I am trying to understand MVVM architecture and I need a bit of a help.
My goal is to prevent lost data when current fragment has some changes.
I have created simple app with product grid as RecyclerView divided by 3 columns. In my HomeFragment.class I have done this:
#Inject
RecyclerViewProductAdapter recyclerViewProductAdapter;
#Inject
HomeViewModel homeViewModel;
private final RecyclerView.LayoutManager layoutManager =
new GridLayoutManager(getContext(), GRID_SPAN_COUNT);
private FragmentHomeBinding binding;
public View onCreateView(#NonNull LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
binding = FragmentHomeBinding.inflate(inflater, container, false);
View root = binding.getRoot();
homeViewModel.getProductList().observe(getViewLifecycleOwner(), userListUpdateObserver);
return root;
}
Observer<ArrayList<Product>> userListUpdateObserver = products -> {
recyclerViewProductAdapter.setProducts(products);
binding.productRecyclerView.setLayoutManager(layoutManager);
binding.productRecyclerView.setAdapter(recyclerViewProductAdapter);
};
I also created HomeViewModel as #Singleton with injected mock data:
#Singleton
public class HomeViewModel extends ViewModel {
#Inject
ArrayList<Product> products;
private MutableLiveData<ArrayList<Product>> productList;
public HomeViewModel(Context context) {
HomeViewModelAccessor homeViewModelAccessor =
EntryPoints.get(context, HomeViewModelAccessor.class);
this.products = homeViewModelAccessor.getProducts();
}
public LiveData<ArrayList<Product>> getProductList() {
if (productList == null) {
productList = new MutableLiveData<>(products);
}
return productList;
}
#EntryPoint
#InstallIn(SingletonComponent.class)
public interface HomeViewModelAccessor {
ArrayList<Product> getProducts();
}
}
And the last one, RecyclerViewAdapter that defines every single item what look like. Standard behaviour should mark as "checked" clicked product. After changing fragment to another one and resuming HomeFragment, it should save state with proper checkbox checked or not:
#Singleton
public class RecyclerViewProductAdapter extends RecyclerView.Adapter<RecyclerViewProductAdapter.ViewHolder> {
private final Context context;
private final DecimalFormat decimalFormat;
private final LayoutInflater layoutInflater;
private ArrayList<Product> products;
public RecyclerViewProductAdapter(Context context) {
this.context = context;
this.layoutInflater = LayoutInflater.from(context);
ProductAdapterAccessor productAdapterAccessor =
EntryPoints.get(context, ProductAdapterAccessor.class);
this.decimalFormat = productAdapterAccessor.decimalFormat();
}
public void setProducts(ArrayList<Product> products) {
this.products = products;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = layoutInflater.inflate(R.layout.product_item, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
holder.lifecycle.setCurrentState(Lifecycle.State.RESUMED);
Product product = products.get(position);
holder.bind(position, product);
}
#Override
public void onViewRecycled(#NonNull ViewHolder holder) {
holder.lifecycle.setCurrentState(Lifecycle.State.DESTROYED);
}
public class ViewHolder extends RecyclerView.ViewHolder implements LifecycleOwner {
LifecycleRegistry lifecycle = new LifecycleRegistry(this);
TextView productNameTextView;
TextView productPriceTextView;
ImageView productImageView;
CheckBox productChecked;
ViewHolder(View itemView) {
super(itemView);
productNameTextView = itemView.findViewById(R.id.product_name);
productPriceTextView = itemView.findViewById(R.id.product_price);
productImageView = itemView.findViewById(R.id.product_image);
productChecked = itemView.findViewById(R.id.product_checked);
}
void bind(int position, Product product) {
productNameTextView.setText(product.getName());
productPriceTextView.setText(decimalFormat.format(product.getPrice()));
Drawable image = Optional.ofNullable(product.getImage())
.map(imageBinary -> new BitmapDrawable(
context.getResources(),
BitmapFactory.decodeByteArray(imageBinary, 0, imageBinary.length)))
.orElse(new BitmapDrawable(context.getResources()));
productImageView.setImageDrawable(image);
productChecked.setChecked(product.isChecked());
itemView.setOnClickListener(v -> {
boolean currentState = !product.isChecked();
product.setChecked(currentState);
productChecked.setChecked(currentState);
products.set(position, product);
});
}
#NonNull
#Override
public Lifecycle getLifecycle() {
return lifecycle;
}
}
#Override
public int getItemCount() {
return products.size();
}
#EntryPoint
#InstallIn(SingletonComponent.class)
public interface ProductAdapterAccessor {
DecimalFormat decimalFormat();
}
}
But my state is lost, even HomeViewModel and RecyclerViewAdapter are singletons. I wonder why observer of product list do not save fragment state?
