Develop Reference

How to make single selection in recyclerview [duplicate]

I know there are no default selection methods in the RecyclerView class, but I have tried in the following way:
public void onBindViewHolder(ViewHolder holder, final int position) {
holder.mTextView.setText(fonts.get(position).getName());
holder.checkBox.setChecked(fonts.get(position).isSelected());
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(isChecked) {
for (int i = 0; i < fonts.size(); i++) {
fonts.get(i).setSelected(false);
}
fonts.get(position).setSelected(isChecked);
}
}
});
}
While trying this code, I got the expected output, but not completely.
I will explain this with images.
By default, the first item is selected from my adapter.
Then I select the 2nd, then the 3rd, then the 4th and finally the 5th one.
Here only the 5th should be selected, but all five are getting selected.
If I scroll the list to the bottom and come again to the top, I get what I expect.
How can I overcome this issue? And sometimes if I scroll the list very fast, some other item gets selected. How can I overcome this problem too?
While I was trying to use notifyDataSetChanged() after fonts.get(position).setSelected(isChecked);, I got the following exception:
java.lang.IllegalStateException: Cannot call this method while RecyclerView is computing a layout or scrolling
at android.support.v7.widget.RecyclerView.assertNotInLayoutOrScroll(RecyclerView.java:1462)
at android.support.v7.widget.RecyclerView$RecyclerViewDataObserver.onChanged(RecyclerView.java:2982)
at android.support.v7.widget.RecyclerView$AdapterDataObservable.notifyChanged(RecyclerView.java:7493)
at android.support.v7.widget.RecyclerView$Adapter.notifyDataSetChanged(RecyclerView.java:4338)
at com.app.myapp.screens.RecycleAdapter.onRowSelect(RecycleAdapter.java:111)

The solution for the issue:
public class yourRecyclerViewAdapter extends RecyclerView.Adapter<yourRecyclerViewAdapter.yourViewHolder> {
private static CheckBox lastChecked = null;
private static int lastCheckedPos = 0;
public void onBindViewHolder(ViewHolder holder, final int position) {
holder.mTextView.setText(fonts.get(position).getName());
holder.checkBox.setChecked(fonts.get(position).isSelected());
holder.checkBox.setTag(new Integer(position));
//for default check in first item
if(position == 0 && fonts.get(0).isSelected() && holder.checkBox.isChecked())
{
lastChecked = holder.checkBox;
lastCheckedPos = 0;
}
holder.checkBox.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
CheckBox cb = (CheckBox)v;
int clickedPos = ((Integer)cb.getTag()).intValue();
if(cb.isChecked())
{
if(lastChecked != null)
{
lastChecked.setChecked(false);
fonts.get(lastCheckedPos).setSelected(false);
}
lastChecked = cb;
lastCheckedPos = clickedPos;
}
else
lastChecked = null;
fonts.get(clickedPos).setSelected(cb.isChecked);
}
});
}
}

It's quite late, but I'm still posting it as it may help someone else.
Use the code below as a reference to check a single item in RecyclerView:
/**
* Created by subrahmanyam on 28-01-2016, 04:02 PM.
*/
public class SampleAdapter extends RecyclerView.Adapter<SampleAdapter.ViewHolder> {
private final String[] list;
private int lastCheckedPosition = -1;
public SampleAdapter(String[] list) {
this.list = list;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = View.inflate(parent.getContext(), R.layout.sample_layout, null);
ViewHolder holder = new ViewHolder(view);
return holder;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.choiceName.setText(list[position]);
holder.radioButton.setChecked(position == lastCheckedPosition);
}
#Override
public int getItemCount() {
return list.length;
}
public class ViewHolder extends RecyclerView.ViewHolder {
#Bind(R.id.choice_name)
TextView choiceName;
#Bind(R.id.choice_select)
RadioButton radioButton;
public ViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
radioButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int copyOfLastCheckedPosition = lastCheckedPosition;
lastCheckedPosition = getAdapterPosition();
notifyItemChanged(copyOfLastCheckedPosition);
notifyItemChanged(lastCheckedPosition);
}
});
}
}
}

This is how it looks:
Inside your Adapter:
private int selectedPosition = -1;
And onBindViewHolder
#Override
public void onBindViewHolder(#NonNull MyViewHolder holder, int position) {
if (selectedPosition == position) {
holder.itemView.setSelected(true); //using selector drawable
holder.tvText.setTextColor(ContextCompat.getColor(holder.tvText.getContext(),R.color.white));
} else {
holder.itemView.setSelected(false);
holder.tvText.setTextColor(ContextCompat.getColor(holder.tvText.getContext(),R.color.black));
}
holder.itemView.setOnClickListener(v -> {
if (selectedPosition >= 0)
notifyItemChanged(selectedPosition);
selectedPosition = holder.getAdapterPosition();
notifyItemChanged(selectedPosition);
});
}
that’s it!
As you can see, I am just notifying (updating) the previous selected item and newly selected item.
My Drawable set it as a background for recyclerview child views:
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_focused="false" android:state_selected="true">
<shape android:shape="rectangle">
<solid android:color="#color/blue" />
</shape>
</item>

You need to clear the OnCheckedChangeListener before setting setChecked():
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
holder.mRadioButton.setOnCheckedChangeListener(null);
holder.mRadioButton.setChecked(position == mCheckedPosition);
holder.mRadioButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
mCheckedPosition = position;
notifyDataSetChanged();
}
});
}
This way it won't trigger the java.lang.IllegalStateException: Cannot call this method while RecyclerView is computing a layout or scrolling error.

