Created ChronometerNotificationService and ChronometerNotificationThread. Modify TimerNotificationService to extend from ChronometerNotificationService.

app/src/main/java/com/philliphsu/clock2/ChronometerNotificationService.java

@@ -0,0 +1,248 @@
+package com.philliphsu.clock2;
+
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.os.IBinder;
+import android.support.annotation.CallSuper;
+import android.support.annotation.DrawableRes;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.app.NotificationCompat;
+
+import com.philliphsu.clock2.timers.ChronometerDelegate;
+
+/**
+ * Created by Phillip Hsu on 9/10/2016.
+ */
+public abstract class ChronometerNotificationService extends Service {
+    public static final String ACTION_START_PAUSE = "com.philliphsu.clock2.timers.action.START_PAUSE";
+    public static final String ACTION_STOP = "com.philliphsu.clock2.timers.action.STOP";
+
+    private NotificationCompat.Builder mNoteBuilder;
+    private NotificationManager mNotificationManager;
+    // TODO: I think we may need a list of threads.
+    private ChronometerNotificationThread mThread;
+    private final ChronometerDelegate mDelegate = new ChronometerDelegate();
+
+    /**
+     * @return the icon for the notification
+     */
+    @DrawableRes
+    protected abstract int getSmallIcon();
+
+    /**
+     * @return an optional content intent that is fired when the notification is clicked
+     */
+    @Nullable
+    protected abstract PendingIntent getContentIntent();
+
+    /**
+     * @return whether the chronometer should be counting down
+     */
+    protected abstract boolean isCountDown();
+
+    /**
+     * @return a tag associated with the notification. The default implementation returns the
+     * name of this class.
+     */
+    protected String getNoteTag() {
+        return getClass().getName();
+    }
+
+    /**
+     * The intent received in {@link #onStartCommand(Intent, int, int)}
+     * has no {@link Intent#getAction() action} set. At this point, you
+     * should configure the notification to be displayed.
+     * @param intent
+     * @param flags
+     * @param startId
+     */
+    protected abstract void handleDefaultAction(Intent intent, int flags, long startId);
+
+    protected abstract void handleStartPauseAction(Intent intent, int flags, long startId);
+
+    protected abstract void handleStopAction(Intent intent, int flags, long startId);
+
+    /**
+     * This will be called if the command in {@link #onStartCommand(Intent, int, int)}
+     * has an action that your subclass defines.
+     * @param action Your custom action.
+     */
+    protected abstract void handleAction(@NonNull String action, Intent intent, int flags, long startId);
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
+        // Create base note
+        mNoteBuilder = new NotificationCompat.Builder(this)
+                .setSmallIcon(getSmallIcon())
+                .setShowWhen(false)
+                .setOngoing(true)
+                .setContentIntent(getContentIntent());
+        mDelegate.init();
+        mDelegate.setCountDown(isCountDown());
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        quitThread();
+        // TODO: Cancel all notifications pushed by this notification manager.
+    }
+
+    @CallSuper
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        if (intent != null) {
+            final String action = intent.getAction();
+            if (action != null) {
+                switch (action) {
+                    case ACTION_START_PAUSE:
+                        handleStartPauseAction(intent, flags, startId);
+                        break;
+                    case ACTION_STOP:
+                        handleStopAction(intent, flags, startId);
+                        break;
+                    default:
+                        // Defer to the subclass
+                        handleAction(action, intent, flags, startId);
+                        break;
+                }
+            } else {
+                handleDefaultAction(intent, flags, startId);
+            }
+        }
+        return super.onStartCommand(intent, flags, startId);
+    }
+
+    @Nullable
+    @Override
+    public final IBinder onBind(Intent intent) {
+        return null;
+    }
+
+    /**
+     * If there is a thread currently running, then this will push any notification updates
+     * you might have configured in the Builder and then call the thread's {@link
+     * ChronometerNotificationThread#quit() quit()}.
+     */
+    public void quitCurrentThread() {
+        if (mThread != null) {
+            // Display any notification updates associated with the current state
+            // of the chronometer. If we relied on the HandlerThread to do this for us,
+            // the message delivery would be delayed.
