Question

I want to make an timer which starts counting when the Android device is woken up and stops when the Android device is set to sleep. I found nothing, how a activity could be triggered
by wake up/sleep.

I hope you can help me with my problem

Answer 1

I used a BroadcastReceiver like timonvlad said but ACTION_SCREEN_ON and ACTION_SCREEN_OFF could not be called by XML so I created an service. The service has to be registered in the XML then I used this code

public class OnOffReceiver extends Service {

@Override
public IBinder onBind(Intent arg0) {
    // TODO Auto-generated method stub
    return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    registerReceiver(new BroadcastReceiver() {

        public void onReceive(Context context, Intent intent) {
                        //This happens when the screen is switched off
          }
        }, new IntentFilter(Intent.ACTION_SCREEN_OFF));


    registerReceiver(new BroadcastReceiver() {

          public void onReceive(Context context, Intent intent) {
                          //This happens when the screen is turned on and screen lock deactivated
          }
        }, new IntentFilter(Intent.ACTION_USER_PRESENT));

    return START_STICKY;
}

@Override
public void onDestroy() {
    super.onDestroy();
}
}