Default value:
private int mCheckedPostion = -1;
Just use mCheckedPosition to save the status:
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.checkBox.setChecked(position == mCheckedPostion);
holder.checkBox.setOnClickListener(v -> {
if (position == mCheckedPostion) {
holder.checkBox.setChecked(false);
mCheckedPostion = -1;
}
else {
mCheckedPostion = position;
notifyDataSetChanged();
}
});
}

It looks like there are two things at play here:
(1) The views are reused, so the old listener is still present.
(2) You are changing the data without notifying the adapter of the change.
I will address each separately.
(1) View reuse
Basically, in onBindViewHolder you are given an already initialized ViewHolder, which already contains a view. That ViewHolder may or may not have been previously bound to some data!
Note this bit of code right here:
holder.checkBox.setChecked(fonts.get(position).isSelected());
If the holder has been previously bound, then the checkbox already has a listener for when the checked state changes! That listener is being triggered at this point, which is what was causing your IllegalStateException.
An easy solution would be to remove the listener before calling setChecked. An elegant solution would require more knowledge of your views - I encourage you to look for a nicer way of handling this.
(2) Notify the adapter when data changes
The listener in your code is changing the state of the data without notifying the adapter of any subsequent changes. I don't know how your views are working so this may or may not be an issue. Typically when the state of your data changes, you need to let the adapter know about it.
RecyclerView.Adapter has many options to choose from, including notifyItemChanged, which tells it that a particular item has changed state. This might be good for your use:
if(isChecked) {
for (int i = 0; i < fonts.size(); i++) {
if (i == position) continue;
Font f = fonts.get(i);
if (f.isSelected()) {
f.setSelected(false);
notifyItemChanged(i); // Tell the adapter this item is updated
}
}
fonts.get(position).setSelected(isChecked);
notifyItemChanged(position);
}

This might help for those who want a single radiobutton to work -->
Radio Button RecycleView - Gist
If lambda expressions aren't supported, use this instead:
View.OnClickListener listener = new View.OnClickListener() {
#Override
public void onClick(View v) {
notifyItemChanged(mSelectedItem); // to update last selected item.
mSelectedItem = getAdapterPosition();
}
};

This happens because RecyclerView, as the name suggests, does a good job at recycling its ViewHolders. This means that every ViewHolder, when it goes out of sight (actually, it takes a little more than going out of sight, but it makes sense to simplify it that way), it is recycled; this implies that the RecyclerView takes this ViewHolder that is already inflated and replaces its elements with the elements of another item in your data set.
Now, what is going on here is that once you scroll down and your first, selected, ViewHolders go out of sight, they are being recycled and used for other positions of your data set. Once you go up again, the ViewHolders that were bound to the first 5 items are not necessarely the same, now.
This is why you should keep an internal variable in your adapter that remembers the selection state of each item. This way, in the onBindViewHolder method, you can know if the item whose ViewHolder is currently being bound was selected or not, and modify a View accordingly, in this case your RadioButton's state (though I would suggest to use a CheckBox if you plan on selecting multiple items).
If you want to learn more about RecyclerView and its inner workings, I invite you to check FancyAdapters, a project I started on GitHub. It is a collection of adapters that implement selection, drag&drop of elements and swipe to dismiss capabilities. Maybe by checking the code you can obtain a good understanding on how RecyclerView works.

This simple one worked for me
private RadioButton lastCheckedRB = null;
...
#Override
public void onBindViewHolder(final CoachListViewHolder holder, final int position) {
holder.priceRadioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
RadioButton checked_rb = (RadioButton) group.findViewById(checkedId);
if (lastCheckedRB != null && lastCheckedRB != checked_rb) {
lastCheckedRB.setChecked(false);
}
//store the clicked radiobutton
lastCheckedRB = checked_rb;
}
});

The following might be helpful for RecyclerView with Single Choice.
Three steps to do that,
1) Declare a global integer variable,
private int mSelectedItem = -1;
2) in onBindViewHolder
mRadio.setChecked(position == mSelectedItem);
3) in onClickListener
mSelectedItem = getAdapterPosition();
notifyItemRangeChanged(0, mSingleCheckList.size());
mAdapter.onItemHolderClick(SingleCheckViewHolder.this);

public class GetStudentAdapter extends
RecyclerView.Adapter<GetStudentAdapter.MyViewHolder> {
private List<GetStudentModel> getStudentList;
Context context;
RecyclerView recyclerView;
public class MyViewHolder extends RecyclerView.ViewHolder {
TextView textStudentName;
RadioButton rbSelect;
public MyViewHolder(View view) {
super(view);
textStudentName = (TextView) view.findViewById(R.id.textStudentName);
rbSelect = (RadioButton) view.findViewById(R.id.rbSelect);
}
}
public GetStudentAdapter(Context context, RecyclerView recyclerView, List<GetStudentModel> getStudentList) {
this.getStudentList = getStudentList;
this.recyclerView = recyclerView;
this.context = context;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.select_student_list_item, parent, false);
return new MyViewHolder(itemView);
}
#Override
public void onBindViewHolder(final MyViewHolder holder, final int position) {
holder.textStudentName.setText(getStudentList.get(position).getName());
holder.rbSelect.setChecked(getStudentList.get(position).isSelected());
holder.rbSelect.setTag(position); // This line is important.
holder.rbSelect.setOnClickListener(onStateChangedListener(holder.rbSelect, position));
}
#Override
public int getItemCount() {
return getStudentList.size();
}
private View.OnClickListener onStateChangedListener(final RadioButton checkBox, final int position) {
return new View.OnClickListener() {
#Override
public void onClick(View v) {
if (checkBox.isChecked()) {
for (int i = 0; i < getStudentList.size(); i++) {
getStudentList.get(i).setSelected(false);
}
getStudentList.get(position).setSelected(checkBox.isChecked());
notifyDataSetChanged();
} else {
}
}
};
}
}