I should create my fragments as singletons? How can I handle this? Thanks.
Related
I have data taken from an API, I have added a button that when pressed will move (title, image, and some data from FRAGMENT to other FRAGMENT), this data is taken from RECYCLERLVIEW and will be shown in RECYCLERVIEW. But when the button is pressed, nothing happens and the data is not transmitted.
The project link if you want to take a deeper look "Mox Project"
Here's the first adapter that I send data from
--- CNNAdapter ---
private List<Item> items = null;
#SuppressLint("NotifyDataSetChanged")
public void setCNNList(List<Item> items) {
this.items = items;
notifyDataSetChanged();
}
#NonNull
#Override
public RecyclerView.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new NewsViewHolder(
LayoutInflater.from(parent.getContext()).inflate(
R.layout.list_news,
parent,
false
)
);
}
#RequiresApi(api = Build.VERSION_CODES.N)
#Override
public void onBindViewHolder(#NonNull RecyclerView.ViewHolder holder, int position) {
Item News = items.get(position);
((NewsViewHolder) holder).setData(News);
((NewsViewHolder) holder).sendData(News);
}
#Override
public int getItemCount() {
if (items == null) return 0;
return items.size();
}
static class NewsViewHolder extends RecyclerView.ViewHolder {
private final ImageView image;
private final TextView title;
private final TextView description;
private final TextView source;
private final TextView author;
private final Button sendDataButton;
private final Activity activity = new Activity();
NewsViewHolder(#NonNull View itemView) {
super(itemView);
image = itemView.findViewById(R.id.image_news);
title = itemView.findViewById(R.id.title_news);
description = itemView.findViewById(R.id.description_news);
source = itemView.findViewById(R.id.source_news);
author = itemView.findViewById(R.id.author_name_news);
sendDataButton = itemView.findViewById(R.id.button_save);
}
#RequiresApi(api = Build.VERSION_CODES.N)
void setData(Item news) {
Glide.get(itemView.getContext()).clearMemory();
// load images in MainThread
activity.runOnUiThread(() -> {
Glide.with(itemView.getContext())
.load((Objects.requireNonNull(news.getEnclosure())).getLink())
.diskCacheStrategy(DiskCacheStrategy.NONE)
.diskCacheStrategy(DiskCacheStrategy.AUTOMATIC)
.skipMemoryCache(true)
.transition(DrawableTransitionOptions.withCrossFade())
.into(image);
Glide.get(itemView.getContext()).clearMemory();
});
title.setText(news.getTitle());
description.setText(Html.fromHtml(Objects.requireNonNull(news.getDescription()).replaceAll("(<(/)img>)|(<img.+?>)", ""), Html.FROM_HTML_MODE_COMPACT));
source.setText(R.string.cnn);
author.setText(R.string.author);
}
void sendData(Item news) {
sendDataButton.setOnClickListener(v -> {
Bundle bundle = new Bundle();
bundle.putString("title", news.getTitle());
bundle.putString("image", Objects.requireNonNull(news.getEnclosure()).getLink());
bundle.putString("source", "CNN");
bundle.putString("author", "CNN editor's");
bundle.putString("link", news.getLink());
FavouriteFragment favouriteFragment = new FavouriteFragment();
favouriteFragment.setArguments(bundle);
});
}
}
Here's the second adapter that I get the data and set it
--- FavoriteAdapter ---
public class FavoriteAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private ArrayList<Item> items = new ArrayList<>();;
private Context context;
#SuppressLint("NotifyDataSetChanged")
public void setFavoriteList(ArrayList<Item> items, Context context) {
this.items = items;
this.context = context;
}
#NonNull
#Override
public RecyclerView.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new FavoriteViewHolder(
LayoutInflater.from(parent.getContext()).inflate(
R.layout.list_save,
parent,
false
)
);
}
#RequiresApi(api = Build.VERSION_CODES.N)
#Override
public void onBindViewHolder(#NonNull RecyclerView.ViewHolder holder, int position) {
