I have two recyclerview in one layout. The vertical recyclerview shows all the user and the horizontal recyclerview shows the selected user from vertical recyclerview. The vertical recyclerview has a checkbox(clickable=false) to know that the user picks it and to do that I created an interface for vertical recyclerview, an ItemCheck and for the horizontal I created an interface of onItemClick. So my plan is when user click in vertical recyclerview it will add the item on the horizontal view and when the user unCheck it, the item will be remove to the horizontal recyclerview. And in the horizontal recyclerview, when the user clicks the item, the item will be remove in the selected user and in the vertical recyclerview it will uncheck the checkbox. This is the code for doing that.
EDIT:
In the Activity:
private void setUpAdapter() {
mUsersAdapter = new PickMemberAdapter(PickMemberActivity.this, mUserNameList,
mUserDescList, mUserPicList, new PickMemberAdapter.RecyclerViewItemClick() {
#Override
public void OnItemCheckClickListener(PickMemberAdapter.UsersViewHolders holder,
String name, int position) {
String userKey = mUserKey.get(position);
if (!holder.mCheckBox.isChecked()) {
holder.mCheckBox.setChecked(true);
mSelectedUser.add(userKey);
mSelectedName.add(name);
} else {
holder.mCheckBox.setChecked(false);
mSelectedUser.remove(userKey);
mSelectedName.remove(name);
}
mUsersAdapter.notifyDataSetChanged();
mSelectedAdapter.notifyDataSetChanged();
Toast.makeText(PickMemberActivity.this, mSelectedUser.toString()
+ "\n" + mSelectedName.toString(), Toast.LENGTH_LONG).show();
}
});
mSelectedAdapter = new SelectedUserAdapter(mSelectedName,
new SelectedUserAdapter.RecyclerViewUnselect() {
#Override
public void ItemRemoveClick(String name, int position) {
String userKey = mUserKey.get(position);
mSelectedUser.remove(userKey);
mSelectedName.remove(name);
mUsersAdapter.notifyDataSetChanged();
mSelectedAdapter.notifyDataSetChanged();
Toast.makeText(PickMemberActivity.this, mSelectedUser.toString()
+ "\n" + mSelectedName.toString(), Toast.LENGTH_LONG).show();
}
});
mSearchList.setAdapter(mUsersAdapter);
mSelectedUserList.setAdapter(mSelectedAdapter);
}
In the Adapter
public void onBindViewHolder(#NonNull final UsersViewHolders holder, int position) {
holder.setName(mUserNameList.get(position));
holder.setDesc(mUserDescList.get(position));
holder.setImage(mUserPicList.get(position));
holder.mCheckBox.setOnCheckedChangeListener(null);
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mListener.OnItemCheckClickListener(holder,
mUserNameList.get(holder.getAdapterPosition()), holder.getAdapterPosition());
}
});
}
public interface RecyclerViewItemClick {
void OnItemCheckClickListener(UsersViewHolders holder, String name, int position);
}
Now my problem is the checkbox is either not checking or checking another position.
It should look like this (from Messenger Lite app)
You are updating data of RecyclerView so you should notify adapter. Call notifyDataSetChanged() after you update list.
mSearchList.notifyDataSetChanged();
mSelectedUserList.notifyDataSetChanged();
I solved this problem to maintain separate boolean for check and uncheck in user model and user it onBindViewHolder to update view.
I have a RecyclerView with each element representing an event. I want to let the user select events by clicking it. Once selected, the event(s) and a report button will be colored:
UI before performing a click: click here.
UI After performing a click: click here.
It's pretty simple and allegedly works; I set an OnClickListener for each ViewHolder which is responsible for coloring the item, and when fired it's triggering another event in the owning activity named onOccurrenceSelected, which is responsible for changing the button's state.
However, when scrolling through the RecyclerView's items, other irrelevant items are colored like their OnClickListener was triggered (though it wasn't), and when scrolling back the selected event is colored as not selected. While this is happening, the only event that's supposed to color the items is not triggered.
Any explanation for such behavior? Thanks!
EDIT: Here are some relevant code from the adapter:
private List<Occurrence> mDataSet;
private Activity activity;
public <OccurrencesActivity extends OnOccurrenceSelectedListener> OccurrencesAdapter(OccurrencesActivity occurrencesActivity, List<Occurrence> occurrences) {
this.activity = (android.app.Activity) occurrencesActivity;
mDataSet = occurrences;
}
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
Occurrence instance = mDataSet.get(position);
...
setOnClickListener(holder, instance);
}
private void setOnClickListener(final ViewHolder holder, final Occurrence occurrence) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (!occurrence.isSelected()) {
holder.itemView.setBackgroundColor(App.getContext().getResources().getColor(R.color.turquoise));
holder.titleTextView.setTextColor(App.getContext().getResources().getColor(R.color.white));
holder.statusTextView.setTextColor(App.getContext().getResources().getColor(R.color.white));
holder.dateTextView.setTextColor(App.getContext().getResources().getColor(R.color.white));
holder.timeTextView.setTextColor(App.getContext().getResources().getColor(R.color.white));
} else {
holder.itemView.setBackgroundColor(App.getContext().getResources().getColor(R.color.white));
holder.titleTextView.setTextColor(App.getContext().getResources().getColor(R.color.turquoise));
holder.statusTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.dateTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.timeTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
}
occurrence.setSelected(!occurrence.isSelected());
((OnOccurrenceSelectedListener)activity).onOccurrenceSelected(mDataSet);
}
});
}
Recyclerview always resuse views while scrolling so you have to store selected positions into temporary arraylist and then keep condition check into onBindViewHolder that whether that particular position is already exists in arraylist or not? I updated your adaper. find the below changes with comment
private List<Occurrence> mDataSet;
private Activity activity;
//Added here temporary ArrayList
private ArrayList<String> mSelectedPosition = new ArrayList<String>;
public <OccurrencesActivity extends OnOccurrenceSelectedListener> OccurrencesAdapter(OccurrencesActivity occurrencesActivity, List<Occurrence> occurrences) {
this.activity = (android.app.Activity) occurrencesActivity;
mDataSet = occurrences;
}
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
//Set ViewTag
holder.itemView.setTag(position);
//Check everyposition during view binding process
if(mSelectedPosition.contains(String.valueOf(position))){
holder.itemView.setBackgroundColor(App.getContext().getResources().getColor(R.color.white));
holder.titleTextView.setTextColor(App.getContext().getResources().getColor(R.color.turquoise));
holder.statusTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.dateTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.timeTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
}else{
holder.itemView.setBackgroundColor(App.getContext().getResources().getColor(R.color.white));
holder.titleTextView.setTextColor(App.getContext().getResources().getColor(R.color.turquoise));
holder.statusTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.dateTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
holder.timeTextView.setTextColor(App.getContext().getResources().getColor(R.color.grey));
}
Occurrence instance = mDataSet.get(position);
...
setOnClickListener(holder, instance);
}
private void setOnClickListener(final ViewHolder holder, final Occurrence occurrence) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// Get Position
int position = (int) view.getTag();
//Remove SelectedPosition if Already there
if(mSelectedPosition.contains(position))
mSelectedPosition.remove(String.valueOf(position));
else
mSelectedPosition.add(String.valueOf(position));
notifyDataSetChanged();
//Not sure about this lines
occurrence.setSelected(!occurrence.isSelected());
((OnOccurrenceSelectedListener)activity).onOccurrenceSelected(mDataSet);
}
});
}
Its the default behaviour of recyclerview. it will recycle/reuse views which are not in use currently. If you want to save the state which is colored or not. Then save a parameter in your List<Object> per position. and as per position in onBindViewHolder method use that position to change the color.
Try by Setting Tag to your item in onBindViewHolder of Adapter
holder.yourItem.setTag(position);
And then Inside the onClickListener,Just save that position in shared Pref. if it's selected, whenever you set adapter then before setting values just check that is it selected or not based on shared Pref. and perform action for same.
public void onClick(View view) {
if (!occurrence.isSelected()) {
//save position in share pref.
}
}
am trying to update my adapter after adding some data in it but its not updating , when i switch through other activities and come back the adapter got updated this time my code :
void updateAdapter(){
adapter.setData(getData());
adapter.notifyDataSetChanged();
Log.d("TAG"," DATA SIZE AFTER UPDATE : "+getData().size() +" items : "+adapter.getItemCount());
}
my adapter :
private void createAdapter(final RecyclerView recyclerView , final List<Information> data) {
List<Information> content = new ArrayList<>();
Log.d("TAG","createAdapter Called");
final int[] currentRowPosition = {0};
content = data;
final List<Information> finalContent = content;
adapter = new ParallaxRecyclerAdapter<Information>(finalContent) {
/// my onBindViewHolder
#Override
public void onBindViewHolderImpl(final RecyclerView.ViewHolder viewHolder, final ParallaxRecyclerAdapter<Information> adapter, final int i) {
currentRowPosition[0] = i;
if ( i <= finalContent.size() -1 ){
((ViewHolder) viewHolder).linearLayout.setVisibility(View.GONE);
final Information current = finalContent.get(i);
((ViewHolder) viewHolder).DESCRIPTION.setText(current.description);
}else {
// this is my loadMore button which stays at the last row of recyclerView
((ViewHolder) viewHolder).setIsRecyclable(false);
((ViewHolder) viewHolder).linearLayout.setVisibility(View.VISIBLE);
((ViewHolder) viewHolder).itemView.getLayoutParams().height = 100;
((ViewHolder) viewHolder).LOADMORE.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
fetchNext();
}
});
}
}
//my on create View Holder
#Override
public RecyclerView.ViewHolder onCreateViewHolderImpl(ViewGroup viewGroup, final ParallaxRecyclerAdapter<Information> adapter, int i) {
return new ViewHolder(getActivity().getLayoutInflater().inflate(R.layout.custom_row, viewGroup, false));
}
#Override
public int getItemCountImpl(ParallaxRecyclerAdapter<Information> adapter) {
return finalContent.size()+1;
}
});
// adding header to recyclerView
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
View header = getActivity().getLayoutInflater().inflate(R.layout.header, recyclerView, false);
headerImageView = (ImageView) header.findViewById(R.id.headerImageView);
//setting CoverImage
adapter.setParallaxHeader(header, recyclerView);
adapter.setData(content);
recyclerView.setAdapter(adapter);
}
any idea how can i add new items with realtime updation on my RecyclerView ?? any guidance will be so helpful for me
I am assuming that when you run the Activity (which has RecyclerView) for the first time it loads everything from the adapter properly.
But when you change to other activities which would change items to your adapter and come back to your Activity which has RecyclerView in it can't get the proper updated information as adapter is not updated.
This may be because you are not refreshing your adapter when your activity resumes in onResume(), something like this. you may have to make other changes to your onResume method as required,
onResume(){
if(adapter != null){
adapter.notifyDataSetChanged();
}
}
Kindly check the lifecycle of an Activity
Example:
This does not directly addresses your issue but help you understand as you come back to activity you should refresh the adapter.
There is a NoteListActivity, with ListView in it, you may Add or edit items to the Adapter in it in NoteEditActivity and as soon as you come back you have to refresh the adapter in the activity where you have your listview
Adapter.class
public void add(List<Information> informations){
try{
finalContent.addAll(informations);
}catch(Exception e){
e.printstacktrace();
}
notifyDataSetChanged();
}
well i ended up with this :
int offset = adapter.getItemCount();
for(int l=0; l<= 4 ; l++){
Log.d("TAG","getData : "+getData().size());
if ((offset - 2) + l < getData().size()){
adapter.addItem(getData().get((offset - 2 ) + l) , adapter.getItemCount() - 2);
adapter.notifyDataSetChanged();
}
}
what i needed was adapter.addItem(item , position) and adapter.notifyDataSetChanged(); the above example is loading 5 images at a time
I have a RecyclerView inside that recyclerView I added two Sections Favorites, All Contacts. For adding the section I used SimpleSectionedRecyclerViewAdapter
now I have rows with section which is hardcoded (the index of rows and section), I want to add rows to favorite section by selecting the rows since there's nothing documented about what I want, I don't know where to start or what I have to do ?
If anybody knows how can I add a row from All Contacts section (which is default location for rows ) by selecting them. then please give me some hints for what I have to do
what I want is something like this :
add to favorite by pressing the button
any guidance will be so helpful for me , thanks
You can achieve it with the library SectionedRecyclerViewAdapter without having to hardcode header/rows indexes.
First create a Section class to group your items:
class MySection extends StatelessSection {
String title;
List<String> list;
public MySection(String title, List<String> list) {
// call constructor with layout resources for this Section header, footer and items
super(R.layout.section_header, R.layout.section_item);
this.title = title;
this.list = list;
}
#Override
public int getContentItemsTotal() {
return list.size(); // number of items of this section
}
#Override
public RecyclerView.ViewHolder getItemViewHolder(View view) {
// return a custom instance of ViewHolder for the items of this section
return new MyItemViewHolder(view);
}
#Override
public void onBindItemViewHolder(RecyclerView.ViewHolder holder, int position) {
MyItemViewHolder itemHolder = (MyItemViewHolder) holder;
// bind your view here
itemHolder.tvItem.setText(list.get(position));
}
#Override
public RecyclerView.ViewHolder getHeaderViewHolder(View view) {
return new SimpleHeaderViewHolder(view);
}
#Override
public void onBindHeaderViewHolder(RecyclerView.ViewHolder holder) {
MyHeaderViewHolder headerHolder = (MyHeaderViewHolder) holder;
// bind your header view here
headerHolder.tvItem.setText(title);
}
}
Then you set up the RecyclerView with your Sections:
// Create an instance of SectionedRecyclerViewAdapter
SectionedRecyclerViewAdapter sectionAdapter = new SectionedRecyclerViewAdapter();
// Create your sections with the list of data
MySection favoritesSection = new MySection("Favorites", favoritesList);
MySection contactsSection = new MySection("Add Favorites", contactsList);
// Add your Sections to the adapter
sectionAdapter.addSection(favoritesSection);
sectionAdapter.addSection(contactsSection);
// Set up your RecyclerView with the SectionedRecyclerViewAdapter
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
recyclerView.setAdapter(sectionAdapter);
You can find an example of how to listen to the button click here.
You can also add new rows to your sections without having to recalculate indexes, just create a method like this in your Section class:
public void addRow(String item) {
this.list.add(item);
}
Then:
favoritesSection.addRow("new item");
sectionAdapter.notifyDataSetChanged();
I have a RecyclerView with an TextView text box and a cross button ImageView. I have a button outside of the recyclerview that makes the cross button ImageView visible / gone.
I'm looking to remove an item from the recylerview, when that items cross button ImageView is pressed.
My adapter:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> implements View.OnClickListener, View.OnLongClickListener {
private ArrayList<String> mDataset;
private static Context sContext;
public MyAdapter(Context context, ArrayList<String> myDataset) {
mDataset = myDataset;
sContext = context;
}
#Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_text_view, parent, false);
ViewHolder holder = new ViewHolder(v);
holder.mNameTextView.setOnClickListener(MyAdapter.this);
holder.mNameTextView.setOnLongClickListener(MyAdapter.this);
holder.mNameTextView.setTag(holder);
return holder;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.mNameTextView.setText(mDataset.get(position));
}
#Override
public int getItemCount() {
return mDataset.size();
}
#Override
public void onClick(View view) {
ViewHolder holder = (ViewHolder) view.getTag();
if (view.getId() == holder.mNameTextView.getId()) {
Toast.makeText(sContext, holder.mNameTextView.getText(), Toast.LENGTH_SHORT).show();
}
}
#Override
public boolean onLongClick(View view) {
ViewHolder holder = (ViewHolder) view.getTag();
if (view.getId() == holder.mNameTextView.getId()) {
mDataset.remove(holder.getPosition());
notifyDataSetChanged();
Toast.makeText(sContext, "Item " + holder.mNameTextView.getText() + " has been removed from list",
Toast.LENGTH_SHORT).show();
}
return false;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView mNumberRowTextView;
public TextView mNameTextView;
public ViewHolder(View v) {
super(v);
mNameTextView = (TextView) v.findViewById(R.id.nameTextView);
}
}
}
My layout is:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="center_vertical"
android:id="#+id/layout">
<TextView
android:id="#+id/nameTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="18sp"
android:padding="5dp"
android:background="#drawable/greyline"/>
<ImageView
android:id="#+id/crossButton"
android:layout_width="16dp"
android:layout_height="16dp"
android:visibility="gone"
android:layout_marginLeft="50dp"
android:src="#drawable/cross" />
</LinearLayout>
How can I get something like an onClick working for my crossButton ImageView? Is there a better way? Maybe changing the whole item onclick into a remove the item? The recyclerview shows a list of locations that need to be edited. Any technical advice or comments / suggestions on best implementation would be hugely appreciated.
I have done something similar.
In your MyAdapter:
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
public CardView mCardView;
public TextView mTextViewTitle;
public TextView mTextViewContent;
public ImageView mImageViewContentPic;
public ImageView imgViewRemoveIcon;
public ViewHolder(View v) {
super(v);
mCardView = (CardView) v.findViewById(R.id.card_view);
mTextViewTitle = (TextView) v.findViewById(R.id.item_title);
mTextViewContent = (TextView) v.findViewById(R.id.item_content);
mImageViewContentPic = (ImageView) v.findViewById(R.id.item_content_pic);
//......
imgViewRemoveIcon = (ImageView) v.findViewById(R.id.remove_icon);
mTextViewContent.setOnClickListener(this);
imgViewRemoveIcon.setOnClickListener(this);
v.setOnClickListener(this);
mTextViewContent.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View view) {
if (mItemClickListener != null) {
mItemClickListener.onItemClick(view, getPosition());
}
return false;
}
});
}
#Override
public void onClick(View v) {
//Log.d("View: ", v.toString());
//Toast.makeText(v.getContext(), mTextViewTitle.getText() + " position = " + getPosition(), Toast.LENGTH_SHORT).show();
if(v.equals(imgViewRemoveIcon)){
removeAt(getPosition());
}else if (mItemClickListener != null) {
mItemClickListener.onItemClick(v, getPosition());
}
}
}
public void setOnItemClickListener(final OnItemClickListener mItemClickListener) {
this.mItemClickListener = mItemClickListener;
}
public void removeAt(int position) {
mDataset.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, mDataSet.size());
}
Edit:
getPosition() is deprecated now, use getAdapterPosition() instead.
first of all, item should be removed from the list!
mDataSet.remove(getAdapterPosition());
then:
notifyItemRemoved(getAdapterPosition());
notifyItemRangeChanged(getAdapterPosition(), mDataSet.size()-getAdapterPosition());
if still item not removed use this magic method :)
private void deleteItem(int position) {
mDataSet.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, mDataSet.size());
holder.itemView.setVisibility(View.GONE);
}
Kotlin version
private fun deleteItem(position: Int) {
mDataSet.removeAt(position)
notifyItemRemoved(position)
notifyItemRangeChanged(position, mDataSet.size)
holder.itemView.visibility = View.GONE
}
The Problem
RecyclerView was built to display data in an efficient and responsive manner.
Usually you have a dataset which is passed to your adapter and is looped through to display your data.
Here your dataset is:
private ArrayList<String> mDataset;
The point is that RecyclerView is not connected to your dataset, and therefore is unaware of your dataset changes.
It just reads data once and displays it through your ViewHolder, but a change to your dataset will not propagate to your UI.
This means that whenever you make a deletion/addition on your data list, those changes won't be reflected to your RecyclerView directly. (i.e. you remove the item at index 5, but the 6th element remains in your recycler view).
A (old school) solution
RecyclerView exposes some methods for you to communicate your dataset changes, reflecting those changes directly on your list items.
The standard Android APIs allow you to bind the process of data removal (for the purpose of the question) with the process of View removal.
The methods we are talking about are:
notifyItemChanged(index: Int)
notifyItemInserted(index: Int)
notifyItemRemoved(index: Int)
notifyItemRangeChanged(startPosition: Int, itemCount: Int)
notifyItemRangeInserted(startPosition: Int, itemCount: Int)
notifyItemRangeRemoved(startPosition: Int, itemCount: Int)
A Complete (old school) Solution
If you don't properly specify what happens on each addition, change or removal of items, RecyclerView list items are animated unresponsively because of a lack of information about how to move the different views around the list.
The following code will allow RecyclerView to precisely play the animation with regards to the view that is being removed (And as a side note, it fixes any IndexOutOfBoundExceptions, marked by the stacktrace as "data inconsistency").
void remove(position: Int) {
dataset.removeAt(position)
notifyItemChanged(position)
notifyItemRangeRemoved(position, 1)
}
Under the hood, if we look into RecyclerView we can find documentation explaining that the second parameter we pass to notifyItemRangeRemoved is the number of items that are removed from the dataset, not the total number of items (As wrongly reported in some others information sources).
/**
* Notify any registered observers that the <code>itemCount</code> items previously
* located at <code>positionStart</code> have been removed from the data set. The items
* previously located at and after <code>positionStart + itemCount</code> may now be found
* at <code>oldPosition - itemCount</code>.
*
* <p>This is a structural change event. Representations of other existing items in the data
* set are still considered up to date and will not be rebound, though their positions
* may be altered.</p>
*
* #param positionStart Previous position of the first item that was removed
* #param itemCount Number of items removed from the data set
*/
public final void notifyItemRangeRemoved(int positionStart, int itemCount) {
mObservable.notifyItemRangeRemoved(positionStart, itemCount);
}
Open source solutions
You can let a library like FastAdapter, Epoxy or Groupie take care of the business, and even use an observable recycler view with data binding.
New ListAdapter
Google recently introduced a new way of writing the recycler view adapter, which works really well and supports reactive data.
It is a new approach and requires a bit of refactoring, but it is 100% worth switching to it, as it makes everything smoother.
here is the documentation, and here a medium article explaining it
Here are some visual supplemental examples. See my fuller answer for examples of adding and removing a range.
Add single item
Add "Pig" at index 2.
String item = "Pig";
int insertIndex = 2;
data.add(insertIndex, item);
adapter.notifyItemInserted(insertIndex);
Remove single item
Remove "Pig" from the list.
int removeIndex = 2;
data.remove(removeIndex);
adapter.notifyItemRemoved(removeIndex);
Possibly a duplicate answer but quite useful for me. You can implement the method given below in RecyclerView.Adapter<RecyclerView.ViewHolder>
and can use this method as per your requirements, I hope it will work for you
public void removeItem(#NonNull Object object) {
mDataSetList.remove(object);
notifyDataSetChanged();
}
I tried all the above answers, but inserting or removing items to recyclerview causes problem with the position in the dataSet. Ended up using delete(getAdapterPosition()); inside the viewHolder which worked great at finding the position of items.
The problem I had was I was removing an item from the list that was no longer associated with the adapter to make sure you are modifying the correct adapter you can implement a method like this in your adapter:
public void removeItemAtPosition(int position) {
items.remove(position);
}
And call it in your fragment or activity like this:
adapter.removeItemAtPosition(position);
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private Context context;
private List<cardview_widgets> list;
public MyAdapter(Context context, List<cardview_widgets> list) {
this.context = context;
this.list = list;
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(this.context).inflate(R.layout.fragment1_one_item,
viewGroup, false);
return new MyViewHolder(view);
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
TextView txtValue;
TextView txtCategory;
ImageView imgInorEx;
ImageView imgCategory;
TextView txtDate;
public MyViewHolder(#NonNull View itemView) {
super(itemView);
txtValue= itemView.findViewById(R.id.id_values);
txtCategory= itemView.findViewById(R.id.id_category);
imgInorEx= itemView.findViewById(R.id.id_inorex);
imgCategory= itemView.findViewById(R.id.id_imgcategory);
txtDate= itemView.findViewById(R.id.id_date);
}
}
#NonNull
#Override
public void onBindViewHolder(#NonNull final MyViewHolder myViewHolder, int i) {
myViewHolder.txtValue.setText(String.valueOf(list.get(i).getValuee()));
myViewHolder.txtCategory.setText(list.get(i).getCategory());
myViewHolder.imgInorEx.setBackgroundColor(list.get(i).getImg_inorex());
myViewHolder.imgCategory.setImageResource(list.get(i).getImg_category());
myViewHolder.txtDate.setText(list.get(i).getDate());
myViewHolder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
list.remove(myViewHolder.getAdapterPosition());
notifyDataSetChanged();
return false;
}
});
}
#Override
public int getItemCount() {
return list.size();
}}
i hope this help you.
