Is there a way to first create a Notification and set some default message (the line below the title of a notification) and then to change that message every X seconds?
I tried finding solution, but those I found proposed constant killing and creating Notification which I do not find a proper way to achieve what I need.
I need to implement a small counter inside the same notification which will be updated every X seconds.
PS. Please do not confuse this with sending data from notification to an Activity. I need the reverse process - send data from activity to the notification.
Please have a look at android documentation
Updating notifications
To set up a notification so it can be updated, issue it with a
notification ID by calling NotificationManager.notify(ID,
notification). To update this notification once you've issued it,
update or create a NotificationCompat.Builder object, build a
Notification object from it, and issue the Notification with the same
ID you used previously. If the previous notification is still visible,
the system updates it from the contents of the Notification object. If
the previous notification has been dismissed, a new notification is
created instead.
The following snippet demonstrates a notification that is updated to
reflect the number of events that have occurred. It stacks the
notification, showing a summary:
Probably setting a notification id and accessing the same notification by id is the solution to your problem. Here is the link to document.
Edit:
Probably I missed one aspect of your question - i.e. creating new instance of notification. To resolve it you can declare an instance of notification in a singleton class. This way, you will not have to create an instance of notification again and again. Just modify the content of notification and use the same instance again and again.
Related
I'm creating a very simple application for myself. Basically, it gives me a certain notification exactly every 2 hours.
The problem is when I don't "check" the notification for 2 hours and the next notification is supposed to come around. It sends a notification even though another notification already exists.
I'm simply sending notifications with NotificationManager.
Is there a way to check if previous notification already exists and only send another one if it doesn't?
Assuming you are using the same notification id (so that only one notification appears in the notification tray), you can use setOnlyAlertOnce(true) to ensure that sound/vibrate only plays the very first time a notification is posted and not when an existing notification is updated.
My little app sends some notifications. We get a callback via a Pendingintent when the notification is clicked on. However, when a notification is simply removed without being clicked on, I don't get any kind of notification and thus wouldn't know if a notification has been removed by the user.
My ultimate goal is to limit the number of active notifications sent by my app to no more than 3. But I haven't been able to find a way to enumerate or simply get the count of active notifications sent by my app. The number of methods available in NotificationManager is rather limited.
Any help will be appreciated.
You can set a PendingIntent with setDeleteIntent() which will be called when the notification is removed from the notification tray (such as when the user swipes to dismiss it).
Do note that the notification design guidelines state:
If a notification of a certain type is already pending when your app tries to send a new notification of the same type, combine them into a single summary notification for the app. Do not create a new object.
A summary notification builds a summary description and allows the user to understand how many notifications of a particular kind are pending.
I.e., don't do this:
Do this (this example uses an InboxStyle notification as is recommended):
Make sure you are not posting multiple notifications of the same type.
the method "Notification.deleteIntent" you can use to set a PendingIntent which the notification was removed by system will be called .And then you can do something you want .
So, whenever someone creates a Post, I want others notified. Hence, I send out a Notification.
I know the logistics of setting the number with setNumber(int num), and how to create an InboxStyle to display multiple posts.
The problem is if a new notification comes in, it has no knowledge of whether or not another notification exists. I can't just request that Notification by its notification_id that I assigned it and then append a String with addLine(String string), nor can I update the number of posts with the setNumber method above. I'm new to creating Notifications and I've been reading about InboxStyle, using it, but every guide leaves out how to keep in sync with if that notification is still up, and how to update it. They brush that off as a trivial matter.
Yes, I understand a Notification can be updated via the NotificationManager.notify(int, notification) method, but unless you recreate what the new notification will look like, it simply overwrites your current notification.
Is there something I'm missing or not understanding about how to simply update notifications?
You should not be trying to "keep in sync with if that notification is still up". Your Notification should reflect the contents of your data model, and it should be updated when the data model changes.
