We Keep Coding

when moving from one fragment to other the elements of the former staying on screen

so i got one main activity that has a Tablayout and a ViewPager to present diffrent fragments.
when i move between the fragments with my Tablayout everything works good, but if i use a button to open fragment, when going back to the former fragment (by pushing the cancel button) the elements of the fragment i left staying on the screen (as in the picture).
i tried to use a method viewPager.setCurrentItem(0); in the fragment to go back to the homepage from the fragment instade of ft.replace(R.id.fragment_edit_reminder, new Main_Activity_fragment()).commit(); but it didn't moved back to my home fragment (with the repalce it does go back but as i saied the elements.
this is my main:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TabLayout tableLayout = findViewById(R.id.Tablayouting);
final ViewPager viewPager = findViewById(R.id.ViewPager);
PagerAdapter pagerAdapter = new
PagerAdapter(getSupportFragmentManager(),tableLayout.getTabCount());
viewPager.setAdapter(pagerAdapter);
tableLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
}
this is the fragment:
public class edit_reminder_fragment extends Fragment implements View.OnClickListener {
private Button cancelButton;
public edit_reminder_fragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #return A new instance of fragment edit_reminder_fragment.
*/
public static edit_reminder_fragment newInstance() {
edit_reminder_fragment fragment = new edit_reminder_fragment();
Bundle args = new Bundle();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
}
}
#RequiresApi(api = Build.VERSION_CODES.O)
public void onClick(View view)//TODO: make a utility method for switching fragments on the main_activity_fragment(see note).
{
switch (view.getId()) {//recognizing what button was pushed
case R.id.ButtonCancelReminder:
//region
FragmentTransaction ft = getFragmentManager().beginTransaction();
Main_Activity_fragment maf = new Main_Activity_fragment();
ft.replace(R.id.fragment_edit_reminder, maf).commit();
break;
//endregion
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_edit_reminder_fragment, container, false);
cancelButton = view.findViewById(R.id.ButtonCancelReminder);
cancelButton.setOnClickListener(this);
return view;
}
}
my pagerAdapted class:
public class PagerAdapter extends FragmentPagerAdapter {
//https://www.youtube.com/watch?v=HHd-Fa3DCng&ab_channel=MasterCoding
private int numOfTabs;
public PagerAdapter(FragmentManager fm, int numOfTabs) {
super(fm);
this.numOfTabs = numOfTabs;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new Main_Activity_fragment();
case 1:
return new key_words_fragment();
case 2:
return new groups_and_points_fragment();
case 3:
return new Fragment_Past_Reminders();
case 4:
return new edit_reminder_fragment();
default:
return null;
}
}
#Override
public int getCount() {
return numOfTabs;
}
}
in the picture we see the home page fragment ,on it 3 buttons (cancel, save, Add a sub reminder) that stayed from a fragment that open when clicking on the ADD NEW REMINDER button (when clicking on cancel in the second fragment it's going back to the home page):

First, try the following as an adaper:
public class PagerAdapter extends
FragmentPagerAdapter {
private final ArrayList<Fragment> mFragments = new ArrayList<>();
private final ArrayList<String> mFragmentTitle = new ArrayList<>();
public PagerAdapter(FragmentManager mManager) {
super(mManager);
}
#Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
#Override
public int getCount() {
return mFragments.size();
}
public void addFragment(Fragment fragment, String title) {
mFragments.add(fragment);
mFragmentTitle.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitle.get(position);
}
public Fragment getFragment(int position) {
if (position < mFragments.size() && position >= 0) {
return mFragments.get(position);
}
return null;
}
}
Then in your MainActivity's onCreate, initialize the following:
mTabs = (TabLayout) findViewById(R.id.tabs);
mPager = (ViewPager) findViewById(R.id.view_pager);
mMainAdapter = new PagerAdapter( getSupportFragmentManager() );
setupContents();
Then the private method setupContents() as follows:
mMainAdapter.addFragment(new FragmentOne(), getResources().getString(R.string.tab_albums));
mMainAdapter.addFragment(new FragmentTwo(), getResources().getString(R.string.tab_songs));
mMainAdapter.addFragment(new FragmentThree(), getResources().getString(R.string.tab_playlists));
// you can add as many fragments as you wish
//just follow the previous method #mMainAdapter.addFragment
mPager.setAdapter(mMainAdapter);
mTabs.setupWithViewPager(mPager);
To get the current fragment:
public Fragment getCurrentFragment() {
return mMainAdapter.getFragment(mPager.getCurrentItem());
}
To check if the current fragment is FragmentOne:
private boolean isFragmentOne() {
return getCurrentFragment() instanceof FragmentOne;
}

