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recyclerview data changed on scrolling (Not Duplicate) and dynamic textview got doubled on scrolling

My recyclerview data changed while I scrolling down/up.
when I scroll the layout it appears every time with new values
I've added both methods and as well and false recyclable too. But, didn't work out.
Here's is how my adapter looks like.
public class DetailListAdapter extends RecyclerView.Adapter<DetailListAdapter.ViewHolder> {
Context context;
ArrayList<KcResponse> kcList;
String birthDate; }
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_client_detail, parent, false);
DetailListAdapter.ViewHolder vh = new DetailListAdapter.ViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(#NonNull DetailListAdapter.ViewHolder holder, int position) {
holder.setIsRecyclable(false);
holder.periodTv.setText(kcList.get(position).getPeriod());
TextView textView1 = new TextView(context);
textView1.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
for (int i = 0; i < arr.length; i++) {
String line = arr[i];
SpannableString ss = new SpannableString(line);
ss.setSpan(new BulletSpan(bulletGap), 0, line.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
ssb.append(ss);
//avoid last "\n"
if (i + 1 < arr.length)
ssb.append("\n");
}
textView1.setTextSize(12);
textView1.setTextColor(ContextCompat.getColor(context, R.color.black_text));
textView1.setPadding(15, 0, 0, 0);
textView1.setText(ssb); // bullet text
holder.effectsLl.addView(textView1);
holder.periodTv.setBackgroundColor(Color.parseColor(kcList.get(position).getColor()));}
#Override
public int getItemCount() {
return kcList.size();
}

You do not have more than one type of views in your recylcerview so one thing for sure that you do not need to override getItemViewType(int position).
Also the usage of method getItemId(int position) is incorrect. That method is used to get the stable ID for the item at position.

Add this overriding method to your custom adapter
#Override
public long getItemId(int position) {
return position;
}
#Override
public int getItemViewType(int position) {
return position;
}

The adapter code you shared is not enough to identify the issue. So I am sharing a very simple recyclerview and its adapter code, just try to use that. I hope it will help you.
Happy coding...
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private DataAdapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.recyclerView);
adapter = new DataAdapter();
recyclerView.setAdapter(adapter);
recyclerView.addItemDecoration(new DividerItemDecoration(this));
}
}
Adapter class code
public class DataAdapter extends RecyclerView.Adapter<DataAdapter.ViewHolder> {
public DataAdapter() {
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
View listItem = layoutInflater.inflate(R.layout.adapter_layout, parent, false);
ViewHolder viewHolder = new ViewHolder(listItem);
return viewHolder;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.textView.setText("TextView1");
holder.textView.setText("TextView2");
}
#Override
public int getItemCount() {
return 20;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView imageView;
public TextView textView;
public ViewHolder(View itemView) {
super(itemView);
this.imageView = itemView.findViewById(R.id.textView1);
this.textView = (TextView) itemView.findViewById(R.id.textView2);
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#f1f1f1"
tools:context=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
adapter_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="4dp"
tools:context=".MainActivity">
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView"
android:textAppearance="#style/TextAppearance.AppCompat.Large"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:text="TextView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/textView1" />
</androidx.constraintlayout.widget.ConstraintLayout>

RecyclerView Databinding Item click

I am trying to listen for row clicks (item clicks) on my recycler view from the Activity itself (not from adapter).
My Adapter so far looks like this:
public class ListMiestnostiAdapter extends RecyclerView.Adapter<ListMiestnostiAdapter.ViewHolder>{
private List<Miestnost> data;
// you provide access to all the views for a data item in a view holder
public static class ViewHolder extends RecyclerView.ViewHolder {
public ViewDataBinding binding;
public ViewHolder(ViewDataBinding binding) {
super(binding.getRoot());
this.binding = binding;
}
public void bind(Object obj){
binding.setVariable(BR.obj, obj);
binding.executePendingBindings();
}
}
public ListMiestnostiAdapter(List<Miestnost> data) {
this.data = data;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
ActivityListMiestnostiRowBinding itemBinding = ActivityListMiestnostiRowBinding.inflate(inflater, parent,false);
return new ViewHolder(itemBinding);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
Miestnost item = data.get(position);
holder.bind(item);
}
#Override
public int getItemCount() {
return data.size();
}
}
And my row layout like this:
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:bind="http://schemas.android.com/apk/res-auto">
<data>
<variable
name="obj"
type="com.example.com.projectname.Models.Miestnost" />
</data>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?android:attr/selectableItemBackground"
android:clickable="true"
android:focusable="true"
android:orientation="horizontal"
android:paddingBottom="#dimen/row_padding_vertical"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/row_padding_vertical">
<TextView
android:id="#+id/txt_miestnost_row_nazov"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:text="#{obj.Name}"
android:textSize="16dp" />
</LinearLayout>
</layout>
As I have already mentioned I am trying to listen to item clicks, but not from Adapter itself (as other posts suggested), but from my Activity which holds this RecyclerView.
Is such action even possible? If yes, then any help would be highly appreciated as I could not find anything on google.