((FavoriteViewHolder) holder).setData();
}
#Override
public int getItemCount() {
if (items == null) return 0;
return items.size();
}
static class FavoriteViewHolder extends RecyclerView.ViewHolder {
private final ImageView image;
private final TextView title;
private final TextView source;
private final TextView author;
private final Activity activity = new Activity();
FavoriteViewHolder(#NonNull View itemView) {
super(itemView);
image = itemView.findViewById(R.id.image_article_save);
title = itemView.findViewById(R.id.title_article_save);
source = itemView.findViewById(R.id.source_article_save);
author = itemView.findViewById(R.id.author_name_article_save);
}
#RequiresApi(api = Build.VERSION_CODES.N)
void setData() {
FavouriteFragment favouriteFragment = new FavouriteFragment();
Bundle bundle = favouriteFragment.getArguments();
String getTitle = bundle.getString("title");
String getImage = bundle.getString("image");
String getSource = bundle.getString("source");
String getAuthor = bundle.getString("author");
String getLink = bundle.getString("link");
Glide.get(itemView.getContext()).clearMemory();
// load images in MainThread
activity.runOnUiThread (() -> {
Glide.with(itemView.getContext())
.load((getImage))
.diskCacheStrategy(DiskCacheStrategy.NONE)
.diskCacheStrategy(DiskCacheStrategy.AUTOMATIC)
.skipMemoryCache(true)
.transition(DrawableTransitionOptions.withCrossFade())
.into(image);
Glide.get(itemView.getContext()).clearMemory();
});
title.setText(getTitle);
source.setText(getSource);
author.setText(getAuthor);
}
}
My fragment that I display the data using recyclerview
--- FavouriteFragment ---
public class FavouriteFragment extends Fragment {
private FragmentFavouriteBinding binding;
ArrayList<Item> arrayList = new ArrayList<>();;
#Override
public View onCreateView(#NotNull LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
binding = FragmentFavouriteBinding.inflate(getLayoutInflater());
View view = binding.getRoot();
requireActivity().setTitle("");
initializeViews();
return view;
}
private void initializeViews() {
FavoriteAdapter adapter = new FavoriteAdapter();
binding.recyclerViewFavorites.setLayoutManager(new LinearLayoutManager(requireContext()));
binding.recyclerViewFavorites.setHasFixedSize(true);
binding.recyclerViewFavorites.setAdapter(adapter);
adapter.setFavoriteList(arrayList,getContext());
}
The project link if you want to take a deeper look "Mox Project"
Thank you for your help.
Possible problems or issues that may cause the button not to show the passed data.
remember a view will only display when it gets data.
Here are some resources that might help:
Passing Data between Fragments on Android Using ViewModel
Managing UI-related data in activity lifecycles
https://heartbeat.fritz.ai/passing-data-between-fragments-on-android-using-viewmodel-d47fa6773f9c
How to pass values between Fragments
https://android-developers.googleblog.com/2011/02/android-30-fragments-api.html
The displaying of Fragments is managed by FragmentManager. You must pass an instance of FragmentManager to CNNAdapter as follows:
public class CNNAdapter extends RecyclerView.Adapter<CNNAdapter.NewsViewHolder> {
private final FragmentManager mFragmentManager;
public CNNAdapter(FragmentManager mFragmentManager) {
this.mFragmentManager = mFragmentManager;
}
public void addData(List<> items) {
list.addAll(items);
notifyDataSetChanged();
}
}
And then you display the fragment as follows:
FavouriteFragment favouriteFragment = new FavouriteFragment();
favouriteFragment.setArguments(bundle);
mFragmentManager.beginTransaction().replace(R.id.fragment_container,favouriteFragment).commit();
R.id.fragment_container is the view ID of the container in the layout xml of the activity that hosts the fragment. The container is usually a FrameLayout.
