ongoing notification opening existing Activity - android

I want to show a notification while a timer is running and when the user clicks the notifiaction it opens the timer activity.
mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
Intent intent = new Intent(this, Activity.class).addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
The problem right now is that when I start the timer and press home and then click the notification it opens the Activity with the running timer.
But when I start the timer, then open another activity (via ActionBar.NAVIGATION_MODE_LIST), then press home and click the notification it opens a new Activity (empty).
I thought addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT); would help (thats what I used to navigate between Activities)
im using android:launchMode="singleTop" and android:configChanges="orientation|screenSize"
for every Activity.

I wouldn't rely on your activity persisting and it is unnecessary
Store the timer start time into sharedpreferences and then simply load up the start time when the activity is recreated.
If something is meant to happen after a certain time, like a countdown time, then you'll need to set up an Alarm and handle it that way.
Remember that activities are just UI. Don't trust an activity to be doing anything when the user isn't looking at it.

Related

How can I create an app with the behavior of the default Android "timer" app?

I want to create an app that allows the user to set a timer. When they start the timer, they see a screen with a countdown. Simultaneously, a notification appears in the system tray (the top bar). This notification contains the current state of the countdown. If the app is minimized and the user taps that notification, they return to the countdown screen in the app.
I'm trying to do this with a foreground Service, and then implementing the notification like so:
Intent notificationIntent = new Intent(this, TimerActivity.class);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
PendingIntent pendingIntent = PendingIntent.getActivity(
this,
0,
notificationIntent,
PendingIntent.FLAG_UPDATE_CURRENT
);
The problem is, this seems to restart the activity, not resume it (onCreate gets called again), so the timer appears zeroed out in the activity. Is there a way around this?

Foreground service start once and display activity on click

I have 5 activities in my app. Every activity starts the same foreground service.
In onStartCommand method of the service foreground notification is created which unfortunately means that every call of startForegroundService() in any activity plays notification sound (even though the service is already running). How can I create the foreground notification only once or at least how not to play notification sound on successive startForegroundService() calls?
The other related question is: how can I go back to my application when I click the foreground notification? I have 5 activites and I would like to reopen the activity that was the last one the user was interacting with.
#1. before starting the service just check if its already running or not. In that case this will help you https://stackoverflow.com/a/5921190/6413387
#2. To reopen your last opened activity, you need to update the pending intent of your notification. Hope you will find your answer here https://stackoverflow.com/a/20142620/6413387
How can I create the foreground notification only once or at least how not to play notification sound on successive startForegroundService() calls?
You can check if the notification is already visible and show it only if it's not visible. You need to have a reference to the notification PendingIntent and notificationId.
fun isNotificationVisible(context: Context, notificationIntent: Intent, notificationId: Int): Boolean {
return PendingIntent.getActivity(context, notificationId, notificationIntent, PendingIntent.FLAG_NO_CREATE) != null
}
how can I go back to my application when I click the foreground notification?
You need a PendingIntent to open the app from a notification. To open the last activity shown you can remember this using Preferences in the onResume() method of each activity and route the notification into a routing activity that starts the right activity according to the value saved into the preferences.
val intent = Intent(context, RouteActivity::class.java)
val notificationBuilder = NotificationCompat.Builder(context, channelId)
.setContentIntent(intent)
val notificationManager = NotificationManagerCompat.from(context)
val notification = notificationBuilder.build()
notificationManager.notify(notificationId, notification)
Another way to do this is to update the notification PendingIntent if it's already visible with the last activity shown. In this case you don't have to store any value on Preferences and you don't need a route activity.

Multiple fullscreen android notifications at the same time not stacking

I am working on an android project that has an alarm clock like functionality.
I schedule an intentService for each alarm instance (fires at 9pm, for example.), this intentService builds the notification and displays it. The notification includes a fullScreenIntent, which works as expected and launches the activity. I use the following code to do this:
alarmActivityIntent = new Intent(this, AlarmActivity.class);
PendingIntent alarmActivityPendingIntent = PendingIntent.getActivity(this, alertSchedule.getIntentId(), alarmActivityIntent, PendingIntent.FLAG_CANCEL_CURRENT);
mBuilder.setFullScreenIntent(alarmActivityPendingIntent, true);
Notification mNotification = mBuilder.build();
mNotificationManager.notify(alertSchedule.getIntentId(), mNotification);
This works as expected when only one alarm is set to fire at a specific time, however if two alarms are set to fire at a specific time the behavior changes.
I want the first fullScreenIntent to start its activity, then when that activity finishes, show the next one. I believe I want to build up a task stack, and push these alarm intents onto it. However this is all new to me.
Is it possible to group these notifications?
If you are using the full screen Intent feature, you don't need to use an IntentService or a Notification at all. Just have the AlarmManager start your Activity when it fires.
You don't want to build a task stack, that is all too complicated. If you have multiple alarms that can fire at the same time, you can have the AlarmManager start the same Activity each time. Set the launch mode of this Activity to singleTop (in the manifest), so that if the Activity is already showing when the alarm fires, it will not create another instance of the Activity on top of the existing one, but instead will deliver the Intent by calling onNewIntent() on the existing instance of the Activity. In onNewIntent() you can save the data (extras) of the Intent in a queue that will be processed when the user finishes the currently shown Activity. To do that, just override onBackPressed() so that when the user presses the BACK button to finish the current Activity, you can check if there are any additional alarms waiting in the queue. If there are none, you can just call super.onBackPressed() to finish the Activity. If there is anything in the queue, you can remove the first element in the queue and display that in your Activity. Keep doing that until the queue is empty.

