Google has its clock app, which includes its stopwatch. I'm currently trying to create in my app a (count-up) timer, or you can call it a stopwatch, that will be able to run in the background, and when it runs in the background I want it to also show a notification, that displays the time it counts and a "Stop" button (all of this happens in google clock app (see here)). For the timer in my app, I'm using a Handler that posts a Runnable, which is posting itself. I'm writing my app in Java.
the code defining the 'timer' (Handler and Runnable):
Handler timerHandler = new Handler();
Runnable timerRunnable = new Runnable() {
@Override
public void run() {
long millis = System.currentTimeMillis() - startTime;
seconds = (millis / 1000) + PrefUtil.getTimerSecondsPassed();
timerHandler.postDelayed(this, 500);
}
};
my onPause function:
@Override
public void onPause() {
super.onPause();
if (timerState == TimerState.Running) {
timerHandler.removeCallbacks(timerRunnable);
//TODO: start background timer, show notification
}
PrefUtil.setTimerSecondsPassed(seconds);
PrefUtil.setTimerState(timerState);
}
How can I implement the background service and the notification in my app?
I've managed to succeed in creating a foreground service that runs my timer, but I have two problems:
Here's my Service
s code:
public class TimerService extends Service {
Long startTime = 0L, seconds = 0L;
boolean notificationJustStarted = true;
Handler timerHandler = new Handler();
Runnable timerRunnable;
NotificationCompat.Builder timerNotificationBuilder = new NotificationCompat.Builder(this, CHANNEL_ID);
public static final String TIMER_BROADCAST_ID = "TimerBroadcast";
Intent timerBroadcastIntent = new Intent(TIMER_BROADCAST_ID);
@Override
public void onCreate() {
Log.d(TAG, "onCreate: started service");
startForeground(1, new NotificationCompat.Builder(this, CHANNEL_ID).setSmallIcon(R.drawable.timer).setContentTitle("Goal In Progress").build());
super.onCreate();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
String goalName = intent.getStringExtra(PublicMethods.getAppContext().getString(R.string.timer_notification_service_current_goal_extra_name));
startTime = System.currentTimeMillis();
notificationJustStarted = true;
timerRunnable = new Runnable() {
@Override
public void run() {
long millis = System.currentTimeMillis() - startTime;
seconds = (millis / 1000) + PrefUtil.getTimerSecondsPassed();
updateNotification(goalName, seconds);
timerHandler.postDelayed(this, 500);
}
};
timerHandler.postDelayed(timerRunnable, 0);
return START_STICKY;
}
public void updateNotification(String goalName, Long seconds) {
try {
if (notificationJustStarted) {
Intent notificationIntent = new Intent(this, MainActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this,
0, notificationIntent, PendingIntent.FLAG_IMMUTABLE);
timerNotificationBuilder.setContentTitle("Goal In Progress")
.setOngoing(true)
.setSmallIcon(R.drawable.timer)
.setContentIntent(pendingIntent)
.setOnlyAlertOnce(true)
.setOngoing(true)
.setPriority(NotificationCompat.PRIORITY_MAX);
notificationJustStarted = false;
}
timerNotificationBuilder.setContentText(goalName + " is in progress\nthis session's length: " + seconds);
startForeground(1, timerNotificationBuilder.build());
} catch (Exception e) {
Log.d(TAG, "updateNotification: Couldn't display a notification, due to:");
e.printStackTrace();
}
}
@Override
public void onDestroy() {
timerHandler.removeCallbacks(timerRunnable);
PrefUtil.setTimerSecondsPassed(seconds);
super.onDestroy();
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
}
And here is how I start it in my fragment:
private void startTimerService() {
Intent serviceIntent = new Intent(getContext(), TimerService.class);
serviceIntent.putExtra(getString(R.string.timer_notification_service_current_goal_extra_name), "*Current Goal Name Here*");
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
Objects.requireNonNull(getContext()).startForegroundService(serviceIntent);
}
}
When I run the app on google pixel emulator, I don't face any of the issues listed
Solution would work much better, even with enabled battery restrictions, if you will replace recursive postDelayed
with scheduleAtFixedRate
in your TimerService
inside onStartCommand
function. Something like this:
TimerTask timerTaskNotify = new TimerTask() {
@Override
public void run() {
// add a second to the counter
seconds++;
//update the notification with that second
updateNotification(goalName, seconds);
//Print the seconds
Log.d("timerCount", seconds + "");
//Save the seconds passed to shared preferences
PrefUtil.setTimerSecondsPassed(TimerService.this,seconds);
}
};
Timer timerNotify = new Timer();
timerNotify.scheduleAtFixedRate(timerTaskNotify, 0, 1000);
P.S. I can update your git repository if you will grant permission)