Listing 11.1  JTextField Components and a Clear Button (TJTextField.java)
// Demonstrates Swing text fields.

/*
 * <Applet code = TJTextField width = 300 height = 150>
 * </Applet>
 */

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class TJTextField extends JApplet {
    Container container;
    JTextField textField1, textField2;

    public void init() {
        // 1. Get the handle on the applet's content pane.
        container = this.getContentPane();

        // 2. Prepare the applet with vertical box layout.
        container.setLayout(new BoxLayout(container, BoxLayout.Y_AXIS));

        // 3. Create two text-fields and a button.
        textField1 = new JTextField(
            "Enter some text here and press return", // Initial string
            20); // 20 columns width
        // Add an action listener to this text field.
        textField1.addActionListener(new TextFieldListener());
        // Assign a line border with black color.
        textField1.setBorder(BorderFactory.createLineBorder(Color.black));

        textField2 = new JTextField(20);   // 20 columns width.
        // Assign a line border with blue color.
        textField2.setBorder(BorderFactory.createLineBorder(Color.blue));

        JButton button = new JButton("Clear");
        // Add an action listener to this button.
        button.addActionListener(new ButtonListener());

        // 4. Add text-fields and button to the applet's content pane.
        container.add(Box.createVerticalGlue()); //Add a glue component.
        container.add(textField1); // Add the textfield1.
        container.add(Box.createVerticalGlue()); // Add another glue component.
        container.add(textField2); // add the textfield2
        container.add(Box.createVerticalGlue()); // Add another glue component.
        container.add(button); // Add the button.
    }

    // 5. The text field listener class.
    class TextFieldListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
             // Retrieve the text entered in textfield1
             // and assign it the other textfield.
             textField2.setText(e.getActionCommand());
        }
    }

    // 6. The button listener class.
    class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            // Clear both the text fields.
            textField1.setText("");
            textField1.requestFocus(); // Get the focus back
            textField2.setText("");
        }
    }
}

Listing 11.2   JPasswordField and JTextField components (TJPasswordField.java)
// Demonstrates Swing password fields.

/*
 * <Applet code=TJPasswordField width=350 height=125>
 * </Applet>
 */

import javax.swing.*;
import java.awt.*;

public class TJPasswordField extends JApplet {
    Container container;

    public void init() {
        // 1. Get the handle on the applet's content pane.
        container = this.getContentPane();

        // 2. Set the applet background color and layout.
        container.setBackground(Color.lightGray);
        GridBagLayout gridbag = new GridBagLayout();
        container.setLayout(gridbag);
        GridBagConstraints c = new GridBagConstraints();
        c.insets = new Insets(5,5,5,5); // top, left, bottom, right
        c.weightx = 1; c.weighty = 1;

        // 3. Create the component objects
        // and add them to the applet using grid bag layout.
        c.fill = c.BOTH;
        c.gridx = 0; c.gridy = 0;
        c.gridwidth = 1; c.gridheight = 1;
        JLabel label1 = new JLabel("Enter the Username: ");
        gridbag.setConstraints(label1, c);
        container.add(label1);

        c.gridx = 0; c.gridy = 1;
        JLabel label2 = new JLabel("Enter the Pass-Word: ");
        gridbag.setConstraints(label2, c);
        container.add(label2);

        c.fill = c.NONE;
        c.anchor = c.WEST;
        c.gridx = 1; c.gridy = 0;
        JTextField textField = new JTextField("satyaraj", 15);
        gridbag.setConstraints(textField, c);
        container.add(textField);

        c.gridx = 1; c.gridy = 1;
        JPasswordField passwordField = new JPasswordField(6);
        passwordField.setBorder(BorderFactory.createLineBorder(Color.red));
        gridbag.setConstraints(passwordField, c);
        container.add(passwordField);

        // 4. Set an echo character for the password field.
        // Note: The default character is "*".
        passwordField.setEchoChar('x');
    }
}

Listing 11.3  JTextArea and Edit Buttons (TJTextArea.java)
// Demonstrates the Swing text area.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class TJTextArea extends JFrame {
    // 1. Declare the references for the following objects.
    Container container;
    JLabel label = null;
    JTextField textField = null;
    JTextArea textArea = null;
    JButton insertButton = null;
    JButton deleteButton = null;
    JButton cutButton = null;
    JButton copyButton = null;
    JButton pasteButton = null;

    public TJTextArea() {
        // 2. Assign a name to the frame and obtain a handle
        // on the frame's content pane.
        super("TJTextArea");
        container = this.getContentPane();

        // 3. Create the fonts for label and text area.
        Font labelFont = new Font("SanSerif", Font.BOLD, 14);
        Font textFont = new Font("Dialog", Font.PLAIN, 12);

        // 4. Use the gridbag layout for the applet.
        GridBagLayout gridbag = new GridBagLayout();
        container.setLayout(gridbag);
        GridBagConstraints c = new GridBagConstraints();

