Listing 17.1  Timer (TTimer.java)
/*
 * <Applet code=TTimer width=400 height=200>
 * </Applet>
 */

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

public class TTimer extends JApplet {
    Container container = null;
    Timer timer = null;
    JLabel label = null;
    JSlider slider1 = null;
    JSlider slider2 = null;
    Color[] color = {Color.blue, Color.green, Color.red,
                     Color.yellow, Color.lightGray};

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

        // 2. Create a label and attach it to the applet.
        label = new JLabel("Swing can flash!", JLabel.CENTER);
        label.setBackground(Color.white);
        label.setFont(new Font("Dialog", Font.BOLD, 40));
        label.setOpaque(true);
        container.add(label);

        // 3. Create a horizontal box and attach it at the
        // bottom portion of the content pane.
        Box box = Box.createHorizontalBox();
        container.add(box, BorderLayout.SOUTH);

        // 4. Create a vertical box and add it to the horizontal box.
        Box vbox1 = Box.createVerticalBox();
        box.add(vbox1);

        // 5. Create labels and sliders and attach them to
        // a vertical box.
        JLabel initDelay = new JLabel("Initial Delay", JLabel.CENTER);
        initDelay.setPreferredSize(new Dimension(200, 25));
        vbox1.add(initDelay);
        slider1 = new JSlider(JSlider.HORIZONTAL, 0, 60000, 0);
        slider1.addChangeListener(new SliderListener());
        vbox1.add(slider1);
        JLabel delay = new JLabel("Timer Delay", JLabel.CENTER);
        delay.setPreferredSize(new Dimension(200, 25));
        vbox1.add(delay);
        slider2 = new JSlider(JSlider.HORIZONTAL, 0, 2000, 1000);
        slider2.addChangeListener(new SliderListener());
        vbox1.add(slider2);

        // 6. Create another vertical box and add it to the
        // horizontal box.
        Box vbox2 = Box.createVerticalBox();
        box.add(vbox2);

        // 7. Create a Swing panel with grid layout and add it to
        // the vertical box created in Snippet 6.
        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(2,2,5,5));
        vbox2.add(panel);

        // 8. Create Start, Stop, and Restart buttons, and add them
        // to the panel.
        String[] buttonLabels = {"Start", "Stop", "Restart"};
        for (int i=0; i<buttonLabels.length; i++) {
            JButton button = new JButton(buttonLabels[i]);
            button.addActionListener(new ButtonListener());
            panel.add(button);
        }

        // 9. Add a toggle button to the panel.
        JToggleButton toggleButton = new JToggleButton("Coalesce");
        toggleButton.setSelected(true); // since coalesced by default
        toggleButton.addActionListener(new ToggleButtonListener());
        panel.add(toggleButton);

        // 10. Create a timer object with prescribed delay and
        // initial delay retrieved from the corresponding
        // slider objects.
        timer = new Timer(slider2.getValue(), new TimerListener());
        timer.setInitialDelay(slider1.getValue()); //initial delay
    }

    // 11. Listener class that implements the "action code."
    class TimerListener implements ActionListener {
        int i;

        public void actionPerformed(ActionEvent e) {
            if (i == color.length) {
                i = 0;
                label.setForeground(color[i]);
            }
            else {
                label.setForeground(color[i]);
            }
            label.repaint();
            i++;
        }
    }

    // 12. Button listener that is used to start, stop, or
    // restart the timer.
    class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            JButton button = (JButton) e.getSource();

            if (button.getText() == "Start") {
                timer.start();
            }
            else if (button.getText() == "Stop") {
                timer.stop();
            }
            else if (button.getText() == "Restart") {
                timer.restart();
            }
        }
    }

    // 13. Toggle button listener to change coalescing status.
    class ToggleButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            if (timer.isCoalesce() == false)
                timer.setCoalesce(true);
            else if (timer.isCoalesce() == true)
                timer.setCoalesce(false);
        }
    }

    // 14. Slider listener to alter the initial delay or
    // timer delay.
    class SliderListener implements ChangeListener {
        public void stateChanged(ChangeEvent e) {
            JSlider slider = (JSlider) e.getSource();

            if (slider == slider1) {
                timer.setInitialDelay(slider1.getValue());
            }
            else if (slider == slider2) {
                timer.setDelay(slider2.getValue());
            }
        }
    }
}


Listing 17.2  A Progress Bar (TJProgressBar.java)
/*
 * <Applet code=TJProgressBar width=400 height=100>
 * </Applet>
 */

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

public class TJProgressBar extends JApplet {
    Container container = null;
    JButton startButton, stopButton;
    JTextField inputTextField, outputTextField;
    JProgressBar pBar = null;
    Timer timer = null;

    static int sum = 0;
    static int counter = 0;

    public void init() {
        // 1. Get the handle on the content pane and
        //    assign the grid layout.
        container = this.getContentPane();
        container.setLayout(new GridLayout(3,1));

