How to tell if application is in the background?

Question

I have the following method which does not work accurately for the Lollipop code segment. The getRunningAppProcesses() method returns all sorts of system tasks and also returns multiple results which I am unable to determine which result represents the equivalent of using getRunningTasks(1).get(0).topActivity.

How is this suppose to be done for API 21 and above?

   public static boolean isAppInBackground(final Context context) {
        ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);

        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT_WATCH) {
            List<ActivityManager.RunningAppProcessInfo> tasks = am.getRunningAppProcesses();
            if (!tasks.isEmpty()) {
                for (ActivityManager.RunningAppProcessInfo fullTaskList : tasks) {
                    if (fullTaskList.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_BACKGROUND) {
                        // NOTE: this condition needs to be changed because
                        // the list returns multiple results and not all 
                        // the results represent IMPORTANCE_BACKGROUND
                        return true;
                    }
                }
            }
        } else {
            List<ActivityManager.RunningTaskInfo> tasks = am.getRunningTasks(1);
            if (!tasks.isEmpty()) {
                ComponentName topActivity = tasks.get(0).topActivity;
                if (!topActivity.getPackageName().equals(context.getPackageName())) {
                    return true;
                }
            }
        }
        return false;
    }

This may be some help;http://stackoverflow.com/questions/24625936/getrunningtasks-doesnt-work-in-android-l — RP-, Sep 03 '15 at 01:02
possible duplicate of [Checking if an Android application is running in the background](http://stackoverflow.com/questions/3667022/checking-if-an-android-application-is-running-in-the-background) — cybersam, Sep 03 '15 at 01:38
@cybersam this isn't a duplicate thread as I am asking about a way of determining this through a function, whereas that thread is explaining a solution using singleton pattern and android lifecycle. I want to know specifically, how to properly use getRunningAppProcessInfo(). — portfoliobuilder, Sep 03 '15 at 16:42

score 1 · Accepted Answer · answered Nov 06 '17 at 10:14

The most simple and straightforward solution that I found is the following:

public class AppStatusHelper {
    private static final String TAG = AppStatusHelper.class.getSimpleName();

    private static int mNumOfActivitiesInOnStarttoOnStopLifeCycle=0;

    public static void onStart()
    {
        mNumOfActivitiesInOnStarttoOnStopLifeCycle++;
    }
    public static void onStop()
    {
        mNumOfActivitiesInOnStarttoOnStopLifeCycle--;
    }

    public static boolean isAppInBackground()
    {
        Log.d(TAG,"num->"+mNumOfActivitiesInOnStarttoOnStopLifeCycle+"\tisOnBackground->"+(mNumOfActivitiesInOnStarttoOnStopLifeCycle==0));
        return mNumOfActivitiesInOnStarttoOnStopLifeCycle==0;
    }

}

Just call onStart on every activity start and onStop on every activity stop. Then check if the counter is equal to 0.

How to tell if application is in the background?

1 Answers1