And then you instantiate CNNAdapter in the Fragment like this:
CNNAdapter cnnAdapter = new CNNAdapter(getFragmentManager());
I'm trying to make a tab layout with each page having a RecyclerView inside of it. I'm using fragments with RecyclerView in them, then i put them inside of ViewPager. The problem is that even though tabs are being shown it's content is always empty.
My Activity class
public class Spells_Act extends AppCompatActivity {
private ViewPager pager;
private Spells_Slide slider;
private TabLayout tabLayout;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.spells);
tabLayout = findViewById(R.id.tab);
pager = findViewById(R.id.pager);
slider = new Spells_Slide(getSupportFragmentManager());
slider.AddFragment(new Fragment1(), "one");
slider.AddFragment(new Fragment1(), "two");
slider.AddFragment(new Fragment1(), "three");
pager.setAdapter(slider);
tabLayout.setupWithViewPager(pager);
}
}
My ViewPager adapter
public class Spells_Slide extends FragmentPagerAdapter {
private Context context;
LayoutInflater inflater;
private List<RecyclerView> pages;
private List<String> list = new LinkedList<>();
private final List<Fragment> stFragment = new ArrayList();
public Spells_Slide(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return stFragment.get(position);
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return list.get(position);
}
#Override
public int getCount() {
return list.size();
}
#Override
public boolean isViewFromObject(#NonNull View view, #NonNull Object
object) {
return false;
}
public void AddFragment(Fragment fragment, String title) {
list.add(title);
stFragment.add(fragment);
}
My Fragment class
public class Fragment1 extends Fragment {
View v;
private RecyclerView recycler;
Adapter_Rec adapter;
private List<Spells> Spells = new LinkedList<>();
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Spells.add(new Spells("Ghost Sound", "Figment sounds", 0));
Spells.add(new Spells("Disrupt Undead", " Deals 1d6 damage to one undead", 0));
Spells.add(new Spells("Resistance", "Subject gains +1 on saving throws", 0));
Spells.add(new Spells("Ray of Frost", "Ray deals 1d3 cold damage", 0));
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, Bundle savedInstanceState) {
v = inflater.inflate(R.layout.frag1, container, false);
recycler = v.findViewById(R.id.frag_recycler);
recycler.setLayoutManager(new LinearLayoutManager(getActivity()));
adapter = new Adapter_Rec(Spells, getContext());
recycler.setAdapter(adapter);
return v;
}
}
And finally my RecyclerViewAdapter
public class Adapter_Rec extends
RecyclerView.Adapter<Adapter_Rec.MyViewHolder> {
private List<Spells> list = new LinkedList<>();
Context context;
public Adapter_Rec(List<Spells> list, Context context)
{
this.context=context;
this.list=list;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v;
v = LayoutInflater.from(context).inflate
(R.layout.spells_recycle,parent,false);
MyViewHolder vholder = new MyViewHolder(v);
return vholder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.check.setOnCheckedChangeListener(null);
holder.name.setText(list.get(position).getName());
holder.benefits.setText(list.get(position).getDescription());
}
#Override
public int getItemCount() {
return list.size();
}
public static class MyViewHolder extends RecyclerView.ViewHolder
{
TextView name;
TextView benefits;
CheckBox check ;
public MyViewHolder(View item)
{ super(item);
name = item.findViewById(R.id.namee);
benefits = item.findViewById(R.id.desc);
check =item.findViewById(R.id.check);
}
}
}
delete isViewFromObject method, or return super.isViewFromObject(view, object);
#Override
public boolean isViewFromObject(#NonNull View view, #NonNull Object
object) {
//return false; // return false will never show this fragment
return super.isViewFromObject(view, object);
}
I've implementend a RecyclerView as follow
The Adapter with the Holder
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyHolder> {
#NonNull
#Override
public MyHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.indovinelloelement,parent,false);
MyHolder holder = new MyHolder(view);
return holder;
}
#Override
public void onBindViewHolder(#NonNull MyHolder holder, int position) {
holder.category.setText(data.get(position).getCategory());
holder.difficulty.setText(""+data.get(position).getDifficulty());
holder.title.setText(data.get(position).getTitle());