        // 2. Add a horizontal box to the container.
        Box hbox1 = Box.createHorizontalBox();
        container.add(hbox1);

        // 3. Add labels and input and output text fields
        //    to the horizontal box.
        hbox1.add(Box.createHorizontalGlue());
        JLabel label1 = new JLabel("Sum of first ", JLabel.LEFT);
        label1.setFont(new Font("Dialog", Font.PLAIN, 15));
        hbox1.add(label1);

        inputTextField = new JTextField("100", 4);
        hbox1.add(inputTextField);

        JLabel label2 = new JLabel(" numbers is ", JLabel.LEFT);
        label2.setFont(new Font("Dialog", Font.PLAIN, 15));
        hbox1.add(label2);

        outputTextField = new JTextField(10);
        hbox1.add(outputTextField);
        hbox1.add(Box.createHorizontalGlue());

        // 4. Add another horizontal box to the container.
        Box hbox2 = Box.createHorizontalBox();
        container.add(hbox2);

        // 5. Add Start and Stop buttons to the container.
        startButton = new JButton("Start");
        startButton.addActionListener(new ButtonListener());
        hbox2.add(Box.createHorizontalGlue());
        hbox2.add(startButton);
        hbox2.add(Box.createHorizontalGlue());
        stopButton = new JButton("Stop");
        stopButton.addActionListener(new ButtonListener());
        hbox2.add(Box.createHorizontalGlue());
        hbox2.add(stopButton);
        hbox2.add(Box.createHorizontalGlue());

        // 6. Create and add a progress bar to the remaining
        //    display area.
        pBar = new JProgressBar();
        pBar.setStringPainted(true);
        Border border = BorderFactory.createLineBorder(Color.red, 2);
        pBar.setBorder(border);
        pBar.setBackground(Color.white);
        pBar.setForeground(Color.blue);
        pBar.setMinimum(0);

        pBar.setMaximum(Integer.parseInt(inputTextField.getText()));
        container.add(pBar);

        // 7. Create a timer object.
        timer = new Timer(0, new TimerListener());
    }

    // 8. Timer listener that computes the sum of natural numbers,
    //    indicates the computation progress, and displays the result.
    class TimerListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            if (Integer.parseInt(inputTextField.getText())> 0){
            counter++;
            sum = sum+counter;
            pBar.setValue(counter);
            outputTextField.setText(Integer.toString(sum));
            }
            else {
                outputTextField.setText("0");
            }

            if (counter >= Integer.parseInt(inputTextField.getText()))
               timer.stop();
        }
    }

    // 9. Button listener that actually starts or stops the
    //    process.
    class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            JButton button = (JButton) e.getSource();

            if (button.getText() == "Start") {
               outputTextField.setText("");
               if (inputTextField.getText() != " ") {
                    pBar.setMaximum(Integer.parseInt(
                               inputTextField.getText()));
                sum = 0;
                counter = 0;
                timer.start();
               }
            }
            else if (button.getText() == "Stop") {
                timer.stop();
                outputTextField.setText("");
                sum = 0;
                counter = 0;
                pBar.setValue(0);
            }
        }
    }
}

Listing 17.3  ProgressMonitor (TProgressMonitor.java)
/*
 * <Applet code=TProgressMonitor width=400 height=100>
 * </Applet>
 */

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

public class TProgressMonitor extends JApplet {
    Container container = null;
    JButton startButton, stopButton;
    JTextField inputTextField, outputTextField;
    ProgressMonitor pMonitor = null;
    Timer timer = null;

    static int sum = 0;
    static int counter = 0;

    public void init() {
        // 1. Get the handle on the content pane and
        //    assign the grid layout.
        container = this.getContentPane();
        container.setLayout(new GridLayout(2,1));

        // 2. Add a horizontal box to the container.
        Box hbox1 = Box.createHorizontalBox();
        container.add(hbox1);

        // 3. Add labels and input and output text fields
        //    to the horizontal box.
        hbox1.add(Box.createHorizontalGlue());
        JLabel label1 = new JLabel("Sum of first ", JLabel.LEFT);
        label1.setFont(new Font("Dialog", Font.PLAIN, 15));
        hbox1.add(label1);

        inputTextField = new JTextField("100", 4);
        hbox1.add(inputTextField);

        JLabel label2 = new JLabel(" numbers is ", JLabel.LEFT);
        label2.setFont(new Font("Dialog", Font.PLAIN, 15));
        hbox1.add(label2);

        outputTextField = new JTextField(10);
        hbox1.add(outputTextField);
        hbox1.add(Box.createHorizontalGlue());

