Develop Reference

RecyclerView not visible

I have this code in MainActivity
public class MainActivity extends AppCompatActivity implements MainViewInterface{
RecyclerView rvMovies;
private String TAG = "MainActivity";
MoviesAdapter adapter;
MainPresenter mainPresenter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setupMVP();
mainPresenter.getMovies();
rvMovies = (RecyclerView)findViewById(R.id.rvMovies);
LinearLayoutManager manager = new LinearLayoutManager(this);
manager.setOrientation(LinearLayoutManager.VERTICAL);
rvMovies.setLayoutManager(manager);
//rvMovies.setHasFixedSize(true);
}
private void setupMVP() {
mainPresenter = new MainPresenter(this);
}
#Override
public void showToast(String s) {
Toast.makeText(MainActivity.this,s,Toast.LENGTH_LONG).show();
}
#Override
public void displayMovies(MovieResponse moviesResponse) {
if(moviesResponse!=null) {
Log.d(TAG,moviesResponse.getResults().get(1).getTitle());
adapter = new MoviesAdapter(moviesResponse.getResults(), MainActivity.this);
rvMovies.setAdapter(adapter);
adapter.notifyDataSetChanged();
}else{
Log.d(TAG,"Movies response null");
}
}
#Override
public void displayError(String s) {
showToast(s);
}
}
But I get this
E/RecyclerView: No adapter attached; skipping layout
I know other people asked the same question. I tried their solutions but didn't work. What am I missing?
This is my adapter code.
public class MoviesAdapter extends RecyclerView.Adapter<MoviesAdapter.MoviesHolder> {
List<Result> movieList;
Context context;
public MoviesAdapter(List<Result> movieList, Context context){
this.movieList = movieList;
this.context = context;
}
#Override
public MoviesHolder onCreateViewHolder( ViewGroup parent, int viewType) {
View v = LayoutInflater.from(context).inflate(R.layout.row_movies,parent,false);
MoviesHolder mh = new MoviesHolder(v);
return mh;
}
#Override
public void onBindViewHolder( MoviesHolder holder, int position) {
holder.tvTitle.setText(movieList.get(position).getTitle());
holder.tvOverview.setText(movieList.get(position).getOverview());
holder.tvReleaseDate.setText(movieList.get(position).getReleaseDate());
Glide.with(context).load("https://image.tmdb.org/t/p/w500/"+movieList.get(position).getPosterPath()).into(holder.ivMovie);
}
#Override
public int getItemCount() {
return movieList.size();
}
public class MoviesHolder extends RecyclerView.ViewHolder {
TextView tvTitle,tvOverview,tvReleaseDate;
ImageView ivMovie;
public MoviesHolder(View itemView) {
super(itemView);
tvTitle = (TextView) itemView.findViewById(R.id.tvTitle);
tvOverview = (TextView) itemView.findViewById(R.id.tvOverView);
tvReleaseDate = (TextView) itemView.findViewById(R.id.tvReleaseDate);
ivMovie = (ImageView) itemView.findViewById(R.id.ivMovie);
}
}
Thanks,
Theo.
SOLVED
In my activivity_main.xml I had both height and with equal to 0dp!!! I honestly don't know how and who put those values in!! That's why the recycler view was not visible!!!

I think you should call rvMovies.setAdapter(new MoviesAdapter(new ArrayList<>())) on your RecyclerView during onCreate - there is nothing bad about setting an empty (from items perspective) adapter on RecyclerView, it will simply show an empty list. Then once you have your data ready (downloaded/loaded from any source you are loading from) you will simply call something like adapter.setItems(newItemsList) and adapter.notifyDataSetChanged().
Also one more note: you should not store Context in class member fields as leaks might occur (I am pretty sure your Android Studio must complain about that as well in a form of a Lint Warning check). You actually don't even need that Context instance passing to your adapter as you can simply retrieve a Context instance from parent View in onCreateViewHolder - rewrite it like this:
#Override
public MoviesHolder onCreateViewHolder( ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_movies,parent,false);
MoviesHolder mh = new MoviesHolder(v);
return mh;
}

