Develop Reference

I can't make my OnClick method work in a RecyclerView

I've been trying to delete data from firebase with an OnClick RecyclerView method, but nothing works. I can't even make my OnClick method works. I have watched videos and tutorials, I've tried so much stuff and nothing helps...
Here is my adapter class:
public class myadapter extends RecyclerView.Adapter<myadapter.myviewholder>{
ArrayList<datamodel> dataholder;
public myadapter(ArrayList<datamodel> dataholder) {
this.dataholder = dataholder;
}
#NonNull
#Override
public myviewholder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_list, parent, false);
return new myviewholder(view);
}
#Override
public void onBindViewHolder(#NonNull myviewholder holder, int position) {
Glide.with(holder.itemView.getContext()).load(dataholder.get(position).getImageurl()).into(holder.CircleImg);
holder.header.setText(dataholder.get(position).getHeader());
holder.descr.setText(dataholder.get(position).getDescr());
holder.price.setText(dataholder.get(position).getPrec());
}
#Override
public int getItemCount() {
return dataholder.size();
}
class myviewholder extends RecyclerView.ViewHolder{
CircleImageView CircleImg;
TextView header, descr, price;
public myviewholder(#NonNull View itemView) {
super(itemView);
CircleImg = itemView.findViewById(R.id.circle1);
header = itemView.findViewById(R.id.txtheader1);
descr = itemView.findViewById(R.id.txtdescr1);
price = itemView.findViewById(R.id.txtprecio1);
}
}
And my fragment (the one that have the recyclerView):
public class articulos extends Fragment {
private FirebaseUser firebaseUser;
private String uid;
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private DatabaseReference myRef;
private Context mContext;
private myadapter myadapter;
RecyclerView recyclerView;
ArrayList<datamodel> dataholder;
public articulos() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment articulos.
*/
// TODO: Rename and change types and number of parameters
public static articulos newInstance(String param1, String param2) {
articulos fragment = new articulos();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_articulos, container, false);
recyclerView = view.findViewById(R.id.rv);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
myRef = FirebaseDatabase.getInstance().getReference();
dataholder= new ArrayList<>();
getDataFromFirebase();
//datamodel ob1 = new datamodel("Esta nueva", "5000MXN", "wwsad.adasd", "asdasdsa");
// dataholder.add(ob1);
//recyclerView.setAdapter(new myadapter(dataholder));
return view;
}
private void getDataFromFirebase() {
firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
uid = firebaseUser.getUid();
Query query = myRef.child("Usuarios").child(uid).child("articulos");
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot snapshot) {
ClearAll();
for(DataSnapshot snapshot1 : snapshot.getChildren()){
datamodel datamodel = new datamodel();
datamodel.setImageurl(snapshot1.child("imageurl").getValue(String.class));
datamodel.setDescr(snapshot1.child("descripcion").getValue(String.class));
datamodel.setHeader(snapshot1.child("nombre").getValue(String.class));
datamodel.setPrec(snapshot1.child("precio").getValue(String.class));
dataholder.add(datamodel);
}
myadapter = new myadapter(dataholder);
recyclerView.setAdapter(new myadapter(dataholder));
myadapter.notifyDataSetChanged();
}
#Override
public void onCancelled(#NonNull DatabaseError error) {
}
});
}
private void ClearAll(){
if(dataholder != null){
dataholder.clear();
if(myadapter != null){
myadapter.notifyDataSetChanged();
}
}
dataholder = new ArrayList<>();
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
Button mbtnNuevoArticulo = view.findViewById(R.id.btnNuevoArticulo);
mbtnNuevoArticulo.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Navigation.findNavController(v).navigate(R.id.agregarart);
}
});
}
If anyone can tell me what to do and how to do it, please.. I need it so bad

Try set onclicklistener on viewholder class
class myviewholder extends RecyclerView.ViewHolder implements View.OnClickListener {
CircleImageView CircleImg;
TextView header, descr, price;
public myviewholder(#NonNull View itemView) {
super(itemView);
CircleImg = itemView.findViewById(R.id.circle1);
header = itemView.findViewById(R.id.txtheader1);
descr = itemView.findViewById(R.id.txtdescr1);
price = itemView.findViewById(R.id.txtprecio1);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View view) {
//do something when clicked
}
}