+            mThread.updateNotification();
+            // If the chronometer has been set to not run, the effect is obvious.
+            // Otherwise, we're preparing for the start of a new thread.
+            quitThread();
+        }
+    }
+
+    /**
+     * Instantiates a new HandlerThread and calls its {@link Thread#start() start()}.
+     * The calling thread will be blocked until the HandlerThread created here finishes
+     * initializing its looper.
+     * @param noteId the id with which the thread created here will be posting notifications.
+     * @param base the new base time of the chronometer
+     */
+    public void startNewThread(int noteId, long base) {
+        // An instance of Thread cannot be started more than once. You must create
+        // a new instance if you want to start the Thread's work again.
+        mThread = new ChronometerNotificationThread(
+                mDelegate,
+                mNotificationManager,
+                mNoteBuilder,
+                getResources(),
+                getNoteTag(),
+                noteId);
+        // Initializes this thread as a looper. HandlerThread.run() will be executed
+        // in this thread.
+        // This gives you a chance to create handlers that then reference this looper,
+        // before actually starting the loop.
+        mThread.start();
+        // If this thread has been started, this method will block *the calling thread*
+        // until the looper has been initialized. This ensures the handler thread is
+        // fully initialized before we proceed.
+        mThread.getLooper();
+        // -------------------------------------------------------------------------------
+        // TOneverDO: Set base BEFORE the thread is ready to begin working, or else when
+        // the thread actually begins working, it will initially show that some time has
+        // passed.
+        mDelegate.setBase(base);
+        // -------------------------------------------------------------------------------
+    }
+
+    /**
+     * Helper method to add the start/pause action to the notification's builder.
+     * @param running whether the chronometer is running
+     * @param requestCode Used to create the PendingIntent that is fired when this action is clicked.
+     */
+    protected final void addStartPauseAction(boolean running, int requestCode) {
+        addAction(ACTION_START_PAUSE,
+                running ? R.drawable.ic_pause_24dp : R.drawable.ic_start_24dp,
+                getString(running ? R.string.pause : R.string.resume),
+                requestCode);
+    }
+
+    /**
+     * Helper method to add the stop action to the notification's builder.
+     * @param requestCode Used to create the PendingIntent that is fired when this action is clicked.
+     */
+    protected final void addStopAction(int requestCode) {
+        addAction(ACTION_STOP, R.drawable.ic_stop_24dp, getString(R.string.stop), requestCode);
+    }
+
+    /**
+     * Clear the notification builder's set actions.
+     */
+    protected final void clearActions() {
+        // TODO: The source indicates mActions is hidden, so how are we able to access it?
+        // Will it remain accessible for all SDK versions? If not, we would have to rebuild
+        // the entire notification with a new local Builder instance.
+        mNoteBuilder.mActions.clear();
+    }
+
+    protected final void setBase(long base) {
+        mDelegate.setBase(base);
+    }
+
+    protected final long getBase() {
+        return mDelegate.getBase();
+    }
+
+    protected final void updateNotification() {
+        mThread.updateNotification();
+    }
+
+    protected final void setContentTitle(CharSequence title) {
+        mNoteBuilder.setContentTitle(title);
+    }
+
+    /**
+     * Adds the specified action to the notification's Builder.
+     */
+    protected final void addAction(String action, @DrawableRes int icon, String actionTitle, int requestCode) {
+        Intent intent = new Intent(this, getClass())
+                .setAction(action);
+        // TODO: We can put the requestCode as an extra to this intent, and then retrieve that extra
+        // in onStartCommand() to figure out which of the multiple timers should we apply this action to.
+//                .putExtra(EXTRA_TIMER, mTimer);
+        PendingIntent pi = PendingIntent.getService(
+                this, requestCode, intent, 0/*no flags*/);
+        mNoteBuilder.addAction(icon, actionTitle, pi);
+    }
+
+    /**
+     * Causes the handler thread's looper to terminate without processing
+     * any more messages in the message queue.
+     */
+    private void quitThread() {
+        if (mThread != null && mThread.isAlive()) {
+            mThread.quit();
+        }
+    }
+}