For example, suppose you are writing an email client. You want a Notification for unread messages. When there are no unread messages, you have no Notification. When your background logic retrieves new messages, you update your data store to reflect those messages, and you call some heyLetTheUserKnowBoutDemEmails() method. That method queries the data store, finds out how many unseen messages there are, and calls notify() on NotificationManager to post a suitable Notification, using setNumber(), addLine(), and so forth, based on what is in the data store. Whether or not there happens to already be a Notification, for some previous heyLetTheUserKnowBoutDemEmails() call, is immaterial. When the user responds to the Notification, or otherwise opens up the inbox, your UI would then update the data store to mark the messages as seen (i.e., no longer need to be notified about) and clears the Notification. Lather, rinse, repeat.
So, it's not so much that it is a "trivial matter", but that:
It is merely a matter of replacing the existing Notification, and
The rules for when you should replace the existing Notification are almost completely dependent upon your app and its business rules, which are outside the scope of Android documentation and many blog posts, Stack Overflow answers, and the like.
I have a custom launcher, and I'm showing a custom notification icon
If user clicks on the notification icon he gets to see the notification. This part is working as expected. I can expand the notification list.
But now my requirement is, since I'm using a custom Notification icon I wish to show the notification count(if there are any notification, or if there are 10 notifications). I wish to show the number of unread/unchecked notification user has.
How to get the number(count) of unchecked notification?
I have gone through couple of examples and link like:
Link 1
Link 2
But all these links show how to create notifications, or how to expand notification list. How to get the notification count?
Any piece of code or example is highly appreciable.
Thanks
I would like to share my strategy on how to get the notification count. As I read the documentation, I have not seen any way to store and retrieve the notification count. I am doing a Note Reminder and this reminder alarms at a particular date. Given I have many reminders, sending notification to each of them simply replaces the one on the notification list. This is not nice. Neither my receiver has any way to know the nth time the notification was called. The notification is lack-luster in this case in my opinion.
So, one strategy I saw is to defer the counting responsibility directly to the database. I have to provide a method which returns the number of lapsed reminders I have on the database, tuck it in as an extra on the intent inside the pending intent which launch my receiver. From there I can unpack the extras and set the notification accordingly. This way, I got the information I need and I can model the notification content as such showing the number of reminders that are left untouched. Adding a count badge right next to the icon does not seem possible given the default android but is possible using third-party solutions or using well known android UI like TouchWiz in Samsung, or the one in Xperia. Searching the web, it seems making it so is another different story. I preferred not to do it and simply show through the content I have n count of lapsed reminders.
I hope this help people who are having similar problem regarding retrieving or storing notification count given a unique-per-application notification id.
Hope this helps!
you can use this exemple it work for me
Notification notification = new Notification(R.drawable.direction, "Cool Notification",
System.currentTimeMillis());
/********LIKE THIS*********/
notification.number = notificationCount++;
/********LIKE THIS*********/
notification.setLatestEventInfo(context, "Cool Notification Title",
"updated notificaiton message", null);
NotificationManager nm = (NotificationManager) context.getSystemService(context.NOTIFICATION_SERVICE);
nm.notify(R.id.my_motification, notification);
So you can increment the notification.number every time you display a notification.
If you're targeting API level 18+, then you're in luck, as you can provide a NotificationListenerService to access the current notifications and/or be alerted whenever they are created or dismissed.
Otherwise, you can use the old trick of registering an AccessbilityService and listening on AccessibilityEvent.TYPE_NOTIFICATION_STATE_CHANGED events. This is a good example of this approach.
I receive Push-Notifications from GCM and want them to be shown in the Notification-Bar. So I generation the Notifications in the GCMIntentService-class.
If there is already a notification in the notification-area, this notification have to be appended with the new message (with use of the BigTextStyle). But how do I know if there is a notification from my app in the notification-area?
You cannot get existing notification, but you can update existing notification by setting up Notification ID.
NotificationManager.notify(NotificationId, NotificationObject);
No, you can't find out if there's already a notification posted; this is something you should keep track of in your app.
Fortunately, however, the API for updating an existing notification is identical to the API for creating a new one: notify(). That is, once you get new information, add it to some internal buffer (possibly just a StringBuilder) representing the complete set of received push notifications, then build a new notification with Notification.Builder and call notify() with the same ID and tag you used last time. Any existing notification with that ID and tag will be replaced with the new content.