How to handle configuration change for fragment with view model

I want to make my fragment wont re-load the data when configuration change with view model.
So, i try to make an App about gitHub User.
My Main Activity contain Search view to search user and show the result with recyclerview.
My Detail Activity is showing the detail of user when one of user in the list clicked, and in my detail activity i use Tab Layout and view pager to show user's followers and following.
My ViewModel for activity works well and can keep my data when orientation change.
But when i do the same to my fragment, my fragment keep re-loading new data when orientation change.
Here my fragment
i use View Model to request data
public class FollowingFragment extends Fragment {
public static final String KEY_FOLLOWING = "key_following";
private RecyclerView recyclerView;
private FollowingViewModel followingViewModel;
private FollowingAdapter followingAdapter;
ShimmerFrameLayout shimmerFrameLayout;
LinearLayoutManager layoutManager = new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false);
ArrayList<FollowingResponse> followingResponse = new ArrayList<>();
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_following, container, false);
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
recyclerView = view.findViewById(R.id.rv_following);
shimmerFrameLayout = view.findViewById(R.id.shimmer_frame_layout2);
followingViewModel = ViewModelProviders.of(this).get(FollowingViewModel.class);
followingAdapter = new FollowingAdapter();
followingAdapter.setOnItemClickCallback(new FollowingAdapter.OnItemClickCallback() {
#Override
public void onItemClicked(FollowingResponse followingResponse) {
showSelectedItem(followingResponse);
}
});
//this is what i've tried and worked, but my fragment result with double or triple the data.
if (savedInstanceState == null){
}
else {
followingResponse = savedInstanceState.getParcelableArrayList(KEY_FOLLOWING);
}
showRecyclerView();
getData();
}
private void getData() {
followingViewModel.setDataFollowing(DetailUserActivity.clickedUser);
followingViewModel.getDataFollowing().observe(getViewLifecycleOwner(), new Observer<ArrayList<FollowingResponse>>() {
#Override
public void onChanged(ArrayList<FollowingResponse> followingResponses) {
shimmerFrameLayout.setVisibility(View.GONE);
shimmerFrameLayout.stopShimmer();
followingAdapter.setData(followingResponse);
followingResponse.addAll(followingResponses);
recyclerView.setAdapter(followingAdapter);
followingAdapter.notifyDataSetChanged();
}
});
}
private void showRecyclerView() {
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(layoutManager);
}
#Override
public void onResume() {
super.onResume();
followingViewModel.setDataFollowing(DetailUserActivity.clickedUser);
}
private void showSelectedItem(FollowingResponse item) {
Intent intent = new Intent(getContext(), DetailUserActivity.class);
intent.putExtra("EXTRA_DATA", item.getLogin());
startActivity(intent);
}
#Override
public void onAttach(#NonNull Context context) {
super.onAttach(context);
}
#Override
public void onSaveInstanceState(#NonNull Bundle outState) {
outState.putParcelableArrayList(KEY_FOLLOWING, followingResponse);
super.onSaveInstanceState(outState);
}
}
Detail Activity
public class DetailUserActivity extends AppCompatActivity {
private TextView tvName, tvNickname, tvLocation, tvCompany, tvEmail, tvWebsite;
private TextView tvCountFollowers, tvCountRepository, tvCountFollowing;
private ImageView imgProfile;
ProgressBar progressBar;
public static String clickedUser;
UserViewModel userViewModel;
private ViewPager viewPager;
TabLayout tabLayout;