This is how the Adapter class looks like :
public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewHolder>{
Context context;
ArrayList<RouteDetailsFromFirestore> routeDetailsFromFirestoreArrayList_;
public int lastSelectedPosition=-1;
public MyRecyclerViewAdapter(Context context, ArrayList<RouteDetailsFromFirestore> routeDetailsFromFirestoreArrayList)
{
this.context = context;
this.routeDetailsFromFirestoreArrayList_ = routeDetailsFromFirestoreArrayList;
}
#NonNull
#Override
public MyRecyclerViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i)
{
// LayoutInflater layoutInflater = LayoutInflater.from(mainActivity_.getBaseContext());
LayoutInflater layoutInflater = LayoutInflater.from(viewGroup.getContext());
View view = layoutInflater.inflate(R.layout.route_details, viewGroup, false);
return new MyRecyclerViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull final MyRecyclerViewHolder myRecyclerViewHolder, final int i) {
/* This is the part where the appropriate checking and unchecking of radio button happens appropriately */
myRecyclerViewHolder.mRadioButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
if(b) {
if (lastSelectedPosition != -1) {
/* Getting the reference to the previously checked radio button and then unchecking it.lastSelectedPosition has the index of the previously selected radioButton */
//RadioButton rb = (RadioButton) ((MainActivity) context).linearLayoutManager.getChildAt(lastSelectedPosition).findViewById(R.id.rbRadioButton);
RadioButton rb = (RadioButton) ((MainActivity) myRecyclerViewHolder.mRadioButton.getContext()).linearLayoutManager.getChildAt(lastSelectedPosition).findViewById(R.id.rbRadioButton);
rb.setChecked(false);
}
lastSelectedPosition = i;
/* Checking the currently selected radio button */
myRecyclerViewHolder.mRadioButton.setChecked(true);
}
}
});
}
#Override
public int getItemCount() {
return routeDetailsFromFirestoreArrayList_.size();
}
} // End of Adapter Class
Inside MainActivity.java we call the ctor of Adapter class like this. The context passed is of MainActivity to the Adapter ctor :
myRecyclerViewAdapter = new MyRecyclerViewAdapter(MainActivity.this, routeDetailsList);

I got a solution that will save your selection when you open a recycler list.
var mSelectedItem = -1
// store saved selection
fun setSelection(position: Int) {
mSelectedItem = position
}
override fun onBindViewHolder(holder: GroupHolder, position: Int) {
holder.bind(dataList[position])
holder.radioButton.isChecked = position == mSelectedItem
}
inner class GroupHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val radioButton: RadioButton = itemView.rbValue
fun bind(data: Data) = with(itemView) {
radioButton.text = data.name
val clickListener = View.OnClickListener {
mSelectedItem = bindingAdapterPosition
notifyDataSetChanged()
setSelection(mSelectedItem)
}
radioButton.setOnClickListener(clickListener)
}
}

After spending so many days over this, this is what I came up with which worked for me, and is good practice as well,
Create an interface, name it some listener: SomeSelectedListener.
Add a method which takes an integer:void onSelect(int position);
Initialise the listener in the recycler adapter's constructor as: a) first declare globally as: private SomeSelectedListener listener b) then in constructor initialise as: this.listener = listener;
Inside onClick() of checkbox inside onBindViewHolder(): update the method of the interface/listener by passing the position as: listener.onSelect(position)
In the model, add a variable for deselect say, mSelectedConstant and initialise it there to 0. This represents the default state when nothing is selected.
Add getter and setter for the mSelectedConstant in the same model.
Now, go to your fragment/activity and implement the listener interface. Then override its method: onSelect(int position). Within this method, iterate through your list which you are passing to your adapter using a for loop and setSelectedConstant to 0 for all:
Code
#Override
public void onTicketSelect(int position) {
for (ListType listName : list) {
listName.setmSelectedConstant(0);
}
Outside this, make the selected position constant 1:
Code
list.get(position).setmSelectedConstant(1);
Notify this change by calling: adapter.notifyDataSetChanged(); immediately after this.
Last step: go back to your adapter and update inside onBindViewHolder() after onClick() add the code to update the checkbox state,
Code
if (listVarInAdapter.get(position).getmSelectedConstant() == 1) {
holder.checkIcon.setChecked(true);
selectedTicketType = dataSetList.get(position);}
else {
commonHolder.checkCircularIcon.setChecked(false);
}

Here is a similar thing I have achieved.
The below code is from the application to select an address from a list of addresses that are displayed in cardview(cvAddress), so that on click of particular item(cardview) the imageView inside the item should set to a different resource (select/unselect):
#Override
public void onBindViewHolder(final AddressHolder holder, final int position)
{
holderList.add(holder);
holder.tvAddress.setText(addresses.get(position).getAddress());
holder.cvAddress.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
selectCurrItem(position);
}
});
}
private void selectCurrItem(int position)
{
int size = holderList.size();
for(int i = 0; i<size; i++)
{
if(i==position)
holderList.get(i).ivSelect.setImageResource(R.drawable.select);
else
holderList.get(i).ivSelect.setImageResource(R.drawable.unselect);
}
}
I don't know if this is the best solution or not, but this worked for me.