You can apply onclick listener by using following code :
holder.header.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//do something.
}
});
add this code in your onBindViewHolder of Adapter. Just make sure to change the id of holder.
full code :
#Override
public void onBindViewHolder(#NonNull myviewholder holder, int position) {
Glide.with(holder.itemView.getContext()).load(dataholder.get(position).getImageurl()).into(holder.CircleImg);
holder.header.setText(dataholder.get(position).getHeader());
holder.descr.setText(dataholder.get(position).getDescr());
holder.price.setText(dataholder.get(position).getPrec());
holder.header.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//do something.
}
});
}

Create object of view inside your view holder and also initialize button.setOnClickListener(this) inside viewHolder itself and setting on click inside onBinfViewHolder(...)(only in JAVA). In kotlin you just need to set on click method inside onBindViewHolder(...).
Example:
class YourAdapter():RecyclerView.Adapter<YourAdapter.YourViewHolder>() {
class YourViewHolder(view: View):RecyclerView.ViewHolder(view){
val yourButton:Button = view.findViewById(R.id.landingViewBtn)
}
override fun onBindViewHolder(holder: YourViewHolder, position: Int) {
holder.yourButton.setOnClickListener {
//do Something
val intent = Intent(context,nextActivity::class.java)
context.startActivity(intent)
}
}
}

Shuffle items from Firebase Database

How to shuffle items from Firebase Database?
Let's say my DB contains 4 items [1,2,3,4]. In my RecyclerView, I want to display shuffled, something like [2,3,1,4]. How can I do that?
This is the code in my Fragment. So it works retrieving data but I need to shuffle it before displaying.
RecyclerView mRecyclerView;
FirebaseDatabase mFirebaseDatabase;
DatabaseReference mRef;
#Override
public View onCreateView(#NotNull LayoutInflater inflater, ViewGroup viewGroup, Bundle savedInstanceState) {
if (rootView == null) {
rootView = inflater.inflate(R.layout.fragment_store, viewGroup, false);
setHasOptionsMenu(false);
mRecyclerView = rootView.findViewById(R.id.recycler_view);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 3));
mFirebaseDatabase = FirebaseDatabase.getInstance();
mRef = mFirebaseDatabase.getReference("Store");
}
return rootView;
}
For retrieving data from Firebase Database I am using the following code:
#Override
public void onStart() {
super.onStart();
FirebaseRecyclerOptions<Store2> options =
new FirebaseRecyclerOptions.Builder<Store2>()
.setQuery(mRef, Store2.class)
.build();
FirebaseRecyclerAdapter<Store2, StoreHolder> firebaseRecyclerAdapter =
new FirebaseRecyclerAdapter<Store2, StoreHolder>(options) {
#NonNull
#Override
public StoreHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.store_gridview, parent, false);
return new StoreHolder(view);
}
#Override
protected void onBindViewHolder(#NonNull final StoreHolder holder, int position, #NonNull final Store2 model) {
holder.setDetails(getContext(), model.getImage(), model.getName(), model.getPrice());
}
};
firebaseRecyclerAdapter.startListening();
mRecyclerView.setAdapter(firebaseRecyclerAdapter);
}

There are no option available for shuffling data in firebase.
But you can do it locally .
Pass your list in this.
Collections.shuffle(arrayList);

When you are using the following reference:
mRef = mFirebaseDatabase.getReference("Store");
It means that you are trying to display all children that exist under Store node. If under this node you store children that are added using the push() method, the default ordering is chronological, since every pushed id contains a time component. If you want to change this behaviour, you need to get all the items and shuffle them manually.
As #DougStevenson mentioned in his comment, you have to use the same reference, get all items, add them to a list, shuffle them and then use a ListAdapter for that.
Please also note, that when you pass a DocumentReference or a Query object to the setQuery() method, where is no further mechanism that can help you shuffle your items. Unfortunately, you'll lose the benefits of the Firebase-UI library but you'll get your work done.