holder.score.setText(""+data.get(position).getScore());
if(data.get(position).isLocked())
holder.setLocked();
else
holder.setUnlocked();
}
public DataGestour.Indovinello getIndovinello(int pos){
return data.get(pos);
}
#Override
public int getItemCount() {
return data.size();
}
public class MyHolder extends RecyclerView.ViewHolder {
public TextView category,score,difficulty,title;
private ImageView lock_state;
public MyHolder(View itemView) {
super(itemView);
category = (TextView)itemView.findViewById(R.id.categoria);
score = (TextView)itemView.findViewById(R.id.punteggio);
difficulty = (TextView) itemView.findViewById(R.id.difficolta);
title = (TextView)itemView.findViewById(R.id.titolo);
lock_state = (ImageView) itemView.findViewById(R.id.lock_state);
}
public void setLocked(){
lock_state.setImageResource(R.drawable.ic_lock_outline_black_24dp);
}
public void setUnlocked(){
lock_state.setImageResource(R.drawable.ic_lock_open_black_24dp);
}
}
ArrayList<DataGestour.Indovinello> data;
Context context;
public MyAdapter(Context context, ArrayList<DataGestour.Indovinello> list){
this.context = context;
this.data = list;
}
}
and the RecyclerView:
rc = (RecyclerView)root_view.findViewById(R.id.lista_domande);
rc.setHasFixedSize(true);
LinearLayoutManager ly = new LinearLayoutManager(getContext());
ly.setOrientation(LinearLayoutManager.VERTICAL);
rc.setLayoutManager(ly);
try{
gestour = new DataGestour(getContext());
}catch (IllegalStateException e){
Log.e("DataManager",e.getMessage());
};
adapter = new MyAdapter(getContext(),gestour.getAllDatas());
rc.setAdapter(adapter);
adapter.notifyDataSetChanged();
where DataGestoure is a class that manipulates some data from a
database and store them in a ArrayList (DataGestour.getAllDatas is the method to return the data under a ArrayList)
The problem start only if the ArrayList contains more then 3 items becouse the RecyclerView doen't show them despite the fact that the adapter holds all the data in ArrayList< DataGestour.Indovinello > data
Well, you need a little more order in your code, since it is not properly structured, by default the RecyclerView has its Scrolleable view unless in the XML this attribute is removed, well I recommend that you use this code in your adapter and use a model to save the information you get from your BD, that is the correct way to work to keep everything in order and it is easier to work it, once this is done you can use this code perfectly that I am sure will work, remember to only pass information to my Model that in my case calls it "Model" and with this the error of your data load will be solved. It is also advisable to use a List <> for these cases since the Arrays <> tend to have errors when you manipulate the data and more if you do it the way you present the code.
private List<Model> mDataList;
public MyAdapter(Context context){
this.context = context;
this.mDataList = new ArrayList<>();
}
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyHolder> {
#NonNull
#Override
public MyHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.indovinelloelement,parent,false);
return new MyHolder(view);
}
#Override
public void onBindViewHolder(#NonNull MyHolder holder, int position) {
MyHolder holder = (MyHolder) MyHolder;
hoder.bind(mDataList.getPosition(position));
}
#Override
public int getItemCount() {
return mDataList.size();
}
public void setData(List<Model> list) {
mDataList.clear();
mDataList.addAll(list);
notifyDataSetChanged();
}
public class MyHolder extends RecyclerView.ViewHolder {
TextView category;
category = (TextView)itemView.findViewById(R.id.categoria);
TextView score;
score = (TextView)itemView.findViewById(R.id.punteggio);
TextView difficulty;
difficulty = (TextView) itemView.findViewById(R.id.difficolta);
TextView title;
title = (TextView)itemView.findViewById(R.id.titolo);
ImageView lock_state;
lock_state = (ImageView) itemView.findViewById(R.id.lock_state);
public MyHolder(View itemView) {
super(itemView);
}
protected void bind(Model model){
category.setText(model.getCategory());
score.setText(model.getScore());
difficulty.setText(model.getDifficulty());
title.setText(model.getTitle());
if(model.isLocked()){
lock_state.setImageResource(R.drawable.ic_lock_outline_black_24dp);
} else {
lock_state.setImageResource(R.drawable.ic_lock_open_black_24dp);
}
}
}
}
And for your class that contains the RecyclerView use the code as follows.