Please try this...
This works for me...
In the adapter, take a sparse Boolean array.
SparseBooleanArray sparseBooleanArray;
In the constructor, initialise this,
sparseBooleanArray = new SparseBooleanArray();
In the bind holder, add:
#Override
public void onBindViewHolder(DispositionViewHolder holder, final int position) {
holder.tv_disposition.setText(dispList.get(position).getName());
if(sparseBooleanArray.get(position,false))
{
holder.rd_disp.setChecked(true);
}
else
{
holder.rd_disp.setChecked(false);
}
setClickListner(holder,position);
}
private void setClickListner(final DispositionViewHolder holder, final int position) {
holder.rd_disp.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
sparseBooleanArray.clear();
sparseBooleanArray.put(position, true);
notifyDataSetChanged();
}
});
}
rd_disp is a radio button in the XML file.
So when the recycler view loads the items, in the bindView Holder, it checks whether the sparseBooleanArray contains the value "true", corresponding to its position.
If the value returned is true then we set the radio button selection true. Else we set the selection false.
In onclickHolder I have cleared the sparseArray and set the value to true corresponding to that position.
When I call notify datasetChange, it again calls the onBindViewHolder and the conditions are checked again. This makes our selection to only select a particular radio.

public class LastTransactionAdapter extends RecyclerView.Adapter<LastTransactionAdapter.MyViewHolder> {
private Context context;
private List<PPCTransaction> ppcTransactionList;
private static int checkedPosition = -1;
public LastTransactionAdapter(Context context, List<PPCTransaction> ppcTransactionList) {
this.context = context;
this.ppcTransactionList = ppcTransactionList;
}
#NonNull
#Override
public LastTransactionAdapter.MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new MyViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.last_transaction_item, parent, false));
}
#Override
public void onBindViewHolder(#NonNull LastTransactionAdapter.MyViewHolder holder, int position) {
holder.setLastTransaction(ppcTransactionList.get(position), position);
}
#Override
public int getItemCount() {
return ppcTransactionList.size();
}
public class MyViewHolder extends RecyclerView.ViewHolder {
private LinearLayout linTransactionItem;
private RadioButton radioButton;
private TextView tvDate, tvMerchantName, tvAmount, tvStatus;
public MyViewHolder(#NonNull View itemView) {
super(itemView);
linTransactionItem = itemView.findViewById(R.id.linTransactionItem);
tvDate = itemView.findViewById(R.id.tvDate);
tvMerchantName = itemView.findViewById(R.id.tvMerchantName);
tvAmount = itemView.findViewById(R.id.tvAmount);
tvStatus = itemView.findViewById(R.id.tvStatus);
radioButton = itemView.findViewById(R.id.radioButton);
}
public void setLastTransaction(PPCTransaction ppcTransaction, int position) {
tvDate.setText(ppcTransaction.getmDate());
tvMerchantName.setText(ppcTransaction.getmMerchantName());
tvAmount.setText(ppcTransaction.getmAmount());
tvStatus.setText(ppcTransaction.getmStatus());
if (checkedPosition == -1) {
radioButton.setChecked(false);
} else {
if (checkedPosition == getAdapterPosition()) {
radioButton.setChecked(true);
} else {
radioButton.setChecked(false);
}
}
linTransactionItem.setOnClickListener(v -> {
radioButton.setChecked(true);
if (checkedPosition != getAdapterPosition()) {
notifyItemChanged(checkedPosition);
checkedPosition = getAdapterPosition();
}
});
}
}

// This work for my with out any visual isue
data class buttonData(val button:RadioButton, val position: Int)
var selectedPosition = -1
override fun onBindViewHolder(holder: SingleChoiceAdapter.OptionHolder, position: Int) {
holder.viewDataBinding.option= options[position]
holder.viewDataBinding.radioButton.setChecked(position == selectedPosition);
buttonList.add( buttonData(holder.viewDataBinding.radioButton,position))
holder.viewDataBinding.radioButton.setOnClickListener {
selectedPosition= position
for(buttonData in buttonList ){
buttonData.button.isChecked = buttonData.position == position
}
}
}

Don't make it too complicated:
SharedPreferences sharedPreferences = getSharedPreferences("appdetails", MODE_PRIVATE);
String selection = sharedPreferences.getString("selection", null);
public void onBindViewHolder(ViewHolder holder, final int position) {
String name = fonts.get(position).getName();
holder.mTextView.setText(name);
if(selection.equals(name)) {
holder.checkBox.setChecked(false); //
holder.checkBox.setChecked(true);
}
holder.checkbox.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
SharedPreferences sharedPreferences = getSharedPreferences("appdetails", MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("selection", name);
r.setChecked(false);
editor.apply();
holder.checkBox.setChecked(true);
}
});
}

