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How to get details when clicking on an item in a RecyclerView?

I am trying to get the details of the Recipe from which Recipe I have clicked in recycler view. I am using this to go to an edit/delete feature. Here is the code for my main activity.
The details that I am trying to get is getting the Name, Ingredients and method.
public class MainActivity extends AppCompatActivity implements RecipeListAdapter.OnItemClickListener {
private RecipeViewModel mRecipeViewModel;
public static final int NEW_WORD_ACTIVITY_REQUEST_CODE = 1;
public String Name;
public String Ingredients;
public String Method;
private RecipeListAdapter mAdapter;
private RecipeDao recDao;
private LiveData<List<Recipe>> RecipeList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
RecyclerView recyclerView = findViewById(R.id.recyclerview);
final RecipeListAdapter adapter = new RecipeListAdapter(this);
recyclerView.setAdapter(adapter);
adapter.setOnItemClickListener(MainActivity.this);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
mRecipeViewModel = new ViewModelProvider(this).get(RecipeViewModel.class);
mRecipeViewModel.getAllRecipes().observe(this, new Observer<List<Recipe>>() {
#Override
public void onChanged(#Nullable final List<Recipe> recipes) {
// Update the cached copy of the words in the adapter.
adapter.setWords(recipes);
}
});
void onItemClick(int position) {
//Delete Below test to pass data through
Recipe recipe = new Recipe("Test", "Yeet", "Jim");
// showAlertDialogBox();
AlertDialog.Builder alertDialog = new AlertDialog.Builder(this);
alertDialog.setTitle("Edit or Delete...");
alertDialog.setPositiveButton("Edit", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
Intent update = new Intent(MainActivity.this, UpdateRecipeActivity.class);
update.putExtra("Name", recipe.getName());
update.putExtra("Ingredients", recipe.getIngredients());
update.putExtra("Method", recipe.getMethod());
startActivity(update);
}
});
alertDialog.setNegativeButton("Delete", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
//Delete
}
});
alertDialog.show();
}
Here is the Recipe.class if you needed it!
#Entity(tableName = "recipe_table")
public class Recipe {
#PrimaryKey(autoGenerate = true)
#ColumnInfo(name= "recipeId")
private int RecipeId;
private String name;
private String Ingredients;
private String Method;
#Ignore
public Recipe(String name, String Ingredients, String Method) {
this.RecipeId = RecipeId;
this.name = name;
this.Ingredients = Ingredients;
this.Method = Method;
}
public Recipe(String name) {
this.name = name;
}
public void changeText1(String text){
name = text;
}
//Add Image somehow!
public int getRecipeId() {
return RecipeId;
}
public void setRecipeId(int recipeId) {
RecipeId = recipeId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getMethod() {
return Method;
}
public void setMethod(String method) {
Method = method;
}
public String getIngredients() {
return Ingredients;
}
public void setIngredients(String ingredients) {
Ingredients = ingredients;
}
}
If you need anymore files, these are the files I have:
- RecipeListAdapter
- RecipeDao
- RecipeRepository
- RecipeRoomDatabase
- RecipeViewModel
Recipe Adapter code
public class RecipeListAdapter extends RecyclerView.Adapter {
private OnItemClickListener mListener;
private List recipeList;
public interface OnItemClickListener{
void onItemClick(int position, Recipe recipe);
}
public void setOnItemClickListener(OnItemClickListener listener){
mListener = listener;
}
class RecipeViewHolder extends RecyclerView.ViewHolder {
private final TextView recipeItemView;
private RecipeViewHolder(View itemView) {
super(itemView);
recipeItemView = itemView.findViewById(R.id.textView);
itemView.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v){
if (mListener != null){
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION){
mListener.onItemClick(position,
recipeList.get(getAdapterPosition()));
}
}
}
});
}
}
private final LayoutInflater mInflater;
private List<Recipe> mRecipes; // Cached copy of words
RecipeListAdapter(Context context) {
mInflater = LayoutInflater.from(context);
this.recipeList = recipeList;
}
#Override
public RecipeViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = mInflater.inflate(R.layout.recyclerview_item, parent,
false);
return new RecipeViewHolder(itemView);
}
#Override
public void onBindViewHolder(RecipeViewHolder holder, int position) {
if (mRecipes != null) {
Recipe current = mRecipes.get(position);
holder.recipeItemView.setText(current.getName());
} else {
// Covers the case of data not being ready yet.
holder.recipeItemView.setText("No Recipes");
}
}
void setWords(List<Recipe> recipes){
mRecipes = recipes;
notifyDataSetChanged();
}
// getItemCount() is called many times, and when it is first called,
// mWords has not been updated (means initially, it's null, and we can't
return null).
#Override
public int getItemCount() {
if (mRecipes != null)
return mRecipes.size();
else return 0;
}
public interface OnNoteListener{}
}

