Develop Reference

How to show income in intent string array at recyclerview android?

In my application I have draft messages which I can edit. Some of my drafts include attachments which I try to send to my edit activity and show it at recyclerview. In general I have managed to send my string arraylist and get it at my activity. But I can't show my attached files, especially their names at the recyclerview. I tried to make smth like that:
adapter.notifyDataSetChanged();
but it didn't help me.
So, firstly I get from my message names of attached files:
file_name = Objects.requireNonNull(response.body()).getAttachesNames();
then put this names into arraylist:
nameList = new ArrayList<>(Arrays.asList(file_name));
such result I can see in my logs:
W: [eZV9f.jpg, index.html]
and then I send my list via intent to another activity:
intent2.putStringArrayListExtra("attached_files", (ArrayList<String>) nameList);
receiving data from intent:
Intent intent = getIntent();
extras = intent.getExtras();
if (extras != null) {
if (extras.containsKey("attached_files")) {
draft_files = getIntent().getStringArrayListExtra("attached_files");
Log.w("MY_TAG", String.valueOf(draft_files));
}
}
results from logcat:
W: [eZV9f.jpg, index.html]
initialising of my adapter and recyclerview:
adapter = new AttachedFileAdapter(mNames);
recyclerView = findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(WriteResponseMess.this, LinearLayoutManager.VERTICAL, false));
and then I try to get single element from this list and add to my ArrayList<>:
for (int i = 0; i < draft_files.size(); i++) {
mNames.addAll(Collections.singleton(draft_files.get(i)));
adapter.notifyDataSetChanged();
recyclerView.setAdapter(adapter);
Log.w("MY_TAG", draft_files.get(i));
Log.w("MY_TAG", String.valueOf(mNames));
}
all previous pieces of code are used at my onCreate() method and as a result of all these actions I would like to see income data from another activity. Sometimes I managed to do it, but one element contained all income data and looked like this:
[eZV9f.jpg, index.html]
and it was wrong for me. I try to create the list which will contain all elements separately. I also tried to use some info from this link which is connected with Collections, but I didn't manage to reach the goal of my task. In general I'm sure that the solution is very simple but I can't see it.
update
all my activity class has more than 1000 lines and I will share all code which is connected with adding attachments and show attached data at my writing form:
Here is my dialog for getting directory list and choosing some files:
#Override
protected Dialog onCreateDialog(int id) {
Dialog dialog = null;
switch (id) {
case CUSTOM_DIALOG_ID:
dialog = new Dialog(WriteResponseMess.this, android.R.style.Theme_DeviceDefault_Light_NoActionBar_Fullscreen);
dialog.setContentView(R.layout.dialog_layout);
dialog.setCanceledOnTouchOutside(true);
Toolbar toolbar = dialog.findViewById(R.id.toolbar_d);
toolbar.setTitle("Add a new file.");
textFolder = dialog.findViewById(R.id.folder);
buttonUp = dialog.findViewById(R.id.up);
buttonUp.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
ListDir(curFolder.getParentFile());
}
});
dialog_ListView = dialog.findViewById(R.id.dialoglist);
final Dialog finalDialog1 = dialog;
dialog_ListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#RequiresApi(api = Build.VERSION_CODES.O)
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
File selected = new File(curFolder, fileList.get(position));
if (selected.isDirectory()) {
ListDir(selected);
}
if (selected.isFile()) {
if (array.size() == 0) {
array = uploadFiles(array, selected.getName(), convertFileToString(selected.getPath()));
adapter.notifyDataSetChanged();
getImages();
} else {
if (array.toString().contains(selected.getName())) {
Toast.makeText(WriteResponseMess.this, R.string.attaching_message, Toast.LENGTH_SHORT).show();
adapter.notifyDataSetChanged();
getImages();
} else {
array = uploadFiles(array, selected.getName(), convertFileToString(selected.getPath()));
adapter.notifyDataSetChanged();
getImages();
}
}
finalDialog1.dismiss();
ms.setArray(array);
}
}
});
break;
}
return dialog;
}
and method for showing attached list, and in general this method works when I create a new message and attach a new file, it works fine:
private void getImages() {
mNames.clear();
adapter.notifyDataSetChanged();
for (int i = 0; i < array.size(); i++) {
JsonObject object = array.get(i).getAsJsonObject();
if (extras != null) {
if (extras.containsKey("attached_files")) {
for (int j = 0; j < draft_files.size(); j++) {
mNames.clear();
mNames.add(draft_files.get(j));
adapter.notifyDataSetChanged();
//Log.w("MY_TAG", draft_files.get(i));
Log.w("MY_TAG", String.valueOf(mNames));
}
mNames.add(object.get("filename").toString().substring(1, object.get("filename").toString().length() - 1));
adapter.notifyDataSetChanged();
//Log.w("MY_TAG", Arrays.toString(draft_files));
Log.w("MY_TAG", Arrays.toString(new ArrayList[]{mNames}));
} else {
mNames.add(object.get("filename").toString().substring(1, object.get("filename").toString().length() - 1));
adapter.notifyDataSetChanged();
Log.w("MY_TAG", String.valueOf(mNames));
}
}
}
}

