Android 4.3 introduces a new API called the
Notification Listener Service. Its main function is to let applications have
the ability to be notified when notifications are posted or removed from the
system. A good example use of this is the Android Wear application, which
receives all the notifications posted on your Android device and routes them to
your Android Wear device.
To create a notification, you can use the NotificationCompat.Builder class:
//---create a
notification---
Notification
notification = new
NotificationCompat.Builder(this)
.setSmallIcon(R.drawable.ic_launcher)
.setContentTitle("Notification Title")
.setContentText("Notification Message")
.setTicker("Ticker Text")
.setAutoCancel(true)
.setNumber(1)
.build();
//---set the sound and
lights---
notification.defaults
|=
Notification.DEFAULT_SOUND;
notification.defaults
|=
Notification.DEFAULT_LIGHTS;
To post a notification on your Android device, you can use the NotificationManager class’s notify() method, passing it a tag,
notification ID, as well as the Notification
object:
NotificationManager
notificationManager;
int notificationID = 0;
//---display the
notification---
notificationManager.notify("tag",
notificationID++,
notification);
To listen for notifications posted on the Android device, you
need to create a new class that extends the NotificationListenerService base class:
package net.learn2develop.notificationservice;
import
android.service.notification.NotificationListenerService;
import android.service.notification.StatusBarNotification;
import android.util.Log;
public class NotificationListener extends
NotificationListenerService
{
@Override
public void
onNotificationPosted(
StatusBarNotification
sbn) {
//---show current
notification---
Log.i("","---Current Notification---");
Log.i("","ID :" + sbn.getId() + "\t" +
sbn.getNotification().tickerText
+ "\t" +
sbn.getPackageName());
Log.i("","--------------------------");
//---show all
active notifications---
Log.i("","===All Notifications===");
for
(StatusBarNotification notif :
this.getActiveNotifications()) {
Log.i("","ID :" + notif.getId() + "\t" +
notif.getNotification().tickerText
+ "\t" +
notif.getPackageName());
}
Log.i("","=======================");
}
@Override
public void
onNotificationRemoved(
StatusBarNotification sbn) {
Log.i("","---Notification Removed---");
Log.i("","ID :" + sbn.getId() + "\t" +
sbn.getNotification().tickerText
+ "\t" +
sbn.getPackageName());
Log.i("","--------------------------");
}
}
You need to override two methods in this class:
·
onNotificationPosted()
– called when a notification is received by the system
·
onNotificationRemoved()
– called when a notification is removed
For these two methods, an instance of the StatusBarNotification class will be passed in, allowing you to know
which application posted the notification, its content, id, etc.
Within the service, you can also list all the notifications
currently available in the notification bar by using the getActiveNotifications() method. You can also remove a particular
notification by using the cancelNotification()
method, passing it the package name of the application that posted the
notification, the tag of the notification, as well as its notification id:
this.cancelNotification(
notif.getPackageName(),
notif.getTag(),
notif.getId());
To remove all notifications, use the cancelAllNotifications() method:
//---remove all
notifications---
this.cancelAllNotifications();
Finally, you need to declare your service in the AndroidManifest.xml file:
<service android:name=".NotificationListener"
android:label="@string/app_name"
android:permission=
"android.permission.BIND_NOTIFICATION_LISTENER_SERVICE">
<intent-filter>
<action android:name=
"android.service.notification.NotificationListenerService" />
</intent-filter>
</service>
When the application is installed on the device, the user must
explicitly give permission to your app to listen for notifications on the
system. They need to do so via the Notification
access page at: Settings | Security
| Notification access:
