Notify your users, the right way

Notifications have been one of the core features in the Android UI since the first public release of the platform.
In this talk, presented at Droidcon Turin 2018, I gave an introduction showing the evolution of notifications in Android and how developers can customise them to give users the best way of accessing important information and perform quick actions at a glance.

1. Notify your users the right way Daniele Bonaldo
2. Daniele Bonaldo Android Developer @danybony_ danybony
3. A notification is a message that Android displays outside your app's UI to provide the user with reminders, communication from other people, or other timely information from your app
4. Donut (1.6)
5. Gingerbread (2.3)
6. Ice Cream Sandwich (4.0)
7. Jelly Bean (4.1 - 4.2 - 4.3) - Kitkat (4.4)
8. Wear 1.x
9. Lollipop (5.0) - Marshmallow (6.0)
10. Nougat (7.0)
11. Wear 2.0
12. Oreo (8.0)
13. Create a Notification val notification = Notification.Builder(context) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("Title") .setContentText("Content") .build() val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager notificationManager.notify(NOTIFICATION_ID, notification)
14. On Android O…
15. On Android O… E/NotificationService: No Channel found for pkg=com.google.android.apps.photos, channelId=null…
16. Channels
17. Channels val channel = NotificationChannel( CHANNEL_ID, "Status updates", NotificationManager.IMPORTANCE_DEFAULT ) channel.description = description channel.lightColor = Color.RED val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager notificationManager.createNotificationChannel(channel)
18. Channels val channel = NotificationChannel( CHANNEL_ID, "Status updates", NotificationManager.IMPORTANCE_DEFAULT ) channel.description = description channel.lightColor = Color.RED val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager notificationManager.createNotificationChannel(channel)
19. Channels val channel = NotificationChannel( CHANNEL_ID, "Status updates", NotificationManager.IMPORTANCE_DEFAULT ) channel.description = description channel.lightColor = Color.RED val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager notificationManager.createNotificationChannel(channel)
20. Channels val notification = Notification.Builder(context) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("Title") .setContentText("Content") .build()
21. Channels val notification = Notification.Builder(context) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("Title") .setContentText("Content") .setChannelId(CHANNEL_ID) .build()
22. Channels val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("Title") .setContentText("Content") .build()
26. Expandable notifications
27. Big text style
28. Big text style val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.new_mail) .setContentTitle(emailSender) .setContentText(emailSubject) .setLargeIcon(emailSenderAvatar) .setStyle(NotificationCompat.BigTextStyle() .bigText(emailSubjectAndSnippet)) .build()
29. Big text style val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.new_mail) .setContentTitle(emailSender) .setContentText(emailSubject) .setLargeIcon(emailSenderAvatar) .setStyle(NotificationCompat.BigTextStyle() .bigText(emailSubjectAndSnippet)) .build()
30. Large image style
31. Large image style val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.new_image) .setContentTitle(imageTitle) .setContentText(imageDescription) .setLargeIcon(largeBitmap) .setStyle(NotificationCompat.BigPictureStyle() .bigPicture(largeBitmap) .bigLargeIcon(null)) .build()
32. Large image style val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.new_image) .setContentTitle(imageTitle) .setContentText(imageDescription) .setLargeIcon(largeBitmap) .setStyle(NotificationCompat.BigPictureStyle() .bigPicture(largeBitmap) .bigLargeIcon(null)) .build()
33. Inbox style
34. Inbox style val notification = NotificationCompat.Builder(this, CHANNEL_ID) .setSmallIcon(R.drawable.ic_inbox) .setContentTitle("New mails") .setContentText("You have 3 new emails") .setLargeIcon(largeBitmap) .setStyle(NotificationCompat.InboxStyle() .addLine(getSubjectAndMessage(...)) .addLine(getSubjectAndMessage(...)) .addLine(getSubjectAndMessage(...)) ) .build()