As #DougStevenson and #frankenstein mentioned, I added all items into a list, then I was able the shuffle it using Collections.shuffle(arrayList);
I couldn't do it using FirebaseRecyclerAdapter, and I needed a custom Adapter for my RecyclerView.ViewHolder.
What is the downside of not using FirebaseRecyclerAdapter? Or is it any? Maybe someone with experience can answer this question.
My fragment:
private View rootView;
private RecyclerView recyclerView;
private StoreAdapter storeAdapter;
private ArrayList<Store> arrayStore;
#Override
public View onCreateView(#NotNull LayoutInflater inflater, ViewGroup viewGroup, Bundle savedInstanceState) {
if (rootView == null) {
rootView = inflater.inflate(R.layout.fragment_store, viewGroup, false);
setHasOptionsMenu(false);
recyclerView = rootView.findViewById(R.id.recycler_view);
recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 3));
DatabaseReference reference = FirebaseDatabase.getInstance().getReference().child("Data");
reference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
arrayStore = new ArrayList<>();
for(DataSnapshot snapshot: dataSnapshot.getChildren()) {
Store store = snapshot.getValue(Store.class);
arrayStore.add(store);
}
storeAdapter = new StoreAdapter(getActivity() ,arrayStore);
recyclerView.setAdapter(storeAdapter);
Collections.shuffle(arrayStore, new Random(3));
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
return rootView;
}
My adapter:
private final Context context;
private ArrayList<Store> arrayStore;
public StoreAdapter(Context context, ArrayList<Store> arrayStore) {
this.context = context;
this.arrayStore = arrayStore;
}
#NonNull
#Override
public StoreAdapter.GameViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
return new StoreAdapter.GameViewHolder(LayoutInflater.from(context).inflate(
R.layout.store_gridview, viewGroup, false));
}
#Override
public void onBindViewHolder(#NonNull final StoreAdapter.GameViewHolder viewHolder, final int position) {
setColor(viewHolder);
viewHolder.itemName.setText(arrayStore.get(position).getName());
Glide.with(viewHolder.view.getContext())
.load(arrayStore.get(position).getImage())
.thumbnail(0.75f)
.into(viewHolder.itemImage);
viewHolder.view.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
sendData(viewHolder, position);
}
});
}
#Override
public int getItemCount() {
return arrayStore.size();
}
class GameViewHolder extends RecyclerView.ViewHolder {
private final View view;
private final ImageView itemImage, itemRarity;
private final TextView itemName;
GameViewHolder(#NonNull View itemView) {
super(itemView);
this.view = itemView;
itemRarity = view.findViewById(R.id.itemRarity);
itemImage = view.findViewById(R.id.itemImage);
itemName = view.findViewById(R.id.itemName);
}
}
private void sendData(#NonNull final StoreAdapter.GameViewHolder viewHolder, int position) {
if (viewHolder.getAdapterPosition() != RecyclerView.NO_POSITION) {
Intent intent = new Intent(context, DetailsActivity.class);
intent.putExtra("name", arrayStore.get(position).getName());
intent.putExtra("rarity", arrayStore.get(position).getRarity());
intent.putExtra("item", arrayStore.get(position).getImage());
intent.putExtra("price", arrayStore.get(position).getPrice());
intent.putExtra("key", "Store");
context.startActivity(intent);
}
}
private void setColor(#NonNull final StoreAdapter.GameViewHolder viewHolder) {
String rarity = arrayStore.get(viewHolder.getAdapterPosition()).getRarity();
if (rarity.contains("legendary")) {
viewHolder.itemRarity.setImageResource(R.drawable.color_legendary_gradient);
} else if (rarity.contains("classic")) {
viewHolder.itemRarity.setImageResource(R.drawable.color_classic_gradient);
} else if (rarity.contains("epic")) {
viewHolder.itemRarity.setImageResource(R.drawable.color_epic_gradient);
} else if (rarity.contains("elite")) {
viewHolder.itemRarity.setImageResource(R.drawable.color_elite_gradient);
} else if (rarity.contains("rare")) {
viewHolder.itemRarity.setImageResource(R.drawable.color_rare_gradient);
} else if (rarity.contains("special")) {
viewHolder.itemRarity.setImageResource(R.drawable.color_special_gradient);
}
}
My bean class:
private String image, name, price, rarity;
public Store() {
}
public String getImage() {
return image;
}
public String getName() {
return name;
}
public String getPrice() {
return price;
}
public String getRarity() {
return rarity;
}