app/src/main/java/com/philliphsu/clock2/ChronometerNotificationThread.java

@@ -0,0 +1,99 @@
+package com.philliphsu.clock2;
+
+import android.annotation.SuppressLint;
+import android.app.NotificationManager;
+import android.content.res.Resources;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Message;
+import android.os.SystemClock;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.app.NotificationCompat;
+
+import com.philliphsu.clock2.timers.ChronometerDelegate;
+
+/**
+ * Created by Phillip Hsu on 9/10/2016.
+ *
+ * A thread that updates a chronometer-based notification. While notifications
+ * have built-in support for using a chronometer, it lacks pause/resume functionality
+ * and the ability to choose between count up or count down.
+ */
+public class ChronometerNotificationThread extends HandlerThread {
+    private static final String TAG = "ChronomNotifThread";
+
+    private static final int MSG_WHAT = 2;
+
+    private final ChronometerDelegate mDelegate;
+    private final NotificationManager mNotificationManager;
+    private final NotificationCompat.Builder mNoteBuilder;
+    private final Resources mResources;
+    private final String mNoteTag;
+    private final int mNoteId;
+
+    private Handler mHandler;
+
+    /**
+     * @param delegate Configured by the client service, including whether to be counting down or not.
+     * @param builder A preconfigured Builder from the client service whose content
+     *                text will be updated and eventually built from.
+     * @param resources Required only if the ChronometerDelegate is configured to count down.
+     *                  Used to retrieve a String resource if/when the countdown reaches negative.
+     *                  TODO: Will the notification be cancelled fast enough before the countdown
+     *                  becomes negative? If so, this param is rendered useless.
+     * @param noteTag A tag associated with the client service, used for posting
+     *                the notification. We require this because we want to avoid
+     *                using a tag associated with this thread, or else the client
+     *                service won't be able to manipulate the notifications that
+     *                are posted from this thread.
+     */
+    public ChronometerNotificationThread(@NonNull ChronometerDelegate delegate,
+                                         @NonNull NotificationManager manager,
+                                         @NonNull NotificationCompat.Builder builder,
+                                         @Nullable Resources resources,
+                                         @NonNull String noteTag,
+                                         int noteId) {
+        super(TAG);
+        mDelegate = delegate;
+        mNotificationManager = manager;
+        mNoteBuilder = builder;
+        mResources = resources;
+        mNoteTag = noteTag;
+        mNoteId = noteId;
+    }
+
+    // There won't be a memory leak since our handler is using a looper that is not
+    // associated with the main thread. The full Lint warning confirmed this.
+    @SuppressLint("HandlerLeak")
+    @Override
+    protected void onLooperPrepared() {
+        // This is called after the looper has completed initializing, but before
+        // it starts looping through its message queue. Right now, there is no
+        // message queue, so this is the place to create it.
+        // By default, the constructor associates this handler with this thread's looper.
+        mHandler = new Handler() {
+            @Override
+            public void handleMessage(Message m) {
+                updateNotification();
+                sendMessageDelayed(Message.obtain(this, MSG_WHAT), 1000);
+            }
+        };
+        // Once the handler is initialized, we may immediately begin our work.
+        mHandler.sendMessageDelayed(Message.obtain(mHandler, MSG_WHAT), 1000);
+    }
+
+    public void updateNotification() {
+        CharSequence text = mDelegate.formatElapsedTime(SystemClock.elapsedRealtime(), mResources);
+        mNoteBuilder.setContentText(text);
+        mNotificationManager.notify(mNoteTag, mNoteId, mNoteBuilder.build());
+    }
+
+    @Override
+    public boolean quit() {
+        // TODO: I think we can call removeCallbacksAndMessages(null)
+        // to remove ALL messages.
+        mHandler.removeMessages(MSG_WHAT);
+        return super.quit();
+    }
+}

app/src/main/java/com/philliphsu/clock2/stopwatch/StopwatchNotificationService.java

@@ -9,6 +9,7 @@ import android.os.IBinder;
 import android.support.annotation.DrawableRes;
 import android.support.v4.app.NotificationCompat;
 
+import com.philliphsu.clock2.ChronometerNotificationThread;
 import com.philliphsu.clock2.MainActivity;
 import com.philliphsu.clock2.R;
 
@@ -20,6 +21,7 @@ public class StopwatchNotificationService extends Service {
     private NotificationCompat.Builder mNoteBuilder;
     private NotificationManager mNotificationManager;
     private AsyncLapsTableUpdateHandler mLapsTableUpdateHandler;
+    private ChronometerNotificationThread mThread;
 