RecyclerView mRecyclerView;
mRecyclerView = (RecyclerView)root_view.findViewById(R.id.lista_domande);
private MyAdapter mAdapter;
private List<Model> mDataList;
private DataGestour gestour;
private void setupRecyclerView(){
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext());
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(linearLayoutManager);
mAdapter = new MyAdapter(getContext());
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.setData(mDataList);
}
private void getDataDB(){
mDataList.add(gestour.getAllDatas);
}
I am trying to implement RecyclerView inside a Fragment. I have designed a CustomAdapter(StateAdapter) class to load the contents of RecyclerView and an interface StateAdapterOnClickHandler to handle onClicks of the items inside RecyclerView but clicking on item doesn't work.
Here's my HomeFragment.java which extends Fragment. I am unable to figure out how to initialize the StateAdapterOnClickHandler and where to call its method onItemClick()
public class HomeFragment extends Fragment implements StateAdapter.StateAdapterOnClickHandler {
private View homeFragment;
private RecyclerView recyclerView;
private StateAdapter stateAdapter;
private List<String> states;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
public static HomeFragment newInstance() {
HomeFragment homeFragment = new HomeFragment();
return homeFragment;
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
homeFragment = inflater.inflate(R.layout.fragment_home,container,false);
recyclerView = homeFragment.findViewById(R.id.recyclerview_states);
states = Arrays.asList(getResources().getStringArray(R.array.india_states));
LinearLayoutManager layoutManager = new LinearLayoutManager(container.getContext(),LinearLayoutManager.VERTICAL,false);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setHasFixedSize(true);
stateAdapter = new StateAdapter();
stateAdapter.setStateNames(states);
recyclerView.setAdapter(stateAdapter);
return homeFragment;
}
#Override
public void onItemClick(String state) {
Intent intent = new Intent(getActivity(),DetailActivity.class);
intent.putExtra("State",state);
startActivity(intent);
}
}
Here's my StateAdapter class
public class StateAdapter extends RecyclerView.Adapter<StateAdapter.StateViewHolder> {
private List<String> stateNames;
private final StateAdapterOnClickHandler stateAdapterOnClickHandler;
StateAdapter(StateAdapterOnClickHandler stateAdapterOnClickHandler){
this.stateAdapterOnClickHandler = stateAdapterOnClickHandler;
}
public interface StateAdapterOnClickHandler {
void onItemClick(String state);
}
#Override
public StateAdapter.StateViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
Context context = parent.getContext();
int idForListItem = R.layout.state_layout;
LayoutInflater inflater = LayoutInflater.from(context);
View view = inflater.inflate(idForListItem,parent,false);
return new StateViewHolder(view);
}
#Override
public void onBindViewHolder(StateAdapter.StateViewHolder holder, int position) {
String stateName = stateNames.get(position);
holder.mTextView.setText(stateName);
}
#Override
public int getItemCount() {
if(stateNames == null) return 0;
return stateNames.size();
}
public class StateViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public final TextView mTextView;
public StateViewHolder(View itemView) {
super(itemView);
mTextView = (TextView) itemView.findViewById(R.id.tv_state_name);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
int clickedPostion = getAdapterPosition();
String state = stateNames.get(clickedPostion);
stateAdapterOnClickHandler.onItemClick(state);
}
}
public void setStateNames(List<String> states) {
stateNames = states;
notifyDataSetChanged();
}
}
Please, tell me what's wrong with the code while handling the clicks. I am new to Android Programming and this is first time I am working with Fragments. Thanks for helping.
I made an Adapter for my recyclerView. This adapter works when I use on any xxxActivity.java but when I try to use is on a Fragment Its hows error. Doesn't let me Pass the onClickHandler() that I created in Adapter.