private final String EXTRA_DATA = "EXTRA_DATA";
private static final String EXTRA_FOLLOW = "extra_follow";
// Fragment followingFragment;
// FragmentTransaction transaction;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.detail_user_activity);
// i've tried this, but when the orientation change, my detail activity force close and throw me to my main activity.
// if (savedInstanceState != null){
// followingFragment = getSupportFragmentManager().getFragment(savedInstanceState, KEY_FOLLOWING);
// } else {
// followingFragment = new FollowingFragment();
//
// getSupportFragmentManager().beginTransaction().replace(R.id.tv_view_pager, followingFragment).commit();
// }
tvName = findViewById(R.id.tv_item_name);
tvNickname = findViewById(R.id.tv_item_nickname);
tvLocation = findViewById(R.id.tv_item_location);
tvCompany = findViewById(R.id.tv_item_company);
tvEmail = findViewById(R.id.tv_item_email);
tvWebsite = findViewById(R.id.tv_item_website);
imgProfile = findViewById(R.id.img_item_photo);
tvCountFollowers = findViewById(R.id.tv_count_follower);
tvCountRepository = findViewById(R.id.tv_count_repo);
tvCountFollowing = findViewById(R.id.tv_count_following);
progressBar = findViewById(R.id.progressbar2);
setForUserData();
setForTabLayout();
}
private void setForUserData(){
Intent detailIntent = getIntent();
clickedUser = detailIntent.getStringExtra("EXTRA_DATA");
userViewModel = new ViewModelProvider(this, new ViewModelProvider.NewInstanceFactory()).get(UserViewModel.class);
userViewModel.setUserUVM(clickedUser);
userViewModel.getUserUVM().observe(this, new Observer<UserResponse>() {
#Override
public void onChanged(UserResponse userResponse) {
progressBar.setVisibility(View.GONE);
Glide.with(getApplicationContext())
.load(userResponse.getAvatarUrl())
.into(imgProfile);
tvName.setText(userResponse.getLogin());
tvLocation.setText(userResponse.getLocation());
tvNickname.setText(userResponse.getName());
tvCompany.setText(userResponse.getCompany());
tvEmail.setText(userResponse.getEmail());
tvWebsite.setText(userResponse.getBlog());
tvCountRepository.setText(String.valueOf(userResponse.getPublicRepos()));
tvCountFollowers.setText(String.valueOf(userResponse.getFollowers()));
tvCountFollowing.setText(String.valueOf(userResponse.getFollowing()));
}
});
}
private void setForTabLayout(){
tabLayout = findViewById(R.id.tv_tab_layout);
viewPager = findViewById(R.id.tv_view_pager);
viewPager.setAdapter(new ViewPagerAdapter(getSupportFragmentManager(), tabLayout.getTabCount()));
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setTabMode(TabLayout.MODE_FIXED);
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
public class ViewPagerAdapter extends FragmentStatePagerAdapter {
int totalTab;
#SuppressWarnings("deprecation")
ViewPagerAdapter(FragmentManager fragmentManager, int totalTabs) {
super(fragmentManager);
this.totalTab = totalTabs;
}
#SuppressWarnings("ConstantConditions")
#NonNull
#Override
public Fragment getItem(int position) {
switch (position){
case 0:
return new FollowersFragment();
case 1:
return new FollowingFragment();
default:
return null;
}
}
#Override
public int getCount() {
return totalTab;
}
}
// #Override
// protected void onSaveInstanceState(#NonNull Bundle outState) {
// getSupportFragmentManager().putFragment(outState, KEY_FOLLOWING, followingFragment );
// super.onSaveInstanceState(outState);
// }
}
im trying to solve my FollowingFragment first, then ill do the same on my FollowerFragment.
im really new in programming, and have no one to ask.. can someone help me to solve my problem with keep data in fragment when orientation change?