Inside the onItemClick there is one more parameter need to add.
void onItemClick(int position, Recipe recipe) {
//Delete selected recipe from recipe list
arrayList.remove(recipe)
}
The onItemClick method will get called from adapter, from there you have to pass the selected receipe. In the adapter you have to use recipeList.get(getAdapterPosition()) to get the clicked receipe and pass this to the interface method, onItemClick along with the position.
So your code will look like this way inside the adapter,
itemClickListener.onItemClick(position,
recipeList.get(getAdapterPosition()))
Just as a note, please ensure instead of List, you need to take ArrayList to perform remove operation.

What's wrong with my DiffUtil implementation?

Update: One of the problems is solved: Now updateList is resolved, the problem was that I defined mAdapter as RecyclerView.Adapter instead of MyAdapter. But now even though I am getting data, nothing shows up on the list, it's empty
--------------------ORIGINAL POST--------------------
I want to update my RecyclerView using DiffUtil to prevent duplicates.
I have 4 classes: The User class, the Activity class where I set data, the Adapter class and the DiffUtil class. I am not sure I combine all these 4 correctly.
This is the User class:
public class User {
private String mUserId;
private Uri mImageUrl;
public User(String userId, String imageUrl) {
mUserId = userId;
mImageUrl = Uri.parse(imageUrl);
}
public String getUserId() {
return mUserId;
}
public Uri getImageUrl() {
return mImageUrl;
}
}
This is how I set data dynamically (I keep getting new Json arrays from the server containing user id's to be displayed, then I set the user image from Firebase storage): (It's a function invoked by an onClick listener:)
This is the method call from the fragment:
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
updateUsersList();
}
});
This is the function:
private void updateUsersList() {
#Override
public void onResponse(JSONArray response) { // the JSON ARRAY response of user ids ["uid1", "uid334", "uid1123"]
myDataset.clear(); // clear dataset to prevent duplicates
for (int i = 0; i < response.length(); i++) {
try {
String userKey = response.get(i).toString(); // the currently iterated user id
final DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference userKeyRef = rootRef.child("users").child(userKey); // reference to currently iterated user
ValueEventListener listener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
myDataset.add(new User(dataSnapshot.getKey(), dataSnapshot.child("imageUrl").getValue().toString())); //add new user: id and image url
mAdapter.updateList(myDataset); // cannot resolve this method, why?
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Log.d(TAG, databaseError.getMessage());
}
};
userKeyRef.addListenerForSingleValueEvent(listener);
}
catch (JSONException e) { Log.d(TAG, "message " + e); }
}
}
This is how my DiffUtil class looks like:
public class MyDiffUtilCallBack extends DiffUtil.Callback{
ArrayList<User> oldUsers;
ArrayList<User> newUsers;
public MyDiffUtilCallBack(ArrayList<User> newUsers, ArrayList<User> oldUsers) {
this.newUsers = newUsers;
this.oldUsers = oldUsers;
}
#Override
public int getOldListSize() {
return oldUsers.size();
}
#Override
public int getNewListSize() {
return newUsers.size();
}
#Override
public boolean areItemsTheSame(int oldItemPosition, int newItemPosition) {
return oldUsers.get(oldItemPosition).getUserId().equals( newUsers.get(newItemPosition).getUserId());
}
#Override
public boolean areContentsTheSame(int oldItemPosition, int newItemPosition) {
return oldUsers.get(oldItemPosition).equals(newUsers.get(newItemPosition));
}
#Nullable
#Override
public Object getChangePayload(int oldItemPosition, int newItemPosition) {
//you can return particular field for changed item.
return super.getChangePayload(oldItemPosition, newItemPosition);
}
}
And this is my adapter:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private ArrayList<User> mDataset;
private MyViewHolder myHolder;
private User user;
public static class MyViewHolder extends RecyclerView.ViewHolder {
public TextView singleItemTextView;
public ImageView singleItemImage;
public View layout;
public ConstraintLayout constraintLayout;
public MyViewHolder(View v) {
super(v);
layout = v;
singleItemImage = (ImageView) v.findViewById(R.id.icon);
singleItemTextView = (TextView) v.findViewById(R.id.singleitemtv);
constraintLayout = (ConstraintLayout) v.findViewById(R.id.nbConstraintLayout);
}
}
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(ArrayList<User> myDataset) {
mDataset = myDataset;
}
// Create new views (invoked by the layout manager)
#Override
public MyAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.nb_image_view, parent, false);
MyViewHolder vh = new MyViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
myHolder = holder;
user = mDataset.get(position);
Uri userImage = user.getImageUrl();
myHolder.singleItemTextView.setText(user.getUserId());
Glide.with(myHolder.itemView.getContext() /* context */)
.load(userImage)
.into(myHolder.singleItemImage);
myHolder.constraintLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Context context = v.getContext();
Intent intent = new Intent(v.getContext(), DisplayUserActivity.class);
context.startActivity(intent);
}
});
}
public void updateList(ArrayList<User> newList) {
DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(new MyDiffUtilCallBack(this.mDataset, newList));
diffResult.dispatchUpdatesTo(this);
}
}
I am not sure I combine all the classes correctly (my first time using DiffUtil), and I also get cannot resolve method updateList(?)
What am I doing wrong?
This is how I define mAdapter in my Fragment:
public class MyFragment extends Fragment {
private ArrayList<User> myDataset;
private RecyclerView.Adapter mAdapter;
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
rootView = inflater.inflate(R.layout.fragment_lks, container, false);
mRecyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
myDataset = new ArrayList<User>();
mAdapter = new MyAdapter(myDataset);