You’ll first need an interface that specifies listener’s behavior. In this example, there is a sample model called ContentItem, so the click will return an item of that type:
public interface OnItemClickListener {
void onItemClick(ContentItem item);
}
The constructor will receive an object that implements this interface, along with the items to be rendered:
private final List<ContentItem> items;
private final OnItemClickListener listener;
public ContentAdapter(List<ContentItem> items, OnItemClickListener listener) {
this.items = items;
this.listener = listener;
}
You could alternatively create a setOnItemClickListener method and assign it that way. Now, in onBindViewHolder the ViewHolder will receive the constructor in the custom bind method:
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.bind(items.get(position), listener);
}
This is how this bind method looks:
public void bind(final ContentItem item, final OnItemClickListener listener) {
...
itemView.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v) {
listener.onItemClick(item);
}
});
}
Use it whenever you need it by creating a new adapter and the listener that will implement the behavior when an item is clicked. A simple example:
recycler.setAdapter(new ContentAdapter(
items,
new ContentAdapter.OnItemClickListener() {
#Override
public void onItemClick(ContentItem item) {
Toast.makeText(getContext(), "Item Clicked", Toast.LENGTH_LONG).show();
}
}));
Source

To add to the answer provided by João Alvares Neto, we can call the OnItemClickListener directly from the layout.
In the variable tag, we can pass the OnItemClickListener and call it using the android:onClick property.
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable
name="storyClickListener"
type="com.hoomanwe.zorro.ui.adapter.OnStoryClickListener" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="#{() -> storyClickListener.onStoryClick(item.id)}" />
</layout>
By this way, you can eliminate the following code from the solution provided by João Alvares Neto
public void bind(final ContentItem item, final OnItemClickListener listener) {
itemView.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v) {
listener.onItemClick(item);
}
});
}

Detecting onClick in recycler view using data binding in android

I am Referring to vogella-tutorial for databinding
What i am trying to do: What is the best way to detect onClick in recycler view row for each Item using the dataBinding
activity_second.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable
name="temp"
type="com.vogella.android.databinding.TemperatureData" />
<variable
name="presenter"
type="com.vogella.android.databinding.MainActivityPresenter"/>
</data>
<android.support.v7.widget.RecyclerView
android:id="#+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical" />
</layout>
rowlayout.xml
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable
name="obj"
type="com.vogella.android.databinding.TemperatureData"
/>
</data>
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="?android:attr/listPreferredItemHeight"
android:padding="6dip"
>
<ImageView
android:id="#+id/icon"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_alignParentBottom="true"
android:layout_alignParentTop="true"
android:layout_marginRight="6dip"
android:contentDescription="TODO"
android:src="#drawable/ic_listentry"
/>
<TextView
android:id="#+id/secondLine"
android:layout_width="fill_parent"
android:layout_height="26dip"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_toRightOf="#id/icon"
android:ellipsize="marquee"
android:text="#{obj.location}"
android:textSize="12sp"
android:maxLines="1"
/>
<TextView
android:id="#+id/firstLine"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_above="#id/secondLine"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_alignWithParentIfMissing="true"
android:layout_toRightOf="#id/icon"
android:gravity="center_vertical"
android:text="#{obj.celsius}"
android:textSize="16sp"
/>
</RelativeLayout>
</layout>
MyAdapter.java
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private List<TemperatureData> data;
// 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 class MyViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
private final ViewDataBinding binding;
public MyViewHolder(ViewDataBinding binding) {
super(binding.getRoot());
this.binding = binding;
}
public void bind(Object obj) {
binding.setVariable(BR.obj,obj);
binding.executePendingBindings();
}
}
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(List<TemperatureData> myDataset) {
data = myDataset;
}
// Create new views (invoked by the layout manager)
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
ViewDataBinding binding = DataBindingUtil.inflate(layoutInflater, R.layout.rowlayout, parent, false);
// set the view's size, margins, paddings and layout parameters
return new MyViewHolder(binding);
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
final TemperatureData temperatureData = data.get(position);
holder.bind(temperatureData);
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return data.size();
}
}
MyAdapter.java
public class MyAdapter extends MyBaseAdapter {
List<TemperatureData> data;
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(List<TemperatureData> myDataset) {
data = myDataset;
}
#Override
public Object getDataAtPosition(int position) {
return data.get(position);
}
#Override
public int getLayoutIdForType(int viewType) {
return R.layout.rowlayout;
}
#Override
public int getItemCount() {
return data.size();
}
}