no need to set Adapter twice . remove this line
recyclerView.setAdapter(adapter);
From
for (int i = 0; i < draft_files.size(); i++) {
mNames.addAll(Collections.singleton(draft_files.get(i)));
adapter.notifyDataSetChanged();
//recyclerView.setAdapter(adapter); no need
Log.w("MY_TAG", draft_files.get(i));
Log.w("MY_TAG", String.valueOf(mNames));
}

how to save the state of those items which have been selected in recyler view even after the app is closed

What I want to do is to show the same selected items on a recycler view even after the activity has been closed and only change items color when I again click on it. For now I have achieved changing the color on click but the state doesn't get saved?
This is my adapter:
public class LightsRecyclerViewAdapter extends
RecyclerView.Adapter<LightsRecyclerViewAdapter.ViewHolder> {
// private List<Integer> mViewColors;
private List<String> mAnimals;
private LayoutInflater mInflater;
private ItemClickListener mClickListener;
// data is passed into the constructor
LightsRecyclerViewAdapter(Context context, List<String>
animals) {
this.mInflater = LayoutInflater.from(context);
this.mAnimals = animals;
}
// inflates the row layout from xml when needed
#Override
#NonNull
public ViewHolder onCreateViewHolder(#NonNull ViewGroup
parent, int viewType) {
View view = mInflater.inflate(R.layout.item, parent,
false);
return new ViewHolder(view);
}
// binds the data to the view and textview in each row
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int
position) {
// int color = mViewColors.get(position);
String animal = mAnimals.get(position);
// holder.myView.setBackgroundColor(color);
holder.myTextView.setText(animal);
}
// total number of rows
#Override
public int getItemCount() {
return mAnimals.size();
}
// stores and recycles views as they are scrolled off screen
public class ViewHolder extends RecyclerView.ViewHolder
implements View.OnClickListener {
View myView;
TextView myTextView;
ViewHolder(View itemView) {
super(itemView);
// myView = itemView.findViewById(R.id.colorView);
myTextView =
itemView.findViewById(R.id.tvAnimalName);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View view) {
if (mClickListener != null)
mClickListener.onItemClick(view, getAdapterPosition());
}
}
// convenience method for getting data at click position
public String getItem(int id) {
return mAnimals.get(id);
}
// allows clicks events to be caught
public 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);
}
}
And this is my activity:
public class DevicesList extends AppCompatActivity implements
LightsRecyclerViewAdapter.ItemClickListener{
private LightsRecyclerViewAdapter adapter,adapter1;
TextView title;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_devices_list);
title = (TextView)findViewById(R.id.textGrid);
// data to populate the RecyclerView with
ArrayList<Integer> viewColors = new ArrayList<>();
viewColors.add(Color.BLUE);
viewColors.add(Color.YELLOW);
viewColors.add(Color.MAGENTA);
viewColors.add(Color.RED);
viewColors.add(Color.BLACK);
ArrayList<String> Lab1LightsList = new ArrayList<>();
Lab1LightsList.add("Light 1");
Lab1LightsList.add("Light 2");
Lab1LightsList.add("Light 3");
Lab1LightsList.add("Light 4");
Lab1LightsList.add("Light 5");
ArrayList<String> Lab1ACList = new ArrayList<>();
Lab1ACList.add("AC 1");
Lab1ACList.add("AC 2");
Lab1ACList.add("AC 3");
Lab1ACList.add("AC 4");
Lab1ACList.add("AC 5");
ArrayList<String> Lab2LightsList = new ArrayList<>();
Lab2LightsList.add("Light 1");
Lab2LightsList.add("Light 2");
Lab2LightsList.add("Light 3");
Lab2LightsList.add("Light 4");
Lab2LightsList.add("Light 5");
Lab2LightsList.add("Light 6");
ArrayList<String> Lab2ACList = new ArrayList<>();
Lab2ACList.add("AC 1");
Lab2ACList.add("AC 2");
Lab2ACList.add("AC 3");
Lab2ACList.add("AC 4");
// set up the RecyclerView
RecyclerView recyclerView = findViewById(R.id.list1);
RecyclerView recyclerView1 =findViewById(R.id.list2);
LinearLayoutManager horizontalLayoutManagaer
= new LinearLayoutManager(DevicesList.this, LinearLayoutManager.HORIZONTAL, false);
LinearLayoutManager horizontalLayoutManager
= new LinearLayoutManager(DevicesList.this, LinearLayoutManager.HORIZONTAL, false);
recyclerView.setLayoutManager(horizontalLayoutManagaer);
recyclerView1.setLayoutManager(horizontalLayoutManager);
Intent mIntent = getIntent();
int intValue = mIntent.getIntExtra("labno", 0);
if(intValue==0) {
adapter = new LightsRecyclerViewAdapter(this, Lab1LightsList);
adapter1 = new LightsRecyclerViewAdapter(this, Lab1ACList);
adapter.setClickListener(this);
adapter1.setClickListener(this);
recyclerView.setAdapter(adapter);
recyclerView1.setAdapter(adapter1);
}
if(intValue==1) {
adapter = new LightsRecyclerViewAdapter(this, Lab2LightsList);
adapter1 = new LightsRecyclerViewAdapter(this, Lab2ACList);
adapter.setClickListener(this);
adapter1.setClickListener(this);
recyclerView.setAdapter(adapter);
recyclerView1.setAdapter(adapter1);
}
}
#Override
public void onItemClick(View view, int position) {
Toast.makeText(this, "You clicked " +
adapter.getItem(position) + " on item position " + position,
Toast.LENGTH_SHORT).show();
view.setBackgroundColor(getResources().getColor(R.color.colorPrimaryDark));
}
}
Please help on this.