Unable to filter query with multiple clauses using Firebase Realtime Database

I'm using Firebase Realtime Database with Firebase UI, however i'm not being able to search with multiple clauses.
What i need is to take the Users that do not have an specific id. As i'm already filtering them by City i need to filter these ones with specific id.
I've been trying to solve it in many ways, however none of them has come to success.
This is my Database
I cant take and render the card with the user with that username.
public class SearchFragment extends android.support.v4.app.Fragment {
private EditText mSearchField;
private ImageButton mSearchBtn;
private RecyclerView mResultList;
private DatabaseReference mUserDatabase;
public static SearchFragment newInstance() { return new SearchFragment(); }
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_search, container, false);
mSearchField = view.findViewById(R.id.search_field);
mSearchBtn = view.findViewById(R.id.search_btn);
mResultList = view.findViewById(R.id.result_list);
mResultList.setHasFixedSize(true);
mResultList.setLayoutManager(new LinearLayoutManager(mResultList.getContext()));
mSearchBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String searchText = mSearchField.getText().toString();
firebaseUserSearch(searchText);
mSearchField.setText("");
}
});
mUserDatabase = FirebaseDatabase.getInstance().getReference("usuarios");
return view;
}
public void firebaseUserSearch(String searchText) {
Toast.makeText(getContext(), "Buscando usuários", Toast.LENGTH_LONG).show();
String searchTextLower = searchText.toLowerCase();
final Query firebaseSearchQuery = mUserDatabase.orderByChild("city").startAt(searchTextLower).endAt(searchTextLower + "\uf8ff");
firebaseSearchQuery.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
GenericTypeIndicator<Map<String, String>> genericTypeIndicator = new GenericTypeIndicator<Map<String, String>>() {};
Map<String, String> map = dataSnapshot.getValue(genericTypeIndicator );
String username = map.get("username").toString();
Log.d("oi", username);
Log.d("olar", UserDetails.username);
if(username != UserDetails.username) {
final FirebaseRecyclerOptions<User> options =
new FirebaseRecyclerOptions.Builder<User>()
.setQuery(firebaseSearchQuery, User.class)
.build();
bindAndBuildFirebaseUi(options);
}
}
public void bindAndBuildFirebaseUi(FirebaseRecyclerOptions options) {
final FirebaseRecyclerAdapter<User, UsersViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<User, UsersViewHolder>(options) {
#Override
public UsersViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_layout, parent, false);
return new UsersViewHolder(v);
}
#Override
protected void onBindViewHolder(final UsersViewHolder holder, int position, final User model) {
holder.bind(model);
Log.d("SearchFragment", "Binded the model");
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
UserDetails.chatWithId = model.getUsername();
UserDetails.chatWith = model.getName();
startActivity(new Intent(getContext(), Chat.class));
}
});
}
};
firebaseRecyclerAdapter.startListening();
mResultList.setAdapter(firebaseRecyclerAdapter);
}
}
As you can see i even tried to filter them throught the database again, howeever, Firebase ui is taking the filter from options which is the first query filtering the users by city.
Does anyone have any idea how to take avoid rendering the users with an specific id???
And i also know that Firebase does not allow to use more than one orderBy.

The Firebase RTDB doesn't support multiple where clauses unfortunately. However, if you denormalize your data properly, you can use one query to link to another ref in the database and effectively filter data in that way. Take a look at the docs: https://github.com/firebase/FirebaseUI-Android/blob/master/database/README.md#using-firebaseui-with-indexed-data.
As a side note, you really shouldn't be using the RTDB to store actual data as it won't scale. It's designed for low latency real-time updates for multiplayer stuff or a ticketing app etc. Instead, I'd recommend looking into Firestore, especially if this is a new app.
Here's the hack I mentioned in my comment below:
public class MyAdapter extends FirebaseRecyclerAdapter {
private static final int TYPE_NORMAL = 0;
private static final int TYPE_HIDDEN = 1;
private final View mEmpty = new View(getContext());
public MyAdapter(#NonNull FirestoreRecyclerOptions options) {
super(options);
mEmpty.setVisibility(View.GONE);
}
#Override
public int getItemViewType(int position) {
if (getItem(position).username.equals(UserDetails.username)) {
return TYPE_HIDDEN;
} else {
return TYPE_NORMAL;
}
}
#Override
public UsersViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_HIDDEN) {
return new UsersViewHolder(mEmpty);
}
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_layout, parent, false);
return new UsersViewHolder(v);
}
#Override
protected void onBindViewHolder(final UsersViewHolder holder, int position, final User model) {
if (getItemViewType(position) == TYPE_HIDDEN) return;
holder.bind(model);
Log.d("SearchFragment", "Binded the model");
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
UserDetails.chatWithId = model.getUsername();
UserDetails.chatWith = model.getName();
startActivity(new Intent(getContext(), Chat.class));
}
});
}
}