     @Override
     public void onCreate() {
@@ -33,13 +35,7 @@ public class StopwatchNotificationService extends Service {
         mNoteBuilder = new NotificationCompat.Builder(this)
                 .setSmallIcon(R.drawable.ic_stopwatch_24dp)
                 .setOngoing(true)
-                // TODO: The chronometer takes the place of the 'when' timestamp
-                // at its usual location. If you don't like this location,
-                // we can write a thread that posts a new notification every second
-                // that updates the content text.
-                // TODO: We would have to write our own chronometer logic if there
-                // is no way to pause/resume the native chronometer.
-                .setUsesChronometer(true)
+//                .setUsesChronometer(true) // No way to pause/resume this native chronometer.
                 .setContentTitle(getString(R.string.stopwatch));
         Intent intent = new Intent(this, MainActivity.class);
         intent.putExtra(null/*TODO:MainActivity.EXTRA_SHOW_PAGE*/, 2/*TODO:MainActivity.INDEX_STOPWATCH*/);
@@ -58,6 +54,7 @@ public class StopwatchNotificationService extends Service {
     @Override
     public void onDestroy() {
         super.onDestroy();
+        quitThread();
     }
 
     @Override
@@ -107,4 +104,14 @@ public class StopwatchNotificationService extends Service {
                 intent, 0/*no flags*/);
         mNoteBuilder.addAction(icon, actionTitle, pi);
     }
+
+    /**
+     * Causes the handler thread's looper to terminate without processing
+     * any more messages in the message queue.
+     */
+    private void quitThread() {
+        if (mThread != null && mThread.isAlive()) {
+            mThread.quit();
+        }
+    }
 }

app/src/main/java/com/philliphsu/clock2/timers/ChronometerDelegate.java

@@ -2,6 +2,7 @@ package com.philliphsu.clock2.timers;
 
 import android.content.res.Resources;
 import android.os.SystemClock;
+import android.support.annotation.Nullable;
 import android.text.SpannableString;
 import android.text.Spanned;
 import android.text.TextUtils;
@@ -80,16 +81,21 @@ public final class ChronometerDelegate {
         return mFormat;
     }
 
-    public CharSequence formatElapsedTime(long now, Resources resources) {
+    public CharSequence formatElapsedTime(long now, @Nullable Resources resources) {
         mNow = now;
         long seconds = mCountDown ? mBase - now : now - mBase;
         boolean negative = false;
-        if (seconds < 0) {
+        // Only modify how negative timers are displayed if we have a Resources.
+        // Otherwise, if we invert the sign of seconds and we don't have a Resources,
+        // the timer will be positive again which will confuse the user.
+        if (seconds < 0 && resources != null) {
             seconds = -seconds;
             negative = true;
         }
         String text = DateUtils.formatElapsedTime(mRecycle, seconds / 1000);
         if (negative) {
+            // The only way this can call through is if the previous null check on
+            // `resources` passed.
             text = resources.getString(R.string.negative_duration, text);
         }
 

app/src/main/java/com/philliphsu/clock2/timers/TimerNotificationService.java

@@ -1,22 +1,15 @@
 package com.philliphsu.clock2.timers;
 
-import android.annotation.SuppressLint;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
-import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
-import android.os.Handler;
-import android.os.HandlerThread;
-import android.os.IBinder;
-import android.os.Message;
 import android.os.SystemClock;
-import android.support.annotation.DrawableRes;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
-import android.support.v4.app.NotificationCompat;
-import android.util.Log;
 
 import com.philliphsu.clock2.AsyncTimersTableUpdateHandler;
+import com.philliphsu.clock2.ChronometerNotificationService;
 import com.philliphsu.clock2.R;
 import com.philliphsu.clock2.Timer;
 