Not sure if you have already found a solution, but I managed to do it quite easily.
1) modify onCreateViewHolder method to look like this:
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
ViewDataBinding binding = DataBindingUtil.inflate(layoutInflater, R.layout.rowlayout, parent, false);
MainActivityPresenter presenter = new MainActivityPresenter(this, parent.getContext());
binding.setVariable(BR.presenter,presenter);
// set the view's size, margins, paddings and layout parameters
return new MyViewHolder(binding);
}
2) make MyAdapter to implement MainActivityContract.View so in the end it looks like following:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> implements MainActivityContract.View
3) Implement necessary methods within MyAdapter; e.g:
#Override
public void showData(TemperatureData data) {
String clickedItemCelsius = data.getCelsius();
}
4) Add Presenter variable to your row layout file:
<variable
name="presenter"
type="com.mvvm.ViewModels.MainActivityPresenter"/>
5) Finally hook your onClick event under RelativeLayout:
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="?android:attr/listPreferredItemHeight"
android:padding="6dip"
android:onClick="#{() -> presenter.onShowData(obj)}"
>
Hope it helps!

our viewModel used in recycler view
class UserViewModel (val name: String?, val onClick: () -> Unit)
layout for user_item.xml
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="model"
type="...model.UserViewModel" />
</data>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clickable="true"
android:focusable="true"
android:onClick="#{()->model.onClick.invoke()}"
android:text="#{model.name}" />
<merge>
creating of models in presenter or modelView or somewhere else
fun loadData() {
// ..
val user = UserViewModel("name") { handleUserEvent() }
.. //
}
fun handleUserEvent() {
// TODO handle on click
}

Probably the most common solution would be to put a click listener on the row layout's root view and call a method on your view model.
For example in rowlayout.xml:
...
<RelativeLayout
android:onClick="#{() -> obj.performClickAction()}"
....

Hey I read that article about a week ago and had the same problem! The article barely mentions how actions should be handled but there is documentation on how to do it. In short, you are going to want a handler.
This handler is defined in your xml
<data>
...
<variable name="handlers" type="com.example.MyHandlers"/>
...
</data>
example usage
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#{user.firstName}"
android:onClick="#{handlers::onClickFriend}"/>
The MyHandlers.java would look like this
public class MyHandlers {
public void onClickFriend(View view) { ... }
}
You would change the add one more line to your MyAdapter.java
public class MyViewHolder extends RecyclerView.ViewHolder {
public void bind(Object obj) {
binding.setVariable(BR.obj,obj);
binding.executePendingBindings();
binding.setHandlers(new MyHandlers());
}
I haven't tested this code but if this doesn't work I can share my adapter .

If other suggestions don't seem to work the way you think it should, take a look at Google Codelab training, specifically "Interacting with RecyclerView items". It's a part of series, but if you are interested in handling the click event in RecyclerView (with Data Binding), you just need to read the aforementioned chapter only.
In short, 1) create a listener class with onClick(), 2) add listener class as data in list item's xml layout file, and 3) use android:onClick="{...}" to map the list item's click event to the listener.
I'm sure there are other ways to achieve the same goal, but this approach seems fairly straightforward.