These 2 lines:
setupMVP();
mainPresenter.getMovies();
must be written after:
rvMovies = (RecyclerView)findViewById(R.id.rvMovies);

you need to set adapter after you set the views.
rvMovies = (RecyclerView)findViewById(R.id.rvMovies);
LinearLayoutManager manager = new LinearLayoutManager(this);
manager.setOrientation(LinearLayoutManager.VERTICAL);
rvMovies.setLayoutManager(manager);
//rvMovies.setHasFixedSize(true);
//call after setting the view
mainPresenter.getMovies();

#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setupMVP();
rvMovies = (RecyclerView)findViewById(R.id.rvMovies);
LinearLayoutManager manager = new LinearLayoutManager(this);
manager.setOrientation(LinearLayoutManager.VERTICAL);
rvMovies.setLayoutManager(manager);
rvMovies.setVisibility(View.VISIBLE);
mainPresenter.getMovies(); <== put this line in last
}

Getting Android RecyclerView to update view inside React Native component

I am making a mobile application using React Native and included list components didn't have high enough performance for it so I started using Android's RecyclerView as the list component. There is a problem though with it. The RecyclerView doesn't update its contents views until I scroll or change RecyclerView's size. What could cause this problem and how I can fix it? I have tried notifyDatasetChanged, notifyItemChanged, forceLayout, invalidate, postInvalidate and many different variations with each.

Try this one this.setIsRecyclable(true);
It will referesh your views
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private ArrayList<String> mSingleItemLists = new ArrayList<>();
private SingleListItemAdapter mSingleListItemAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view_single_item);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(linearLayoutManager);
setDummyData();
}
private void setDummyData() {
for (int i = 0; i <= 30; i++)
mSingleItemLists.add("item" + i);
}
#Override
protected void onResume() {
super.onResume();
mSingleListItemAdapter = new SingleListItemAdapter(mSingleItemLists);
mRecyclerView.setAdapter(mSingleListItemAdapter);
}
class SingleListItemAdapter extends RecyclerView.Adapter<SingleListItemAdapter.SingleListItemHolder> {
private ArrayList<String> mSingleItemLists;
private SingleListItemAdapter(ArrayList<String> singleItemLists) {
mSingleItemLists = singleItemLists;
//You can do notifydatasetchange if u r having any saved value
}
#Override
public SingleListItemAdapter.SingleListItemHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View inflatedView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.row_recyclerview, parent, false);
return new SingleListItemHolder(inflatedView);
}
#Override
public void onBindViewHolder(SingleListItemAdapter.SingleListItemHolder holder, int position) {
holder.mItemDate.setText(mSingleItemLists.get(position));
}
#Override
public int getItemCount() {
return mSingleItemLists.size();
}
class SingleListItemHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private TextView mItemDate;
SingleListItemHolder(View v) {
super(v);
mItemDate = (TextView) v.findViewById(R.id.textview_recycler_list_item);
v.setOnClickListener(this);
this.setIsRecyclable(true); // This will help u
}
#Override
public void onClick(View v) {
//do your stuff
notifyDataSetChanged();
}
}
}
}

How to add user data to my Recyclerview through onClick?