@@ -27,21 +20,16 @@ import com.philliphsu.clock2.Timer;
  * a single task and immediately destroy itself, which means we lose all of
  * our instance state.
  */
-public class TimerNotificationService extends Service {
+public class TimerNotificationService extends ChronometerNotificationService {
     private static final String TAG = "TimerNotifService";
 
     public static final String ACTION_ADD_ONE_MINUTE = "com.philliphsu.clock2.timers.action.ADD_ONE_MINUTE";
-    public static final String ACTION_START_PAUSE = "com.philliphsu.clock2.timers.action.START_PAUSE";
-    public static final String ACTION_STOP = "com.philliphsu.clock2.timers.action.STOP";
 
     public static final String EXTRA_TIMER = "com.philliphsu.clock2.timers.extra.TIMER";
 
-    private Timer mTimer; // TODO: I think we may need a list of timers.
+    // TODO: I think we may need a list of timers.
+    private Timer mTimer;
     private TimerController mController;
-    private NotificationCompat.Builder mNoteBuilder;
-    private NotificationManager mNotificationManager;
-    private final ChronometerDelegate mCountdownDelegate = new ChronometerDelegate();
-    private MyHandlerThread mThread; // TODO: I think we may need a list of threads.
 
     /**
      * Helper method to start this Service for its default action: to show
@@ -62,29 +50,23 @@ public class TimerNotificationService extends Service {
      *                you want to cancel
      */
     public static void cancelNotification(Context context, long timerId) { // TODO: remove long param
-        NotificationManager nm = (NotificationManager)
-                context.getSystemService(Context.NOTIFICATION_SERVICE);
-        nm.cancel(TAG, (int) timerId);
+        // TODO: We do this in onDestroy() for a single notification.
+        // Multiples will probably need something like this.
+//        NotificationManager nm = (NotificationManager)
+//                context.getSystemService(Context.NOTIFICATION_SERVICE);
+//        nm.cancel(getNoteTag(), (int) timerId);
+        // TODO: We only do this for a single notification. Remove this for multiples.
         context.stopService(new Intent(context, TimerNotificationService.class));
-        // After being cancelled due to time being up, sometimes the active timer notification posts again
-        // with a static 00:00 text, along with the Time's up notification. My theory is
-        // our thread has enough leeway to sneak in a final call to post the notification before it
-        // is actually quit().
-        // TODO: Write an API in MyHandlerThread that removes its messages. Then, write and
-        // handle a service command that calls that API. Alternatively, we may not need the
-        // command because we could just call that API in your quitThread() helper method.
     }
 
     @Override
-    public void onCreate() {
-        super.onCreate();
-        mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
+    protected int getSmallIcon() {
+        return R.drawable.ic_timer_24dp;
+    }
 
-        // Create base note
-        mNoteBuilder = new NotificationCompat.Builder(this)
-                .setSmallIcon(R.drawable.ic_timer_24dp)
-                .setShowWhen(false)
-                .setOngoing(true);
+    @Nullable
+    @Override
+    protected PendingIntent getContentIntent() {
         // TODO: Set content intent so that when clicked, we launch
         // TimersFragment and scroll to the given timer id. The following
         // is merely pseudocode.
@@ -99,176 +81,86 @@ public class TimerNotificationService extends Service {
 //                // per notification when retrieving the PendingIntent..
 //                contentIntent,
 //                0/*Shouldn't need a flag..*/));
+        return null;
+    }
 
-        mCountdownDelegate.init();
-        mCountdownDelegate.setCountDown(true);
+    @Override
+    protected boolean isCountDown() {
+        return true;
     }
 
     @Override
     public void onDestroy() {
         super.onDestroy();
-        quitThread();
+        // After being cancelled due to time being up, sometimes the active timer notification posts again
+        // with a static 00:00 text, along with the Time's up notification. My theory is
+        // our thread has enough leeway to sneak in a final call to post the notification before it
+        // is actually quit().
+        // As such, try cancelling the notification with this (tag, id) pair again.
+        NotificationManager nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
+        nm.cancel(getNoteTag(), mTimer.getIntId());
     }
 