I am Setting Adapter Like this -
events_recyclerview.setAdapter(new FixedPlaceListAdapter(getContext(), placelist, mClickHandler)); //ClickListener doesn't work :'(
Another try was like --
events_recyclerview.setAdapter(new FixedPlaceListAdapter(getContext(), placelist, getmClickHandler()));
Here, I implemented getClickHandler() in the Fragment--
public FixedPlaceListAdapter.FixedPlaceListAdapterOnclickHandler getmClickHandler() {
return mClickHandler;
} //Still doesn't work :'(
and the Adapter Part--
Constructor like this-
public FixedPlaceListAdapter(Context mContext, List<PlaceBean>
placeBeanList, FixedPlaceListAdapterOnclickHandler mClickHandler) {
this.mContext = mContext;
this.placeBeanList = placeBeanList;
this.mClickHandler = mClickHandler;
}
I tried to do this ... but still doesn't work--
events_recyclerview.setAdapter(new FixedPlaceListAdapter(getContext(), placelist, FixedPlaceListAdapter.FixedPlaceListAdapterOnclickHandler.mClickhandler));
here is my full adapter code-
public class FixedPlaceListAdapter extends RecyclerView.Adapter<FixedPlaceListAdapter.FixedPlaceListAdapterViewHolder> {
private final FixedPlaceListAdapterOnclickHandler mClickHandler;
Context mContext;
List<PlaceBean> placeBeanList;
public FixedPlaceListAdapter(Context mContext, List<PlaceBean> placeBeanList, FixedPlaceListAdapterOnclickHandler mClickHandler) {
this.mContext = mContext;
this.placeBeanList = placeBeanList;
this.mClickHandler = mClickHandler;
}
public void setData(List<PlaceBean> placeBeanList) {
this.placeBeanList = placeBeanList;
notifyDataSetChanged();
}
#Override
public FixedPlaceListAdapterViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(mContext);
View view = inflater.inflate(R.layout.top_list_single, parent, false);
return new FixedPlaceListAdapterViewHolder(view);
}
#Override
public void onBindViewHolder(FixedPlaceListAdapterViewHolder holder, int position) {
PlaceBean pb = placeBeanList.get(position);
holder.nameTextView.setText(pb.getName());
holder.addressTextView.setText(pb.getVicinity());
holder.rating.setRating(pb.getRating());
if (pb.getPhotoref() != null) {
String imageUrl = UrlsUtil.getSinglePhotoUrlString(mContext, pb.getPhotoref(), "350", "300");
Picasso.with(mContext)
.load(imageUrl)
.into(holder.thumbnailImage);
}
}
#Override
public int getItemCount() {
return placeBeanList.size();
}
public interface FixedPlaceListAdapterOnclickHandler {
void onClick(String id);
}
public class FixedPlaceListAdapterViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
TextView nameTextView;
TextView addressTextView;
RatingBar rating;
ImageView thumbnailImage;
public FixedPlaceListAdapterViewHolder(View itemView) {
super(itemView);
nameTextView = (TextView) itemView.findViewById(R.id.place_name_now_in_list);
addressTextView = (TextView) itemView.findViewById(R.id.address_in_list);
rating = (RatingBar) itemView.findViewById(R.id.rating_single_place_in_list);
thumbnailImage = (ImageView) itemView.findViewById(R.id.place_image_thumb);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
String placeID = placeBeanList.get(getAdapterPosition()).getPlaceref();
mClickHandler.onClick(placeID);
}
}
}
Need Help!