I'm trying to build a simple To Do List app using a RecyclerView with a custom Adapter. I've build a model data class to get and set my todos. My problem is that each time I click the button to add my item, nothing happens. I did call notifyDataSetChanged() method but it still doesn't work.
This is a practice app that I'm building to learn RecyclerViews and custom adapters so I'd appreciate it if someone could explain why it doesn't work and perhaps explain to me how I can fix it.
This is my code where I'm retrieving the user input from the EditText field and placing it in my data:
public class MainActivity extends AppCompatActivity {
private ToDoData toDoData;
private List<ToDoData> toDoList = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ToDoAdapter toDoAdapter = new ToDoAdapter(toDoList, this);
toDoData = new ToDoData(this);
final EditText toDoInput = (EditText)findViewById(R.id.add_todo);
Button toDoAdd = (Button)findViewById(R.id.add_item);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this);
RecyclerView toDoDisplay = (RecyclerView) findViewById(R.id.toDoDisplayRecyclerView);
toDoDisplay.setAdapter(toDoAdapter);
toDoDisplay.setHasFixedSize(true);
toDoDisplay.setLayoutManager(layoutManager);
toDoAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
toDoData.setToDo(toDoInput.getText().toString());
toDoAdapter.notifyDataSetChanged();
}
});
}
}
This is my model class with getters and setters. The list-item has only 1 field so its rather small:
public class ToDoData {
private String toDoString;
public ToDoData(String todoString){
this.toDoString = todoString;
}
public ToDoData(Context context){}
public String getToDo() {
return toDoString;
}
public void setToDo(String toDoString) {
this.toDoString = toDoString;
}
}
And this is my custom adapter. I followed through a tutorial while building this but I do however think that my problem stems from the adapter:
public class ToDoAdapter extends RecyclerView.Adapter<ToDoAdapter.ViewHolder> {
private List<ToDoData> toDoList;
private Context context;
public ToDoAdapter(List<ToDoData> todoList, Context context) {
this.toDoList = todoList;
this.context = context;
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView todoView;
public ViewHolder(View itemView) {
super(itemView);
todoView = (TextView) itemView.findViewById(R.id.to_do_display);
}
}
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.to_do_list_item, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
ToDoData todo = toDoList.get(position);
holder.todoView.setText(todo.getToDo());
}
#Override
public int getItemCount() {
return (toDoList == null) ? 0 : toDoList.size();
}
}

Add one setter method in your adapter class for setting the collection and then invoke notifyDataSetChanged.
Declare the ToDoAdapter as class member and then invoke the setter function on Button click as follows,
adapter.setTodoList(/* pass collection */);
adapter.notifyDataSetchanged();

RecycleView displays data only first time

I have a RecycleView to which I give an Array of Post objects. When it's loaded first time, everything works fine but trying to replace the data or just entering in the Fragment again then the RecycleView does not show anything. Also I have checked the size of the new data and it's different from zero. Here is my code:
// Init the list
list = (RecyclerView) view.findViewById(R.id.list);
list.setLayoutManager(new LinearLayoutManager(mContext));
...
if (adapter != null) {
adapter.replaceCurrentPosts(new ArrayList<>(postList));
}
else {
adapter = new PostAdapter(mContext, new ArrayList<>(postList), this);
list.setAdapter(adapter);
}
...
public PostAdapter(Context context, List<Post> posts, onPostElementClickListener listener) {
this.context = context;
this.posts = posts;
this.mListener = listener;
}
public void replaceCurrentPosts(List<Post> newPosts) {
this.posts.clear();
this.posts.addAll(newPosts);
this.notifyDataSetChanged();
}
#Override
public int getItemCount() {
return posts.size();
}