followingViewModel = ViewModelProviders.of(this).get(FollowingViewModel.class);
In Fragment insted of writing this code in onViewCreated() write it inside OnCreate()
onViewCreated() will get called everytime the orientation changes so it will create new instance of view model everytime the orientation changes making viewmodel to reload the data

If you need to load data only once for the FollowingViewModel a good place to do it should be inside the constructor of the view model in this way you won't need to worry about the orientation change of the fragment.

How to create an custom alertDialog from a tabbed fragment?

Problem:
I'm trying to open a custom dialog after pressing a button in my tabbed fragment.
It's seems like my MainActivity activity is sent to the dialog while i want my tabbed fragment(GroupFragment) to be sent so i can change the editText(for now) in this fragment.
Code:
public class GroupFragment extends Fragment implements AddGroupDialog.AddGroupDialogListener {
private Button addGroupButton;
private TextView textViewNoGroups;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_group, container, false);
addGroupButton = view.findViewById(R.id.addGroupButton);
textViewNoGroups = view.findViewById(R.id.textViewNoGroups);
addGroupButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
addNewGroupDialog();
}
});
scaleAnimation(addGroupButton);
return view;
}
private void scaleAnimation(View v){
Animator scale = ObjectAnimator.ofPropertyValuesHolder(v,
PropertyValuesHolder.ofFloat(View.SCALE_X, 0, 1.2f, 1),
PropertyValuesHolder.ofFloat(View.SCALE_Y, 0, 1.2f, 1)
);
scale.setDuration(600);
scale.start();
}
private void addNewGroupDialog(){
AddGroupDialog dialog = new AddGroupDialog();
assert getFragmentManager() != null;
dialog.show(getFragmentManager(), "add new group dialog");
}
#Override
public void applyString(String groupName) {
textViewNoGroups.setText(groupName);
}
}
public class AddGroupDialog extends AppCompatDialogFragment {
private EditText editTextGroupName;
private AddGroupDialogListener listener;
#NonNull
#Override
public Dialog onCreateDialog(#Nullable Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
LayoutInflater inflater = getActivity().getLayoutInflater();
View view = inflater.inflate(R.layout.layout_add_new_group_dialog, null);
builder.setView(view)
.setTitle("")
.setPositiveButton(R.string.confirm, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
String groupName = editTextGroupName.getText().toString();
listener.applyString(groupName);
}
});
editTextGroupName = view.findViewById(R.id.editTextGroupName);
return builder.create();
}
#Override
public void onAttach(#NonNull Context context) {
super.onAttach(context);
try {
listener = (AddGroupDialogListener) context;
} catch (ClassCastException e){
throw new ClassCastException(context.toString() +
"Must implement AddGroupDialogListener");
}
}
public interface AddGroupDialogListener{
void applyString(String groupName);
}
}
public class MainActivity extends AppCompatActivity{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SectionsPagerAdapter sectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());
ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(sectionsPagerAdapter);
TabLayout tabs = findViewById(R.id.tabs);
tabs.setupWithViewPager(viewPager);
}
}
public class SectionsPagerAdapter extends FragmentPagerAdapter {
#StringRes
private static final int[] TAB_TITLES = new int[]{R.string.tab_text_1, R.string.tab_text_2, R.string.tab_text_3};
private final Context mContext;
public SectionsPagerAdapter(Context context, FragmentManager fm) {
super(fm);
mContext = context;
}
#Override
public Fragment getItem(int position) {
Fragment fragment = null;
switch (position){
case 0:
fragment = new GroupFragment();
break;
case 1:
fragment = new AttendanceFragment();
break;
case 2:
fragment = new StatisticsFragment();
break;
}
return fragment;
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return mContext.getResources().getString(TAB_TITLES[position]);
}
#Override
public int getCount() {
return TAB_TITLES.length;
}
}
Error:
java.lang.ClassCastException: com.example.attendencetaker.MainActivity#26602bcMust implement AddGroupDialogListener
I hope my explanation of the problem is clear. Thank you!

Make the activity implement your interfaces and so on and then pass all data to the fragment with an method on the fragment. You will need an reference to actual Fragment that is displayed.
In your fragment add a method similar to this:
public void updateData(String data) {
editText.setText(data);
}
And in the override method of the interface in your activity to this:
#Override
public void update(String data) {
fragment.updateData(data);
}
Update
Use this Adapter instead:
public class SectionTabAdapter extends FragmentPagerAdapter {
private ArrayList<Fragment> fragments = new ArrayList<>();
private ArrayList<String> titles = new ArrayList<>();
public SectionTabAdapter(#NonNull FragmentManager fm, int behavior) {
super(fm, behavior);
}
public void addFragment(Fragment fragment, String title) {
fragments.add(fragment);
titles.add(title);
}
#NonNull
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public int getCount() {
return fragments.size();
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return titles.get(position);
}
}
In your activity then do this:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SectionsPagerAdapter sectionTabAdapter = new SectionTabAdapter(this, getSupportFragmentManager());
Fragment groupFragment = new GroupFragment();
Fragment attendanceFragment = new AttendanceFragment();
Fragment statisticsFragment = new StatisticsFragment();
sectionTabAdapter.addFragment(groupFragment, context.getString(R.string.title_1);
sectionTabAdapter.addFragment(attendanceFragment, context.getString(R.string.title_2);
sectionTabAdapter.addFragment(statisticsFragment, context.getString(R.string.title_3);
ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(sectionTabAdapter);
TabLayout tabs = findViewById(R.id.tabs);
tabs.setupWithViewPager(viewPager);
}