        // 5. Add a label.
        c.fill = c.BOTH;
        c.insets = new Insets(2,2,2,2);
        c.gridx = 0; c.gridy = 0;
        c.gridwidth = 5; c.gridheight = 1;
        c.anchor = c.WEST;
        c.weightx = 1.0; c.weighty = 1.0;
        label = new JLabel("Enter Text: ");
        label.setFont(labelFont);
        gridbag.setConstraints(label, c);
        container.add(label);  // add the label

        // 6. Add a text field.
        c.anchor = c.CENTER;
        c.gridx = 0; c.gridy = 1;
        textField = new JTextField();
        gridbag.setConstraints(textField, c);
        container.add(textField);  // add the text-field

        // 7. Add the Insert button.
        c.gridx = 0; c.gridy = 2;
        c.gridwidth = 1; c.gridheight = 1;
        c.fill = c.BOTH; 
        insertButton = new JButton("Insert");
        insertButton.setBackground(Color.lightGray);
        gridbag.setConstraints(insertButton, c);
        container.add(insertButton);  // add insert button
        ButtonListener inButtonListener = new ButtonListener();
        insertButton.addActionListener(inButtonListener);

        // 8. Add the Delete button.
        c.gridx = 1; c.gridy = 2;
        deleteButton = new JButton("Delete");
        deleteButton.setBackground(Color.lightGray);
        gridbag.setConstraints(deleteButton, c);
        container.add(deleteButton); // add the delete button
        ButtonListener dlButtonListener = new ButtonListener();
        deleteButton.addActionListener(dlButtonListener);

        // 9. Add the Cut button.
        c.gridx = 2; c.gridy = 2;
        cutButton = new JButton("Cut");
        cutButton.setBackground(Color.lightGray);
        gridbag.setConstraints(cutButton, c);
        container.add(cutButton); // add the cut button
        ButtonListener ctButtonListener = new ButtonListener();
        cutButton.addActionListener(ctButtonListener);

        // 10. Add the Copy button.
        c.gridx = 3; c.gridy = 2;
        copyButton = new JButton("Copy");
        copyButton.setBackground(Color.lightGray);
        gridbag.setConstraints(copyButton, c);
        container.add(copyButton); // add the copy button
        ButtonListener cpButtonListener = new ButtonListener();
        copyButton.addActionListener(cpButtonListener);

        // 11. Add the Paste button.
        c.gridx = 4; c.gridy = 2;
        pasteButton = new JButton("Paste");
        pasteButton.setBackground(Color.lightGray);
        gridbag.setConstraints(pasteButton, c);
        container.add(pasteButton); // add the paste button
        ButtonListener psButtonListener = new ButtonListener();
        pasteButton.addActionListener(psButtonListener);

        // 12. Add the text area.
        c.gridx = 0; c.gridy = 3;
        c.gridwidth = 5; c.gridheight = 1;
        c.weightx = 1.0; c.weighty = 1.0;
        c.anchor = c.CENTER;
        c.fill = c.BOTH;
        String someText = "The Swing 'JTextArea' is a " +
                          "light-weight component.";
        textArea = new JTextArea(someText, // To be displayed initially
                                 6, // Number of rows.
                                 30); // Number of columns.
        textArea.setFont(textFont);
        textArea.setBackground(Color.white);
        textArea.setSelectionColor(Color.yellow);
        textArea.setTabSize(5); // The tab size.
        textArea.setLineWrap(true); // Wrap the line at the container end.
        gridbag.setConstraints(textArea, c);
        container.add(textArea); // Add the text area.

        // 13. Add the window listener to close the frame
        // and display it with the specified size.
        addWindowListener(new WindowEventHandler());       
        setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        setSize(400, 200); // width=400, height=200
        show(); // Display the frame.
    }

    // 14. Button listener class.
    class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            JButton b = (JButton) e.getSource();
            if (b == insertButton) {
                try { 
                    // Insert text at the caret position. The text is 
                    // is retrieved from the text field by using getText().
                    textArea.insert(textField.getText(),
                                    textArea.getCaretPosition());
                }
                catch (IllegalArgumentException excep) {
                }
            }
            else if (b == deleteButton) {
                textArea.replaceSelection(""); // Selected text is deleted.
            }
            else if (b == cutButton) {
                textArea.cut(); // Cut operation.
            }
            else if (b == copyButton) {
                textArea.copy(); // Copy operation.
            }
            else if (b == pasteButton) {
                textArea.paste(); // Paste operation.
            }
        }
    }

    // 15. The listener class to handle closing of the frame.
    class WindowEventHandler extends WindowAdapter {
        public void windowClosing(WindowEvent evt) {
            System.exit(0);
        }
    }   

    // 16. The main method.
    public static void main(String[] args){
        new TJTextArea();
    }
}

Listing 11.4  JEditorPane Displaying a Web Page (TJEditorPane.java)
// Demonstrates the Swing editor pane.