package com.example.jiteshmohite.myapplication;
public class PostAdapter extends RecyclerView.Adapter {
private Context context;
private List<Post> posts;
private onPostElementClickListener mListener;
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public static class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView mTextView;
public ViewHolder(View v) {
super(v);
mTextView = (TextView) v.findViewById(R.id.info_text);
}
}
public PostAdapter(Context context, List<Post> posts, onPostElementClickListener listener) {
this.context = context;
this.posts = posts;
this.mListener = listener;
}
public void replaceCurrentPosts(List<Post> newPosts) {
posts.clear();
posts = newPosts;
this.notifyDataSetChanged();
}
#Override
public PostAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.my_text_view, parent, false);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(PostAdapter.ViewHolder holder, final int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
holder.mTextView.setText(posts.get(position).getName());
holder.mTextView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mListener.onClick(position);
}
});
}
#Override
public int getItemCount() {
return posts.size();
}
interface onPostElementClickListener {
public void onClick(int pos);
}
}
private RecyclerView list;
private PostAdapter postAdapter;
private RecyclerView.LayoutManager layoutManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_recycler_example);
list = (RecyclerView) findViewById(R.id.list);
layoutManager = new LinearLayoutManager(getApplicationContext());
list.setLayoutManager(layoutManager);
postAdapter = new PostAdapter(getApplicationContext(), getPostData(), listener);
list.setAdapter(postAdapter);
}
private PostAdapter.onPostElementClickListener listener = new PostAdapter.onPostElementClickListener() {
#Override
public void onClick(int pos) {
Toast.makeText(getApplicationContext(), pos + "" , Toast.LENGTH_SHORT).show();
List<Post> posts = getPostData();
posts.get(pos).setName("abc");
postAdapter.replaceCurrentPosts(posts);
}
};
// get post list which contains name
public List<Post> getPostData() {
Post post = new Post();
post.setName("xyz");
List<Post> posts = new ArrayList<Post>();
posts.add(post);
posts.add(post);
posts.add(post);
posts.add(post);
posts.add(post);
return posts;
}
}
I suggesting rather then notifyDataSetChanged() you should refer notifyItemChange which modify specific positions.
please let me know if it is not work for you.

why don't you try to add one element (or maybe more) instead of remove all and re-add all items?

android: Sort List after Adding items to the existing list using RecyclerView.Adapter

I have a RecyclerView which shows list of items sorted in descending order that works fine when I initially launch the screen, but when I add some more items to the existing list and setting it to the adapter with notifyDataSetChanged() method the existing list gets sorted in ascending order and the new items get added at the bottom of the view.
below is adapter
public class RecycleAdapter extends RecyclerView.Adapter<RecycleAdapter.ViewHolder> {
private List<Cinema> lists;
private int savedItems;
public RecycleAdapter(List<Cinema> cinemas, int savedItems) {
this.lists = cinemas;
this.savedItems = savedItems;
}
public class ViewHolder extends RecyclerView.ViewHolder {
public TextView cinemaTitle;
public TextView cinemaDescription;
public TextView cinemaDate;
public LinearLayout newLayout;
public ViewHolder(View view) {
super(view);
cinemaTitle = (TextView) view.findViewById(R.id.cinema_title);
cinemaDescription = (TextView) view.findViewById(R.id.description_text);
cinemaDate = (TextView) view.findViewById(R.id.cinema_date);
newLayout = (LinearLayout) view.findViewById(R.id.new_cinema_layout);
}
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.item_cinema, parent, false);
return new ViewHolder(itemView);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
Cinema cinema = cinemas.get(position);
if (cinema.getId() > savedItems) {
holder.newLayout.setVisibility(View.VISIBLE);
} else {
holder.newLayout.setVisibility(View.INVISIBLE);
}
String title = cinema.getMessage().trim();
String description = cinema.getDescription().trim();
String date = cinema.getPublishedDate().trim();
holder.cinemaTitle.setText(title);
holder.cinemaDescription.setText(description);
holder.cinemaDate.setText(date);
}
public void setCineams(List<Cinema> cinemas) {
this.cinemas = cinemas;
notifyDataSetChanged();
}
#Override
public int getItemCount() {
return cinemas.size();
}
}
and the method which updates the list from Fragment is given below:
#Override
public void onCinemaUpdated() {
cinemas = firebaseHelper.getAllCinemas();
//Method which sorts the lists in descending order after adding new items into it
sortCinemas();
if (recycleAdapterAdapter != null) {
recycleAdapterAdapter.setCineams(cinemas);
}
}
I am not sure why am I getting this behaviour. Can anyone clarify on this?

Change your constructor and setCinemas method code to : Let me know if it helps..
public RecycleAdapter(List<Cinema> cinemas, int savedItems) {
this.lists = cinemas;
this.savedItems = savedItems;
}
public void setCineams(List<Cinema> cinemas) {
this.lists = cinemas;
notifyDataSetChanged();
}