     @Override
-    public int onStartCommand(Intent intent, int flags, int startId) {
-        if (intent != null) {
-            final String action = intent.getAction();
-            if (action == null) {
-                if ((mTimer = intent.getParcelableExtra(EXTRA_TIMER)) == null) {
-                    throw new IllegalStateException("Cannot start TimerNotificationService without a Timer");
-                }
-                mController = new TimerController(mTimer, new AsyncTimersTableUpdateHandler(this, null));
-                // The note's title should change here every time,
-                // especially if the Timer's label was updated.
-                String title = mTimer.label();
-                if (title.isEmpty()) {
-                    title = getString(R.string.timer);
-                }
-                mNoteBuilder.setContentTitle(title);
-                syncNotificationWithTimerState(mTimer.isRunning());
-            } else if (ACTION_ADD_ONE_MINUTE.equals(action)) {
-                // While the notification's countdown would automatically be extended by one minute,
-                // there is a noticeable delay before the minute gets added on.
-                // Update the text immediately, because there's no harm in doing so.
-                mCountdownDelegate.setBase(mCountdownDelegate.getBase() + 60000);
-                // Dispatch a one-time (non-looping) message so as not to conflate
-                // with the current set of looping messages.
-                mThread.sendMessage(MSG_DISPATCH_TICK);
-                mController.addOneMinute();
-            } else if (ACTION_START_PAUSE.equals(action)) {
-                mController.startPause();
-                syncNotificationWithTimerState(mTimer.isRunning());
-            } else if (ACTION_STOP.equals(action)) {
-                mController.stop();
-                stopSelf();
-                // We leave removing the notification up to AsyncTimersTableUpdateHandler
-                // when it calls cancelAlarm() from onPostAsyncUpdate().
-            }
+    protected void handleDefaultAction(Intent intent, int flags, long startId) {
+        if ((mTimer = intent.getParcelableExtra(EXTRA_TIMER)) == null) {
+            throw new IllegalStateException("Cannot start TimerNotificationService without a Timer");
         }
-        return super.onStartCommand(intent, flags, startId);
+        mController = new TimerController(mTimer, new AsyncTimersTableUpdateHandler(this, null));
+        // The note's title should change here every time,
+        // especially if the Timer's label was updated.
+        String title = mTimer.label();
+        if (title.isEmpty()) {
+            title = getString(R.string.timer);
+        }
+        setContentTitle(title);
+        syncNotificationWithTimerState(mTimer.isRunning());
     }
 
-    @Nullable
     @Override
-    public IBinder onBind(Intent intent) {
-        return null;
+    protected void handleStartPauseAction(Intent intent, int flags, long startId) {
+        mController.startPause();
+        syncNotificationWithTimerState(mTimer.isRunning());
+    }
+
+    @Override
+    protected void handleStopAction(Intent intent, int flags, long startId) {
+        mController.stop();
+        stopSelf();
+        // We leave removing the notification up to AsyncTimersTableUpdateHandler
+        // when it calls cancelAlarm() from onPostAsyncUpdate().
+    }
+
+    @Override
+    protected void handleAction(@NonNull String action, Intent intent, int flags, long startId) {
+        if (ACTION_ADD_ONE_MINUTE.equals(action)) {
+            // While the notification's countdown would automatically be extended by one minute,
+            // there is a noticeable delay before the minute gets added on.
+            // Update the text immediately, because there's no harm in doing so.
+            setBase(getBase() + 60000);
+            updateNotification();
+            mController.addOneMinute();
+        } else {
+            throw new IllegalArgumentException("TimerNotificationService cannot handle action " + action);
+        }
     }
 
     private void syncNotificationWithTimerState(boolean running) {
         // The actions from the last time we configured the Builder are still here.
         // We have to retain the relative ordering of the actions while updating
         // just the start/pause action, so clear them and set them again.
-        // TODO: The source indicates mActions is hidden, so how are we able to access it?
-        // Will it remain accessible for all SDK versions? If not, we would have to rebuild
-        // the entire notification with a new local Builder instance.
-        mNoteBuilder.mActions.clear();
-        addAction(ACTION_ADD_ONE_MINUTE, R.drawable.ic_add_24dp, getString(R.string.minute));
-        addAction(ACTION_START_PAUSE,
-                running ? R.drawable.ic_pause_24dp : R.drawable.ic_start_24dp,
-                getString(running ? R.string.pause : R.string.resume));
-        addAction(ACTION_STOP, R.drawable.ic_stop_24dp, getString(R.string.stop));
-
-        // Post the notification immediately, as the HandlerThread will delay its first
-        // message delivery.
-        updateNotification();
-        // Quit any previously executed thread. If running == false, the effect is obvious;
-        // otherwise, we're preparing for the start of a new thread.
-        quitThread();
+        clearActions();
+        final int timerId = mTimer.getIntId();
+        addAction(ACTION_ADD_ONE_MINUTE,
+                R.drawable.ic_add_24dp,
+                getString(R.string.minute),
+                timerId);
+        addStartPauseAction(running, timerId);
+        addStopAction(timerId);
 