if you want to remove item you should do this:
first remove item:
phones.remove(position);
in next step you should notify your recycler adapter that you remove an item by this code:
notifyItemRemoved(position);
notifyItemRangeChanged(position, phones.size());
but if you change an item do this:
first change a parameter of your object like this:
Service s = services.get(position);
s.done = "Cancel service";
services.set(position,s);
or new it like this :
Service s = new Service();
services.set(position,s);
then notify your recycler adapter that you modify an item by this code:
notifyItemChanged(position);
notifyItemRangeChanged(position, services.size());
hope helps you.
String str = arrayList.get(position);
arrayList.remove(str);
MyAdapter.this.notifyDataSetChanged();
To Method onBindViewHolder Write This Code
holder.remove.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Cursor del=dbAdapter.ExecuteQ("delete from TblItem where Id="+values.get(position).getId());
values.remove(position);
notifyDataSetChanged();
}
});
Incase Anyone wants to implement something like this in Main class instead of Adapter class, you can use:
public void removeAt(int position) {
peopleListUser.remove(position);
friendsListRecycler.getAdapter().notifyItemRemoved(position);
friendsListRecycler.getAdapter().notifyItemRangeChanged(position, peopleListUser.size());
}
where friendsListRecycler is the Adapter name
you must to remove this item from arrayList of data
myDataset.remove(holder.getAdapterPosition());
notifyItemRemoved(holder.getAdapterPosition());
notifyItemRangeChanged(holder.getAdapterPosition(), getItemCount());
//////// set the position
holder.cancel.setTag(position);
///// click to remove an item from recycler view and an array list
holder.cancel.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
int positionToRemove = (int)view.getTag(); //get the position of the view to delete stored in the tag
mDataset.remove(positionToRemove);
notifyDataSetChanged();
}
});
make interface into custom adapter class and handling click event on recycler view..
onItemClickListner onItemClickListner;
public void setOnItemClickListner(CommentsAdapter.onItemClickListner onItemClickListner) {
this.onItemClickListner = onItemClickListner;
}
public interface onItemClickListner {
void onClick(Contact contact);//pass your object types.
}
#Override
public void onBindViewHolder(ItemViewHolder holder, int position) {
// below code handle click event on recycler view item.
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
onItemClickListner.onClick(mContectList.get(position));
}
});
}
after define adapter and bind into recycler view called below code..
adapter.setOnItemClickListner(new CommentsAdapter.onItemClickListner() {
#Override
public void onClick(Contact contact) {
contectList.remove(contectList.get(contectList.indexOf(contact)));
adapter.notifyDataSetChanged();
}
});
}
In case you are wondering like I did where can we get the adapter position in the method getadapterposition(); its in viewholder object.so you have to put your code like this
mdataset.remove(holder.getadapterposition());
In the activity:
mAdapter.updateAt(pos, text, completed);
mAdapter.removeAt(pos);
In the your adapter:
void removeAt(int position) {
list.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, list.size());
}
void updateAt(int position, String text, Boolean completed) {
TodoEntity todoEntity = list.get(position);
todoEntity.setText(text);
todoEntity.setCompleted(completed);
notifyItemChanged(position);
}
in 2022, after trying everything the whole internet given below is the answer
In MyViewHolder class
private myAdapter adapter;
inside MyViewHolder function initalise adapter
adapter = myAdapter.this
inside onclick
int position = getAdapterPosition()
list.remove(position);
adapter.notifyItemRemoved(position);