telephone.java

SMC takes a state machine stored in a .sm file and generates a State pattern in twelve programming l

        gridConstraints.ipady = 2;
        gridConstraints.weightx = 0.0;
        gridConstraints.weighty = 0.0;
        gridbag.setConstraints(_dialButtons[10], gridConstraints);
        pane.add(_dialButtons[10]);

        gridConstraints.anchor = GridBagConstraints.CENTER;
        gridConstraints.gridx = 1;
        gridConstraints.gridy = 6;
        gridConstraints.gridwidth = 1;
        gridConstraints.gridheight = 1;
        gridConstraints.ipadx = 2;
        gridConstraints.ipady = 2;
        gridConstraints.weightx = 0.0;
        gridConstraints.weighty = 0.0;
        gridbag.setConstraints(_dialButtons[0], gridConstraints);
        pane.add(_dialButtons[0]);

        gridConstraints.anchor = GridBagConstraints.CENTER;
        gridConstraints.gridx = 2;
        gridConstraints.gridy = 6;
        gridConstraints.gridwidth = 1;
        gridConstraints.gridheight = 1;
        gridConstraints.ipadx = 2;
        gridConstraints.ipady = 2;
        gridConstraints.weightx = 0.0;
        gridConstraints.weighty = 0.0;
        gridbag.setConstraints(
            _dialButtons[11], gridConstraints);
        pane.add(_dialButtons[11]);

        return;
    }

    private void _soundPhoneNumber(List<AudioData> audioList)
    {
        int i;
        String digit;

        // If this is a long distance number, sound out the
        // area code first.
        if (_callType == LONG_DISTANCE)
        {
            for (i = 0; i < _areaCode.length(); ++i)
            {
                digit = _areaCode.substring(i, (i + 1));
                audioList.add(_audioMap.get(digit));
            }
        }

        // All types have an exchange.
        for (i = 0; i < _exchange.length(); ++i)
        {
            digit = _exchange.substring(i, (i + 1));
            audioList.add(_audioMap.get(digit));
        }

        // Only long distance and local numbers have a local
        // portion.
        if (_callType == LONG_DISTANCE || _callType == LOCAL)
        {
            for (i = 0; i < _local.length(); ++i)
            {
                digit = _local.substring(i, (i + 1));
                audioList.add(_audioMap.get(digit));
            }
        }

        return;
    }

    private void _soundMeridian(int am_pm,
                                List<AudioData> audioList)
    {
        AudioData clip;

        if (am_pm == Calendar.AM)
        {
            clip = _audioMap.get("AM");
        }
        else
        {
            clip = _audioMap.get("PM");
        }

        audioList.add(clip);

        return;
    }

    private void _soundNumber(int number,
                              boolean zeroFlag,
                              List<AudioData> audioList)
    {
        if (number < 10 && zeroFlag == true)
        {
            audioList.add(_audioMap.get("oh"));
            audioList.add(
                _audioMap.get(Integer.toString(number)));
        }
        else if (number < 20)
        {
            audioList.add(
                _audioMap.get(Integer.toString(number)));
        }
        else
        {
            int onesDigit = number % 10;
            int tensDigit = number - onesDigit;

            // Read the ten's digit first and then the
            // remainder - if not zero.
            audioList.add(
                _audioMap.get(Integer.toString(tensDigit)));

            if (onesDigit != 0)
            {
                audioList.add(
                    _audioMap.get(Integer.toString(onesDigit)));
            }
        }

        return;
    }

    private void _playbackDone(PlaybackThread thread)
    {
        _playbackThread = null;
        _fsm.PlaybackDone();
    }

    private void _callRoute(int route)
    {
        switch (route)
        {
            case EMERGENCY:
                _fsm.Emergency();
                break;

            case NYC_TEMP:
                _fsm.NYCTemp();
                break;

            case TIME:
                _fsm.Time();
                break;

            case DEPOSIT_MONEY:
                _fsm.DepositMoney();
                break;

            case LINE_BUSY:
                _fsm.LineBusy();
                break;

            case INVALID_NUMBER:
                _fsm.InvalidNumber();
                break;
        }

        return;
    }

// Member data.

    // The telphone state machine.
    private TelephoneContext _fsm;

    // The type of call being dialed.
    private int _callType;

    // Store dialed numbers here.
    private String _areaCode;
    private String _exchange;
    private String _local;
    private String _display;

    // Display the dialed digits here.
    private JTextField _numberDisplay;

    // This button is used to pick-up/put-down the receiver.
    private JButton _receiverButton;

    // Dialing buttons.
    private JButton[] _dialButtons;

    // Zounds! It's sounds!
    private AudioClip[] _dtmf;
    private Map<String, AudioData> _audioMap;
    private PlaybackThread _playbackThread;

    // Timer objects.
    private Map<String, TelephoneTimer> _timerMap;
    private static Timer _timer;
    private static Map<String, Method> _timerTransitionMap;

    // The telephone's time display.
    private static SimpleDateFormat _ClockFormatter = null;

    // Constants.
    public static final int LONG_DISTANCE = 1;
    public static final int LOCAL = 2;
    public static final int EMERGENCY = 3;

    private static final int NYC_TEMP = 4;
    private static final int TIME = 5;
    private static final int DEPOSIT_MONEY = 6;
    private static final int LINE_BUSY = 7;
    private static final int INVALID_NUMBER = 8;

    private static final long MILLIS_PER_MINUTE = 60000;

    static
    {
        _timer = new Timer(true);
        _timerTransitionMap = new HashMap<String, Method>();

        _ClockFormatter =
            new SimpleDateFormat("    HH:mm a    MMMM dd, yyyy");