        // 4. Add another horizontal box to the container.
        Box hbox2 = Box.createHorizontalBox();
        container.add(hbox2);

        // 5. Add Start and Stop buttons to the container.
        startButton = new JButton("Start");
        startButton.addActionListener(new ButtonListener());
        hbox2.add(Box.createHorizontalGlue());
        hbox2.add(startButton);
        hbox2.add(Box.createHorizontalGlue());
        stopButton = new JButton("Stop");
        stopButton.addActionListener(new ButtonListener());
        hbox2.add(Box.createHorizontalGlue());
        hbox2.add(stopButton);
        hbox2.add(Box.createHorizontalGlue());

        // 6. Create a timer object.
        timer = new Timer(0, new TimerListener());
    }

    // 7. Timer listener that computes the sum of natural numbers,
    //    indicates the computation progress, and displays the result.
    class TimerListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            if (Integer.parseInt(inputTextField.getText())> 0){
            counter++;
            sum = sum+counter;
            pMonitor.setProgress(counter);
            pMonitor.setNote("Currently Adding " + counter);
            outputTextField.setText(Integer.toString(sum));
            }
            else {
                outputTextField.setText("0");
            }

            if (counter >= Integer.parseInt(inputTextField.getText())){
               timer.stop();
               startButton.setEnabled(true);
            }
        }
    }

    // 8. Button listener that actually starts or stops the process.
    class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            JButton button = (JButton) e.getSource();

            if (button.getText() == "Start") {
               startButton.setEnabled(false);
               //9. Create a progress monitor.
               pMonitor = new ProgressMonitor(container,
                                  "Computation in Progress...",
                                  "Note", 0, 100);
               pMonitor.setMillisToPopup(5000);
               outputTextField.setText("");
               if (inputTextField.getText() != " ") {
                    pMonitor.setMaximum(Integer.parseInt(
                                inputTextField.getText()));
                  sum = 0;
                  counter = 0;
                  timer.start();
               }
            }
            else if (button.getText() == "Stop") {
                startButton.setEnabled(true);
                timer.stop();
                pMonitor.close();
                outputTextField.setText("");
                sum = 0;
                counter = 0;
            }
        }
    }
}

Listing 17.4  ProgressMonitorInputStream (TProgressMonitorIS.java)
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;

class TProgressMonitorIS {
    static ProgressMonitorInputStream progressInput = null;
    static JFrame frame = null;
    static WindowEventHandler handler = null;

    public static void main(String[] args) {
        // 1. Create a frame and get its content pane.
        frame = new JFrame ("Parent Frame");
        Container container = frame.getContentPane();
        frame.setVisible(true);
        frame.setDefaultCloseOperation(
                     WindowConstants.DISPOSE_ON_CLOSE);
        frame.setSize(350, 200);
        frame.show();

        // 2. Event handler for closing the window.
        handler = new WindowEventHandler();
        frame.addWindowListener(handler);

        // 3. Give the correct usage at the command line.
        //    in case it is needed
        if (args.length != 1) {
            System.out.println("Legal Usage: " +
                           "java TProgressMonitorIS <file>");
            System.exit(-1);
        }

        try {
            // 4. Create a file and file input stream objects.
            File file = new File(args[0]);
            FileInputStream inputStream =  new FileInputStream(file);

            // 5. Create the progress monitor for the input stream.
            progressInput = new ProgressMonitorInputStream(
                                    container,
                                    "Reading File: " + args[0],
                                    inputStream);

            // 6. Get a handle on the progress monitor of the
            // progressInput object, and assign the time periods
            // to decide to pop up and to pop up the dialog box.
            ProgressMonitor monitor =
                          progressInput.getProgressMonitor();
            monitor.setMillisToDecideToPopup(0);
            monitor.setMillisToPopup(0);

            // 7. Read the bytes and write on the screen.
            int curByte;
            while((curByte = progressInput.read()) != -1) {
                System.out.print((char) curByte);

                try {
                    // 8. Make this thread sleep, if the process
                    // is too quick to notice the progress dialog box.
                    Thread.sleep(0); // Set this to some value,
                                     // say 100, on faster machines
                } catch (InterruptedException ie) {
                    System.out.println(
                          "Thread Interruption Occurred!");
                }

                // 9. Close the progress input stream filter.
                if(monitor.isCanceled()) {
                    progressInput.close();
                }
             }
             10. //Close the progressInputstream.
             progressInput.close();
        } catch (Exception e) {
            System.out.println("....File Reading Interrupted....");
        }
    }
}

// 11. Create the listener class for window closing.
class WindowEventHandler extends WindowAdapter {
    public void windowClosing(WindowEvent evt) {
        System.exit(-1);
    }
}