35. Inbox style val notification = NotificationCompat.Builder(this, CHANNEL_ID) .setSmallIcon(R.drawable.ic_inbox) .setContentTitle("New mails") .setContentText("You have 3 new emails") .setLargeIcon(largeBitmap) .setStyle(NotificationCompat.InboxStyle() .addLine(getSubjectAndMessage(...)) .addLine(getSubjectAndMessage(...)) .addLine(getSubjectAndMessage(...)) ) .build()
36. Messaging style
37. Messaging style val message1 = NotificationCompat.MessagingStyle.Message( messages[0].getText(), messages[0].getTime(), messages[0].getSender() ) val message2 = NotificationCompat.MessagingStyle.Message( messages[1].getText(), messages[1].getTime(), messages[1].getSender() ) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.new_message) .setStyle(NotificationCompat.MessagingStyle(disaplayedUserName) .addMessage(message1) .addMessage(message2)) .build()
38. Media style
39. Media style val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setVisibility(NotificationCompat.VISIBILITY_PUBLIC) .setSmallIcon(R.drawable.ic_stat_player) .addAction(R.drawable.ic_thumb_down, "Dislike", thumbDownPendingIntent) .addAction(R.drawable.ic_prev, "Previous", prevPendingIntent) .addAction(R.drawable.ic_pause, "Pause", pausePendingIntent) .addAction(R.drawable.ic_next, "Next", nextPendingIntent) .addAction(R.drawable.ic_thumb_up, “Like", thumbDownPendingIntent) .setStyle(NotificationCompat.MediaStyle() .setShowActionsInCompactView(1, 2, 3) .setMediaSession(mediaSession.getSessionToken())) .setContentTitle("Wonderful song") .setContentText("Awesome Band") .setLargeIcon(albumArtBitmap) .build()
40. val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setVisibility(NotificationCompat.VISIBILITY_PUBLIC) .setSmallIcon(R.drawable.ic_stat_player) .addAction(R.drawable.ic_thumb_down, "Dislike", thumbDownPendingIntent) .addAction(R.drawable.ic_prev, "Previous", prevPendingIntent) .addAction(R.drawable.ic_pause, "Pause", pausePendingIntent) .addAction(R.drawable.ic_next, "Next", nextPendingIntent) .addAction(R.drawable.ic_thumb_up, “Like", thumbDownPendingIntent) .setStyle(NotificationCompat.MediaStyle() .setShowActionsInCompactView(1, 2, 3) .setMediaSession(mediaSession.getSessionToken())) .setContentTitle("Wonderful song") .setContentText("Awesome Band") .setLargeIcon(albumArtBitmap) .build() Media style
41. val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setVisibility(NotificationCompat.VISIBILITY_PUBLIC) .setSmallIcon(R.drawable.ic_stat_player) .addAction(R.drawable.ic_thumb_down, "Dislike", thumbDownPendingIntent) .addAction(R.drawable.ic_prev, "Previous", prevPendingIntent) .addAction(R.drawable.ic_pause, "Pause", pausePendingIntent) .addAction(R.drawable.ic_next, "Next", nextPendingIntent) .addAction(R.drawable.ic_thumb_up, “Like", thumbDownPendingIntent) .setStyle(NotificationCompat.MediaStyle() .setShowActionsInCompactView(1, 2, 3) .setMediaSession(mediaSession.getSessionToken())) .setContentTitle("Wonderful song") .setContentText("Awesome Band") .setLargeIcon(albumArtBitmap) .build() Media style
42. Remote views
43. Remote views val remoteViews = RemoteViews(packageName, R.layout.custom_notification) val bigRemoteViews = RemoteViews(packageName, R.layout.custom_notification_big) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setStyle(NotificationCompat.DecoratedCustomViewStyle()) .setSmallIcon(R.drawable.ic_notification) .setCustomContentView(remoteViews) .setCustomBigContentView(bigRemoteViews) .build()
44. Remote views val remoteViews = RemoteViews(packageName, R.layout.custom_notification) val bigRemoteViews = RemoteViews(packageName, R.layout.custom_notification_big) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setStyle(NotificationCompat.DecoratedCustomViewStyle()) .setSmallIcon(R.drawable.ic_notification) .setCustomContentView(remoteViews) .setCustomBigContentView(bigRemoteViews) .build()
