIndex(today.get(MONTH));
	borYear.setSelectedIndex(today.get(YEAR) - 2005);

	// Create borrow button
        borrowButton = new JButton(borrowAction);

	// Create text fields
	borISBN = new JTextField(15);
	borCustID = new JTextField(15);

	// Create panel and layout
	JPanel pane = new JPanel();
	pane.setOpaque(false);
	GridBagLayout gb = new GridBagLayout();
	pane.setLayout(gb);
	GridBagConstraints c = new GridBagConstraints();
	c.insets = new Insets(1, 5, 1, 5);

	// Fill panel
	c.anchor = GridBagConstraints.EAST;
	addToGridBag(gb, c, pane, new JLabel("ISBN:"),        0, 0, 1, 1);
	addToGridBag(gb, c, pane, new JLabel("Customer ID:"), 0, 1, 1, 1);
	addToGridBag(gb, c, pane, new JLabel("Due Date:"),    0, 2, 1, 1);

	c.anchor = GridBagConstraints.WEST;
	c.fill = GridBagConstraints.HORIZONTAL;
	addToGridBag(gb, c, pane, borISBN,  1, 0, 3, 1);
	addToGridBag(gb, c, pane, borCustID, 1, 1, 3, 1);

	c.fill = GridBagConstraints.NONE;
	addToGridBag(gb, c, pane, borDay,   1, 2, 1, 1);
	addToGridBag(gb, c, pane, borMonth, 2, 2, 1, 1);
	addToGridBag(gb, c, pane, borYear,  3, 2, 1, 1);

	addToGridBag(gb, c, pane, borrowButton, 4, 0, 1, 3);

	// Set up VK_ENTER triggering the borrow button in this panel
	InputMap input = pane.getInputMap(WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
	input.put(getKeyStroke("ENTER"), "borrowAction");
	pane.getActionMap().put("borrowAction", borrowAction);

	return pane;
    }

    private Container createReturnPane() {
	// Create return button
        returnButton = new JButton(returnAction);

	// Create text fields
	retISBN = new JTextField(15);
	retCustID = new JTextField(15);

	// Create panel and layout
	JPanel pane = new JPanel();
	pane.setOpaque(false);
	GridBagLayout gb = new GridBagLayout();
	pane.setLayout(gb);
	GridBagConstraints c = new GridBagConstraints();
	c.insets = new Insets(1, 5, 1, 5);

	// Fill panel
	c.anchor = GridBagConstraints.EAST;
	addToGridBag(gb, c, pane, new JLabel("ISBN:"),        0, 0, 1, 1);
	addToGridBag(gb, c, pane, new JLabel("Customer ID:"), 0, 1, 1, 1);

	c.anchor = GridBagConstraints.WEST;
	c.fill = GridBagConstraints.HORIZONTAL;
	addToGridBag(gb, c, pane, retISBN,  1, 0, 3, 1);
	addToGridBag(gb, c, pane, retCustID, 1, 1, 3, 1);

	c.fill = GridBagConstraints.NONE;
	addToGridBag(gb, c, pane, returnButton, 4, 0, 1, 3);

	// Set up VK_ENTER triggering the return button in this panel
	InputMap input = pane.getInputMap(WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
	input.put(getKeyStroke("ENTER"), "returnAction");
	pane.getActionMap().put("returnAction", returnAction);

	return pane;
    }

    private void addToGridBag(GridBagLayout gb, GridBagConstraints c,
			      Container cont, JComponent item,
			      int x, int y, int w, int h) {
	c.gridx = x;
	c.gridy = y;
	c.gridwidth = w;
	c.gridheight = h;
	gb.setConstraints(item, c);
	cont.add(item);
    }

    private class ExitAction extends AbstractAction {
	public ExitAction() {
	    super("Exit");
	    putValue(MNEMONIC_KEY, VK_E);
	    putValue(ACCELERATOR_KEY, getKeyStroke("ctrl Q"));
	}
	public void actionPerformed(ActionEvent evt) {
	    doExit();
	}
    }

    private class ClearTextAction extends AbstractAction {
	public ClearTextAction() {
	    super("Clear Text");
	    putValue(MNEMONIC_KEY, VK_T);
	    putValue(ACCELERATOR_KEY, getKeyStroke("ctrl T"));
	}
	public void actionPerformed(ActionEvent evt) {
	    Document document = outputArea.getDocument();
	    try {
		document.remove(0, document.getLength());
	    } catch(BadLocationException ble) {
	    }
	}
    }

