How to show list in fragment on back pressed from next fragment?

Question

I have MyTrips fragment which contains ViewPager. So it contains two tabs i.e two fragments one is ScheduleListFrgment and another is TripHistoryFragment.

Now As I replace MyTrips fragment it first shows ScheduleListFragment, loads data from server and shows in a list, it also loads data of tripHistory from server.

So now I have given click event to the list item of ScheduleListFragment so onClick it replaces ScheduleListFragment with PostDetailsFragment.

Now after I press back from PostDetailsFragment it shows empty ScheduleListFragment with no list.

I want to show the list when user press from from PostDetailsFragment.

ScheduleListFragment

public class ScheduledTravelFragment extends Fragment implements GetScheduledTripsAsyncTask.GetScheduleTripsCallBack{

    public RecyclerView mRecyclerView_list;
    private ArrayList<Trips> mTripsList;
    private ScheduledTravelAdapter mTripsAdapter;
    public TextView mTextViewData;
    private String mDateTime;
    private SessionData sessionData;

    private RelativeLayout parentLayout;

    public ScheduledTravelFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_scheduled_travel, container, false);


        setUpUI(view);


        return view;
    }
    @Override
    public void onStart()
    {
        super.onStart();

        GetScheduledTripsAsyncTask getScheduledTripsAsyncTask = new GetScheduledTripsAsyncTask(getActivity(),parentLayout,ScheduledTravelFragment.this,ScheduledTravelFragment.this);
        getScheduledTripsAsyncTask.execute(mDateTime,sessionData.getString("api_key",""));
    }

    public void setUpUI(View view)
    {

        mRecyclerView_list = (RecyclerView) view.findViewById(R.id.rv_tripList);
        mTextViewData = (TextView) view.findViewById(R.id.textViewData);
        parentLayout = (RelativeLayout) view.findViewById(R.id.parentPanel);

        mTripsList = new ArrayList<Trips>();
        mTripsAdapter = new ScheduledTravelAdapter(getActivity(),mTripsList, ScheduledTravelFragment.this);
        mRecyclerView_list.setLayoutManager(new LinearLayoutManager(getActivity()));
        mRecyclerView_list.setAdapter(mTripsAdapter);
        mRecyclerView_list.setHasFixedSize(true);
        mRecyclerView_list.setItemViewCacheSize(50);
        mRecyclerView_list.setDrawingCacheEnabled(true);
        mRecyclerView_list.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);

        sessionData = new SessionData(getActivity());
        mDateTime = String.valueOf(CommonUtils.getCurrentDateTime());

    }

    @Override
    public void doPostExecute(ArrayList<Trips> list)
    {
        mTripsList.addAll(list);

        mTripsAdapter.notifyDataChanged();

    }


}

ScheduleListAdapter

public class ScheduledTravelAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {


    private Context context;
    private ArrayList<Trips> list;
    private ScheduledTravelFragment tripListFragment;
    static final int TYPE_LOAD_TRIP = 0, TYPE_LOAD_PROGRESS = 1;
    boolean isLoading = false, isMoreDataAvailable = true;
    TransportListAdapter.OnLoadMoreListener loadMoreListener;

    public ScheduledTravelAdapter(Context context, ArrayList<Trips> list,ScheduledTravelFragment tripListFragment) {
        this.context = context;
        this.list = list;
        this.tripListFragment = tripListFragment;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, final int viewType) {

        RecyclerView.ViewHolder viewHolder = null;
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        switch (viewType) {

            case TYPE_LOAD_TRIP:
                View v_order_header = inflater.inflate(R.layout.trip_layout, parent, false);
                viewHolder = new TripsHolder(v_order_header);
                break;

        }

        return viewHolder;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

        if (position >= getItemCount() - 1 && isMoreDataAvailable && !isLoading && loadMoreListener != null) {
            isLoading = true;
            loadMoreListener.onLoadMore();
        }

        if (getItemViewType(position) == TYPE_LOAD_TRIP) {
            TripsHolder tripsHolder = (TripsHolder) holder;
            retriveAllTrips(tripsHolder, position);
        } else {
        }

    }

    @Override
    public int getItemViewType(int position) {

        Object obj = list.get(position);

        if (obj instanceof Transport) {
            return TYPE_LOAD_TRIP;
        }

        return super.getItemViewType(position);
    }

    @Override
    public int getItemCount() {
        return list.size();
    }


    public void retriveAllTrips(final TripsHolder holder, int position) {


        final Trips data = (Trips) list.get(position);

        final String newDate = CommonUtils.formateDateFromstring("yyyy-MM-dd HH:mm:ss", "dd MMM, yyyy", data.getmDate());


        holder.tv_date.setText(newDate);
        holder.tv_from.setText(data.getmFrom());
        holder.tv_to.setText(data.getmTo());