Problems calling notifyDataSetChange in RecyclerViewHolder

I am having problems updating my RecyclerView with new data. If I press a confirmation button on a CardView in the first tab, the card should get added to the second tab but it won't update it there until I rotate the screen. I get the data for the card from reading a text file. Please advise me how to call the notifyDataSetChange method after I have added the new data to my text file. I have tried everything and all I get is NullPointerExceptions. The RecyclerViews are in fragments and I use FragementStatePagerAdapter.
I'll put some of my classes here. Ask if you need more information.
RecyclerViewAdapter.java
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewHolder> {
private List<String> mListTitle;
private List<String> mListDesc;
private List<String> mListPoints;
private List<String> mListDates;
private String fragment_tag;
public RecyclerViewAdapter() {
}
public RecyclerViewAdapter(List<List<String>> super_list, String tag) {
this.mListTitle = super_list.get(0);
this.mListDesc = super_list.get(1);
this.mListPoints = super_list.get(2);
this.mListDates = super_list.get(3);
fragment_tag = tag;
}
#Override
public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
return new RecyclerViewHolder(inflater, parent, fragment_tag);
}
#Override
public void onBindViewHolder(RecyclerViewHolder holder, int position) {
holder.mTitleText.setText(mListTitle.get(position));
holder.mDescText.setText(mListDesc.get(position));
holder.mPointsText.setText(mListPoints.get(position));
if (fragment_tag.equals("completed")) {
holder.mDateText.setText(mListDates.get(position));
}
}
#Override
public int getItemCount() {
return mListTitle.size();
}
}
class RecyclerViewHolder extends RecyclerView.ViewHolder {
RecyclerView recyclerView;
RecyclerViewAdapter mAdapter;
public TextView mTitleText, mDescText, mDateText, mPointsText, popupTitle;
public Button mConfButton, popCancelBtn, popAcceptBtn;
public RecyclerViewHolder(View itemView) {
super(itemView);
}
public RecyclerViewHolder(final LayoutInflater inflater, final ViewGroup container, String tag) {
// Inflating the card layout depending on the tag parameter.
super(inflater.inflate
((tag.equals("challenges")) ? R.layout.card_view_chall : R.layout.card_view_comp, container,
false));
mTitleText = itemView.findViewById(R.id.title_holder);
mDescText = itemView.findViewById(R.id.desc_holder);
mPointsText = itemView.findViewById(R.id.points_holder);
mDateText = itemView.findViewById(R.id.date_holder);
if (tag.equals("challenges")) {
mConfButton = itemView.findViewById(R.id.card_conf_button);
mConfButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// Setting the layout inflater for popup window.
LayoutInflater pInflater = (LayoutInflater) itemView.getContext().getSystemService(LAYOUT_INFLATER_SERVICE);
ViewGroup container1 = (ViewGroup) pInflater.inflate(R.layout.confirmation_popup, null);
final PopupWindow popupWindow = new PopupWindow(container1, 700, 600, true);
popupTitle = container1.findViewById(R.id.popuptext);
popAcceptBtn = container1.findViewById(R.id.accept_button);
popCancelBtn = container1.findViewById(R.id.cancel_button);
popupTitle.setText(mTitleText.getText().toString());
// Dismisses the popup window
popCancelBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
popupWindow.dismiss();
}
});
// Click listener for dialog accept button.
popAcceptBtn.setOnClickListener(new View.OnClickListener() {
String date;
#Override
public void onClick(View view) {
List<String> list = new ArrayList<>();
list.add(mTitleText.getText().toString());
list.add(mDescText.getText().toString());
list.add(mPointsText.getText().toString());
list.add(date = new SimpleDateFormat("dd-MM-yyyy", Locale.getDefault()).format(new Date()));
// Saving data from current card into the completed challenges list.
TempDataReader reader = new TempDataReader(itemView.getContext());
new TempDataReader(itemView.getContext()).saveFile(list);
// I want to notify the dataset change here if possible!
popupWindow.dismiss();
}
});
popupWindow.showAtLocation(itemView, Gravity.CENTER, 25, 100);
}
});
}
}
}
SectionsPagerAdapter.java
public class SectionsPagerAdapter extends FragmentStatePagerAdapter{
private ViewPager viewPager;
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public void addFragment(Fragment fragment, String title){
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
#Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
#Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
}
}
CompletedFragment.java
public class CompletedFragment extends Fragment {
RecyclerView recyclerView;
RecyclerViewAdapter adapter;
public Fragment newInstance() {
return new CompletedFragment();
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.completed_fragment, container, false);
recyclerView = view.findViewById(R.id.completed_frag);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
TempDataReader reader = new TempDataReader(getActivity());
List<List<String>> super_list = reader.readCompFile();
if(super_list == null || super_list.size() < 1){
return null;
} else{
adapter = new RecyclerViewAdapter(super_list,"completed");
recyclerView.setAdapter(adapter);
return view;
}
}
}
EDIT:
Added the code for the second fragment, which is the one that should be updated after the onClick at RecyclerViewHolder-class.