How to use getChildFragmentManager with a class that extends Dialog fragment

I am a having a fragment with TabLayout. As soon as I move from TabLayout Fragment to the next Fragment and press the back key. The content on the default TabLayout fragment disappears. I found a possible solution to this in the post. Following is the code for the TabLayout.
public class IndividualCollectionSheetFragment extends MifosBaseFragment {
private TabLayout tabLayout;
private ViewPager viewPager;
private View rootView;
public IndividualCollectionSheetFragment() {
}
public static IndividualCollectionSheetFragment newInstance() {
Bundle args = new Bundle();
IndividualCollectionSheetFragment fragment = new IndividualCollectionSheetFragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater,
#Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_individual_recycler, container, false);
ButterKnife.bind(this, rootView);
setToolbarTitle(getStringMessage(R.string.individual_collection_sheet));
viewPager = rootView.findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = rootView.findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
return rootView;
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getActivity().getSupportFragmentManager());
adapter.addFragment(new NewIndividualCollectionSheetFragment(), Constants.NEW);
adapter.addFragment(new SavedIndividualCollectionSheetFragment(), Constants.SAVED);
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
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);
}
}
}
The solution in the post suggested using getChildFramentManager instead of getSupportFragmentManager. As soon as I changed to getChildFragmentManager. I got the error.
java.lang.IllegalStateException: Fragment CollectionSheetDialogFragment{572dd42 #0 Identifier Dialog Fragment} declared target fragment NewIndividualCollectionSheetFragment{45e8153 #0 id=0x7f090361 android:switcher:2131297121:0} that does not belong to this FragmentManager!
which might be because of the class CollectionSheetDialogFragment which extends DialogFragment and there must be inconsistencies with the different Fragment Managers being used.
NewIndividualCollectionSheet.java(first fragment in tablayout)
public class NewIndividualCollectionSheetFragment extends MifosBaseFragment implements
IndividualCollectionSheetMvpView, MFDatePicker.OnDatePickListener,
Spinner.OnItemSelectedListener, View.OnClickListener {
#BindView(R.id.btn_fetch_collection_sheet)
Button btnFetchSheet;
#BindView(R.id.sp_office_list)
Spinner spOffices;
#BindView(R.id.sp_staff_list)
Spinner spStaff;
#BindView(R.id.tv_repayment_date)
TextView tvRepaymentDate;
#Inject
NewIndividualCollectionSheetPresenter presenter;
private IndividualCollectionSheet sheet;
private DialogFragment datePicker;
private RequestCollectionSheetPayload requestPayload;
private View rootView;
private ArrayAdapter<String> officeAdapter;
private ArrayList<String> officeNameList;
private List<Office> officeList;
private ArrayAdapter<String> staffAdapter;
private ArrayList<String> staffNameList;
private List<Staff> staffList;
private int officeId;
private int staffId;
private int requestCode = 1;
private boolean success = true;
private String actualDisbursementDate;
private String transactionDate;
public NewIndividualCollectionSheetFragment() {
}
public static NewIndividualCollectionSheetFragment newInstance() {
Bundle args = new Bundle();
NewIndividualCollectionSheetFragment fragment = new NewIndividualCollectionSheetFragment();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
((MifosBaseActivity) getActivity()).getActivityComponent().inject(this);
if (savedInstanceState != null) {
sheet = (IndividualCollectionSheet) savedInstanceState.get(
Constants.EXTRA_COLLECTION_INDIVIDUAL);
}
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_new_collection_sheet, container, false);
ButterKnife.bind(this, rootView);
setToolbarTitle(getStringMessage(R.string.individual_collection_sheet));
presenter.attachView(this);
setUpUi();
return rootView;
}
private void setUpUi() {
setRepaymentDate();
officeNameList = new ArrayList<>();
officeAdapter = new ArrayAdapter<>(getActivity(),
android.R.layout.simple_spinner_item, officeNameList);
officeAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spOffices.setAdapter(officeAdapter);
spOffices.setOnItemSelectedListener(this);
staffNameList = new ArrayList<>();
staffAdapter = new ArrayAdapter<>(getActivity(),
android.R.layout.simple_spinner_item, staffNameList);
staffAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spStaff.setAdapter(staffAdapter);
tvRepaymentDate.setOnClickListener(this);
btnFetchSheet.setOnClickListener(this);
presenter.fetchOffices();
}
void setRepaymentDate() {
datePicker = MFDatePicker.newInsance(this);
String date = DateHelper.
getDateAsStringUsedForCollectionSheetPayload(MFDatePicker.getDatePickedAsString());
tvRepaymentDate.setText(date.replace('-', ' '));
transactionDate = date.replace('-', ' ');
actualDisbursementDate = transactionDate;
}
private void prepareRequestPayload() {
requestPayload = new RequestCollectionSheetPayload();
requestPayload.setOfficeId(officeId);