Android RecyclerView checkbox checks itself

I have a RecyclerView which has a checkbox and textview.Numbers 10,20,30,40... till 500 should be shown in textview.The Checked checkboxes should add the numbers in the textview corresponding to the checkbox.For eg. if User checks the value 10 only, the textView would show 10. If user checks 20 as well, then
TextView would show 30 ( 20 +10).
If user uncheck 10 again, the TextView would show 20, and so on.When i click on checkbox some random checkbox is also checked.I tried one solution in stackoverflow. It did not work.I am stuck with this.Please help me..Here is my code:
RecyclerAdapter.java:
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.RecyclerHolder>
{
#NonNull
#Override
public RecyclerHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new RecyclerHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_lyt,parent,false));
}
#Override
public void onBindViewHolder(#NonNull RecyclerHolder holder, final int position) {
holder.number.setText(Integer.toString((Integer) alldata.get(position)));
final String text=holder.number.getText().toString();
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
Log.e("Checked","Checked");
if(checkeddata!=null)
{
if (checkeddata.size()==0)
{
checkeddata.add(text);
}
else {
if(checkeddata.contains(text))
{
checkeddata.remove(text);
}
else {
checkeddata.add(text);
}
}
Iterator iterator=checkeddata.iterator();
int sumnumber=0;
while (iterator.hasNext())
{
sumnumber= sumnumber+Integer.parseInt((String) iterator.next());
}
sum.setText(Integer.toString(sumnumber));
}
}
});
}
#Override
public int getItemCount() {
return alldata.size();
}
public class RecyclerHolder extends RecyclerView.ViewHolder
{
TextView number;
CheckBox checkBox;
public RecyclerHolder(View itemView) {
super(itemView);
number=itemView.findViewById(R.id.number);
checkBox=itemView.findViewById(R.id.check);
}
}
}
public void data()
{
int g=1;
for(int i=10;i<=500;i++)
{
if((i/10)==g)
{
g=g+1;
alldata.add(i);
}
}
}
recycler_lyt.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto">
<TextView
android:layout_width="150dp"
android:layout_height="wrap_content"
android:id="#+id/number"
android:textSize="20sp"/>
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/check"
android:checked="false"
app:layout_constraintRight_toRightOf="parent"/>
</android.support.constraint.ConstraintLayout>

It's normal. You are not setting your checkbox selected or not. You are selecting one and View holder keeps it selected
You may look at my example. You can do something like that:
#Override
public void onBindViewHolder(ViewHolder holder, final int position) {
final Data data = myItems.get(position);
//in some cases, it will prevent unwanted situations
holder.checkBox.setOnCheckedChangeListener(null);
//if true, your checkbox will be selected, else unselected
holder.checkBox.setChecked(data.isSelected());
holder.checkBox.setOnCheckedChangeListener(new OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
//set your object's last status
data.setSelected(isChecked);
}
});
}
inside your onBindViewHolder you have to set your checkbox either checked or unchecked.
if true, your checkbox will be selected, else unselected
holder.checkBox.setChecked(boolean);

You must store your checkbox state. You can do that in your model, for example:
class Model {
String title;
boolean checked;
}
Next you must pass List of Model items to your adapter and check/uncheck checkbox determined by your model.
if (listOfItems.get(position).checked) {
viewHolder.checkbox.setChecked(true);
} else {
viewHolder.checkbox.setChecked(false);
}
Remember that you always need to manage opposite state of views (like checkbox or visibility of view) in adapter.

Try This:
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.RecyclerHolder>
{
private OnClickListener onClickListener;
private int sum =0;
#NonNull
#Override
public RecyclerHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new RecyclerHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_lyt,parent,false));
}
#Override
public void onBindViewHolder(#NonNull RecyclerHolder holder, final int position) {
holder.number.setText(Integer.toString((Integer) alldata.get(position)));
final String text=holder.number.getText().toString();
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(isChecked){
sum += Integer.parseInt(holder.number.getText().toString());
}else{
sum -= Integer.parseInt(holder.number.getText().toString());
}
if (onClickListener != null) {
onClickListener.onItemClick(sum);
}
});
}
#Override
public int getItemCount() {
return alldata.size();
}
public class RecyclerHolder extends RecyclerView.ViewHolder
{
TextView number;
CheckBox checkBox;
public RecyclerHolder(View itemView) {
super(itemView);
number=itemView.findViewById(R.id.number);
checkBox=itemView.findViewById(R.id.check);
}
}
public void setOnClickListener(OnClickListener onClickListener) {
this.onClickListener = onClickListener;
}
public interface OnClickListener {
void onItemClick(int sum);
}
}
Now In activity use adapter instance like this:
private RecyclerAdapter adapter;
...
...
cardAdapter.setOnClickListener(new CardAdapter.OnClickListener() {
#Override
public void onItemClick(int sum) {
txtSum.setText(String.valueOf(sum));
});

You need to have a field (like "isSelected") in your model class so that all the checked entries can be tracked.you can try following:
checkboxRecyclerView

Basically, RecyclerView recycles the view so you need a model to store the state of the checkbox.
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.RecyclerHolder> {
private List<Model> alldata = new ArrayList<>();
#NonNull
#Override
public RecyclerHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new RecyclerHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_lyt, parent, false));
}
#Override
public void onBindViewHolder(#NonNull RecyclerHolder holder, final int position) {
final Model model = alldata.get(position);
holder.number.setText(String.valueOf(model.value));
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
model.setChecked(isChecked); // Saves the state of the checkbox.
if (checkeddata != null) {
if (checkeddata.size() == 0) {
checkeddata.add(text);
} else {
if (checkeddata.contains(model.getValue())) {
checkeddata.remove(model.getValue());
} else {
checkeddata.add(model.getValue());
}
}
Iterator iterator = checkeddata.iterator();
int sumnumber = 0;
while (iterator.hasNext()) {
sumnumber = sumnumber + Integer.parseInt((String) iterator.next());
}
sum.setText(Integer.toString(sumnumber));
}
}
});
holder.checkBox.setChecked(model.isChecked()); // Retrieves the state of your checkbox.
}
#Override
public int getItemCount() {
return alldata.size();
}
public class RecyclerHolder extends RecyclerView.ViewHolder {
TextView number;
CheckBox checkBox;
public RecyclerHolder(View itemView) {
super(itemView);
number = itemView.findViewById(R.id.number);
checkBox = itemView.findViewById(R.id.check);
}
}
public void data() {
int g = 1;
for (int i = 10; i <= 500; i++) {
if ((i / 10) == g) {
g = g + 1;
alldata.add(new Model(i));
}
}
}
private class Model {
private int value;
private boolean checked = false;
Model(int value) {
this.value = value;
}
public int getValue() {
return value;
}
public boolean isChecked() {
return checked;
}
public void setChecked(boolean checked) {
this.checked = checked;
}
}
}

If you made the necessary changes to store the state of the checkbox, then:
in onBindViewHolder() after final String text=holder.number.getText().toString(); add this:
holder.checkBox.setOnCheckedChangeListener(null);
holder.checkBox.setChecked(-- stored value --);
and then add the listener for the checkbox.

On Scrolling Check Boxes are getting Unchecked or Vice versa in a RecyclerView

I have a check box in RecyclerView Adapter's View Item.
When scrolling, some check boxes are getting checked and some are getting unchecked.
I have taken help from this and this
But I am unable to find the exact solution to this.
Here is my code
public class AllContactsAdapter extends RecyclerView.Adapter<AllContactsAdapter.ViewHolder> {
private Context context;
private ArrayList<PhoneContactsModel> listOfContacts = new ArrayList<>();
PhoneContactsModel phoneContactsModel;
private ArrayList<PhoneContactsModel> copyOfListOfContacts = new ArrayList<>();
public AllContactsAdapter(Context context, ArrayList<PhoneContactsModel> listOfContacts) {
this.context = context;
this.listOfContacts = listOfContacts;
// copyOfListOfContacts.addAll(listOfContacts);
}
#Override
public AllContactsAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.
adapter_load_allusers_contacts_listitem, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(final AllContactsAdapter.ViewHolder holder, final int position) {
Log.d("tag", "adapter========3");
phoneContactsModel = listOfContacts.get(position);
holder.name.setText(phoneContactsModel.getContactName());
holder.phoneNumber.setText(phoneContactsModel.getContactNumber());
holder.checkBox.setSelected(phoneContactsModel.isChecked());
holder.contactLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (holder.checkBox.isChecked()) {
phoneContactsModel.setChecked(false);
holder.checkBox.setChecked(false);
copyOfListOfContacts.remove(listOfContacts.get(position));
} else {
phoneContactsModel.setChecked(true);
holder.checkBox.setChecked(true);
copyOfListOfContacts.add(listOfContacts.get(position));
}
}
});
}
#Override
public int getItemCount() {
return listOfContacts.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView name, phoneNumber;
private CheckBox checkBox;
private LinearLayout contactLayout;
public ViewHolder(View view) {
super(view);
name = view.findViewById(R.id.contactNameId);
phoneNumber = view.findViewById(R.id.contactNumberId);
checkBox = view.findViewById(R.id.checkBoxId);
contactLayout = view.findViewById(R.id.contactLayoutId);
}
}
}
For example, I have checked 1,2,3 items in list. When I scrolled down and come up , then 13 is checked and 2 is unchecked along with other some items.Please help me.
Any solution is appreciated.

A simple way arround is do not use OnCheckedChangeListener just set OnClickListener on Check box . Move checkBox onclick inside ViewHolder class.
public class ViewHolder1 extends RecyclerView.ViewHolder implements View.OnClickListener {
CheckBox checkBox;
public ViewHolder1(View itemView) {
super(itemView);
checkBox = (TextView) itemView.findViewById(R.id.checkBox);
checkBox.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if(getAdapterPosition()!=-1) {
phoneContactsModel.get(getAdapterPosition()).setChecked(!phoneContactsModel.get(getAdapterPosition()).isChecked());
notifyItemChanged(getAdapterPosition());
}
}
}
And
public void onBindViewHolder(final AllContactsAdapter.ViewHolder holder, final int position) {
holder.checkBox.setChecked(phoneContactsModel.isChecked());
}

notify your adapter.
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
phoneContactsModel.setChecked(b);
//notifyItemChanged(position);(if you want to notify change in single item)
//or
//notifyDataSetChanged();(if you want to notify change in all)
}
});
no need to use this line of code twice
holder.checkBox.setSelected(phoneContactsModel.isChecked());
//this section seems buggy i assume you want to add the item to the list when ever the check box is checked and remove it from the list when ever the check box is unchecked.
holder.contactLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (phoneContactsModel.isChecked()) {
holder.checkBox.setSelected(false);
copyOfListOfContacts.remove(listOfContacts.get(position));
} else {
holder.checkBox.setSelected(true);
copyOfListOfContacts.add(listOfContacts.get(position));
}
}
}
);

#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
final PhoneContactsModel phoneContactsModel = listOfContacts.get(position);
holder.name.setText(phoneContactsModel.getContactName());
holder.phoneNumber.setText(phoneContactsModel.getContactNumber());
holder.checkBox.setChecked(/* gets value from the modal */ phoneContactsModel.isChecked());
holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton compoundButton, boolean value) {
if (compoundButton.isPressed()) {
holder.checkBox.setChecked(value);
// set the value into the modal.
phoneContactsModel.setChecked(value);
if (value) {
copyOfListOfContacts.remove(phoneContactsModel);
} else {
copyOfListOfContacts.add(phoneContactsModel);
}
}
}
});
}
Change your onBindViewHolder method like this. There won't be any unnecessary checks.

how to implement checkbox in recyclerView?

I have an adapter for recyclerview. Where i pass array list from my activity like where data is ArrayList having some data.
AlternativeAdapter alternativeAdapter= new AlternativeAdapter(AlternativeActivity.this, data);
recyclerView.setAdapter(alternativeAdapter);
In the AlternativeAdapter class i have a textview and check box. I am able to display all text item with check boxes.
In the AlternativeAdapter class
public class AlternativeCurrencyAdapter extends RecyclerView.Adapter<AlternativeCurrencyAdapter.ViewHolder>{
ArrayList<String> currencyListArray;
Context context;
View view1;
ViewHolder viewHolder1;
TextView textView;
private int selectedPosition = -1;// no selection by default
public AlternativeCurrencyAdapter(Context context1, ArrayList<String> currencyListArray){
this.currencyListArray = currencyListArray;
context = context1;
}
public class ViewHolder extends RecyclerView.ViewHolder{
public TextView username;
public CheckBox chkSelected;
public ViewHolder(View v){
super(v);
username = (TextView)v.findViewById(R.id.username);
chkSelected = (CheckBox) v.findViewById(R.id.chkSelected);
itemView.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v) {
// get position
int pos = getAdapterPosition();
// check if item still exists
if(pos != RecyclerView.NO_POSITION){
String clickedDataItem = currencyListArray.get(pos);
Toast.makeText(v.getContext(), "You clicked " + clickedDataItem, Toast.LENGTH_SHORT).show();
}
}
});
}
}
#Override
public AlternativeCurrencyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType){
view1 = LayoutInflater.from(context).inflate(R.layout.alternative_currency_adapter_list,parent,false);
viewHolder1 = new ViewHolder(view1);
return viewHolder1;
}
#Override
public void onBindViewHolder(ViewHolder holder, final int position){
holder.username.setText(currencyListArray.get(position));
}
#Override
public int getItemCount(){
return currencyListArray.size();
}
}
By this way the item of array list is displaying but my need is at item should display at left corner and checkbox of each item should display at right corner . when some one clicks on check box toast message should come like you selected XYZ item. And only single selection is required not multi selection.
when i use
holder.chkSelected.setChecked(currencyListArray.get(position).isSelected());
I shows compile time error. Can not resolve isSelected()
Please guide me.

First thing, your currencyListArray is arraylist of string so it doesnot return for "isSelected()" sorry!
and now come to your requirement, you need to show message when any of checkbox is selected.
So code like this:
#Override
public void onBindViewHolder(ViewHolder holder, final int position){
holder.username.setText(currencyListArray.get(position));
holder.chkSelected.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
//do your toast programming here.
}
});
}
now come to your second requirement, for selecting only one item at a time: here is code for that::
chkSelected.setChecked(position== selectedPosition);
chkSelected.setOnCheckedChangeListener(new OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if(isChecked)
{
selectedPosition = position;
}
else{
selectedPosition = -1;
}
notifyDataSetChanged();
}
});

Working example
class ApplicationsAdapter(val userList: ArrayList<DataX>, var callBack: AdapterCallback) :
RecyclerView.Adapter<ApplicationsAdapter.ViewHolder>() {
interface AdapterCallback {
fun onAppLockedUnlocked(position: Int, status: Boolean)
}
//this method is returning the view for each item in the list
override fun onCreateViewHolder(
parent: ViewGroup,
viewType: Int
): ViewHolder {
val v =
LayoutInflater.from(parent.context).inflate(R.layout.item_view_app_list, parent, false)
return ViewHolder(v)
}
//this method is binding the data on the list
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.bindItems(userList[position], callBack)
}
//this method is giving the size of the list
override fun getItemCount(): Int {
return userList.size
}
//the class is hodling the list view
class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
fun bindItems(
dataX: DataX,
callBack: AdapterCallback
) {
val tvAppName = itemView.findViewById(R.id.tvAppName) as TextView
val checkboxLockUnlock = itemView.findViewById(R.id.checkboxLockUnlock) as CheckBox
tvAppName.text = dataX.appName
// set listener null here
checkboxLockUnlock.setOnCheckedChangeListener(null)
if (dataX.isLocked) {
checkboxLockUnlock.isChecked = true
} else {
checkboxLockUnlock.isChecked = false
}
// initialize listener after checkbox state changed
checkboxLockUnlock.setOnCheckedChangeListener(CompoundButton.OnCheckedChangeListener { buttonView, isChecked ->
if (isChecked) {
callBack.onAppLockedUnlocked(adapterPosition, true)
} else {
callBack.onAppLockedUnlocked(adapterPosition, false)
}
}
)
}
}
}