This way we can use the item click on databinding
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.CustomView> {
List<NewsModel> newsList;
private LayoutInflater layoutInflater;
public CustomAdapter(List<NewsModel> newsList)
{
this.newsList = newsList;
}
#Override
public CustomView onCreateViewHolder(final ViewGroup parent, final int viewType) {
if(layoutInflater == null)
{
layoutInflater = LayoutInflater.from(parent.getContext());
}
final NewsBinding newsBinding = NewsBinding.inflate(layoutInflater,parent,false);
newsBinding.setPresenter(new ClickListener() {
#Override
public void onclickListener() {
Log.d("click me ","click me "+newsBinding.getNewsview().Title);
Toast.makeText(parent.getContext(),""+newsBinding.getNewsview().Title,Toast.LENGTH_LONG).show();
}
});
// View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.innerlayout,parent,false);
return new CustomView(newsBinding);
}
#Override
public void onBindViewHolder(CustomView holder, int position) {
// News news = newsList.get(position);
// holder.title.setText(news.getTitle());
// holder.desc.setText(news.getDesc());
NewsModel newsModel = newsList.get(position);
holder.bind(newsModel);
}
#Override
public int getItemCount() {
return newsList.size();
}
public class CustomView extends RecyclerView.ViewHolder {
private NewsBinding newsBinding;
// TextView title, desc;
public CustomView(NewsBinding newsBinding) {
super(newsBinding.getRoot());
this.newsBinding = newsBinding;
//title = (TextView)itemView.findViewById(R.id.titleval);
//desc =(TextView)itemView.findViewById(R.id.descval);
}
public void bind(NewsModel newsModel)
{
this.newsBinding.setNewsview(newsModel);
}
public NewsBinding getNewsBinding()
{
return newsBinding;
}
}
}
complete project is https://github.com/Vishulucky/DataBinding-MVVM.git

class MyAdapter() :
RecyclerView.Adapter<MyAdapter.MyViewHolder> {
inner class MyViewHolder(private val binding: ItemMyListBinding) :
RecyclerView.ViewHolder(binding.root) {
fun bind(yourItem: YourItem) {
binding.setVariable(BR.item, yourItem)
binding.executePendingBindings()
binding.animeListCard.setOnClickListener {
onItemClickListener?.let { click ->
click(yourItem)
}
}
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
val layoutInflater = LayoutInflater.from(parent.context)
val binding: ItemMyListBinding = DataBindingUtil.inflate(
layoutInflater,
R.layout.item_My_list,
parent,
false
)
return MyViewHolder(binding)
}
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.bind(getItem(position))
}
//add these
private var onItemClickListener: (( YourItem) -> Unit)? = null
fun setOnItemClickListener(listener: ( YourItem) -> Unit) {
onItemClickListener = listener
}
}
R.layout.item_My_list layout:
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="item"
type="com.temp.example.data.MyItem" />
</data>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginHorizontal="8dp"
android:orientation="vertical">
<TextView
android:id="#+id/title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#{item.title}"
/>
</LinearLayout>
</layout>
then in your activity :
myAdapter.setOnItemClickListener { item->
//your code here
}

access RecyclerView.Adapter's method from ViewHolder or ViewModel of ViewHolder

I need to access a method of RecyclerView Adapter from View Holder. I don't find any solution for this.
Or is it possible to access adpater'method(get an instance of adapter) from ViewModel class (I've defined a viewModel for items of RecyclerView in MVVM pattern) of ViewHolder.
Regards,
Habib

Thanks to all, here is code snippets. in ItemViewModel class I want to get adapter's methods.
Adapter && ViewHolder :
public class MoviesAdapter extends RecyclerView.Adapter<MoviesAdapter.MyViewHolder> {
public class MyViewHolder extends RecyclerView.ViewHolder {
........
public MyViewHolder(View view) {
super(view);
......
}
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return itemView;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
........
}
#Override
public int getItemCount() {
.........
}
}
list_item.xml :
<?xml version="1.0" encoding="utf-8"?>
<data>
<variable
name="viewModel"
type="program.viewmodel.ItemViewModel" />
</data>
<android.support.v7.widget.CardView
android:id="#+id/cvMain"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="#{viewModel.onClickCard()}"
android:onLongClick="#{viewModel.onLongClickCard()}" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:paddingLeft="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="#+id/engM"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left"
android:paddingLeft="5dp"
android:text="#{viewModel.engligh}"
android:textSize="20sp" />
</LinearLayout>
</LinearLayout>
</android.support.v7.widget.CardView>
ItemViewModel class :
public class ItemViewModel{
private Proverb proverb; //Proverb is model class
public ItemViewModel(Proverb item) {
this.proverb = item;
notifyChange();
}
#Bindable
public String getEngligh() {
return proverb.getEngligh();
}
/**
* click each item
* #return
*/
public View.OnClickListener onClickProverb() {
return new View.OnClickListener() {
#Override
public void onClick(View view) {
// here I need to access adapter's method
}
};
}
/**
* long click listener
* #return
*/
public View.OnLongClickListener onLongClickProverb() {
return new View.OnLongClickListener() {
#Override
public boolean onLongClick(View view) {
// here I need to access adapter's method
return true;
}
};
}
}