How to start an app the same way Android Launcher does (resume)

There are a lot of questions/answers about how to start an application from within your application in Android. But those solutions do not produce the same flow as if an icon was tapped in Android launcher.
For example, I do this (this is used with notifications):
intent = context.getPackageManager().getLaunchIntentForPackage("com.test.startup");
intent.setAction(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
pendingIntent = PendingIntent.getActivity(context, 0,
intent, PendingIntent.FLAG_UPDATE_CURRENT);
Then when I tap on notification the app is started, however, it is started somewhat differently than when I tap the icon in the App drawer. Specifically: with this approach my main Activity is always created (i.e. onCreate() then onResume() is called). However, if application was already started and then put in background, then starting it from Launcher will only cause onResume() of currently shown activity to be called (not onCreate() on the main one). Is there a way to trigger the same resume flow programmatically from within my app?
To summarize the task: when user taps on notification I need my app to be either started (if it's not already), or brought to the foreground in its current state (if it's in background) and have some data passed to it. The app will then take care of handling/rendering that data.
Your app is behaving the way it supposed to. Even if you try the launch the app from App drawer it will call the same callback. You have to understand the lifecycle. As your activity is in the background onCreate will not get called. But for the handling the data from the notification intent you should utilize callback method OnNewIntent() in activity. You should override this method and extract the data the from the new intent and should update UI. After onNewIntent onresume will be called.
I hope this solves your problem.
Here is my onPause code which works the way you expected i.e when user clicks on the notification it doesnt call onCreate again:
notificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
intent = new Intent(getApplicationContext(), PlayerActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP| Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent pIntent = PendingIntent.getActivity(getBaseContext(), 0, intent,0);
NotificationCompat.Builder noti =
new NotificationCompat.Builder(this)
.setSmallIcon(android.R.drawable.ic_media_play)
.setContentTitle("Nepali Music And more")
.setContentText("Playing");
noti.setContentIntent(pIntent);
noti.setAutoCancel(true);
noti.setOngoing(true);
Notification notification = noti.getNotification();
notificationManager.notify(1, notification);
Focus mainly on the intent flags
You want to use the intent flags Intent.FLAG_ACTIVITY_CLEAR_TOP to find your activity and clear the stack above it. You also need the Intent.FLAG_ACTIVITY_SINGLE_TOP flag to prevent your activity from being recreated (to resume).
The Intent.FLAG_ACTIVITY_SINGLE_TOP is necessary since by default, the launch mode is "standard" which lets you create multiple instances of your activity. If you were to set your launch mode to SingleTop, then this flag own't be necessary

How to cancel a countdown timer when a notification is clicked?

I know this has been asked a million times in other forums, but I haven't got a perfect answer yet. This is my requirement:
When the activity goes to bacground, the timer starts and after 10 sec the notification appears. If the user doesn't click on the notification after 10 sec the notification changes.
When the user clicks on the first notification, the last viewed screen appears - i.e the activity comes to the foreground. This is achieved by:
Intent notificationIntent = new Intent(TimedAlert.this, FirstActivity.class);
notificationIntent.setAction(Intent.ACTION_MAIN);
notificationIntent.addCategory(Intent.CATEGORY_LAUNCHER);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
But i want the timer to stop immediately after the activity comes to foreground. I.e in onResume () I give timer.cancel() but this doesn't seem to work. I also tried onNewIntent() but it works only when I am on the first activity when the app goes to background from the second activity. On coming to foreground the onNewIntent() method is not called, even though I have given single top for the second activity.
How can I achieve this behavior?
when the user click on the Notification, the system will call your notificationIntent, in your case the system will start FirstActivity, then in your FirstActivity you can stop the count down.

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