The problem comes from definition of mAdapter. You defined it as RecyclerView.Adapter which is super class of your MyAdapter and it does not contain updateList(). You should change it as following:
private MyAdapter mAdapter;
Updated 1/13/2019:
I've revised your adapter with AsyncListDiffer which calculates the diffrence asynchronously then applies it to the adapter.
MyAdapter.java
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.support.annotation.NonNull;
import android.support.constraint.ConstraintLayout;
import android.support.v7.recyclerview.extensions.AsyncListDiffer;
import android.support.v7.util.DiffUtil;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.bumptech.glide.Glide;
import java.util.List;
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private AsyncListDiffer<User> mAsyncListDiffer;
public static class MyViewHolder extends RecyclerView.ViewHolder {
public TextView singleItemTextView;
public ImageView singleItemImage;
public View layout;
public ConstraintLayout constraintLayout;
public MyViewHolder(View v) {
super(v);
layout = v;
singleItemImage = (ImageView) v.findViewById(R.id.icon);
singleItemTextView = (TextView) v.findViewById(R.id.singleitemtv);
constraintLayout = (ConstraintLayout) v.findViewById(R.id.nbConstraintLayout);
}
}
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter() {
DiffUtil.ItemCallback<User> diffUtilCallback = new DiffUtil.ItemCallback<User>() {
#Override
public boolean areItemsTheSame(#NonNull User newUser, #NonNull User oldUser) {
return newUser.getUserId().equals(oldUser.getUserId());
}
#Override
public boolean areContentsTheSame(#NonNull User newUser, #NonNull User oldUser) {
return newUser.equals(oldUser);
}
};
mAsyncListDiffer = new AsyncListDiffer<>(this, diffUtilCallback);
}
// Create new views (invoked by the layout manager)
#Override
public MyAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.nb_image_view, parent, false);
MyViewHolder vh = new MyViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
User user = mAsyncListDiffer.getCurrentList().get(position);
Uri userImage = user.getImageUrl();
holder.singleItemTextView.setText(user.getUserId());
Glide.with(holder.itemView.getContext() /* context */)
.load(userImage)
.into(holder.singleItemImage);
holder.constraintLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Context context = v.getContext();
Intent intent = new Intent(v.getContext(), DisplayUserActivity.class);
context.startActivity(intent);
}
});
}
#Override
public int getItemCount() {
return mAsyncListDiffer.getCurrentList().size();
}
public void updateList(List<User> newList) {
mAsyncListDiffer.submitList(newList);
}
}
User.java
public class User {
private String mUserId;
private Uri mImageUrl;
public User(String userId, String imageUrl) {
mUserId = userId;
mImageUrl = Uri.parse(imageUrl);
}
public String getUserId() {
return mUserId;
}
public Uri getImageUrl() {
return mImageUrl;
}
#Override
public boolean equals(Object other) {
if (other instanceof User) {
User user = (User) other;
return mUserId.equals(user.getUserId()) && mImageUrl.equals(user.getImageUrl());
} else {
return false;
}
}
}

In addition to #aminography's answer, I suggest you to use ListAdapter, a RecyclerView.Adapter implementation that makes it easier to update you RecyclerView with the correct animations. This class is included in the recyclerview support library.
Below is an example of usage based on your use case:
public class MyAdapter extends ListAdapter<User, UserViewHolder> {
public MyAdapter() {
super(new UserDiffCallback());
}
public UserViewHolder onCreateViewHolder(int position, int viewType) { ... }
public void onBindViewHolder(UserViewModel holder, int position) {
User userAtPosition = getItem(position); // getItem is a protected method from ListAdapter
// Bind user data to your holder...
}
}
public class UserDiffCallback extends DiffUtil.ItemCallback<User> {
#Override
public boolean areItemsTheSame(#NonNull User oldUser, #NonNull User newUser) {
return oldUser.getUserId().equals(newUser.getUserId());
}
#Override
public boolean areContentsTheSame(#NonNull User oldUser, #NonNull User newUser) {
// No need to check the equality for all User fields ; just check the equality for fields that change the display of your item.
// In your case, both impact the display.
return oldUser.getUserId().equals(newUser.getUserId())
&& (oldUser.getImageUrl() == null) ? newUser.getImageUrl() == null : oldUser.getImageUrl().equals(newUser.getImageUrl());
}
}
Then, when you need to update the list with new users, call myAdapter.submitList(newList). Juste like with AsyncListDiffer, the diff between the two list is calculated on a background Thread.

Modify your method:
public void updateList(ArrayList<User> newList) {
DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(new MyDiffUtilCallBack(this.mDataset, newList));
this.mDataSet.clear()
this.mDataSet.addAll(newList)
diffResult.dispatchUpdatesTo(this);
}

Looks like
public void onBindViewHolder(#NonNull ViewHolder holder, int position, #NonNull List<Object> payloads) not implemented
Implement this to use DiffUtils properly, as this method will be called for the changes, and based on the payload you can update your recyclerview items instead of calling notifyDataSetChanged()

Getting data from Button inside RecyclerView

So I have a RecyclerView that displays a list of open games in a lobby. Each time the RecyclerView is updated, a button is added to the screen and I want to make it so that whenever a user clicks that button, it gets the ID of the section it is in.
So, games are added to database like this.
public void createLobbyGame () {
User current = new User(userName, 0, getSide());
String id = FCGames.push().getKey();
gameMaker = new GameMaker(current, null, 0, numGames, false, false);
FCGames.child(id)
.setValue(gameMaker).addOnCompleteListener(new OnCompleteListener<Void>() {
#Override
public void onComplete(#NonNull Task<Void> task) {
if (task.isSuccessful()) {
Toast.makeText(FlipCoinLobby.this, "Game creation successful.", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(FlipCoinLobby.this, task.getException().getMessage(), Toast.LENGTH_SHORT).show();
}
}
});
}
And that creates a node in my database that looks like this:
So right now the ID is set at 0 but that's just because I forgot to make the ID equal to the name of the node.
So when something is added to my database, it is drawn in the app with a button. I am not sure how to make this button display the ID of the database node that it correlates to.
This is the clicklistener I have setup for the button in my ViewHolder class
Button joinButton = itemView.findViewById(R.id.joinRV);
joinButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(v.getContext(), gm.getId(), Toast.LENGTH_SHORT).show();
}
});
Just having the getId() method called does not work at all, and I wasn't expecting it to. But I am kind of lost on how to grab the correlating ID of the button whenever I click it
Adapter Class:
package com.example.brent.fifty_fifty;
import android.content.Intent;
import android.util.Log;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.content.Context;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;
import static android.view.LayoutInflater.*;
public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.ViewHolder> {
GameMaker gm;
private OnItemClickListener listener;
private List<String> mData;
private LayoutInflater mInflater;
private ItemClickListener mClickListener;
// data is passed into the constructor
MyRecyclerViewAdapter(Context context, List<String> data) {
this.mInflater = from(context);
this.mData = data;
}
public MyRecyclerViewAdapter(List<String> data, OnItemClickListener listener) {
this.mData = data;
this.listener = listener;
}
public interface OnItemClickListener {
void onItemClick(String id);
}
// inflates the row layout from xml when needed
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = mInflater.inflate(R.layout.recyclerview_row, parent, false);
return new ViewHolder(view);
}
// binds the data to the TextView in each row
#Override
public void onBindViewHolder(ViewHolder holder, final int position) {
String userName = mData.get(position);
//Double wager = Double.parseDouble(mData.get(position));
holder.userName.setText(userName);
//holder.wager.setText(wager.toString());
}
// total number of rows
#Override
public int getItemCount() {
return mData.size();
}
// stores and recycles views as they are scrolled off screen
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
TextView userName, wager;
RelativeLayout parentLayout;
ViewHolder(View itemView) {
super(itemView);
userName = itemView.findViewById(R.id.UsernameRV);
//wager = itemView.findViewById(R.id.wagerRV);
itemView.setOnClickListener(this);
Button joinButton = itemView.findViewById(R.id.joinRV);
joinButton.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v) {
listener.onItemClick(data);
Toast.makeText(itemView.getContext(), "It worked", Toast.LENGTH_SHORT).show();
}
});
}
public void bind(final String data, final OnItemClickListener listener) {
}
public void onBindViewHolder(ViewHolder holder, int position) {
holder.bind(mData.get(position), listener);
}
#Override
public void onClick(View view) {
if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
}
}
// convenience method for getting data at click position
String getItem(int id) {
return mData.get(id);
}
// allows clicks events to be caught
void setClickListener(ItemClickListener itemClickListener) {
this.mClickListener = itemClickListener;
}
// parent activity will implement this method to respond to click events
public interface ItemClickListener {
void onItemClick(View view, int position);
}
}

Please have a look at implementation of interface as Listener for recyclerview.
Please look this implementation. This is good one if you are using JAVA.
Here clicklistener is set on itemView you just need to replace itemView with your button.
public class MyRecyclerViewAdapter extends RecyclerView.Adapter< MyRecyclerViewAdapter.ViewHolder> {
public interface OnButtonClickListener {
void onButtonClick(String id);
}
private final List<String> items;
private final OnButtonClickListener listener;
public MyRecyclerViewAdapter(List<String> items, OnButtonClickListener listener) {
this.items = items;
this.listener = listener;
}
#Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout. recyclerview_row, parent, false);
return new ViewHolder(v);
}
#Override public void onBindViewHolder(ViewHolder holder, int position) {
holder.bind(items.get(position), listener);
}
#Override public int getItemCount() {
return items.size();
}
static class ViewHolder extends RecyclerView.ViewHolder {
private Button joinButton;
public ViewHolder(View itemView) {
super(itemView);
joinButton = (Button) itemView.findViewById(R.id. joinRV);
}
public void bind(final String id, final OnButtonClickListener listener) {
joinButton.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v) {
listener.onItemClick(id);
}
});
}
}}
For your activity :
recycler.setAdapter(new MyRecyclerViewAdapter(items, new MyRecyclerViewAdapter.OnButtonClickListener() {
#Override public void onButtonClick(String id) {
Toast.makeText(this, id, Toast.LENGTH_LONG).show();
}}));

How to update textview of fragment "continuously" from viewpageradpater?viewpager adapter is in main fragment

My viewpager adapter is in another fragment(i.e. in main fragment) i.e. i used viewpager in another fragment.so viewpager adapter having 2 fragments.
I am getting heart rate value continuously from main fragment and need to send it to viewpager adapter.then viewpager adapter send this value to fragment and upadate the textview here.
//Main Fragment were i initialize fragmentpageradapter with updated heart rate value:-((readingdata)samplePagerAdapter).passdata(value);
used interface to update value:-
public interface readingdata
{
void passdata(int value);
}
//Adapter code:-
public class SamplePagerAdapter extends FragmentStatePagerAdapter implements readingdata {
private final Random random = new Random();
private int mSize = 2;
private int heart_rate;
FragmentManager fm;
private Map<Integer, String> mFragmentTags;
public SamplePagerAdapter(FragmentActivity activity, FragmentManager supportFragmentManager, int heart) {
super(supportFragmentManager);
fm = supportFragmentManager;
mFragmentTags = new HashMap<Integer, String>();
}
#Override
public int getCount() {
return mSize;
}
#Override
public Fragment getItem(int position) {
Fragment f = null;
if (position == 0) {
f = new MyFragment().newInstance(heart_rate);
} else if (position == 1) {
f = new SecondFragment();
}
return f;
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
Object object = super.instantiateItem(container, position);
if (object instanceof Fragment) {
Fragment fragment = (Fragment) object;
String tag = fragment.getTag();
mFragmentTags.put(position, tag);
}
return object;
}
public Fragment getFragment(int position) {
Fragment fragment = null;
String tag = mFragmentTags.get(position);
if (tag != null) {
fragment = fm.findFragmentByTag(tag);
}
return fragment;
}
#Override
public void passdata(int value) {
heart_rate=value;
}
}
//Fragment code were textview updated on regular interval
public class MyFragment extends Fragment{
private int heart_rate;
private ArcProgress arc_progress;
private TextView tv_heartrate;
private Handler handler;
private Runnable runnable;
private View view;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle saveBundle) {
view = inflater.inflate(R.layout.ecg_layout, container, false);
handler=new Handler();
arc_progress = (ArcProgress) view.findViewById(R.id.arc_progress);
tv_heartrate = (TextView) view.findViewById(R.id.tv_heart_rate);
handler=new Handler();
handler.post(runnable = new Runnable() {
#Override
public void run() {
MyFragment myFragment=new MyFragment();
arc_progress.setProgress(heart_rate);
tv_heartrate.setText(String.valueOf(heart_rate));
handler.postDelayed(this, 1000);
}
});
return view;
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
public static Fragment newInstance(int heartvalue) {
MyFragment f = new MyFragment();
f.heart_rate = heartvalue;
return f;
}
}
So how should i update textview continuously inside the fragment?

In MainFragment
private static HeartRateListener heartRateListener;
public static void setHeartRateListener(HeartRateListener listener){
heartRateListener = listener;
}
public static interface HeartRateListener{
void onHeartRate(int yourValue);
}
// Send your continuously updated value
heartRateListener.onHeartRate(yourValue);
In ViewPager Fragment (inside onViewCreated())
MainFragment.setHeartRateListener(new MainFragment.HeartRateListener() {
#Override
public void onHeartRate(int yourValue) {
// Update your textview with yourValue
}
});

create Method
public void updateScreenData(String text)
{
tv_heartrate.setText(text);
}
in fragment and then call this method from activity
make sure that fragment reference is not null whenever call this method

Take Help from this and save reference to view you are inflating
package com.mtg.workapp_v2.listing.wanted.add_wanted;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.TextView;
import com.mtg.classes.AddressView;
import com.mtg.classes.ListingVisibilityLayout;
import com.mtg.utils.CommonMethods;
import com.mtg.workapp.R;
public class WantedBasicInfoFragment extends Fragment implements View.OnClickListener{
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
View FragmentView ;
Context myContext;
TextView text_continue;
EditText edit_title;
EditText edit_description;
private OnFragmentInteractionListener mListener;
//this is add by ahsan according to new design
ListingVisibilityLayout listingVisibilityLayout = null;
public WantedBasicInfoFragment() {
}
public static WantedBasicInfoFragment newInstance(String param1, String param2) {
WantedBasicInfoFragment fragment = new WantedBasicInfoFragment();
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);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
FragmentView= inflater.inflate(R.layout.fragment_wanted_basic, container, false);
init();
return FragmentView;
}
/********************************************************************************/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
/********************************************************************************/
public void setListener(OnFragmentInteractionListener listener) {
this.mListener = listener;
}
/********************************************************************************/
public void setInitValues()
{
}
/***********************************************************************************/
public void updateScreenData()
{
edit_title.setText(wantedInformation.csName);
edit_description.setText(wantedInformation.csDescription);
}
/***********************************************************************************/
public void init()
{
myContext=getActivity();
text_continue=(TextView) FragmentView.findViewById(R.id.text_continue);
edit_title = (EditText) FragmentView.findViewById(R.id.edit_title);
edit_description = (EditText) FragmentView.findViewById(R.id.edit_description);
text_continue.setOnClickListener(this);
edit_title.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
wantedInformation.csListingLanguage = CommonMethods.getInputLanguage(myContext);
}
#Override
public void afterTextChanged(Editable s) {
wantedInformation.csListingLanguage = CommonMethods.getInputLanguage(myContext);
}
});
initVisibilitySpinner();
}
/***********************************************************************************/
public void initVisibilitySpinner()
{
listingVisibilityLayout = new ListingVisibilityLayout(myContext);
View visibilityView = (View)FragmentView.findViewById(R.id.id_visibility_layout);
listingVisibilityLayout.ListingVisibilityInit(visibilityView);
}
/***********************************************************************************/
#Override
public void onClick(View view) {
int itemID = view.getId();
switch (itemID) {
case R.id.text_continue:
{
moveToNextScreen(true);
}
}
}
/***********************************************************************************/
public void moveToNextScreen(boolean isContinueClicked)
{
String csName = edit_title.getText().toString().trim();
String csDescription = edit_description.getText().toString().trim();
if(csName.length() <= 0 && csDescription.toString().length() <= 0)
{
CommonMethods.showMessageBox("", getResources().getString(R.string.id_please_enter_name_and_description), myContext);
return;
}
else if(csName.length() <= 0)
{
CommonMethods.showMessageBox("", getResources().getString(R.string.id_please_enter_name), myContext);
return;
}
else if(csDescription.length() <= 0)
{
CommonMethods.showMessageBox("", getResources().getString(R.string.id_please_enter_description), myContext);
return;
}
else if(listingVisibilityLayout.selectedProfileVisibility.csOptionID.equalsIgnoreCase("-1"))
{
CommonMethods.showMessageBox("", getResources().getString(R.string.id_select_visibility_option_msg), myContext);
return;
}
wantedInformation.csName = csName;
wantedInformation.csDescription = csDescription;
wantedInformation.visibilityOption = listingVisibilityLayout.selectedProfileVisibility;
//MH: If continue clicked then continue Button listener will be called
//MH: If only tick is clicked in Edit Mode then onUpdate listener will be called
//MH: and data will be updated before sent to api
//MH: The below statements are repeated in all fragments of Wanted
if(isContinueClicked)
mListener.continueButtonPressed(wantedInformation);
else
mListener.onUpdate(wantedInformation);
}
}