You have to add a function in your adapter for adding data:
public void addData(String title, String desc, String point, String date) {
this.mListTitle.add(title);
this.mListDesc.add(desc);
this.mListPoints.add(point);
this.mListDates.add(date);
notifyDataSetChanged();
}
If you want to enable animations call notifyItemInserted() instead of notifyDataSetChanged();
It is important that you add a String to every list because in your onBindViewHolder() you get the item to display from every list with list.get(position). Otherwise you'll get a IndexOutOfBoundsException.

You can create an interface and use as a callback. Send it as a parameter of the RecyclerViewAdapter and then to your RecyclerViewHolder. When the item should be added you call the callback that will get you back to your fragment. There you can read the file again and call notifyDataSetChanged.
I know i explain pretty bad so i will try to change your code so that it does what i said:
this will be your RecyclerViewAdapter:
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewHolder> {
private List<String> mListTitle;
private List<String> mListDesc;
private List<String> mListPoints;
private List<String> mListDates;
private String fragment_tag;
private Runnable callback;
public RecyclerViewAdapter() {
}
public RecyclerViewAdapter(List<List<String>> super_list, String tag, Runnable callBack) {
//add the callback here(Runnable) and save it into a local variable
this.callback=callback;
this.mListTitle = super_list.get(0);
this.mListDesc = super_list.get(1);
this.mListPoints = super_list.get(2);
this.mListDates = super_list.get(3);
fragment_tag = tag;
}
#Override
public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
return new RecyclerViewHolder(inflater, parent, fragment_tag, callback);
//send the callback to your viewHolder
}
#Override
public void onBindViewHolder(RecyclerViewHolder holder, int position) {
holder.mTitleText.setText(mListTitle.get(position));
holder.mDescText.setText(mListDesc.get(position));
holder.mPointsText.setText(mListPoints.get(position));
if (fragment_tag.equals("completed")) {
holder.mDateText.setText(mListDates.get(position));
}
}
#Override
public int getItemCount() {
return mListTitle.size();
}
}
class RecyclerViewHolder extends RecyclerView.ViewHolder {
RecyclerView recyclerView;
RecyclerViewAdapter mAdapter;
public TextView mTitleText, mDescText, mDateText, mPointsText, popupTitle;
public Button mConfButton, popCancelBtn, popAcceptBtn;
public RecyclerViewHolder(View itemView) {
super(itemView);
}
public RecyclerViewHolder(final LayoutInflater inflater, final ViewGroup container, String tag, Runnable callback) {
//ADD the callback to the parameters list here
// Inflating the card layout depending on the tag parameter.
super(inflater.inflate
((tag.equals("challenges")) ? R.layout.card_view_chall : R.layout.card_view_comp, container,
false));
mTitleText = itemView.findViewById(R.id.title_holder);
mDescText = itemView.findViewById(R.id.desc_holder);
mPointsText = itemView.findViewById(R.id.points_holder);
mDateText = itemView.findViewById(R.id.date_holder);
if (tag.equals("challenges")) {
mConfButton = itemView.findViewById(R.id.card_conf_button);
mConfButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// Setting the layout inflater for popup window.
LayoutInflater pInflater = (LayoutInflater) itemView.getContext().getSystemService(LAYOUT_INFLATER_SERVICE);
ViewGroup container1 = (ViewGroup) pInflater.inflate(R.layout.confirmation_popup, null);
final PopupWindow popupWindow = new PopupWindow(container1, 700, 600, true);
popupTitle = container1.findViewById(R.id.popuptext);
popAcceptBtn = container1.findViewById(R.id.accept_button);
popCancelBtn = container1.findViewById(R.id.cancel_button);
popupTitle.setText(mTitleText.getText().toString());
// Dismisses the popup window
popCancelBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
popupWindow.dismiss();
}
});
// Click listener for dialog accept button.
popAcceptBtn.setOnClickListener(new View.OnClickListener() {
String date;
#Override
public void onClick(View view) {
List<String> list = new ArrayList<>();
list.add(mTitleText.getText().toString());
list.add(mDescText.getText().toString());
list.add(mPointsText.getText().toString());
list.add(date = new SimpleDateFormat("dd-MM-yyyy", Locale.getDefault()).format(new Date()));
// Saving data from current card into the completed challenges list.
TempDataReader reader = new TempDataReader(itemView.getContext());
new TempDataReader(itemView.getContext()).saveFile(list);
// I want to notify the dataset change here if possible!
//call the callback
callback.run();
popupWindow.dismiss();
}
});
popupWindow.showAtLocation(itemView, Gravity.CENTER, 25, 100);
}
});
}
}
}
And this will be your fragment:
public class CompletedFragment extends Fragment {
RecyclerView recyclerView;
RecyclerViewAdapter adapter;
public Fragment newInstance() {
return new CompletedFragment();
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.completed_fragment, container, false);
recyclerView = view.findViewById(R.id.completed_frag);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
TempDataReader reader = new TempDataReader(getActivity());
List<List<String>> super_list = reader.readCompFile();
if(super_list == null || super_list.size() < 1){
return null;
} else{
adapter = new RecyclerViewAdapter(super_list,"completed", new Runnable() {
#Override
public void run() {
//here read the list again and call notifyDataSetChanged on your recycler
}
});
);
recyclerView.setAdapter(adapter);
return view;
}
}
}
Hope it helps and it works for you. If i did anything wrong, let me know, i can't run the code right now so...
edited, i forgot to add code in the callback

