DialogCallbackHandler.java

package org.objectweb.jonas.security.auth.callback;

import java.awt.GridLayout;
import java.io.IOException;

import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.callback.UnsupportedCallbackException;
import javax.swing.BoxLayout;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class DialogCallbackHandler implements CallbackHandler {

    private JTextField loginField = null;

    private JTextField passwordField = null;

    private boolean cancelled = false;

    private String title = "Login Dialog";

    private String username = "Username  ";

    private String password = "Password  ";

    private String loginButton = "Login !";

    private String cancelButton = "Cancel";

    private static final int MAX_FIELD_LENGTH = 20;

    private int passwordLength = MAX_FIELD_LENGTH;

    private int usernameLength = MAX_FIELD_LENGTH;

    private char echoChar = '*';

    private boolean echoCharOn = false;

    private String[] connectOptionNames;

    public DialogCallbackHandler() {
        int i = 0;
        connectOptionNames = new String[2];
        connectOptionNames[i] = loginButton;
        connectOptionNames[++i] = cancelButton;
    }

    public DialogCallbackHandler(String title) {
        this();
        this.title = title;
    }

    public DialogCallbackHandler(String title, String username, String password) {
        this();
        this.title = title;
        this.username = username;
        this.password = password;
    }

    public DialogCallbackHandler(String title, String username, String password, String loginButton,
            String cancelButton, int usernameLength, int passwordLength, char echoChar) {
        this(title, username, password);
        this.echoCharOn = true;
        this.echoChar = echoChar;
        this.loginButton = loginButton;
        this.cancelButton = cancelButton;
        this.passwordLength = passwordLength;
        this.usernameLength = usernameLength;
        this.echoChar = echoChar;
    }

    private void dialogInit(boolean isEchoOn) {

        // to determine whether the echo char must be displayed or not
        // we use a "OR" between the isEchoOn=passwordCallback.isEchoOn() and
        // the echoCharOn=the value of the variable echoCharOn set in the
        // OptionPaneCallbackHandler constructor.
        echoCharOn = (isEchoOn || echoCharOn);
        dialogInit();
    }

    private void dialogInit() {

        // for the login
        JLabel userNameLabel = new JLabel(username, JLabel.RIGHT);
        loginField = new JTextField("");

        // for the password
        JLabel passwordLabel = new JLabel(password, JLabel.RIGHT);

        // because of the bug of Java (in SDK 1.3) it isn't possible to display
        // password without an echo character in a password field, we have to
        // create a JTextField or a JPasswordField depending on echoCharOn.
        if (!echoCharOn) { // password needs to be hidden
            passwordField = new JPasswordField(passwordLength);
            ((JPasswordField) passwordField).setEchoChar(echoChar);
        } else {
            passwordField = new JTextField(passwordLength);
        }

        // creation of a JPanel to put the other panels on
        JPanel connectionPanel = new JPanel(false);
        connectionPanel.setLayout(new BoxLayout(connectionPanel, BoxLayout.X_AXIS));

        // to this panel we add the labels
        JPanel namePanel = new JPanel(false);
        namePanel.setLayout(new GridLayout(0, 1));
        namePanel.add(userNameLabel);
        namePanel.add(passwordLabel);

        // to this panel we add the fields
        JPanel fieldPanel = new JPanel(false);
        fieldPanel.setLayout(new GridLayout(0, 1));
        fieldPanel.add(loginField);
        fieldPanel.add(passwordField);

        // we add the 2 panels created in the first one
        connectionPanel.add(namePanel);
        connectionPanel.add(fieldPanel);

        // Connect or quit
        //System.out.println("Displaying dialog...");
        int choice = JOptionPane.showOptionDialog(null, // the default frame
                connectionPanel, // the object to display
                title, // the title string
                JOptionPane.OK_CANCEL_OPTION, // the options available
                JOptionPane.INFORMATION_MESSAGE, // the kind of message
                null, // the icon to display
                connectOptionNames, // the possible choices
                loginField); // the default selection

        if (choice == JOptionPane.OK_OPTION) {
            cancelled = false;
        } else if (choice == JOptionPane.CANCEL_OPTION) {
            // why is this value never got ?
            // JOptionPane.CANCEL_OPTION=2 but choice=1
            cancelled = true;
        } else if (choice == JOptionPane.CLOSED_OPTION) {
            cancelled = true;
        } else {
            cancelled = true; // another bug of Java
        }

        if (cancelled) {
            loginField.setText("Invalid");
            passwordField.setText("Invalid");
        }
    }

    public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException {

        // if the user clicked on the cancel button the the system won't
        // prompt him its informations
        if (cancelled) {
            return;
        }

        // recreate a new JDialog with the property to display or not
        // the password echo
        int i = 0;
        boolean found = false;
        while ((i < callbacks.length) && !found) {
            if (callbacks[i] instanceof PasswordCallback) {
                found = true;
                dialogInit(((PasswordCallback) callbacks[i]).isEchoOn());
            }
            // maybe we'll have to create a ObjectCallback object see later.
            i++;
        }
        // if there's no instance of PasswordCallback in the parameter
        // callbacks then there's a problem here !
        // TO DO : a new dialogInit to integrate an ObjectCallback for example
        // (for pki...)
        // while waiting...
        if (!found) {
            dialogInit();
        }

        // get the informations of the user
        for (i = 0; i < callbacks.length; i++) {

            if (callbacks[i] instanceof NameCallback) {
                ((NameCallback) callbacks[i]).setName(loginField.getText());
            } else if (callbacks[i] instanceof PasswordCallback) {
                ((PasswordCallback) callbacks[i]).setPassword((passwordField.getText()).toCharArray());
            } else {
                throw new UnsupportedCallbackException(callbacks[i], "Unrecognized Callback");
            }
        }
    }
}

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