Automatically assign requestCodes to PendingIntent.getBroadcast (using AlarmManager) - android

I am essentially providing an interface to another application inside my android app. The client requested a system where he can either schedule a new local notification to be displayed at a specific time but also the ability to cancel all the local scheduled notifications. Is there a way that automatically assigns (practically unlimited) requestCodes(/ids) to PendingIntent objects while using them with AlarmManager?
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, requestCode, someNotificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);
...
AlarmManager alarmManager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, futureTimeInMillis, pendingIntent);
I also want to be able to cancel all these pending intents without keeping track of the requestCodes:
for(int requestCode : somehowGetAllUsedRequestCodes){
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, requestCode, someNotificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);
pendingIntent.cancel();
alarmManager.cancel(pendingIntent);
}
Is that thing even possible without manually keeping track of request codes?

You would need to keep track of the request codes in a database or whatever to be able to cancel them later. You can ensure the id is unique if you store the values in a database as well.

Related

android pendingintent sending duplicate data

My PendingIntent is working on time broadcast receiver. The problem is when I set my time and send first data it work successfully but when I send other data it again displays the first data and not the new one, below is my code.
All my mServiceIntenyt code is perfect but what is the error
mServiceIntent.putExtra("unique",lackmyData);
PendingIntent pintent = PendingIntent.getService(MessageActivity.this, 0, mServiceIntent, 0);
AlarmManager alarm = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
alarm.set(AlarmManager.RTC_WAKEUP,targetCal.getTimeInMillis(), pintent);
If you do not pass any flag then the PendingIntent ignores changes in extras when comparing Intent, causing the same old Intent to be spent again. You need to ask the PendingIntent to update the Intent as below:
PendingIntent pintent = PendingIntent.getService(MessageActivity.this,
0, mServiceIntent, PendingIntent.FLAG_UPDATE_CURRENT);
Or in order to make sure your intent is unqiue based on extras, you may play with setData as below:
mServiceIntent.setData(Uri.parse(mServiceIntent.toUri(Intent.URI_INTENT_SCHEME)));

Android widget change alarm interval

I have created a configure activity for my widget, where the user can choose from various update frequencies.. Until now I started the alarm in the OnEnabled() method, like this:
Intent intent = new Intent(CLOCK_WIDGET_UPDATE);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.RTC, System.currentTimeMillis(), 1000 * 60,
pendingIntent);
The settings are saved in shared preferences with a unique name (widgetId) and in this OnEnabled() method I can't retrieve the settings here because I can't get the widgetId yet.
There's an another problem, the user can change the frequency anytime, but this method is called just once, at the beginning. So I think I need to start the alarm in OnUpdate(), but I don't know how to do it, I don't want to make multiple instances of an alarm accidentally so I would like to ask for some advice.
To answer your second problem, calling setRepeating multiple times will not create multiple alarm as far as you provide same PendingIntent and same request code along with PendingIntent.FLAG_UPDATE_CURRENT flag. I would also suggest to use setInexactRepeating instead of setRepeating. So you can use the same code in OnUpdate() too with new frequency. Go through docs of FLAG_UPDATE_CURRENT and setInexactRepeating for more detials.

AlarmManager entries

I set up an alarm for my PendingIntent. Now I want to show in my activity, if this alarm is set or not.
Intent service = new Intent(context, MyService.class);
PendingIntent pendingIntent = PendingIntent.getService(context, 0, service, 0);
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, firstStart, interval, pendingIntent);
Is there any way to check is this alarm is set?
You can't query the AlarmManager to find out if the alarm is set. You pretty much need to remember yourself. You can store something in shared preferences to indicate that you set the alarm. However, once the phone is restarted your alarms are gone, so you also need to either reschedule the alarms on a reboot OR clear your preferences to indicate the alarm is no longer set.
Unfortunately, this is one of those things that Android really lacks (a way to query the alarmManager).