RecyclerView adapter's item click not working according to need

I have a RecyclerView and I have 9 items inside it and when I click on one item it should get selected, but when I select another item it should get selected and the other item should get un-selcted, automatically.
What am I doing wrong, any help is appreciable thanks.
Here is my Adapter's code
class ItemAdapter extends RecyclerView.Adapter<ItemAdapter.DataViewHolder> {
private final int mItemCount;
List<ServicesMenuModel> mServiceList;
SparseBooleanArray mArray = new SparseBooleanArray();
int pos;
ItemAdapter(int itemCount, List<ServicesMenuModel> mServiceList) {
mItemCount = itemCount;
this.mServiceList = mServiceList;
}
#Override
public DataViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.fragment_item_list_dialog_item6, parent, false);
return new DataViewHolder(v);
}
public void changeAt(int position, DataViewHolder holder) {
mArray.delete(position);
notifyItemChanged(position);
holder.mServiceText.setSelected(false);
}
#Override
public void onBindViewHolder(final DataViewHolder holder, int position) {
holder.mServiceText.setText(mServiceList.get(position).getMenuText());
holder.mServiceText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
holder.mServiceText.setSelected(mArray.get(holder.getAdapterPosition(), false));
pos = holder.getAdapterPosition();
//When same item is clicked
if (mArray.get(holder.getAdapterPosition(), false)) {
mArray.delete(pos);
holder.mServiceText.setSelected(false);
} else
//When new item is selected
{
for (int i = 0; i < mServiceList.size(); i++) {
changeAt(i, holder);//checking to remove other items
}
mArray.put(holder.getAdapterPosition(), true);
holder.mServiceText.setSelected(true);
}
if (mListener != null) {
mListener.onItemClicked(holder.getAdapterPosition());
dismiss();
}
}
});
}
#Override
public int getItemCount() {
return mServiceList.size();
}
class DataViewHolder extends RecyclerView.ViewHolder {
TextView mServiceText;
DataViewHolder(View v) {
super(v);
mServiceText = (TextView) v.findViewById(R.id.text);
}
}
}

I presume your requirement is to select one item at a time. I would recommend the following method rather than keeping an array of boolean.
Declare a variable to hold last selected item's index in the adapter class.
int mLastSelectedIndex = -1;
Inside the ViewHolder define the onClick method like this.
void setUpOnClick(final int position) {
boolean selection = position == mLastSelectedPosition;
mServiceText.setSelected(selection);
mServiceText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int tempOldIndex = mLastSelectedPosition;
mLastSelectedPosition = position;
if (tempOldIndex >= 0) {
notifyItemChanged(tempOldIndex);
}
notifyItemChanged(position);
// your regular code
}
}
}
at last, call it inside onBindViewHolder
#Override
public void onBindViewHolder(final DataViewHolder holder, int position {
holder.setUpOnClick(position);
// your regular code
}

This is certainly a wrong way to do this:
holder.mServiceText.setSelected(false);
Because this ViewHolder is being reused for another items of your RecyclerView too, which will make other items of RecyclerView to be selected as you scroll up and forth.
Instead, declare a field in ViewHolder, e.g. boolean isSelected and mutate that field:
holder.isSelected = true;
Then in onBindViewHolder() show the content depending on that boolean:
if (holder.isSelected) {
// display selected content
} else {
// display unselected content
}

I didn't test but it would work. Main key is using list instance.
Hope it's helpful. Also if your listener make some UI change I would put notify~ function to the place where your adapter is being used.
package net.deali.ssmarket.view;
import android.support.v7.widget.RecyclerView;
import android.util.SparseBooleanArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import net.deali.ssmarket.R;
import java.util.List;
import static android.media.CamcorderProfile.get;
/**
* Created by soochun on 2017-04-24.
*/
class ItemAdapter extends RecyclerView.Adapter<ItemAdapter.DataViewHolder> {
List<ServicesMenuModel> mServiceList;
ItemAdapter(int itemCount, List<ServicesMenuModel> mServiceList) {
this.mServiceList = mServiceList;
}
#Override
public DataViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.fragment_item_list_dialog_item6, parent, false);
return new DataViewHolder(v);
}
public void changeAt(int position, DataViewHolder holder) {
notifyItemChanged(position);
holder.mServiceText.setSelected(false);
}
#Override
public void onBindViewHolder(final DataViewHolder holder, final int position) {
final ServicesMenuModel item = mServiceList.get(position);
holder.mServiceText.setText(item.getMenuText());
holder.mServiceText.setSelected(item.isSelected());
holder.mServiceText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
boolean setValue = !item.isSelected();
item.setSelected(setValue);
notifyItemChanged(position, item);
//if even one item is selected, should make other items make unselected.
if (setValue) {
int i = 0;
for (ServicesMenuModel servicesMenuModel : mServiceList) {
if (i != position) {
servicesMenuModel.setSelected(false);
}
i++;
}
notifyDataSetChanged(); //if recyclerView move top postion try to use notifyItemRangeChanged(0, mServiceList.size());
}
if (mListener != null) {
mListener.onItemClicked(position);
dismiss();
}
}
});
}
#Override
public int getItemCount() {
return mServiceList.size();
}
class DataViewHolder extends RecyclerView.ViewHolder {
TextView mServiceText;
DataViewHolder(View v) {
super(v);
mServiceText = (TextView) v.findViewById(R.id.text);
}
}
class ServicesMenuModel {
String menuText;
boolean isSelected;
public String getMenuText() {
return menuText;
}
public void setMenuText(String menuText) {
this.menuText = menuText;
}
public boolean isSelected() {
return isSelected;
}
public void setSelected(boolean selected) {
isSelected = selected;
}
}
}