requestPayload.setStaffId(staffId);
requestPayload.setTransactionDate(tvRepaymentDate.getText().toString());
}
#Override
public void setOfficeSpinner(List<Office> offices) {
officeList = offices;
officeNameList.clear();
officeNameList.add(getString(R.string.spinner_office));
officeNameList.addAll(presenter.filterOffices(officeList));
officeAdapter.notifyDataSetChanged();
}
#Override
public void onDatePicked(String date) {
String d = DateHelper.getDateAsStringUsedForCollectionSheetPayload(date);
tvRepaymentDate.setText(d.replace('-', ' '));
}
public void retrieveCollectionSheet() {
prepareRequestPayload();
presenter.fetchIndividualCollectionSheet(requestPayload);
}
public void setTvRepaymentDate() {
datePicker.show(getActivity().getSupportFragmentManager(),
FragmentConstants.DFRAG_DATE_PICKER);
}
#Override
public void setStaffSpinner(List<Staff> staffs) {
spStaff.setOnItemSelectedListener(this);
staffList = staffs;
staffNameList.clear();
staffNameList.add(getString(R.string.spinner_staff));
staffNameList.addAll(presenter.filterStaff(staffList));
staffAdapter.notifyDataSetChanged();
}
#Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
switch (adapterView.getId()) {
case R.id.sp_office_list:
if (i == officeList.size() || i == 0) {
Toaster.show(rootView, getStringMessage(R.string.error_select_office));
} else {
Toaster.show(rootView, officeNameList.get(i));
officeId = officeList.get(i - 1).getId();
presenter.fetchStaff(officeId);
}
break;
case R.id.sp_staff_list:
if (i == staffList.size() || i == 0) {
Toaster.show(rootView, getStringMessage(R.string.error_select_staff));
} else {
staffId = staffList.get(i - 1).getId();
}
break;
}
}
public void popupDialog() {
CollectionSheetDialogFragment collectionSheetDialogFragment =
CollectionSheetDialogFragment.newInstance(tvRepaymentDate.getText().toString(),
sheet.getClients().size());
collectionSheetDialogFragment.setTargetFragment(this, requestCode);
FragmentTransaction fragmentTransaction = getActivity().getSupportFragmentManager()
.beginTransaction();
fragmentTransaction.addToBackStack(FragmentConstants.FRAG_DOCUMENT_LIST);
collectionSheetDialogFragment.show(fragmentTransaction, "Identifier Dialog Fragment");
}
public void getResponse(String response) {
switch (response) {
case "FillNow":
FragmentManager fm = getActivity()
.getSupportFragmentManager();
fm.popBackStack();
IndividualCollectionSheetDetailsFragment frag = new
IndividualCollectionSheetDetailsFragment().newInstance(sheet,
actualDisbursementDate, transactionDate);
((MifosBaseActivity) getActivity()).replaceFragment(frag,
true, R.id.container);
break;
}
}
#Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
#Override
public void showSheet(IndividualCollectionSheet individualCollectionSheet) {
sheet = individualCollectionSheet;
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putParcelable(Constants.EXTRA_COLLECTION_INDIVIDUAL, sheet);
}
#Override
public void showSuccess() {
if (success) {
popupDialog();
}
}
#Override
public void showError(String message) {
Toaster.show(rootView, message);
}
#Override
public void showNoSheetFound() {
success = false;
Toaster.show(rootView, getStringMessage(R.string.no_collectionsheet_found));
}
#Override
public void showProgressbar(boolean b) {
if (b) {
showMifosProgressDialog();
} else {
hideMifosProgressDialog();
}
}
#Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.tv_repayment_date:
setTvRepaymentDate();
break;
case R.id.btn_fetch_collection_sheet:
retrieveCollectionSheet();
break;
}
}
}
CollectionSheetDialogFragment.java
public class CollectionSheetDialogFragment extends DialogFragment {
#BindView(R.id.tv_due_date)
TextView tvDueDate;
#BindView(R.id.tv_members)
TextView tvMembers;
#BindView(R.id.btn_fillnow)
Button btnFillnow;
#BindView(R.id.btn_cancel)
Button btnCancel;
private View rootView;
private String date;
private int members;
public CollectionSheetDialogFragment() {
}
public static CollectionSheetDialogFragment newInstance(String date, int members) {
CollectionSheetDialogFragment collectionSheetDialogFragment =
new CollectionSheetDialogFragment();
Bundle args = new Bundle();
args.putString(Constants.REPAYMENT_DATE, date);
args.putInt(Constants.MEMBERS, members);
collectionSheetDialogFragment.setArguments(args);
return collectionSheetDialogFragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
((MifosBaseActivity) getActivity()).getActivityComponent().inject(this);
date = getArguments().getString(Constants.REPAYMENT_DATE);
members = getArguments().getInt(Constants.MEMBERS);
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable
ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_collection_sheet_dialog, container, false);
ButterKnife.bind(this, rootView);
return rootView;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
tvDueDate.setText(date);
tvMembers.setText(Integer.toString(members));
}
#OnClick(R.id.btn_fillnow)
public void setBtnFillnow() {
((NewIndividualCollectionSheetFragment) getTargetFragment()).getResponse("FillNow");
}
#OnClick(R.id.btn_cancel)
public void setBtnCancel() {
getDialog().dismiss();
}
}
Can someone help me get around this error so I can persist the TabLayout On back press?