How to store and retrive RecyclerView Items for offline use

Guys please dont make this question as a duplicate as I have not found any simple or easy implementation of realm in my app. I am in the process of creating a chat app and what I want to do is make it possible for the user to be able to access and read earlier messages that he received even without internet connection.
In short I want my app to be still accessible without an internet connection but am finding it difficult doing that as am new to local data storage.
Below are my codes for your perusal:
Fragment
public class ChatFragment extends Fragment {
public RecyclerView mChatsList;
public View mView;
public List<ChatsModel> mChatsModel;
public ChatsAdapter mChatsAdapter;
private Realm realm;
public ChatFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
mView = inflater.inflate(R.layout.fragment_chat, container, false);
((AppCompatActivity) getActivity()).getSupportActionBar().setShowHideAnimationEnabled(true);
initUI();
realm = Realm.getDefaultInstance();
return mView;
}
//Method and views initializer
public void initUI() {
mChatsList = (RecyclerView) mView.findViewById(R.id.chatsList);
LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
mChatsModel = new ArrayList<ChatsModel>();
mChatsAdapter = new ChatsAdapter(getActivity(), mChatsModel);
mChatsList.setLayoutManager(layoutManager);
mChatsList.setHasFixedSize(true);
mChatsAdapter.notifyDataSetChanged();
mChatsList.setAdapter(mChatsAdapter);
RecyclerView.ItemAnimator itemAnimator = new DefaultItemAnimator();
itemAnimator.setAddDuration(1000);
itemAnimator.setRemoveDuration(1000);
mChatsList.setItemAnimator(itemAnimator);
prepareItems();
Realm realm = Realm.getInstance(getActivity());
realm.executeTransaction(new Realm.Transaction() {
#Override
public void execute(Realm realm) {
ChatsModel chat = realm.createObject(ChatsModel.class);
chat.setUsername("username");
chat.setDate("date");
chat.setPicture("Picture");
}
}, new Realm.Transaction.Callback() {
#Override
public void onSuccess() {
Main.Mess(getString(R.string.real_sucess));
}
#Override
public void onError(Exception e) {
Main.Mess(getString(R.string.real_error));
}
});
}
// This is a simple method to add items to our recyclerview
private void prepareItems() {
Rests mRests = RestService.createService(Rests.class, Session.getToken(getActivity()));
mRests.suggest(new Callback<List<ChatsModel>>() {
#Override
public void success(List<ChatsModel> mChatsModel, Response response) {
RealmList<ChatsModel> mChatsModel2 = new RealmList<ChatsModel>();
mChatsAdapter.setUsers(mChatsModel);
}
#Override
public void failure(RetrofitError error) {
Main.Mess(getString(R.string.server_error));
}
});
}
}
My Adapter
public class ChatsAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static final int TYPE_HEADER = 0;
private static final int TYPE_ITEM = 1;
private RealmList<ChatsModel> mChatsModel;
private Realm realm;
public Activity mActivity;
public ChatsAdapter(#NonNull Activity mActivity) {
super();
this.mChatsModel = new RealmList<>();
this.realm = Realm.getDefaultInstance();
this.mActivity = mActivity;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder (ViewGroup parent, int viewType) {
if(viewType == TYPE_HEADER) {
