Tukukkk

I have an Activity which loads a Fragment using getFragmentManager() . The fragment is working perfecty until an android notification appears. After that, the fragment becomes empty.

This is my application after the activity has loaded the fragment. The red square is the fragment.

Here, a external notification arrives to the mobile:

Only the fragment becomes empty:

Here my Activity:

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener, FragmentSettings.OnFragmentInteractionListener{



FragmentManager fragmentManager;



    @Override

protected void onCreate(Bundle savedInstanceState) {



    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

if (fragmentManager == null) {

        fragmentManager = getSupportFragmentManager();



    }

}

@SuppressWarnings("StatementWithEmptyBody")

@Override

public boolean onNavigationItemSelected(MenuItem item) {



        if (id == R.id.nav_locker_room) {

            fragmentNameSection = "FragmentLockerRoom";

            fragment = FragmentLockerRoom.newInstance(user, "");



        }

        fragmentManager.beginTransaction().replace(R.id.flContent, fragment, fragmentNameSection).commit();



        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);

        drawer.closeDrawer(GravityCompat.START);

}

@Override

public void onResume() {

    super.onResume();

}

}

Here the activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:app="http://schemas.android.com/apk/res-auto"

xmlns:tools="http://schemas.android.com/tools"

android:id="@+id/drawer_layout"

android:layout_width="match_parent"

android:layout_height="match_parent"



tools:openDrawer="start">



<include

    layout="@layout/app_bar_main"

    android:layout_width="match_parent"

    android:layout_height="match_parent" />



<android.support.design.widget.NavigationView



    android:id="@+id/nav_view"

    android:layout_width="wrap_content"

    android:layout_height="match_parent"

    android:layout_gravity="start"

    android:background="@drawable/side_nav_menu"

    app:itemTextColor="@android:color/white"

    app:itemIconTint="@android:color/white"

    app:headerLayout="@layout/nav_header_main"

    app:menu="@menu/activity_main_drawer" />



</android.support.v4.widget.DrawerLayout>

And finally this is my Fragment:

public class FragmentSettings extends Fragment {



private static final String ARG_USER = "user";

private static final String ARG_PARAM2 = "param2";





private String mParam1;

private String mParam2;

getUser user;



View v;

DatabaseManager db;

private OnFragmentInteractionListener mListener;

ToggleButton notificationTrain, notificationNextMatch, liveSounds;

LayoutInflater inflater;

ViewGroup container;

FragmentSettings fragmentSettings;



public FragmentSettings() {



}



public static FragmentSettings newInstance(getUser user, String param2) {

    FragmentSettings fragment = new FragmentSettings();

    Bundle args = new Bundle();

    args.putSerializable(ARG_USER, user);

    args.putString(ARG_PARAM2, param2);

    fragment.setArguments(args);

    return fragment;

}



@Override

public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    if (getArguments() != null) {

        user = (com.androidsrc.futbolin.communications.http.auth.get.getUser) getArguments().getSerializable(ARG_USER);

        mParam2 = getArguments().getString(ARG_PARAM2);

    }

    this.fragmentSettings = this;

}



@Override

public View onCreateView(LayoutInflater inflater, ViewGroup container,

                         Bundle savedInstanceState) {

    // Inflate the layout for this fragment

    this.inflater = inflater;

    this.container = container;



    buildLayout();



    return v;

}



// TODO: Rename method, update argument and hook method into UI event

public void onButtonPressed(Uri uri) {

    if (mListener != null) {

        mListener.onFragmentInteraction(uri);

    }

}



@Override

public void onAttach(Context context) {

    super.onAttach(context);

    if (context instanceof OnFragmentInteractionListener) {

        mListener = (OnFragmentInteractionListener) context;

    } else {

        throw new RuntimeException(context.toString()

                + " must implement OnFragmentInteractionListener");

    }

}



@Override

public void onDetach() {

    super.onDetach();

    mListener = null;

}



/**

 * This interface must be implemented by activities that contain this

 * fragment to allow an interaction in this fragment to be communicated

 * to the activity and potentially other fragments contained in that

 * activity.

 * <p/>

 * See the Android Training lesson <a href=

 * "http://developer.android.com/training/basics/fragments/communicating.html"

 * >Communicating with Other Fragments</a> for more information.

 */

public interface OnFragmentInteractionListener {

    // TODO: Update argument type and name

    void onFragmentInteraction(Uri uri);

}



public void buildLayout(){

    db = new DatabaseManager(getActivity());

    v = inflater.inflate(R.layout.fragment_fragment_settings, container, false);



    notificationTrain = v.findViewById(R.id.fragment_settings_notification_trainment_toggle);

    notificationNextMatch = v.findViewById(R.id.fragment_settings_notification_next_match_toggle);

    liveSounds = v.findViewById(R.id.fragment_settings_notification_live_sounds_toggle);



    notificationTrain.setChecked(db.findNotification().isTrainActive());

    notificationNextMatch.setChecked(db.findNotification().isMatchActive());

    liveSounds.setChecked(db.findNotification().isLiveSoundsActive());

    Log.e("notif",db.findNotification().toString());



    notificationTrain.setOnCheckedChangeListener( new CompoundButton.OnCheckedChangeListener() {

        @Override

        public void onCheckedChanged(CompoundButton toggleButton, boolean isChecked) {

            if(db == null){

                db = new DatabaseManager(getActivity());

            }

            Notification notification = db.findNotification();

            notification.setTrainActive(isChecked);

            db.saveNotification(notification);

        }

    }) ;

    notificationNextMatch.setOnCheckedChangeListener( new CompoundButton.OnCheckedChangeListener() {

        @Override

        public void onCheckedChanged(CompoundButton toggleButton, boolean isChecked) {

            if(db == null){

                db = new DatabaseManager(getActivity());

            }

            Notification notification = db.findNotification();

            notification.setMatchActive(isChecked);

            db.saveNotification(notification);

        }

    }) ;

    liveSounds.setOnCheckedChangeListener( new CompoundButton.OnCheckedChangeListener() {

        @Override

        public void onCheckedChanged(CompoundButton toggleButton, boolean isChecked) {

            if(db == null){

                db = new DatabaseManager(getActivity());

            }

            Notification notification = db.findNotification();

            notification.setLiveSoundsActive(isChecked);

            db.saveNotification(notification);

        }

    }) ;

}



}

And the layout of my Fragment is:

    <?xml version="1.0" encoding="utf-8"?>

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        xmlns:app="http://schemas.android.com/apk/res-auto">





        <ScrollView

            android:id="@+id/fragment_locker_room_scrollview"

            android:layout_width="match_parent"

            android:layout_height="match_parent"

            app:layout_constraintLeft_toLeftOf="parent"

            app:layout_constraintRight_toRightOf="parent"

            app:layout_constraintTop_toTopOf="parent"

            app:layout_constraintBottom_toBottomOf="parent"

            android:layout_marginBottom="60dp"

            >

            <androidx.constraintlayout.widget.ConstraintLayout

                android:id="@+id/fragment_locker_room_total_constraint_layout"

                android:layout_width="match_parent"

                android:layout_height="wrap_content"

                >

                    <!-- 

                        REST OF VIEWS

                    -->

        </androidx.constraintlayout.widget.ConstraintLayout>

        </ScrollView>

    </LinearLayout>

Finally I found the solution. And ScrollView that has a layout_height="match_parent" when a notification is received changes his layout_height to 0.

Changing layout_height="match_parent" to layout_height="wrap_content" in ScrollView solves the issue.