Re: Trying to get JComboBox to "repopulate" with increased java.util.Vector

package com.ppowell.applications;

import java.io.*;
import java.awt.*;
import java.net.*;
import java.util.*;
import javax.swing.*;
import java.awt.event.*;

public class Blah
        extends JFrame
        implements
        Serializable {

    private String urlPath;
    private URL url;
    private GridBagConstraints c;
    private JPanel p1;
    private JButton b;
    private String myName = "Blah";

    protected int screenWidth = 0;
    protected int screenHeight = 0;
    protected JComboBox webAddressBox;
    protected Vector<URL> historyURLVector;

    private static boolean hasAddedInitialURL = false;
    private static boolean hasEnteredAdditionalURL = false;

    protected static final String DEFAULT_URL_PATH = "http://
java.net";
    protected static final int DEFAULT_SCREEN_WIDTH =

(int)Toolkit.getDefaultToolkit().getScreenSize().getWidth();
    protected static final int DEFAULT_SCREEN_HEIGHT =

(int)Toolkit.getDefaultToolkit().getScreenSize().getHeight();
    protected static final int DEFAULT_WEB_ADDRESS_BAR_HEIGHT = 50;

    //-------------------------- --* CONSTRUCTORS
*------------------------------
    public Blah() {
        super();
        setupBlah();
    }

    //--------------------- --* GETTER/SETTER METHODS
*----------------------------
    private int getScreenHeight() {
        return this.screenHeight;
    }

    private int getScreenWidth() {
        return this.screenWidth;
    }

    private URL getURL() {
        return this.url;
    }

    private String getURLPath() {
        return this.urlPath;
    }

    private void setScreenHeight(int screenHeight) {
        this.screenHeight = screenHeight;
    }

    private void setScreenWidth(int screenWidth) {
        this.screenWidth = screenWidth;
    }

    private void setURL(String urlPath) {
        try {
            URL url = new URL(urlPath);
            setURL(url);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
    }

    private void setURL(URL url) {
        this.url = url;
    }

    private void setURLPath(String urlPath) {
        this.urlPath = urlPath;
    }

    //--------------- --* END OF GETTER/SETTER METHODS
*-----------------------

    public void addToFrame() {
        setLayout(new GridBagLayout());
        c = new GridBagConstraints();
        c.gridx = 0;
        c.gridy = 0;
        c.anchor = GridBagConstraints.NORTHWEST;
        add(p1, c);
    }

    protected void addToHistoryURLVector() throws Exception {
        URL url;
        if (getURL() == null) {
            url = new URL(getURLPath());
            setURL(url);
        } else {
            url = getURL();
        }
        if (historyURLVector != null && !
                historyURLVector.contains(url)) {
            historyURLVector.add(url);
        } else if (historyURLVector == null) {
            historyURLVector = new Vector<URL>();
            historyURLVector.add(url);
        }
    }

    protected void addToHistoryURLVector(URL url) throws Exception {
        setURL(url);
        addToHistoryURLVector();
    }

    public void addToPanel() {
        layoutTopPanel();
    }

    private void generateJButton() {
        b = new JButton("Go");
        ActionListener listener = new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                processURL();
            }
        };
        // WILL ENTER URL ON CTRL-G
        b.registerKeyboardAction(listener,
                KeyStroke.getKeyStroke(KeyEvent.VK_G,
InputEvent.CTRL_MASK, true),
                JComponent.WHEN_IN_FOCUSED_WINDOW);
        // WILL ENTER URL ON CR
        b.registerKeyboardAction(listener,
                KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, true),
                JComponent.WHEN_IN_FOCUSED_WINDOW);
        b.addActionListener(listener);
        b.setSelected(false);
        // WILL ENTER URL ON ALT-G
        b.setMnemonic('G');
    }

    private void generateJComboBox() {
        if (Blah.hasAddedInitialURL && historyURLVector !=
                null && historyURLVector.size() > 0) {
            webAddressBox = new JComboBox(historyURLVector);
        } else if (Blah.hasAddedInitialURL) {
            webAddressBox = new JComboBox();
        }

        if (getScreenWidth() == 0)
            setScreenWidth(Blah.DEFAULT_SCREEN_WIDTH);
        Dimension dim = new Dimension((int)(getScreenWidth() / 1.14),
                (int)(Blah.DEFAULT_WEB_ADDRESS_BAR_HEIGHT /
                2));
        webAddressBox.setMaximumSize(dim);
        webAddressBox.setPreferredSize(dim);
        webAddressBox.setEditable(true);
        webAddressBox.setBackground(Color.WHITE);

        /** For more info <a href="https://lists.xcf.berkeley.edu/
         * lists/advanced-java/1999-September/000508.html">click here</
a> **/
        webAddressBox.setModel(new
                DefaultComboBoxModel(historyURLVector));

    }
    private void initComponents() {
        setTitle(myName);
        if (getScreenWidth() == 0)
            setScreenWidth(Blah.DEFAULT_SCREEN_WIDTH);
        generateJComboBox();
        generateJButton();
        p1 = new JPanel(true);
        addToPanel(); // FOR NOW WILL ONLY ADD JPanel p1
        addToFrame();
        showFrame();
    }

    private void initObjects() {
        if (getURL() == null && getURLPath() == null)
            setURLPath(Blah.DEFAULT_URL_PATH);
        historyURLVector = new Vector<URL>();
        try {
            addToHistoryURLVector();
            Blah.hasAddedInitialURL = true;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void layoutTopPanel() {
        c = new GridBagConstraints();
        c.gridx = 0;
        c.gridy = 0;
        c.anchor = GridBagConstraints.NORTHWEST;

        p1.setLayout(new GridBagLayout());
        p1.add(new JLabel("Your URL:"), c);

        c.gridx++;
        c.gridy = 0;
        c.fill = GridBagConstraints.HORIZONTAL;
        p1.add(webAddressBox, c); // ADD JComboBox

        c.gridx++;
        c.gridy = 0;
        c.fill = GridBagConstraints.NONE;
        p1.add(b, c); // ADD JBUTTON
        if (getScreenWidth() <= 0)
            setScreenWidth(Blah.DEFAULT_SCREEN_WIDTH);
        p1.setSize(new Dimension(getScreenWidth(),
                Blah.DEFAULT_WEB_ADDRESS_BAR_HEIGHT));
        p1.setOpaque(true);
        p1.setBackground(Color.WHITE);
        p1.setVisible(true);
    }

    protected void processURL() {
        Blah.hasEnteredAdditionalURL = true;
        Blah.hasAddedInitialURL = false;
        setURLPath(webAddressBox.getSelectedItem().toString());
        try {
            addToHistoryURLVector(new URL(getURLPath()));
        } catch (Exception e) {
            e.printStackTrace();
        }
        generateJComboBox();
        webAddressBox.setSelectedItem(getURL());

        p1.remove(webAddressBox);
        p1.add(webAddressBox, 1);
        p1.revalidate();
        remove(p1);
        add(p1, 0);
        validate();
     }

    private void setupBlah() {
        initObjects();
        initComponents();
    }

    public void showFrame() {
        pack();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

    public static void main(String[] args) {
        Blah blah = new Blah();
    }

}