Delete AlarmManager Alarm ONLY for a Deleted Alarm

My app will have several alarms set simultaneously. Unfortunately, each alarm is being set with the same PendingIntent object. Here's the code I'm using to set the alarm:
//Use AlarmManager to trigger the notification/alarm.
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
//PendingIntent to launch activity when the alarm triggers.
Intent i = new Intent("com.testapp.DisplayNotification");
//Assign the reminder's primary key as the notification ID.
i.putExtra("Reminder_Name", editRemindMeTo.getText().toString());
i.putExtra("Reminder_Primary_Key", reminderPrimaryKey);
PendingIntent displayIntent = PendingIntent.getActivity(
getBaseContext(), 0, i, 0);
//Set the alarm to trigger.
alarmManager.set(AlarmManager.RTC_WAKEUP,
c.getTimeInMillis(), displayIntent);
I know that I can delete an alarm by using the following code:
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(context, MyPendingIntentService.class);
PendingIntent displayIntent = PendingIntent.getService(context, 0, i, 0);
alarmManager.cancel(displyIntent);
However, using this code will delete ALL my alarms (correct me if I'm wrong here). Is there a way to delete just the alarm that a user has deleted from the database? The alarm should be deleted from my app right after the user deletes an alarm entry in my app's database. I'm guessing that using different PendingIntent names would be the way to go, but I have no idea how to do this for each new alarm that a user creates. Thoughts on how to do this? Thanks!
See the same problem i faced here previously...
So the solution is to pass unique pending intent to the alarm service.. So here i how it can be done
PendingIntent pIntent = PendingIntent.getBroadcast(context, (int) alarm_id, intent, PendingIntent.FLAG_CANCEL_CURRENT);
here in the pending intent i have passed unique request id to the pending intent. Which you have to remember while cancelling the alarm.
So in my case what i have done to generate the unique id is put it in the database i have retrieved the id of the tables row and passed to the pending Intent.
So if you want to cancel the particular alarm you have to remember the same request id of the pending intent with the use of the same table entry...
I am sure it will work..
Use a different requestCode when registering each alarm. This is the second parameter of PendingIntent.getActivity/Service().
From the Android Documentation, cancel() will cancel all alarms with same pendingIntent. So the only way out is to create different pendingIntents. OR you could resort to scheduling repeating alarms as well, in this way you could use the same pendingIntents.

Best way to set multiple alarms when some are of repeating in nature in Android

I'm building a reminders application where one time, weekly, monthly reminders and we notify the user of the reminder on due date and time. Reminders can be updated any time by the user to update the reminding time or delete the reminder altogether. I have thought of two ways I can solve the particular problem.
Whenever user sets a reminder, schedule an alarm accordingly with an unique Id and update or delete it in case user updates or deletes the alarm.
Since I store the reminding time in DB, better approach would be to schedule an alarm for the nearest reminder. And have the Service which is triggered by the alarm schedule a new alarm for the next nearest reminder.
2nd approach seems clean approach but how do we tackle the case where the Service triggered by alarm gets killed by the system before it schedules a new alarm for the next reminder?
Edit
Looks like if the system kills a Service for memory, it will re-create the Service. Does it mean it is safe to rely on the Service to schedule alarm every time it is run?
Edit 2
I've realized that Android kills any alarms whenever the device is restarted. This makes approach 2 a better solution. I've implemented it for now.
The pending intent needs to be created exactly in the same way for canceling the already set alarm. You can cancel previous alarm when you set a new alarm, if you want to have a single alarm activated at some time.
For setting alarm use:
Intent myIntent = new Intent(getApplicationContext(), SessionReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1, myIntent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC, now.getTimeInMillis(), pendingIntent);
For canceling the alarm use:
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent myIntent = new Intent(getApplicationContext(), SessionReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1, myIntent, PendingIntent.FLAG_UPDATE_CURRENT);
alarmManager.cancel(pendingIntent);

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