Maybe This Work :
Replace getFragmentManager() instead of getChildFragmentManager()

Try this changing seupViewPager() in IndividualCollectionSheetFragment.java like this
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getActivity().getChildFragmentManager());
adapter.addFragment(new NewIndividualCollectionSheetFragment(), Constants.NEW);
adapter.addFragment(new SavedIndividualCollectionSheetFragment(), Constants.SAVED);
viewPager.setAdapter(adapter);
}

Change displayed fragment inside ViewPager

I have ViewPager that is showing fragments : SearchFragment,FriendFragment. What I am struggling to do is to change SearchFragment to ChatFragment
There is a lot of feedback in replace-fragment-inside-a-viewpager/ yet I have some trouble with making any of these solutions work.
I think there might be something wrong with my way of creating interface, I had some trouble to make it callable from ViewPager as SearchActivity.newInstance(new MyListener {...} )
I reached the point now where I get
java.lang.NullPointerException: Attempt to invoke virtual method
'android.support.v4.app.FragmentTransaction
android.support.v4.app.FragmentManager.beginTransaction()' on a null
object reference
at
com.example.ashaneen.firebaseapp.adapters.MainScreenAdapter$1.onFragmentChange(MainScreenAdapter.java:44)
at
com.example.ashaneen.firebaseapp.fragments.SearchFragment$4.onComplete(SearchFragment.java:132)
MainScreenAdapter.class
public class MainScreenAdapter extends FragmentPagerAdapter implements SearchFragment.MyListener {
private static final String TAG = "MainScreenAdapter";
private FragmentManager fragmentManager;
private Fragment fragment1;
public MainScreenAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position)
{
switch (position)
{
case 0:
if (fragment1 == null)
{
fragment1 = SearchFragment.newInstance(new SearchFragment.MyListener() {
#Override
public void onFragmentChange() {
fragmentManager.beginTransaction().remove(fragment1).commit();
fragment1 = ChatFragment.newInstance();
notifyDataSetChanged();
}
});
}
return fragment1;
case 1:
return new FriendsFragment();
default:
return new ChatFragment();
}
}
#Override
public int getItemPosition(#NonNull Object object) {
return POSITION_NONE;
}
#Override
public void onFragmentChange() {
}
SearchFragment.class
public class SearchFragment extends android.support.v4.app.Fragment {
public SearchFragment() {
}
private String TAG = "Profile2Fragment";
public interface MyListener
{
void onFragmentChange();
}
static MyListener myListener = new MyListener() {
public void onFragmentChange() {
}
};
public static SearchFragment newInstance(MyListener myListener) {
SearchFragment.myListener = myListener;
return new SearchFragment();
}
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_search, container, false);
button = view.findViewById(R.id.btn_search);
waitingRoomReference = db.collection("awaiting_room");
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view)
{
myListener.onFragmentChange();
}
}
});
return view;
}

Try changing this
public MainScreenAdapter(FragmentManager fm) {
super(fm);
}
to
public MainScreenAdapter(FragmentManager fm) {
super(fm);
fragmentManager = fm;
}