View v = LayoutInflater.from (parent.getContext ()).inflate (R.layout.ad_view, parent, false);
return new HeaderViewHolder (v);
} else if(viewType == TYPE_ITEM) {
View v = LayoutInflater.from (parent.getContext ()).inflate (R.layout.chats_item, parent, false);
return new ContentViewHolder (v);
}
return null;
}
private ChatsModel getItem (int position) {
return mChatsModel.get (position);
}
#Override
public void onBindViewHolder (RecyclerView.ViewHolder holder, final int position) {
if (holder instanceof HeaderViewHolder) {
HeaderViewHolder headerHolder = (HeaderViewHolder) holder;
if (Constant.SHOW_ADS) {
headerHolder.mAdView.setVisibility(View.VISIBLE);
AdRequest adRequest = new AdRequest.Builder().build();
headerHolder.mAdView.loadAd(adRequest);
} else {
headerHolder.mAdView.setVisibility(View.GONE);
}
}else if (holder instanceof ContentViewHolder) {
ContentViewHolder contentHolder = (ContentViewHolder) holder;
ChatsModel item = getItem (position - 1);
contentHolder.username.setText(item.getUsername());
contentHolder.date.setText(item.getDate());
contentHolder.message.setText(item.getMessage());
Picasso.with(mActivity.getApplicationContext())
.load(Constant.IMAGE_SMALL + item.getPicture())
.error(R.drawable.user)
.into(contentHolder.picture);
}
}
#Override
public int getItemViewType (int position) {
if(isPositionHeader (position)) {
return TYPE_HEADER;
}
return TYPE_ITEM;
}
public void setUsers(RealmList<ChatsModel> friendsItems) {
this.mChatsModel = friendsItems;
notifyDataSetChanged();
}
public List<ChatsModel> getSuggestionsModel() {
return this.mChatsModel;
}
private boolean isPositionHeader (int position) {
return position == 0;
}
#Override
public int getItemCount () {
return mChatsModel.size ();
}
public class HeaderViewHolder extends RecyclerView.ViewHolder {
public AdView mAdView;
public HeaderViewHolder(View itemView) {
super(itemView);
mAdView = (AdView) itemView.findViewById(R.id.ad_view);
}
}
public class ContentViewHolder extends RecyclerView.ViewHolder {
public ImageView picture;
public TextView username, date, message;
public LinearLayout chat;
public ContentViewHolder(View v) {
super(v);
picture = (ImageView) v.findViewById(R.id.picture);
username = (TextView) v.findViewById(R.id.username);
date = (TextView) v.findViewById(R.id.date);
message = (TextView) v.findViewById(R.id.message);
}
}
}
Okay so thats my code.

You can use a SQLite database for storing the chats offline, watch this YouTube tutorial, it is extensive but you can skip through some parts.
When downloading/sending chat messages, mirror them into your database and use the database and ONLY THE DATABASE as the data source for your RecyclerView (never let any online data directly go into the list, always store it in the database first and read it from the database when putting it into your layout).
To improve performance, you can store relevant chat messages in memory (in a separate ArrayList for example) instead of always reading data from the DB that you just wrote into it.

As #geisshirt says in comment, use RealmRecyclerViewAdapter instead of RecyclerView.Adapter. Couple words about android realm adapters you can found in official doc.
Also, you can look at RealmRecyclerViewAdapter example