check android application is in foreground or not? [duplicate]

Answer 1

There is no global callback for this, but for each activity it is onStop(). You don't need to mess with an atomic int. Just have a global int with the number of started activities, in every activity increment it in onStart() and decrement it in onStop().

public class BaseActivity extends ActionBarActivity {
public static int count = 0;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}


@Override
protected void onStart() {
    super.onStart();
    count = count + 1;
    Log.d(TAG, "onStart" + count);
    if (count == 1) {

       Toast.makeText(getApplicationContext(), "online", Toast.LENGTH_SHORT).show();

    }

}



protected void onStop() {
    super.onStop();
    count = count - 1;
    if (count == 0) {

        Toast.makeText(getApplicationContext(), "offline", Toast.LENGTH_SHORT).show();

    }
}


}

Answer 2

cesards's answer is correct, but only for API > 15. For lower API versions I decided to use getRunningTasks() method:

   private boolean isAppInForeground(Context context)
    {
        if (android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP)
        {
            ActivityManager am = (ActivityManager) context.getSystemService(ACTIVITY_SERVICE);
            ActivityManager.RunningTaskInfo foregroundTaskInfo = am.getRunningTasks(1).get(0);
            String foregroundTaskPackageName = foregroundTaskInfo.topActivity.getPackageName();

            return foregroundTaskPackageName.toLowerCase().equals(context.getPackageName().toLowerCase());
        }
        else
        {
            ActivityManager.RunningAppProcessInfo appProcessInfo = new ActivityManager.RunningAppProcessInfo();
            ActivityManager.getMyMemoryState(appProcessInfo);
            if (appProcessInfo.importance == IMPORTANCE_FOREGROUND || appProcessInfo.importance == IMPORTANCE_VISIBLE)
            {
                return true;
            }

            KeyguardManager km = (KeyguardManager) context.getSystemService(Context.KEYGUARD_SERVICE);
            // App is foreground, but screen is locked, so show notification
            return km.inKeyguardRestrictedInputMode();
        }
    }

Please, let me know if it works for you all.

Answer 3

@user370305's answer is error prone and discouraged by Android OS Developers (check https://groups.google.com/forum/#!msg/android-developers/zH-2bovZSLg/L2YM8Z1N-HwJ)

There is a much more simpler approach:

On a BaseActivity that all Activities extend:

protected static boolean isVisible = false;

@Override
public void onResume() {
   super.onResume();
   setVisible(true);
}

@Override
public void onPause() {
    super.onPause();
    setVisible(false);
}

Whenever you need to check if any of your application activities is in foreground just check isVisible();

To understand this approach check this answer of side-by-side activity lifecycle: Activity side-by-side lifecycle

Answer 4

From Android 19, you can register an app life cycle callback in your Application class's onCreate() like this:

@Override
public void onCreate() {
    super.onCreate();
    registerActivityLifecycleCallbacks(new AppLifecycleCallback());
}

The AppLifecycleCallback looks like this:

class AppLifecycleCallback implements Application.ActivityLifecycleCallbacks {
    private int numStarted = 0;

    @Override
    public void onActivityCreated(Activity activity, Bundle savedInstanceState) {

    }

    @Override
    public void onActivityStarted(Activity activity) {
        if (numStarted == 0) {
           //app went to foreground
        }
        numStarted++;
    }

    @Override
    public void onActivityResumed(Activity activity) {

    }

    @Override
    public void onActivityPaused(Activity activity) {

    }

    @Override
    public void onActivityStopped(Activity activity) {
        numStarted--;
        if (numStarted == 0) {
            // app went to background
        }
    }

    @Override
    public void onActivitySaveInstanceState(Activity activity, Bundle outState) {

    }

    @Override
    public void onActivityDestroyed(Activity activity) {

    }
}

Answer 5

With the new Android Architecture of Lifecycle extensions, we can achieve this with utmost ease.

Just ensure you pull this dependency in your build.gradle file:

dependencies {
    implementation "android.arch.lifecycle:extensions:1.1.0"
}

Then in your Application class, use this:

class ArchLifecycleApp : Application(), LifecycleObserver {

    override fun onCreate() {
        super.onCreate()
        ProcessLifecycleOwner.get().lifecycle.addObserver(this)
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
    fun onAppBackgrounded() {
        Log.d("MyApp", "App in background")
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_START)
    fun onAppForegrounded() {
        Log.d("MyApp", "App in foreground")
    }
}

In the end, update your AndroidManifest.xml file with:

<application
    android:name=".ArchLifecycleApp"
    //Your extra code
    ....>
</application>

Now, on everytime the Application goes to Foreground or Background, we are going to receive the Logs associated with the two methods declared.

Answer 6

Try ActivityLifecycleCallbacks in your Application class.