45. Spannables val builder = SpannableStringBuilder() val subjectSpannable = SpannableString(subject) val boldSpan = StyleSpan(Typeface.BOLD) subjectSpannable.setSpan(boldSpan, 0, subject.length, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE) builder.append(subjectSpannable).append(' ') builder.append(message)
46. Timeout
47. Timeout val notification = NotificationCompat.Builder(this, CHANNEL_ID) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("Title") .setContentText("Notification content") .setTimeoutAfter(TimeUnit.MINUTES.toMillis(10)) .setPriority(NotificationCompat.PRIORITY_DEFAULT) .build()
48. Timeout val notification = NotificationCompat.Builder(this, CHANNEL_ID) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("Title") .setContentText("Notification content") .setTimeoutAfter(TimeUnit.MINUTES.toMillis(10)) .setPriority(NotificationCompat.PRIORITY_DEFAULT) .build()
49. Actions
50. Notification tap action val intent = Intent(context, MainActivity::class.java) intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK val pendingIntent = PendingIntent.getActivity(context, REQUEST_CODE, intent, 0) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("Title") .setContentText("Content") .setContentIntent(pendingIntent) .setAutoCancel(true) .build()
51. Notification tap action val intent = Intent(context, MainActivity::class.java) intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK val pendingIntent = PendingIntent.getActivity(context, REQUEST_CODE, intent, 0) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("Title") .setContentText("Content") .setContentIntent(pendingIntent) .setAutoCancel(true) .build()
52. PendingIntent PendingIntent.getActivity(context, REQUEST_CODE, intent, 0) PendingIntent.getService(context, REQUEST_CODE, intent, 0) PendingIntent.getBroadcast(context, REQUEST_CODE, intent, 0)
53. Additional actions
54. Additional actions val intent = Intent(context, MainActivity::class.java) intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK val pendingIntent = PendingIntent.getActivity(context, REQUEST_CODE, intent, 0) val shareIntent = Intent(context, NotificationBroadcastReceiver::class.java) shareIntent.action = ACTION_SHARE shareIntent.putExtra(EXTRA_NOTIFICATION_ID, NOTIFICATION_ID) val sharePendingIntent = PendingIntent.getBroadcast(context, 0, shareIntent, 0) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("My notification") .setContentText("Hello World!") .setPriority(NotificationCompat.PRIORITY_DEFAULT) .setContentIntent(pendingIntent) .setAutoCancel(true) .addAction(R.drawable.ic_share, "Share", sharePendingIntent) .build()
55. Additional actions val intent = Intent(context, MainActivity::class.java) intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK val pendingIntent = PendingIntent.getActivity(context, REQUEST_CODE, intent, 0) val shareIntent = Intent(context, NotificationBroadcastReceiver::class.java) shareIntent.action = ACTION_SHARE shareIntent.putExtra(EXTRA_NOTIFICATION_ID, NOTIFICATION_ID) val sharePendingIntent = PendingIntent.getBroadcast(context, 0, shareIntent, 0) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("My notification") .setContentText("Hello World!") .setPriority(NotificationCompat.PRIORITY_DEFAULT) .setContentIntent(pendingIntent) .setAutoCancel(true) .addAction(R.drawable.ic_share, "Share", sharePendingIntent) .build()
56. Additional actions - dismiss val intent = Intent(context, MainActivity::class.java) intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK val pendingIntent = PendingIntent.getActivity(context, REQUEST_CODE, intent, 0) val shareIntent = Intent(context, NotificationBroadcastReceiver::class.java) shareIntent.action = ACTION_SHARE shareIntent.putExtra(EXTRA_NOTIFICATION_ID, NOTIFICATION_ID) val sharePendingIntent = PendingIntent.getBroadcast(context, 0, shareIntent, 0) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("My notification") .setContentText("Hello World!") .setPriority(NotificationCompat.PRIORITY_DEFAULT) .setContentIntent(pendingIntent) .setAutoCancel(true) .addAction(R.drawable.ic_share, "Share", sharePendingIntent) .build() override fun onReceive(context: Context, intent: Intent) { val manager = context.getSystemService(NOTIFICATION_SERVICE) as NotificationManager val notificationId = intent.getIntExtra(Notification.EXTRA_NOTIFICATION_ID, -1) manager.cancel(notificationId) }