    /**
     * An Action that catches any exception thrown in the doAction method.
     */
    private abstract class CatchAction extends AbstractAction {
	public CatchAction(String name) {
	    super(name);
	}
	public void actionPerformed(ActionEvent e) {
	    try {
		doAction();
	    } catch(Exception ex) {  showExceptionDialog(ex);  }
	}
	/** Subclasses implement this for their behaviour */
	protected abstract void doAction();
    }

    private class ReturnAction extends CatchAction {
	public ReturnAction() {
	    super("Return");
	}
	public void doAction() {
	    try {
		int isbn = Integer.parseInt(retISBN.getText());
		int cusID = Integer.parseInt(retCustID.getText());
		appendOutput(model.returnBook(isbn, cusID));
	    } catch ( NumberFormatException nfe ) {
		showMessageDialog(dialogParent, "The values entered for ISBN or customer ID do not have number format. Please try again.",
				  "Format Error", ERROR_MESSAGE);
	    }
	}
    }

    private class BorrowAction extends CatchAction {
	public BorrowAction() {
	    super("Borrow");
	}
	public void doAction() {
	    try {
		int isbn = Integer.parseInt(borISBN.getText());
		int cusID = Integer.parseInt(borCustID.getText());
		int day = Integer.parseInt((String)borDay.getSelectedItem());
		int year = Integer.parseInt((String)borYear.getSelectedItem());
		int month = borMonth.getSelectedIndex();
		appendOutput(model.borrowBook(isbn, cusID, day, month, year));
	    } catch ( NumberFormatException nfe ) {
		showMessageDialog(dialogParent,
				  "The values entered for ISBN or customer ID do not have a numeric format. Please try again.",
				  "Format Error", ERROR_MESSAGE);
	    }
	}
    }

    // Convenience method for the LookupAction constructor
    private static boolean isVowel(char c) {
	switch(Character.toLowerCase(c)) {
	case 'a': case 'e': case 'i': case 'o': case 'u':
	    return true;
	default:
	    return false;
	}
    }

     /**
     * A base class for lookup-based actions: prompt for a number with
     * various strings in the right places and call the doLookup method.
     */
    private abstract class LookupAction extends CatchAction {
	String title, itemDesc, a;
	public LookupAction(String name, String itemDesc) {
	    this(name, itemDesc, isVowel(itemDesc.charAt(0)) ? "an" : "a");
	}
	public LookupAction(String name, String itemDesc, String a) {
	    super(name);
	    title = name;
	    this.itemDesc = itemDesc;
	    this.a = a;
	}
	protected void doAction() {
	    try {
		Object in = showInputDialog(dialogParent,
					    "Enter " + a + " " + itemDesc,
					    title,
					    QUESTION_MESSAGE,
					    null, null, null);
		if (in == null)
		    return;
		int item = Integer.parseInt((String)in);
		doLookup(item);
	    } catch ( NumberFormatException nfe ) {
		String message =
		    "The " + itemDesc + " entered does not have a numeric " +
		    "format.  Please try again.";
		showMessageDialog(dialogParent, message,
				  "Format Error", ERROR_MESSAGE);
	    }
	}
	/** Subclasses implement this for their behaviour */
	protected abstract void doLookup(int id);
   }

    private class ShowCustomerAction extends LookupAction {
	public ShowCustomerAction() {
	    super("Show Customer", "customer ID");
	}
	protected void doLookup(int customerID) {
	    appendOutput(model.showCustomer(customerID));
	}
    }

    private class ShowAuthorAction extends LookupAction {
	public ShowAuthorAction() {
	    super("Show Author", "author ID");
	}
	protected void doLookup(int authorID) {
	    appendOutput(model.showAuthor(authorID));
	}
    }

