Android O - Notification Channels and NotificationCompat

Question

I cannot change this feeling: again, the Android developers came up with something new and leave everybody in the dark about how they would think the feature is used.

I am talking about Notification Channels in Android O.

For years I have been using the compatibility support libraries to avoid dealing with specific platform details. Namely: NotificationCompat.

Now, the Builder requires me to supply a notification channel id, which is nice, but completely leaves me alone with creating such a channel. I cannot find any compat support for creating channels. Nor can I find a reasonable way to create them at the right point.

The docs simply state that it should be done "somewhere" and "probably not when issuing a notification". But what exactly am I supposed to do? I hate writing version specific stuff for simple tasks - that's why I use the compat libraries.

Does anybody have a suggestion on how to handle it? Is it "expensive" to do the creating each and every time when I want a notification to be displayed?

Answer 1

This is my solution to generate notifications on Android O and maintain backward compatibility:

        String idChannel = "my_channel_01";
        Intent mainIntent;

        mainIntent = new Intent(context, LauncherActivity.class);

        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, mainIntent, 0);

        NotificationManager mNotificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

        NotificationChannel mChannel = null;
        // The id of the channel.

        int importance = NotificationManager.IMPORTANCE_HIGH;

        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, null);
        builder.setContentTitle(context.getString(R.string.app_name))
                .setSmallIcon(getNotificationIcon())
                .setContentIntent(pendingIntent)
                .setContentText(context.getString(R.string.alarm_notification) + ManagementDate.getIstance().hourFormat.format(getAlarm(context, 0)));

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            mChannel = new NotificationChannel(idChannel, context.getString(R.string.app_name), importance);
            // Configure the notification channel.
            mChannel.setDescription(context.getString(R.string.alarm_notification));
            mChannel.enableLights(true);
            mChannel.setLightColor(Color.RED);
            mChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});
            mNotificationManager.createNotificationChannel(mChannel);
        } else {
            builder.setContentTitle(context.getString(R.string.app_name))
                    .setPriority(NotificationCompat.PRIORITY_HIGH)
                    .setColor(ContextCompat.getColor(context, R.color.transparent))
                    .setVibrate(new long[]{100, 250})
                    .setLights(Color.YELLOW, 500, 5000)
                    .setAutoCancel(true);
        }
        mNotificationManager.notify(1, builder.build());

Answer 2

It's not as expensive as you think! All you need to do is creating a notification channel and bind it to notification.

You can solve this in two ways but for both of them you need to create a notification channel with a specific channel id.

NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
String id = "my_channel_01";
int importance = NotificationManager.IMPORTANCE_LOW;
NotificationChannel mChannel = new NotificationChannel(id, name,importance);
mChannel.enableLights(true);
mNotificationManager.createNotificationChannel(mChannel);

First way is to set channel for notification in constructor:

Notification notification = new Notification.Builder(MainActivity.this , id).setContentTitle("Title");
mNotificationManager.notify("your_notification_id", notification);

Second way is to set the channel by Notificiation.Builder.setChannelId()

Notification notification = new Notification.Builder(MainActivity.this).setContentTitle("Title").
setChannelId(id);
mNotificationManager.notify("your_notification_id", notification);

Hope this helps