Show RecyclerView in popup window

I have a RecyclerView, when RecyclerView item clicked, want to open a popup window which contains another RecyclerView. It is almost done, but in popup window, cardviews don't appear. I can't figure out why, can any one help?
1- My Main RecyclerView Adapter
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private ArrayList<Mission> mDataset;
private Context mContext;
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(ArrayList<Mission> myDataset, Context context) {
mDataset = myDataset;
this.mContext = context;
}
// Create new views (invoked by the layout manager)
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(mContext)
.inflate(R.layout.mission_card_item, parent, false);
// set the view's size, margins, paddings and layout parameters
MyViewHolder vh = new MyViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.mTextView.setText(mDataset.get(position).getName());
holder.mPuanView.setText(mDataset.get(position).getPoint());
holder.mRankView.setText(mDataset.get(position).getRank());
holder.btnAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(mContext,"Buton Clicked", Toast.LENGTH_SHORT).show();
}
});
}
#Override
public int getItemCount() {
return mDataset.size();
}
// 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 class MyViewHolder extends RecyclerView.ViewHolder {
public CardView mCardView;
public TextView mTextView;
public TextView mPuanView;
public TextView mRankView;
public Button btnAdd;
public MyViewHolder(final View itemView) {
super(itemView);
mCardView = (CardView) itemView.findViewById(R.id.card_view);
mTextView = (TextView) itemView.findViewById(R.id.tv_text);
mRankView = (TextView) itemView.findViewById(R.id.tv_rank);
mPuanView = (TextView) itemView.findViewById(R.id.tv_puan);
btnAdd = (Button) itemView.findViewById(R.id.button_add);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
showPopup();
Toast.makeText(itemView.getContext(),"Element " + getAdapterPosition() + " clicked", Toast.LENGTH_SHORT).show();
Log.d("hello", "Element " + getAdapterPosition() + " clicked.");
}
});
}
}
public void showPopup(){
final View popupView = LayoutInflater.from(mContext).inflate(R.layout.recycler_popup_window, null);
final PopupWindow popupWindow = new PopupWindow(popupView, WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT);
Button btn = (Button) popupView.findViewById(R.id.button);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
popupWindow.dismiss();
}
});
RecyclerView recyclerView = (RecyclerView) popupView.findViewById(R.id.rv_recycler_view);
ArrayList<String> data = new ArrayList<>();
data.add("my data");
data.add("my test data");
PopupRecyclerViewAdapter adapter = new PopupRecyclerViewAdapter(mContext,data);
recyclerView.setAdapter(adapter);
popupWindow.showAtLocation(popupView,Gravity.CENTER, 0, 0);
}
}
2- My second RecyclerView adapter, its for popup window
public class PopupRecyclerViewAdapter extends RecyclerView.Adapter<PopupRecyclerViewAdapter.MyViewHolder>{
private Context mContext;
private ArrayList<String> data;
public PopupRecyclerViewAdapter(Context mContext, ArrayList<String> data) {
this.mContext = mContext;
this.data = data;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(mContext).inflate(R.layout.recycler_popup_card_item, parent,false);
MyViewHolder vh = new MyViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.mTextView.setText(data.get(position));
}
#Override
public int getItemCount() {
return data.size();
}
//View Holder
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView mTextView;
public MyViewHolder(View itemView) {
super(itemView);
mTextView = (TextView) itemView.findViewById(R.id.tv_text2);
}
}
}
3- Layout for Recycler popup window
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content" android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="#+id/rv_recycler_view2"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/button"
android:background="#ff4545">
</android.support.v7.widget.RecyclerView>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Close"
android:id="#+id/button"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
</RelativeLayout>
4- CardView Layout for popup RecyclerView
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<android.support.v7.widget.CardView
android:id="#+id/card_view"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_margin="10dp"
android:layout_height="wrap_content"
card_view:cardCornerRadius="4dp"
card_view:elevation="14dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:gravity="center">
<ImageView
android:layout_width="match_parent"
android:layout_height="175dp"
android:id="#+id/imageView2"
android:src="#mipmap/testimage"
android:layout_marginBottom="10dp"
android:scaleType="centerCrop"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/tv_text2"
android:text="Blah blah blah..."
android:gravity="center"
android:layout_marginBottom="10dp"/>
</LinearLayout>
</android.support.v7.widget.CardView>
</RelativeLayout>