    private class BookLookupAction extends LookupAction {
	public BookLookupAction() {
	    super("Book Lookup", "ISBN");
	}
	protected void doLookup(int isbn) {
	    appendOutput(model.bookLookup(isbn));
	}
    }
    
    private class DeleteCustomerAction extends LookupAction {
    	public DeleteCustomerAction() {
    	    super("Delete Customer", "customer ID");
    	}
    	protected void doLookup(int customerID) {
    	    appendOutput(model.deleteCus(customerID));
    	}
    }
    
    private class DeleteAuthorAction extends LookupAction {
    	public DeleteAuthorAction() {
    	    super("Delete Author", "author ID");
    	}
    	protected void doLookup(int authorID) {
    	    appendOutput(model.deleteAuthor(authorID));
    	}
    }
    private class DeleteBookAction extends LookupAction {
    	public DeleteBookAction() {
    	    super("Delete Book", "ISBN");
    	}
    	protected void doLookup(int isbn) {
    	    appendOutput(model.deleteBook(isbn));
    	}
    }

    private class ShowAllCustomersAction extends CatchAction {
	public ShowAllCustomersAction() {
	    super("Show All Customers");
	}
	protected void doAction() {
	    appendOutput(model.showAllCustomers());
	}
    }

    private class ShowAllAuthorsAction extends CatchAction {
	public ShowAllAuthorsAction() {
	    super("Show All Authors");
	}
	protected void doAction() {
	    appendOutput(model.showAllAuthors());
	}
    }

    private class ShowCatalogueAction extends CatchAction {
	public ShowCatalogueAction() {
	    super("Show Catalogue");
	}
	protected void doAction() {
	    appendOutput(model.showCatalogue());
	}
    }

    private class ShowLoanedBooksAction extends CatchAction {
	public ShowLoanedBooksAction() {
	    super("Show Loaned Books");
	}
	protected void doAction() {
	    appendOutput(model.showLoanedBooks());
	}
    }

    private void appendOutput(String str) {
	if (str != null && !str.equals(""))
	    outputArea.append(str + "\n\n");
	outputArea.setCaretPosition(outputArea.getDocument().getLength());
    }

    private void showExceptionDialog(Exception e) {
	showMessageDialog(this,
			  e.toString(),
			  "Error performing action",
			  ERROR_MESSAGE);
    }

    /** Exit the Application */
    private void doExit() {
        model.closeDBConnection();
        System.exit(0);
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
	// Build the UI on the Swing thread
	EventQueue.invokeLater(new Runnable() {
		public void run() {
		    new LibraryUI();
		}
	    });
    }
}

class AuthDialog extends JDialog {
    private boolean okButtonClicked = false;

    String introText = "Please enter your username and database password";
    private JPanel dialogPanel = new JPanel();
    private JPanel labelPanel = new JPanel();
    private JPanel inputPanel = new JPanel();
    private JTextField usernameTf = new JTextField(20);
    private JPasswordField passwdTf =  new JPasswordField(20);

    public AuthDialog() {
	this(null, "Authentication", false);
    }

    public AuthDialog(JFrame parent) {
	this(parent, "Authentication", true);
    }
    
    public AuthDialog(JFrame parent, String title) {
	this(parent, title, true);
    }
    
    public AuthDialog(final JFrame parent, String title, boolean modal) {
	super(parent, title, modal);

	// Set up close behaviour
	setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
	addWindowListener(new WindowAdapter() {
		public void windowClosing(WindowEvent e) {
		    if (!okButtonClicked)
			System.exit(0);
		}
	    });

	// Set up OK button behaviour
	JButton okButton = new JButton("OK");
	okButton.addActionListener(new ActionListener() {
		public void actionPerformed(ActionEvent e) { 
		    if (getUserName().length() == 0) {
			showMessageDialog(AuthDialog.this,
					  "Please enter a username",
					  "Format Error",
					  ERROR_MESSAGE);
			return;
		    }
		    if (getDatabasePassword().length() == 0) {
			showMessageDialog(AuthDialog.this,
					  "Please enter a password",
					  "Format Error",
					  ERROR_MESSAGE);
			return;
		    }
		    okButtonClicked = true;
		    setVisible(false);
		}
	    });
	JButton cancelButton = new JButton("Cancel");
	cancelButton.addActionListener(new ActionListener() {
		public void actionPerformed(ActionEvent e) {
		    System.exit(0);
		}
	    });