57. Direct replies
58. Direct replies val remoteInput = RemoteInput.Builder(KEY_TEXT_REPLY) .setLabel("Your reply") .build()
59. Direct replies val remoteInput = RemoteInput.Builder(KEY_TEXT_REPLY) .setLabel("Your reply") .build() val replyIntent = Intent(context, NotificationBroadcastReceiver::class.java) replyIntent.action = ACTION_REPLY replyIntent.putExtra(EXTRA_NOTIFICATION_ID, NOTIFICATION_ID) val replyPendingIntent = PendingIntent.getBroadcast(context, ACTION_REQUEST_CODE, replyIntent, 0) val action = NotificationCompat.Action.Builder( R.drawable.ic_reply, "Reply", replyPendingIntent) .addRemoteInput(remoteInput) .build()
60. Direct replies val remoteInput = RemoteInput.Builder(KEY_TEXT_REPLY) .setLabel("Your reply") .build() val replyIntent = Intent(context, NotificationBroadcastReceiver::class.java) replyIntent.action = ACTION_REPLY replyIntent.putExtra(EXTRA_NOTIFICATION_ID, NOTIFICATION_ID) val replyPendingIntent = PendingIntent.getBroadcast(context, ACTION_REQUEST_CODE, replyIntent, 0) val action = NotificationCompat.Action.Builder( R.drawable.ic_reply, "Reply", replyPendingIntent) .addRemoteInput(remoteInput) .build() val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.ic_notification) .setContentTitle("Message from Bob") .setContentText("Hey there, how are you doing?") .addAction(action) .build()
61. Direct replies private fun getReplyText(intent: Intent): CharSequence? { val remoteInput = RemoteInput.getResultsFromIntent(intent) return remoteInput?.getCharSequence(KEY_TEXT_REPLY) }
62. Wear support
63. Wear-only actions val actionExtender = NotificationCompat.Action.WearableExtender() .setHintLaunchesActivity(true) .setHintDisplayActionInline(true); val action = NotificationCompat.Action.Builder(R.drawable.ic_reply, "Reply", pendingIntent) .addRemoteInput(remoteInput) .extend(actionExtender) .build() val wearableExtender = NotificationCompat.WearableExtender() wearableExtender.addAction(action) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .extend(wearableExtender) .build()
64. Remote input smart reply val remoteInput = RemoteInput.Builder(KEY_TEXT_REPLY) .setLabel("Your reply") .build() val action = NotificationCompat.Action.Builder(R.drawable.ic_reply, "Reply", pendingIntent) .addRemoteInput(remoteInput) .build()
65. val remoteInput = RemoteInput.Builder(KEY_TEXT_REPLY) .setLabel("Your reply") .setChoices(arrayOf("Yes", "No", "Maybe")) .build() val action = NotificationCompat.Action.Builder(R.drawable.ic_reply, "Reply", pendingIntent) .addRemoteInput(remoteInput) .build() Remote input smart reply
66. val remoteInput = RemoteInput.Builder(KEY_TEXT_REPLY) .setLabel("Your reply") .setChoices(arrayOf("Yes", "No", "Maybe")) .build() val action = NotificationCompat.Action.Builder(R.drawable.ic_reply, "Reply", pendingIntent) .addRemoteInput(remoteInput) .setAllowGeneratedReplies(true) .build() Remote input smart reply
67. Image in MessagingStyle val message = NotificationCompat.MessagingStyle.Message( messages[0].getText(), messages[0].getTime(), messages[0].getSender() ) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.new_message .setStyle(NotificationCompat.MessagingStyle(disaplayedUserName) .addMessage(message) .addMessage(message2)) .build()
68. Image in MessagingStyle val message = NotificationCompat.MessagingStyle.Message( messages[0].getText(), messages[0].getTime(), messages[0].getSender() ).setData("image/png", imageUri) val notification = NotificationCompat.Builder(context, CHANNEL_ID) .setSmallIcon(R.drawable.new_message .setStyle(NotificationCompat.MessagingStyle(disaplayedUserName) .addMessage(message) .addMessage(message2)) .build()
69. More info Wearable features for Notifications https://developer.android.com/training/wearables/notifications/index.html Notifications Design Guidelines https://material.io/guidelines/patterns/notifications.html Notifications overview https://developer.android.com/guide/topics/ui/notifiers/notifications.html
70. Daniele Bonaldo Thank You! Any questions? @danybony_ danybony