Add the below lines in your recyclerview popup:
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
recyler_view.setLayoutManager(mLayoutManager);

You may, like me, find this becomes rather a lot of boilerplate code just for a simple Popup Window with a list of clickable items, and so I made a custom Drop Down class which is easily reusable. You just need the PopupWindow custom class, and the RecyclerView adapter, as well as an item data class (in Kotlin), and this is then easily reusable.
The DropDown class:
class DropDown(context: Context, items: List<DropDownItem>, val listener: DropDownClickListener) : PopupWindow(context) {
private val binding = DropdownLayoutBinding.inflate(LayoutInflater.from(context))
init {
contentView = binding.root
setBackgroundDrawable(null)
elevation = 8f
isOutsideTouchable = true
isFocusable = true
binding.recyclerView.adapter = DropDownItemAdapter(items) { item -> onItemClicked(item) }
setOnDismissListener { listener.onMenuDismissed() }
}
private fun onItemClicked(item: DropDownItem) {
listener.onMenuItemClicked(item)
dismiss()
}
fun show(anchor: View) {
showAsDropDown(anchor, 0, 20)
}
interface DropDownClickListener {
fun onMenuItemClicked(item: DropDownItem)
fun onMenuDismissed()
}
}
data class DropDownItem(
val text: String,
val icon: Int
)
With accompanying layout code:
<?xml version="1.0" encoding="utf-8"?>
<androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#drawable/rounded_corners"
android:id="#+id/recycler_view"
xmlns:tools="http://schemas.android.com/tools"
tools:listitem="#layout/item_drop_down"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toTopOf="parent" />
Explanation: This reusable new DropDown class uses ViewBinding of a simple layout that is simply a RecyclerView (with whatever Item layout you want, again mine is a reusable one called item_drop_down, a TextView with a Drawable.)
The constructor just needs three things, the context, the list of drop down items (I made a DropDownItem data class, which for simplicity I put in the same file), and then the listener - an interface also defined in this class).
In the init for this class, we set the content view, setBackgroundDrawable to null to get rid of an ugly border, give it some elevation, then make it dismissable by touching outside or pressing the back button. We then set the recyclerview adapter here from the list of items in the constructor. Finally, we set the on dismiss listener and defer to our interface.
Now the adapter code:
class DropDownItemAdapter(val items: List<DropDownItem>, val clickListener: (DropDownItem) -> Unit) : RecyclerView.Adapter<DropDownItemAdapter.ViewHolder>() {
override fun getItemCount() = items.size
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
return ViewHolder(ItemDropDownBinding.inflate(LayoutInflater.from(parent.context), parent, false))
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.bind(items[position])
}
inner class ViewHolder(val binding: ItemDropDownBinding) : RecyclerView.ViewHolder(binding.root) {
fun bind(item: DropDownItem) {
binding.textView.text = item.text
binding.textView.setCompoundDrawablesWithIntrinsicBounds(ContextCompat.getDrawable(binding.root.context, item.icon), null, null, null)
itemView.setOnClickListener { clickListener(item) }
}
}
}
This is just a straight forward RecyclerView adapter, and rather than another interface, the only thing this needs to notify is when an item is clicked, so simply accept a function parameter in the constructor for handling the clicks.
Altogether, it looks like this in the calling code:
DropDown(view.context, dropDownMenu, this).show(view)
Where dropDownMenu is a list of DropDownItem.
You can then handle the interface functions as desired:
override fun onMenuItemClicked(item: DropDownItem) {
when (item.text) {
"Delete" -> // respond as desired
"Edit" -> // simply inspect the text, or alter your DropDownItem to have an ID
}
}
override fun onMenuDismissed() {
// it may be useful to know when the popup is dismissed
// in my case, I select the item which has been long pressed, and want to know when to un-select it
}
With a nice rounded corners background on my DropDown layout, and being able to know when popup showing and when dismissed to highlight my chosen item, I get this nice effect: