public class StopwatchActivity extends ListActivity {
    private static String TAG = "StopwatchActivity";

    // View elements in stopwatch.xml
    private TextView m_elapsedTime, tvRow;
    private Button m_start;
    private Button m_pause;
    private Button m_reset;
    private Button m_lap;
    private Context mContext;
    private int id;

    private ArrayAdapter<String> m_lapList;

    // Timer to update the elapsedTime display
    private final long mFrequency = 100; // milliseconds
    private final int TICK_WHAT = 2;
    private Handler mHandler = new Handler() {
        public void handleMessage(Message m) {
            updateElapsedTime();
            sendMessageDelayed(Message.obtain(this, TICK_WHAT), mFrequency);
        }
    };

    // Connection to the backgorund StopwatchService
    private StopwatchService m_stopwatchService;
    private ServiceConnection m_stopwatchServiceConn = new ServiceConnection() {
        public void onServiceConnected(ComponentName name, IBinder service) {
            m_stopwatchService = ((StopwatchService.LocalBinder) service)
                    .getService();
            showCorrectButtons();
        }

        public void onServiceDisconnected(ComponentName name) {
            m_stopwatchService = null;
        }
    };

    private void bindStopwatchService() {
        bindService(new Intent(this, StopwatchService.class),
                m_stopwatchServiceConn, Context.BIND_AUTO_CREATE);
    }

    private void unbindStopwatchService() {
        if (m_stopwatchService != null) {
            unbindService(m_stopwatchServiceConn);
        }
    }

    @SuppressWarnings("unchecked")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.stopwatch);

        startService(new Intent(this, StopwatchService.class));
        bindStopwatchService();

        m_elapsedTime = (TextView) findViewById(R.id.ElapsedTime);
        Typeface typeface = Typeface.createFromAsset(getAssets(),
                "Fonts/DS-DIGIT.TTF");
        m_elapsedTime.setTypeface(typeface);
        m_start = (Button) findViewById(R.id.StartButton);
        m_pause = (Button) findViewById(R.id.PauseButton);
        m_reset = (Button) findViewById(R.id.ResetButton);
        m_lap = (Button) findViewById(R.id.LapButton);

        setListAdapter(new ArrayAdapter<String>(this, R.layout.laps_row));
        m_lapList = (ArrayAdapter<String>) getListAdapter();

        mHandler.sendMessageDelayed(Message.obtain(mHandler, TICK_WHAT),
                mFrequency);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindStopwatchService();
    }

    private void showCorrectButtons() {
        Log.d(TAG, "showCorrectButtons");

        if (m_stopwatchService != null) {
            if (m_stopwatchService.isStopwatchRunning()) {
                showPauseLapButtons();
            } else {
                showStartResetButtons();
            }
        }
    }

    private void showPauseLapButtons() {
        Log.d(TAG, "showPauseLapButtons");

        m_start.setVisibility(View.GONE);
        m_reset.setVisibility(View.GONE);
        m_pause.setVisibility(View.VISIBLE);
        m_lap.setVisibility(View.VISIBLE);
    }

    private void showStartResetButtons() {
        Log.d(TAG, "showStartResetButtons");

        m_start.setVisibility(View.VISIBLE);
        m_reset.setVisibility(View.VISIBLE);
        m_pause.setVisibility(View.GONE);
        m_lap.setVisibility(View.GONE);
    }

    public void onStartClicked(View v) {
        Log.d(TAG, "start button clicked");
        m_stopwatchService.start();

        showPauseLapButtons();
    }

    public void onPauseClicked(View v) {
        Log.d(TAG, "pause button clicked");
        m_stopwatchService.pause();

        showStartResetButtons();
    }

    public void onResetClicked(View v) {
        Log.d(TAG, "reset button clicked");
        m_stopwatchService.reset();

        m_lapList.clear();
    }

    public void onLapClicked(View v) {
        Log.d(TAG, "lap button clicked");
        m_stopwatchService.lap();

        m_lapList.insert(m_stopwatchService.getFormattedElapsedTime(), 0);
    }

    public void updateElapsedTime() {
        if (m_stopwatchService != null)
            m_elapsedTime.setText(m_stopwatchService.getFormattedElapsedTime());
    }