Create one selected item position list and store it in prefs when an app goes to background or closed. Load that list when launching an app and compare that list in an adapter's onBindViewHolder's position parameter and marks it selected/unselected based on a comparison.

As per my understandings about your question, you want to save the state of the selected items even after the app is closed, and then you want to reload it whenever the app is launched again. You need to refer to this link Android Save Data
For the above solution, there can be various ways to save state, I am mentioning a few below:
Use SQLite Database to save the selected items. Then, whenever the app is loaded, fetch all the selected data from the DB and then mark them selected with whatever colour you want on the list.
You can also use Shared Preferences, to store the selection. And, same as above, you can reload the data when the app is launched.
You can also store the data in a specific format, maybe CSV, JSON, XML etc., in a file and save it either in Internal Storage or External Storage of the device. And when the app is launched, fetch all the selected values from the file and process accordingly.
You can also use a web server, Firebase Storage, or other cloud storage services to save the data and then fetch the data on new app launch.
Do note: All these techniques require you to save the state before the app is closed. So it is better to store the states, either on click of the item, or onPause method of the activity.
If you face any problems with these solutions, you can post another comment and I will give it a look.

Save these clicked item position in a hashmap in Shareprefence. suppose u close the activity after u coming back the activity just pass the saved list with ur data in adapter and compare the shareprefence list with ur data list if position or data match than make the itemview layout colored.
// save clicked item is a list and save it sharePreference.
List<Integer> clikedList = new ArrayList<>();
if (clicked item){
ClikedList.add(position)
}
String value = gson.toJson(list);
SharedPreferences prefs = context.getSharedPreferences("mylist",
Context.MODE_PRIVATE);
Editor e = prefs.edit();
e.putString("list", value);
e.commit();
// for getting cliked position list from SharePreference
SharedPreferences prefs = context.getSharedPreferences("mylist",
Context.MODE_PRIVATE);
String value = prefs.getString("list", null);
GsonBuilder gsonb = new GsonBuilder();
Gson gson = gsonb.create();
MyObject[] list = gson.fromJson(value, MyObject[].class);
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
// suppose clicked position 4 u get from shaved cliked list
in here u neddd to retreive cliked list position and clored those item
int select = 4;
if (select == position) {
holder.itemView.setBackgroundColor(Color.BLUE);
Toast.makeText(context, "" + position, Toast.LENGTH_SHORT).show();
} else {
holder.itemView.setBackgroundColor(Color.parseColor("#214F4B"));
Toast.makeText(context, "" + position, Toast.LENGTH_SHORT).show();
}
holder.tv_title.setText(data.get(position));
}

Get the values from GridView items

I am working on a project where I have a let's say 5x5 grid of TextViews and I want to check if an entire row or column has equal elements. I am using an Adapter class to inflate my gridview with simply one textview element. Here is the code that I have tried but I cannot seem to make it work:
final int size = gridView.getCount(); //25
int temp = 0;
for (int i = 0; i < size; i++) {
ViewGroup gridChild = (ViewGroup) gridView.getChildAt(i);
childSize = gridChild.getChildCount();
for (int j = 0; j < childSize; j++) {
if (gridChild.getChildAt(j) instanceof TextView &&
((TextView) gridChild.getChildAt(j)).getText().toString().equals("x")) {
temp++;
}
The thing is when i tried to debug, debugger showed null values for childSize variable and could not properly get the value from getChildAt. Basically, what I am trying to do is get inside the if statement. Also this is the first time I am working with ViewGroup calss, and the methods that I call. Any help would be appreciated.
Edit:I am looking for a way to do this outside the getView method in the adapter class and not in a onClick method as well. (Code sample answers would be highly appreciated). Also, the getChildAt method call returns null so the code I have shown would not work because I am assigning a null value to the gridChild.
This is the onClick that I use for the TextViews:
`
public void numberFill(View view) {
if (((TextView) view).getText().toString().isEmpty()) {
((TextView) view).setText(String.valueOf(numbCounter + 1));
numbCounter++;
}
else if (!((TextView) view).getText().toString().isEmpty() && numbCounter >= 16) {
((TextView) view).setText("x");
}
}
This is my adapter class:
public class GridAdapter extends BaseAdapter {
private final Context mContext;
private String[] numbers;
public GridAdapter(Context context, String[] numbers) {
this.mContext = context;
this.numbers = numbers;
}
#Override
public int getCount() {
return numbers.length;
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
public Object getItem(int position) {
return numbers[position];
//return null;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater)
mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View gridView;
if (convertView == null) {
gridView = new View(mContext);
gridView = inflater.inflate(R.layout.textview_layout, null);
TextView textView = (TextView) gridView.findViewById(R.id.cell);
textView.setText(numbers[position]);
} else {
gridView = (View) convertView;
}
return gridView;
}
}
numberFill reworked:
public void numberFill(View view) {
int index = (Integer) view.getTag();
if (numbers[index].toString().isEmpty()) {
numbers[index] = String.valueOf(numbCounter + 1);
numbCounter++;
}
else if (!numbers[index].toString().isEmpty() && numbCounter >= 25) {
numbers[index] = "x";
}
gridAdapter.notifyDataSetChanged();
}
`

When using an AdapterView – such as your GridView – you generally don't want to directly access and manipulate its child Views outside of its Adapter. Instead, the dataset backing the Adapter should be updated, and the GridView then refreshed.
In your case, you presumably have a setup similar to this in your Activity:
private GridAdapter gridAdapter;
private String[] numbers;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
numbers = new String[25];
gridAdapter = new GridAdapter(this, numbers);
}
Here, the numbers array is what you want to directly modify, rather than the text on the GridView's child TextViews. That array is then easily iterated over to do your row and column value checks.
Since the array will be modified in the Activity, we need a way to pass the clicked TextView's position in the Adapter to the Activity's click method, as we'll need it to access the correct array element. For this, we can utilize the tag property available on all View's, via the setTag() and getTag() methods. For example, in GridAdapter's getView() method:
...
TextView textView = (TextView) gridView.findViewById(R.id.cell);
textView.setText(numbers[position]);
textView.setTag(position);
...
In the click method, the position can be easily retrieved with getTag(), and used as the index to get the clicked TextView's text from the numbers array. You can then do the necessary processing or calculation with that text, set the modified value back to the array element, and trigger a refresh on the Adapter.
public void numberFill(View view) {
int index = (Integer) view.getTag();
// Do your processing with numbers[index]
numbers[index] = "new value";
gridAdapter.notifyDataSetChanged();
}
The notifyDataSetChanged() call will cause the GridView to update its children, and your new value will be set in the appropriate TextView. The numbers array now also has the current values, and is readily available in the Activity to perform the necessary checks there.