+        quitCurrentThread();
         if (running) {
-            // An instance of Thread cannot be started more than once. You must create
-            // a new instance if you want to start the Thread's work again.
-            mThread = new MyHandlerThread();
-            // Initializes this thread as a looper. HandlerThread.run() will be executed
-            // in this thread.
-            // This gives you a chance to create handlers that then reference this looper,
-            // before actually starting the loop.
-            mThread.start();
-            // If this thread has been started, this method will block *the calling thread*
-            // until the looper has been initialized. This ensures the handler thread is
-            // fully initialized before we proceed.
-            mThread.getLooper();
-            Log.d(TAG, "Looper initialized");
-            mCountdownDelegate.setBase(SystemClock.elapsedRealtime() + mTimer.timeRemaining());
-            mThread.sendMessage(MSG_WHAT);
-        }
-    }
-
-    /**
-     * Builds and adds the specified action to the notification's mNoteBuilder.
-     */
-    private void addAction(String action, @DrawableRes int icon, String actionTitle) {
-        Intent intent = new Intent(this, TimerNotificationService.class)
-                .setAction(action);
-//                .putExtra(EXTRA_TIMER, mTimer);
-        PendingIntent pi = PendingIntent.getService(this,
-                mTimer.getIntId(), intent, 0/*no flags*/);
-        mNoteBuilder.addAction(icon, actionTitle, pi);
-    }
-
-    /**
-     * Causes the handler thread's looper to terminate without processing
-     * any more messages in the message queue.
-     */
-    private void quitThread() {
-        if (mThread != null && mThread.isAlive()) {
-            mThread.quit();
-        }
-    }
-
-    private void updateNotification() {
-        CharSequence text = mCountdownDelegate.formatElapsedTime(SystemClock.elapsedRealtime(), getResources());
-        mNoteBuilder.setContentText(text);
-        mNotificationManager.notify(TAG, mTimer.getIntId(), mNoteBuilder.build());
-    }
-
-    private static final int MSG_WHAT = 2;
-    private static final int MSG_DISPATCH_TICK = 3;
-
-    private class MyHandlerThread extends HandlerThread {
-        private Handler mHandler;
-
-        public MyHandlerThread() {
-            super("MyHandlerThread");
-        }
-
-        // There won't be a memory leak since our handler is using a looper that is not
-        // associated with the main thread. The full Lint warning confirmed this.
-        @SuppressLint("HandlerLeak")
-        @Override
-        protected void onLooperPrepared() {
-            Log.d(TAG, "Looper fully prepared");
-            // This is called after the looper has completed initializing, but before
-            // it starts looping through its message queue. Right now, there is no
-            // message queue, so this is the place to create it.
-            // By default, the constructor associates this handler with this thread's looper.
-            mHandler = new Handler() {
-                @Override
-                public void handleMessage(Message m) {
-                    updateNotification();
-                    if (m.what != MSG_DISPATCH_TICK) {
-                        sendMessageDelayed(Message.obtain(this, MSG_WHAT), 1000);
-                    }
-                }
-            };
-        }
-
-        public void sendMessage(int what) {
-            // We've encountered NPEs because the handler was still
-            // uninitialized even at this point. I assume we cannot rely on any
-            // defined order in which different threads execute their code.
-            // Block the calling thread from proceeding until the handler thread
-            // completes the handler's initialization.
-            while (mHandler == null);
-
-            Log.d(TAG, "Sending message");
-            Message msg = Message.obtain(mHandler, what);
-            if (what == MSG_DISPATCH_TICK) {
-                mHandler.sendMessage(msg);
-            } else if (what == MSG_WHAT) {
-                mHandler.sendMessageDelayed(msg, 1000);
-            }
+            startNewThread(timerId, SystemClock.elapsedRealtime() + mTimer.timeRemaining());
         }
     }
 }