Passing List Info to New Activity

I'm building on a tutorial I did in which I created a RecyclerView screen with cards with selectable options. I want one of the selectable options to bring the user to a new activity that has more information & options about the card they selected. My problem is when I try to transfer traits of that specific card to the next SlideViewActivity.java activity I am unable to successfully do so. I tried transforming my list into an array then sending that, but I keep obtaining a null value (which could be due to my syntax for all I know).
Any clarification & guidance would be appreciated, let me know if you would want any of the other code as well.
public class Adapter extends RecyclerView.Adapter<Adapter.MyViewHolder> {
private Context mContext;
private List<Properties> dogList;
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView title, count;
public ImageView thumbnail, overflow;
public MyViewHolder(View view) {
super(view);
title = (TextView) view.findViewById(R.id.title);
count = (TextView) view.findViewById(R.id.count);
thumbnail = (ImageView) view.findViewById(R.id.thumbnail);
overflow = (ImageView) view.findViewById(R.id.overflow);
}
}
public Adapter(Context mContext, List<Properties> dogList) {
this.mContext = mContext;
this.dogList = dogList;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.card, parent, false);
return new MyViewHolder(itemView);
}
#Override
public void onBindViewHolder(final MyViewHolder holder, int position) {
Properties dog = dogList.get(position);
holder.title.setText(dog.getName());
// loading dog cover using Glide library
Glide.with(mContext).load(dog.getThumbnail()).into(holder.thumbnail);
holder.overflow.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
showPopupMenu(holder.overflow);
}
});
}
/**
* Showing popup menu when tapping on icon
*/
private void showPopupMenu(View view) {
// inflate menu
PopupMenu popup = new PopupMenu(mContext, view);
MenuInflater inflater = popup.getMenuInflater();
inflater.inflate(R.menu.menu, popup.getMenu());
popup.setOnMenuItemClickListener(new MyMenuItemClickListener());
popup.show();
}
/**
* Click listener for popup menu items
*/
class MyMenuItemClickListener implements PopupMenu.OnMenuItemClickListener {
public MyMenuItemClickListener() {
}
#Override
public boolean onMenuItemClick(MenuItem menuItem) {
switch (menuItem.getItemId()) {
case R.id.action_add_favourite:
Toast.makeText(mContext, "Add to favourite", Toast.LENGTH_SHORT).show();
return true;
case R.id.action_more_info:
Intent slideStart = new Intent(mContext, SlideViewActivity.class);
String[] dogArray = new String[dogList.size()];
slideStart.putExtra("List", dogArray);
Log.e("putting extra", String.valueOf(dogArray[0]));
//TODO:MAKE NAME TRANSFERS WORK
mContext.startActivity(slideStart);
return true;
default:
}
return false;
}
}
Adding Properties.java:
public class Properties {
private String name;
private String info;
private int thumbnail;
public Properties() {
}
public Properties(String name, String info, int thumbnail) {
this.name = name;
this.info = info;
this.thumbnail = thumbnail;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getInfo() {
return info;
}
public void getInfo(String info) {
this.info = info;
}
public int getThumbnail() {
return thumbnail;
}
public void setThumbnail(int thumbnail) {
this.thumbnail = thumbnail;
}
}