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

public class TJEditorPane extends JFrame {
    JTextField textField;
    JEditorPane editorPane;

    public TJEditorPane () {
        // 1. Assign a title to the frame and obtain
        // a reference to the frame's content pane.
        super("TJEditorPane");
        Container container = this.getContentPane();

        // 2. Create a label and attach it to a panel.
        JLabel label = new JLabel("Enter a URL: ");
        JPanel panel = new JPanel(new GridLayout(2,1));
        panel.add(label);

        // 3. Create a text field and add it to the panel.
        textField = new JTextField();
        textField.addActionListener(new TextFieldListener());
        panel.add(textField);

        // 4. Add the panel to the content pane.
        container.add(panel, BorderLayout.NORTH);

        // 5. Create an editor pane and add it to the content pane
        // through a scroll pane.
        editorPane = new JEditorPane();
        JScrollPane scrollPane = new JScrollPane(editorPane);                        
        container.add(scrollPane);

        // 6. Add the window listener to close the frame
        // and display it with the specified size.
        addWindowListener(new WindowEventHandler());       
        setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        setSize(350, 200); // width=350, height=200
        setBackground(Color.lightGray);
        setForeground(Color.black);
        show(); // Display the frame

        // 7. Get the focus to textField.
        textField.requestFocus();
    }

    // 8. The text field listener class.
    class TextFieldListener implements ActionListener {
        public void actionPerformed(ActionEvent ae) {
            URL pageURL = null;

            // 9. Create the URL object for the text that has been
            // entered in the text field.
            try {
                pageURL = new URL(textField.getText());
            } catch (MalformedURLException me) {
                System.out.println("MalformedURL");
            }

            // 10. Assign the page to the editor pane so that the
            // page is displayed.
            try {
                editorPane.setPage(pageURL);
            } catch (java.io.IOException ioe) {
                 System.out.println("IOException while loading page");
            }
        }
    }
    // 11. The main method.
    public static void main(String[] args) {
        new TJEditorPane();
    }

    // 12. The listener class to handle closing of the frame.
    class WindowEventHandler extends WindowAdapter {
        public void windowClosing(WindowEvent evt) {
            System.exit(0);
        }
    }
}

Listing 11.5  JTextPane Displaying Styled Text (TJTextPane.java)
// TJTextPane.java/* * <Applet code=TJTextPane.class width=400 height=300>
 * </Applet>
 */

import javax.swing.*;
import javax.swing.text.*;
import java.awt.*;

public class TJTextPane extends JApplet {
    JTextPane textPane = null;
    MutableAttributeSet centerAlign;
    MutableAttributeSet charStyle1, charStyle2, charStyle3;

    public void init() {
        // 1. Create a text pane object.
        textPane = new JTextPane();

        // 2. Prepare the paragraph attribute for center alignment.
        centerAlign = new SimpleAttributeSet(); 
        StyleConstants.setAlignment(centerAlign,
                                    StyleConstants.ALIGN_CENTER);

        // 3. Prepare the character attribute set called style1.
        charStyle1 = new SimpleAttributeSet();
        StyleConstants.setFontFamily(charStyle1, "Serif");
        StyleConstants.setFontSize(charStyle1, 75);

        // 4. Prepare another character attribute set called style2.
        charStyle2 = new SimpleAttributeSet();
        StyleConstants.setFontSize(charStyle2, 35);
        StyleConstants.setUnderline(charStyle2, true);
        StyleConstants.setForeground(charStyle2, Color.red);
        StyleConstants.setBold(charStyle2, true);
        StyleConstants.setItalic(charStyle2, true);

        // 5. Prepare one more character attribute set called style3.
        charStyle3 = new SimpleAttributeSet();
        StyleConstants.setFontSize(charStyle3, 20);

        // 6. Get a reference to the content model of the text pane.
        Document contentModel = textPane.getDocument();

        try {
            // 7. Assign a position to the caret.
            textPane.setCaretPosition(contentModel.getLength());
            // Insert the Java Duke icon.
            textPane.insertIcon(new ImageIcon("javaIcon1.gif"));

            // 8. Assign character attributes to the text pane.
            textPane.setCharacterAttributes(charStyle1, false);
            // Assign paragraph attributes to the text pane
            textPane.setParagraphAttributes(centerAlign, true);

            String javaText = "Java\n";
            // 9. Insert the string in the content of text pane.
            contentModel.insertString(contentModel.getLength(),
                                      javaText, charStyle1);

            // 10. Assign new character attributes to the text pane.
            textPane.setCharacterAttributes(charStyle2, true);

            String coolText = "JFC Swing is Cool!\n";
            // 11. Insert the string in the content of text pane.
            contentModel.insertString(contentModel.getLength(),
                                      coolText, charStyle2);

            // 12. Assign new character attributes to the text pane.
            textPane.setCharacterAttributes(charStyle3, true);

            String doneText = "Done!";
            // 13. Insert the string in the content of text pane.
            contentModel.insertString(contentModel.getLength(),
                                      doneText, charStyle3);
        } catch(BadLocationException blexcep) {
            System.err.println("Exception while inserting the string.");
            blexcep.printStackTrace();
        }

        // 14. Add the text pane to a scroll pane.
        JScrollPane scrollPane = new JScrollPane(textPane);
        // 15. Finally, add the scroll pane to the content pane.
        getContentPane().add(scrollPane);
    }
}