Is there a way to handle the task switcher active?

Question

So our app is handling when the app goes to background via this hack found elsewhere:

 public static boolean isAppGoingToBackground(Context context)
    {
        boolean retVal = false;
        ActivityManager mgr = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        List<ActivityManager.RunningTaskInfo> runningTasks = mgr.getRunningTasks(1);
        if (!runningTasks.isEmpty())
        {
            // If the package name of the current activity doesn't equal the context's
            // package name, then the user is no longer in the context's app.
            ComponentName currentActivity = runningTasks.get(0).topActivity;
            retVal = !currentActivity.getPackageName().equals(context.getPackageName());
        }
        return retVal;
    }

However this doesn't handle if the screen is turned off via the power button, so we added a broadcast receiver for that event:

_receiver = new BroadcastReceiver()
        {
            @Override
            public void onReceive(Context context, Intent intent)
            {
                if(intent.getAction() == Intent.ACTION_SCREEN_ON)
                {
                    //resume
                }
                else if(intent.getAction() == Intent.ACTION_SCREEN_OFF)
                {
                    handleAppGoingToBackground(_context);
                }
            }
        };

However neither of these give the correct response when users background the app using the task switcher:

If you background the app in this manner, the isGoingToBackground returns false. I was hoping there was another event in the broadcast receiver I could use to handle this event, but I haven't found anything. Is there anyway to know within your app when it is backgrounding in this manner?

score 0 · Answer 1 · answered Aug 18 '15 at 18:10

0

I would recommend using the onPause() method. So if your app goes to 'bagrounding' the onPause() method is called. It is just like onCreate() and your app simply runs the method onPause() whenever your app goes to the background. You can also use the BroadcastReceiver to check how your app was sent to the background by a screen power-off or by the user. If you want more info on how to do this. Comment below.

answered Aug 18 '15 at 18:10

KISHORE_ZE

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The problem with onPause is it's called for way more than just backgrounding. I don't need this called when rotating or transitioning between activities, I need it specifically when the app goes to background. – Kevin DiTraglia Aug 18 '15 at 19:41

score 0 · Accepted Answer · answered Aug 18 '15 at 20:20

OK so I got a working solution, I took a little different approach to using the getTasks call as it's deprecated. This seems to work for everything I've tested so far, but I'll continue to test to see if I have any other problems. Essentially all my activities have a super class defined as such:

public abstract class BaseActivity extends AppCompatActivity
{
    boolean isStartingActivity = false;
    boolean appWentToBackground = false;
    @Override
    protected void onPostResume()
    {
        super.onPostResume();

        if (appWentToBackground) 
        {
            appWentToBackground = false;
            handleAppComingToForeground();
        }
    }

    @Override
    protected void onStop()
    {
        super.onStop();
        if (!isFinishing() && !isStartingActivity && getChangingConfigurations() == 0)
        {
            appWentToBackground = true;
            //If all of the above is true the app must be going to background
            handleAppGoingToBackground();
        }
        isStartingActivity = false;
    }

    @Override
    public void startActivityForResult(Intent intent, int requestCode, Bundle options)
    {
        isStartingActivity = true;
        super.startActivityForResult(intent, requestCode, options);
    }

    @Override
    public void startActivityFromFragment(Fragment fragment, Intent intent, int requestCode)
    {
        isStartingActivity = true;
        super.startActivityFromFragment(fragment, intent, requestCode);
    }
}

The thought process is ChangingConfigs check handles rotation, isFinishing handles back pressed (it doesn't handle going back to the point of being in another app, but that case is OK in my situation), and isStartingActivity handles the case I'm transitioning to another activity, if all those conditions are met it must mean I'm backgrounding in some form or another (works for me for app switcher and normal background).

I'll update if I notice anything else that could use improvements, or cases I missed.

Is there a way to handle the task switcher active?

2 Answers2