public class CategoryNewsListAdapter extends RecyclerView.Adapter<CategoryNewsListAdapter.ViewHolder> {
private List<CategoryNews> actors = new ArrayList<>();
private Context mContext;
private Queue<List<CategoryNews>> pendingUpdates =
new ArrayDeque<>();
**public interface NewsItemClickListener {
void onNewsItemClick(int pos, CategoryNews categoryNews, ImageView shareImageView);
}**
**NewsItemClickListener newsItemClickListener;**
public CategoryNewsListAdapter(List<CategoryNews> personList, Context mContext, NewsItemClickListener newsItemClickListener) {
this.actors.addAll(personList);
this.mContext = mContext;
this.newsItemClickListener = newsItemClickListener;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
final LayoutInflater inflater = LayoutInflater.from(parent.getContext());
final View view = inflater.inflate(R.layout.particular_cat_news_list_row, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
Log.d("BusinessSubCategoryListAdapter", "Bindviewholder without payload");
final CategoryNews newsCategory = actors.get(position);
holder.news_title.setText(newsCategory.getPostTitle());
holder.news_date.setText(newsCategory.getPostDate());
holder.news_category.setText(newsCategory.getCategoryName());
holder.news_description.setText(newsCategory.getPostContent());
// GlideApp
// .with(mContext).load(newsCategory.getPostImage())
// .placeholder(R.mipmap.ic_launcher) // can also be a drawable
// .error(R.drawable.placeholder_image) // will be displayed if the image cannot be loaded
// .crossFade()
// .into(holder.news_image);
Picasso.with(mContext).load(newsCategory.getPostImage()).placeholder(R.drawable.placeholder_image).error(R.drawable.placeholder_image).into(holder.news_image);
**holder.itemView.setOnClickListener(v -> {
newsItemClickListener.onNewsItemClick(position, newsCategory, holder.news_image);
});**
}
#Override
public void onBindViewHolder(ViewHolder holder, int position, List<Object> payloads) {
if (payloads.isEmpty()) {
// if empty, do full binding;
onBindViewHolder(holder, position);
return;
}
Bundle bundle = (Bundle) payloads.get(0);
String newTitle = bundle.getString("NAME_CHANGE");
if (newTitle != null) {
// add some animation if you want
final CategoryNews actor = actors.get(position);
holder.news_title.setText(actor.getPostTitle());
holder.news_date.setText(actor.getPostDate());
holder.news_category.setText(actor.getCategoryName());
holder.news_description.setText(actor.getPostContent());
}
}
public void addItems(List<CategoryNews> newItems) {
// record this value before making any changes to the existing list
int curSize = getItemCount();
// update the existing list
actors.addAll(newItems);
// curSize should represent the first element that got added
// newItems.size() represents the itemCount
notifyItemRangeInserted(curSize, newItems.size());
}
public void updtateItems(List<CategoryNews> newItems) {
// record this value before making any changes to the existing list
int curSize = getItemCount();
// update the existing list
actors.addAll(newItems);
// curSize should represent the first element that got added
// newItems.size() represents the itemCount
notifyItemRangeInserted(0,newItems.size()- getItemCount()-1);
}
#Override
public int getItemCount() {
return actors.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
private TextView news_title, news_date, news_category, news_description;
private ImageView news_image;
public ViewHolder(View itemView) {
super(itemView);
news_title = (TextView) itemView.findViewById(R.id.news_title);
news_date = (TextView) itemView.findViewById(R.id.news_date);
news_category = (TextView) itemView.findViewById(R.id.news_category);
news_description = (TextView) itemView.findViewById(R.id.news_description);
news_image = (ImageView) itemView.findViewById(R.id.news_image);
}
}
}
And In your activity
implements NewsItemClickListener
create object NewsItemClickListener newsItemClickListner;
inside oncreate newsItemClickListner=this; (you mush have implemented 1)
pass that object to recyclerview.
In adapter it is received by this
public CategoryNewsListAdapter(List personList, Context mContext, NewsItemClickListener newsItemClickListener) {
this.actors.addAll(personList);
this.mContext = mContext;
this.newsItemClickListener = newsItemClickListener;
}
In your activity
CategoryNewsListAdapter categoryNewsListAdapter= new CategoryNewsListAdapter(list,this,newsItemClickListner)
After doing all this your overriden method will be called when you click in item of recycler view where you have set onclick listner
Okay .. The Problem is Fixed now ...
I was passing the wrong value or maybe the method of passing the ClickHandler was wrong.
The Solution of the Problem :
I Created another Class for ClickHandler-
public class PlaceCardClickHandler implements
FixedPlaceListAdapter.FixedPlaceListAdapterOnclickHandler,
PlaceListAdapter.PlaceListAdapterOnclickHandler {
Context mContext;
public PlaceCardClickHandler(Context mContext) {
this.mContext = mContext;
}
#Override
public void onClick(String id) {
Intent intentToStartDetail = new Intent(mContext, PlaceDetailActivity.class);
intentToStartDetail.putExtra("id", id);
mContext.startActivity(intentToStartDetail);
}
}
and the change in the Fragment was like this- (Just passed a object from the ClickHandler class)
events_recyclerview.setAdapter(new FixedPlaceListAdapter(getContext(), placelist, new PlaceCardClickHandler(getContext())));