You can pass ArrayList<T>, if T is Serializable.
for example:
ArrayList<String> list = new ArrayList<String>();
intent.putExtra("list", list);
use getSerializableExtra to extract data

Your array is dogList.size()-d null values.
String[] dogArray = new String[dogList.size()];
slideStart.putExtra("List", dogArray);
You should see null logged here.
Log.e("putting extra", String.valueOf(dogArray[0]));
It's not clear what type of class you have for Properties, but if it is your class, and not java.util.Properties, you should implement Parcelable on that class, then you'd have
intent.putParcelableArrayList("List", dogList)
(Tip: You should rename that class to Dog to avoid confusion for yourself and others)
But if you are just worried about getting null, case matters. You put a key="List", so make sure you aren't getting key="list" or anything else but "List"

Two ways possible for that::
First
While Sending the list using intent::
Intent slideStart = new Intent(mContext, SlideViewActivity.class);
slideStart.putExtra("List", dogList);
mContext.startActivity(slideStart);
In This just pass the list as is it is ::
But your class Properties should be implements "Serializable"
Now while receiving that intent ::
ArrayList<Properties> dogList =(ArrayList<Properties>) getIntent().getExtras().getSerializable("List");
Second way :: using Library
One library is there for converting string to arraylist & vice versa ,
compile 'com.google.code.gson:gson:2.4'
So, for this while sending list convert that list to string like ::
Type listType = new TypeToken<List<Properties>>() {
}.getType();
String listString=new Gson().toJson(dogList,listType );
pass this simple as string with intent:::
Intent slideStart = new Intent(mContext, SlideViewActivity.class);
slideStart.putExtra("List", listString);
mContext.startActivity(slideStart);
And while getting it back in other activity::
String listString =getIntent().getExtras().getString("List");
Type listType = new TypeToken<List<Properties>>() {}.getType();
List<Properties> list=new Gson().fromJson(listString, listType);
Tell me if need more help..

I have done a similar project I will share my code. Please take a look and if have doubts ping me
DataAdapter.java
package com.example.vishnum.indiavideo;
import android.content.Context;
import android.content.Intent;
import android.provider.MediaStore;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.bumptech.glide.Glide;
import java.util.ArrayList;
import java.util.List;
public class DataAdapter extends RecyclerView.Adapter<DataAdapter.ViewHolder> {
private Context context;
List<Video_Details> video;
public DataAdapter(List<Video_Details> video, Context context) {
super();
this.context = context;
this.video = video;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.card_row, parent, false);
ViewHolder viewHolder = new ViewHolder(v);
return viewHolder;
}
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
final Video_Details videoDetails = video.get(position);
String url;
final String VideoID;
holder.title.setText(video.get(position).getTitle());
VideoID= video.get(position).getV_id();
url = video.get(position).getThumb();
Glide.with(context)
.load(url)
.override(150,70)
.into(holder.thumb);
//viewHolder.thumb.setText(android.get(i).getVer());
// viewHolder.tv_api_level.setText(android.get(i).getApi());
holder.vm.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(v.getContext(), "You Clicked"+video.get(position).getV_id(), Toast.LENGTH_SHORT).show();
Intent intent = new Intent(v.getContext(),Play_Video.class);
intent.putExtra("VideoId",(video.get(position).getV_id()));
intent.putExtra("Title",(video.get(position).getTitle()));
v.getContext().startActivity(intent);
}
}
);
}
#Override
public int getItemCount() {
return video.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
public TextView title;
public ImageView thumb;
public String videoid;
public View vm;
public ViewHolder(View view) {
super(view);
vm = view;
title = (TextView)view.findViewById(R.id.title);
thumb = (ImageView) view.findViewById(R.id.thumb);
//tv_version = (TextView)view.findViewById(R.id.tv_version);
//tv_api_level = (TextView)view.findViewById(R.id.tv_api_level);
}
}
}
Video_Details.java
package com.example.vishnum.indiavideo;
public class Video_Details {
private String id;
private String v_id;
private String title;
private String thumb;
public String getId() {
return id;
}
public String getV_id() {
return v_id;
}
public String getTitle() {
return title;
}
public String getThumb() {
return (Constants.urlvideo+v_id+"/0.jpg");
}
public void setId(String id) {
this.id = id;
}
public void setV_id(String v_id) {
this.v_id = v_id;
}
public void setTitle(String title) {
this.title = title;
}
public void setThumb(String v_id) {
this.thumb =Constants.urlvideo+v_id+"/0.jpg";
}
}