	// Set up dialog contents
	labelPanel.setBorder(BorderFactory.createEmptyBorder(20,20,5,5));
	inputPanel.setBorder(BorderFactory.createEmptyBorder(20,5,5,20));

	labelPanel.setLayout(new GridLayout(2, 1));
	labelPanel.add(new JLabel("User Name: "));
	labelPanel.add(new JLabel("Password:"));
	inputPanel.setLayout(new GridLayout(2, 1));
	inputPanel.add(usernameTf);
	inputPanel.add(passwdTf);

	Box buttonPane = new Box(X_AXIS);
	buttonPane.add(Box.createHorizontalGlue());
	buttonPane.add(okButton);
	buttonPane.add(Box.createHorizontalStrut(5));
	buttonPane.add(cancelButton);
	buttonPane.add(Box.createHorizontalGlue());
	buttonPane.setBorder(BorderFactory.createEmptyBorder(10, 0, 10, 0));

	JLabel introLabel = new JLabel(introText);
	introLabel.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
	getContentPane().add(introLabel, BorderLayout.NORTH);
	getContentPane().add(labelPanel, BorderLayout.WEST);
	getContentPane().add(inputPanel, BorderLayout.CENTER);
	getContentPane().add(buttonPane, BorderLayout.SOUTH);

	// Ensure the enter key triggers the OK button
	getRootPane().setDefaultButton(okButton);

	// And that the escape key exits
	InputMap inputMap = 
	    getRootPane().getInputMap(WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
	ActionMap actionMap = getRootPane().getActionMap();
	inputMap.put(getKeyStroke("ESCAPE"), "exitAction");
	actionMap.put("exitAction", new AbstractAction() {
		public void actionPerformed(ActionEvent e) {
		    System.exit(0);
		}
	    });

	// Pack it all
	pack();

	// Center on the screen
	setLocationRelativeTo(null);
    }
	
    public String getUserName() {
	return usernameTf.getText();
    }

    public String getDatabasePassword() {
	return new String(passwdTf.getPassword());
    }
}

/**
 * A custom focus traversal policy that allows components to be set
 * and knows about tabbed panes.
 */
class MapFocusTraversalPolicy extends FocusTraversalPolicy {
    private FocusTraversalPolicy defaultPolicy;
    private JTabbedPane tabbedPane;

    private Map<Component,Component> before =
	new HashMap<Component,Component>();
    private Map<String,Component> tabBefore =
	new HashMap<String,Component>();
    private Map<Component,Component> after =
	new HashMap<Component,Component>();

    public MapFocusTraversalPolicy(FocusTraversalPolicy def,
				   JTabbedPane tab) {
	defaultPolicy = def;
	tabbedPane = tab;
    }

    public void putAfter(Component a, Component b) {
	after.put(a, b);
    }

    public void putBefore(Component a, Component b) {
	before.put(a, b);
    }

    public void putTabBefore(String a, Component b) {
	tabBefore.put(a, b);
    }

    public Component getComponentAfter(Container cont,
				       Component comp) {
	Component next = after.get(comp);
	if (next != null)
	    return next;
	return defaultPolicy.getComponentAfter(cont, comp);
    }
    public Component getComponentBefore(Container cont,
					Component comp) {
	if (comp == tabbedPane) {
	    String tabTitle =
		tabbedPane.getTitleAt(tabbedPane.getSelectedIndex());
	    Component prev = tabBefore.get(tabTitle);
	    if (prev != null)
		return prev;
	}
	Component prev = before.get(comp);
	if (prev != null)
	    return prev;
	return defaultPolicy.getComponentBefore(cont, comp);
    }
    public Component getDefaultComponent(Container root) {
	return defaultPolicy.getDefaultComponent(root);
    }

    public Component getLastComponent(Container root) {
	return defaultPolicy.getLastComponent(root);
    }

    public Component getFirstComponent(Container root) {
	return defaultPolicy.getFirstComponent(root);
    }
}