        //go to post detail fragment

            holder.lay_row.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {

                    Bundle bundle = new Bundle();
                    bundle.putString("pt_id", data.getmPostId());
                    bundle.putString("pt_name", data.getmPostName());
                    bundle.putString("pt_details", data.getmPostDetails());
                    bundle.putString("pt_photo", data.getmImage());
                    bundle.putString("pt_date", data.getmDate());
                    bundle.putString("from", data.getmFrom());
                    bundle.putString("to", data.getmTo());

                    //go to post details screen
                    FragmentManager fragmentManager = tripListFragment.getFragmentManager();
                    PostDetailsFragment fragment = new PostDetailsFragment();
                    fragment.setArguments(bundle);
                    fragmentManager.beginTransaction().replace(R.id.mycontainer, fragment, "POST_DETAILS_FRAGMENT").addToBackStack("O").commit();

                }
            });

 }
    public void notifyDataChanged() {
        notifyDataSetChanged();
        isLoading = false;
    }

}

EDIT:

MyTrips frgament:

public class MyTripsFragment extends Fragment {

    private ViewPager viewPager;
    private TabsPagerAdapter mAdapter;
    private CharSequence Titles[]={"Scheduled Travel","Travel History"};
    private int Numboftabs =2;
    private SlidingTabLayout tabs;
    private TabLayout tabLayout;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_my_trips, container, false);

        final Toolbar toolbar = (Toolbar) ((HomeActivity) getActivity()).findViewById(R.id.toolbar);
        ((HomeActivity) getActivity()).setSupportActionBar(toolbar);

        ImageView mLogo = (ImageView) getActivity().findViewById(R.id.imgLogo);
        mLogo.setVisibility(View.GONE);

        TextView title = (TextView) getActivity().findViewById(R.id.textTitle);
        title.setVisibility(View.VISIBLE);
        title.setText(R.string.myTrips);

        mAdapter =  new TabsPagerAdapter(getActivity().getFragmentManager(),Titles,Numboftabs);
        viewPager = (ViewPager)view.findViewById(R.id.pager);

        setupViewPager(viewPager);

        tabLayout = (TabLayout)view.findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);

        return view;
    }

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

    private void setupViewPager(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getFragmentManager());
        adapter.addFragment(new ScheduledTravelFragment(), "Scheduled Travel");
        adapter.addFragment(new TravelHistoryFragment(), "Travel History");
        viewPager.setAdapter(adapter);
    }
    class ViewPagerAdapter extends FragmentStatePagerAdapter {
        private final List<Fragment> mFragmentList = new ArrayList<>();
        private final List<String> mFragmentTitleList = new ArrayList<>();

        public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
        }

        @Override
        public Fragment getItem(int position) {
            return mFragmentList.get(position);
        }

        @Override
        public int getCount() {
            return mFragmentList.size();
        }

        public void addFragment(Fragment fragment, String title) {
            mFragmentList.add(fragment);
            mFragmentTitleList.add(title);
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return mFragmentTitleList.get(position);
        }
    }

}

At first time when fragment created title is mytrips.

on next fragment changing text.`

final Toolbar toolbar = (Toolbar) ((HomeActivity) getActivity()).findViewById(R.id.toolbar); ((HomeActivity) getActivity()).setSupportActionBar(toolbar);

    ImageView mLogo = (ImageView)getActivity().findViewById(R.id.imgLogo);
    mLogo.setVisibility(View.GONE);

    TextView title = (TextView) getActivity().findViewById(R.id.textTitle);
    title.setVisibility(View.VISIBLE);
    title.setText(R.string.tripDetails);`

OnBackpress of next fragment. Carry app logo is set on main fragment that i visible.

Answer 1

You should not use replace. For your purpose try add.

fragmentManager
.beginTransaction()
.add(R.id.mycontainer, fragment, "POST_DETAILS_FRAGMENT")
.addToBackStack("O")
.commit();

This way your last fragment remain at its state won't change and won't create again.

Don't forget to make your next fragment root layout clickable. This way, if you click anywhere, it won't click the bottom fragment.

android:clickable="true"

Also don't forget to give background to your next fragment