        // Fill in the static associations between timer names
        // and their transition.
        Class context = TelephoneContext.class;
        Class[] parameters = new Class[0];

        try
        {
            _timerTransitionMap.put(
                "ClockTimer",
                context.getDeclaredMethod(
                    "ClockTimer", parameters)
                );
            _timerTransitionMap.put(
                "OffHookTimer",
                context.getDeclaredMethod(
                    "OffHookTimer", parameters)
                );
            _timerTransitionMap.put(
                "LoopTimer",
                context.getDeclaredMethod(
                    "LoopTimer", parameters)
                );
            _timerTransitionMap.put(
                "RingTimer",
                context.getDeclaredMethod(
                    "RingTimer", parameters)
                );
        }
        catch (NoSuchMethodException nsmex)
        {
            nsmex.printStackTrace(System.out);
        }
    }

// Inner classes.

    private final class TelephoneTimer
        extends TimerTask
    {
    // Member methods.

        public void run()
        {
            _owner.issueTimeout(_name);
        }

        private TelephoneTimer(String name,
                               long delay,
                               Telephone owner)
        {
            _name = name;
            _delay = delay;
            _owner = owner;
        }

        private long getDelay()
        {
            return (_delay);
        }

        // Member data.

        private String _name;
        private long _delay;
        private Telephone _owner;
    }

    // When playing a series of audio clips, it is neccessary
    // to wait for one clip to finish before starting the next.
    // Since Java audio clips don't know how long they are, it
    // is necessary to store with each sound clip its duration.
    private final class AudioData
    {
    // Member methods.

        public void play()
            throws InterruptedException
        {
            if (_clip != null ||
                (_clip = Applet.newAudioClip(_url)) != null)
            {
                _clip.play();

                try
                {
                    Thread.sleep(_duration);
                }
                catch (InterruptedException interrupt)
                {
                    // Stop the audio clip before rethrowing the
                    // intettupt.
                    _clip.stop();
                    _clip = null;

                    throw (interrupt);
                }
            }

            return;
        }

        public void loop()
        {
            if (_clip != null ||
                (_clip = Applet.newAudioClip(_url)) != null)
            {
                _clip.loop();
            }

            return;
        }

        public void stop()
        {
            if (_clip != null)
            {
                _clip.stop();
                _clip = null;
            }

            return;
        }

        private AudioData(URL url, long duration)
        {
            _url = url;
            _clip = null;
            _duration = duration;
        }

        private URL getURL()
        {
            return (_url);
        }

        private long getDuration()
        {
            return (_duration);
        }

    // Member data.

        private URL _url;
        private AudioClip _clip;
        private long _duration;
    }

    // Play several audio clips, one after another in a
    // separate thread.
    private final class PlaybackThread
        extends Thread
    {
    // Member methods.

        public void run()
        {
            Iterator<AudioData> it;
            AudioData clip = null;

            _thread = Thread.currentThread();

            try
            {
                for (it = _audioList.iterator();
                     it.hasNext() == true;
                    )
                {
                    clip = it.next();

                    clip.play();
                    clip = null;
                }
            }
            catch (InterruptedException interrupt)
            {}

            // Stop the currently playing sound.
            if (clip != null)
            {
                clip.stop();
            }

            _audioList.clear();

            if (_owner != null)
            {
                _owner._playbackDone(this);
            }

            return;
        }

        public void halt()
        {
            // Since the telephone object is telling us to
            // stop, don't tell the telephone that we are
            // stopped.
            _owner = null;

            _continueFlag = false;
            _thread.interrupt();

            return;
        }

        private PlaybackThread(List<AudioData> audioList,
                               Telephone owner)
        {
            _audioList = audioList;
            _owner = owner;
            _thread = null;
            _continueFlag = false;
        }

    // Member data.

        private List<AudioData> _audioList;
        private Telephone _owner;
        private boolean _continueFlag;
        private Thread _thread;
    }

    // Call routing needs to be done asynchronouzly in order to
    // avoid issuing a transition within a transition.
    private final class CallRoutingThread
        extends Thread
    {
    // Member methods.

        public void run()
        {
            int route;

            if (_callType == Telephone.EMERGENCY)
            {
                route = Telephone.EMERGENCY;
            }
            else if (_callType == Telephone.LONG_DISTANCE &&
                     _areaCode.compareTo("1212") == 0 &&
                     _exchange.compareTo("555") == 0 &&
                     _local.compareTo("1234") == 0)
            {
                route = Telephone.NYC_TEMP;
            }
            else if (_exchange.compareTo("555") == 0)
            {
                if (_local.compareTo("1212") == 0)
                {
                    route = Telephone.TIME;
                }
                else
                {
                    route = Telephone.LINE_BUSY;
                }
            }
            else if (_callType == Telephone.LOCAL)
            {
                route = Telephone.DEPOSIT_MONEY;
            }
            else
            {
                route = Telephone.INVALID_NUMBER;
            }

            _areaCode = null;
            _exchange = null;
            _local = null;

            // There is a race condition between this thread
            // and the main thread which contains the FSM.
            // Apparently this thread can complete while the
            // FSM is still in transition, causing an exception.
            // so sleep a bit before issuing the callback.
            try
            {
                Thread.sleep(1);
            }
            catch (InterruptedException interrupt)
            {
                // Ignore.
            }

            _owner._callRoute(route);

            return;
        }

        private CallRoutingThread(int callType,
                                  String areaCode,
                                  String exchange,
                                  String local,
                                  Telephone owner)
        {
            _callType = callType;
            _areaCode = new String(areaCode);
            _exchange = new String(exchange);
            _local = new String(local);
            _owner = owner;
        }

    // Member data.

        private int _callType;
        private String _areaCode;
        private String _exchange;
        private String _local;
        private Telephone _owner;
    }
}