List.setAdapter(thadapter); not work always + screen errors

Hello I have a problwm witch Listview.
I use listview for show items in list.
I have activity where is Listview. And If I longpress on row in listview open popup (dialog) where I can edit word in row.
If edit finish I Call this
AddItemInPacage.obnovitem=true;
AddItemInPacage.indexitem=poz;
AddItemInPacage.novyitem=novypacage;
Boolean is for Timer if is true Start This method
public void ZmenItem(int indexzmeny,String nove) {
ListAdapter.clear();
for (int i=1;i<prvy.getPacageItem2(indexpacage)+1;i++) {
ListAdapter.add(String.valueOf(prvy.citajItem(indexpacage,i)));
}
ListAdapter.set(indexzmeny,nove);
Toast.makeText(this, "citam "+ ListAdapter.get(indexzmeny), Toast.LENGTH_SHORT).show();
thadapter = new MyThumbnailAdapter(getApplication(), R.layout.list_row, ListAdapter);
List.setAdapter(thadapter);
thadapter.notifyDataSetChanged();
}
Everything is OK when I while I not open the same row. If edited row for some times in row Program not work good.
Everything is good while this line List.setAdapter(thadapter); after thise line is Variables good too, but listview in display not rewrite.
Why?
I have three times this List.setAdapter(thadapter); on program but on OnCreate method and when Put new row in listview... So when Edited row I call only thise method ↑↑ which sometimes rewrite good and sometimes not.
Because Thise program isn't it 100% good :(
ListView List;
MyThumbnailAdapter thadapter = null;
ArrayList<String> ListAdapter = new ArrayList<String>();
This is my Adapter
public class MyThumbnailAdapter extends ArrayAdapter<String> {
ArrayList<String> arr;
private TextView text;
public MyThumbnailAdapter(Context context, int textViewResourceId, ArrayList<String> objects) {
super(context, textViewResourceId, objects);
this.arr = objects;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
View view = null;
LayoutInflater inflater = getLayoutInflater();
view = inflater.inflate(R.layout.list_row, parent, false);
TextView textnumber = (TextView) view.findViewById(R.id.text);
ImageView delButton = (ImageView) view.findViewById(R.id.btn_del);
Typeface robtoLight = Typeface.createFromAsset(getContext().getAssets(), "fonts/Roboto-Light.ttf");
textnumber.setTypeface(robtoLight);
delButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
arr.remove(position);
thadapter.notifyDataSetChanged();
Toast.makeText(getContext(), "Item deleted", Toast.LENGTH_SHORT).show();
}
});
textnumber.setText(arr.get(position));
textnumber.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
for (int i=ListAdapter.size()-1;i>=0;i--) {
// for (int i = 0; i < ListAdapter.size() ; i++) {
try {
prvy.pridajItemRemove(ListAdapter.get(i), indexpacage, i+1);
} catch(IndexOutOfBoundsException e) {
prvy.Nulak(indexpacage,i);
}
}
prvy.setPacageItem2(ListAdapter.size(),indexpacage);
prvy.setPocItem(ListAdapter.size());
for (int i=ListAdapter.size();i<99;i++) {
prvy.Nulak(indexpacage,i+1);
}
Serializuj(prvy,nazovtripu);
EditItemDialog cdd=new EditItemDialog(AddItemInPacage.this,nazovtripu,position,indexpacage);
cdd.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
cdd.show();
return true;
}
});
return view;
}
}
I put picture
Sometimes if I edit row Toas read good string, but Listview no rewrite.

This may help you
ListAdapter.notifyDataSetChanged()
Hoping ListAdapter is name of your adapter

I need synchronized confirm edit in Dialog with medhod which rewrite Listview.
Or switch sequence from
AddItemInPacage.obnovitem=true;
AddItemInPacage.indexitem=poz;
AddItemInPacage.novyitem=novypacage;
to
AddItemInPacage.indexitem=poz;
AddItemInPacage.novyitem=novypacage;
AddItemInPacage.obnovitem=true;
Because If AddItemInPacage.obnovitem=true; first Activity work with old information in variable novypacage. And when variable novypacage is full from dialog. Listview finish work with old information in this variable.

Android RecyclerView addition & removal of items

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);