How to Get Selected Item Count, Select/De-Select all Items in Recyclerview WIth Checkboxes?

Question

I have a fragment which has a list of items in a recycled view. Underneath them is a checkbox which has "invisible" state. When an item is clicked, I toggle this state. So far I have gotten this to work but not sure I used the best approach.

The issue here is that I want to be able to check/uncheck all items from the main checkbox in the fragment's toolbar and also get the total count of selected and un-selected items and send them to display in the host activity. I always get the wrong values and not able to check all the items from the activity. Is this implementation right?

I have initialized all views properly and able to display the lsit but when I tried passing a method with values from adapter viewholder to parent fragment, nothing reflects.

Fragment Code: // skipped initializations

 public class MarkAttendanceFragment extends DialogFragment implements View.OnClickListener, CompoundButton.OnCheckedChangeListener {

private static final String TAG = MarkAttendanceFragment.class.getSimpleName();

private Toolbar toolbar;
private ImageView closeIV;
private TextView sessionNameAttendanceTV, totalTV, presentTV, absentTV;
private Button doneBtn;

private CheckBox checkAll;

private RecyclerView attRV;
private MarkAttendanceAdapter adapter;
private List<PlayerSession> playersList = new ArrayList<>();

private int numPresent = 0, numAbsent = 0, sumPlayers = 0;

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_mark_attendance, container, false);

    init(view);
    ((AppCompatActivity) getActivity()).setSupportActionBar(toolbar);

    closeIV.setOnClickListener(this);
    checkAll.setOnCheckedChangeListener(this);
    doneBtn.setOnClickListener(this);

    return view;
}

private void init(View view) {
    numPresent = adapter.sendNumChecked();
    Log.d(TAG, "Num Checked:\t" + numPresent);
    presentTV.setText(numPresent + "");

    sumPlayers = adapter.getItemCount();
    Log.d(TAG, "Sum Players:\t" + sumPlayers);
    totalTV.setText(sumPlayers + "");

    numAbsent = sumPlayers - numPresent;
    Log.d(TAG, "Num Absent:\t" + numAbsent);
    absentTV.setText(numAbsent + "");
  }

and check all method using the compound button of fragment checkbox:

 @Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    if (isChecked) {
        adapter.checkAll();
    } else {
        adapter.unCheckAll();
    }
}

Here's the adapter methods:

 @Override
public void onBindViewHolder(final MarkAttendanceViewHolder viewholder, int position) {
    final PlayerSession players = itemsList.get(position);
    viewholder.namePlayerTV.setText(players.getFirstName() + " " + players.getLastName());
    Picasso.with(context)
            .load(players.getImageURL())
            .placeholder(R.drawable.app_logo_resized)
            .into(viewholder.playerAvatarIV);

    final boolean isClicked = players.isSelected();
    viewholder.playerAvatarIV.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

    //                viewholder.checkBoxPlayer.setVisibility(isClicked ? View.VISIBLE : View.INVISIBLE);
   //                players.setSelected(!players.isSelected());
   //                players.setSelected(!isClicked);
   //                Log.d(TAG, "Sel Status " + players.isSelected());

   //                boolean isChecked = viewholder.checkBoxPlayer.isChecked();

            if (viewholder.checkBoxPlayer.isChecked()) {

    //                    if (selectedList.contains(players.getFirstName())) {
   //                        selectedList.remove(players.getFirstName());
   //                        Log.d(TAG, "Removed:\t" + players.getFirstName());
   //                    }

                viewholder.checkBoxPlayer.setChecked(false);
                viewholder.checkBoxPlayer.setVisibility(View.INVISIBLE);

            } else {
  //                    if (!selectedList.contains(players.getFirstName())) {
  //                        selectedList.add(players.getFirstName());
  //                        Log.d(TAG, "Added:\t" + players.getFirstName());
 //                    }
                viewholder.checkBoxPlayer.setChecked(true);
                viewholder.checkBoxPlayer.setVisibility(View.VISIBLE);
            }
        }
    });

    viewholder.checkBoxPlayer.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            Log.d(TAG, "Checked:\t" + isChecked);
            if (isChecked) {
                viewholder.checkBoxPlayer.setVisibility(View.VISIBLE);
                players.setSelected(isChecked);
                numPresent++;
                Log.d(TAG, "Checkbox visible:\t and count:\t" + numPresent);
            } else {
                viewholder.checkBoxPlayer.setVisibility(View.INVISIBLE);
                players.setSelected(isChecked);
                numPresent--;
                Log.d(TAG, "Checkbox invisible:\t and count:\t" + numPresent);
            }
        }
    });
}

@Override
public int getItemCount() {
    if (itemsList == null) {
        return 0;
    }
    return itemsList.size();
}

public void checkAll() {
    vh.checkBoxPlayer.setChecked(true);
}

public void unCheckAll() {
    vh.checkBoxPlayer.setChecked(false);
}

public int sendNumChecked() {
    return numPresent;
}     

The text views in fragment should get dynamic updates of checked state from the recycled view adapter and also when all items are checked or unchecked. How do I finish this implementation? Thanks.

Answer 1

I use the below method and it works for me. You have defined onCheckedChanged() now when use check/uncheck the checkbox in fragment I assign particular value to my data source ArrayList using Iterator and set the adapter to list.

chk_select_all_users.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
   selectUsers(b);
}
});

now in selectUsers() check boolean to true/false and set adapter again.

private void selectUsers(boolean check) {
    Iterator<PlayerSession> iterator = userdata.iterator();
    while (iterator.hasNext()) {
        PlayerSession temp = iterator.next();
        temp.setSelected(check);
    }

        //set adapter to list again.
}

You will need to check your list item check box based on value set in model. So, put below code in onBindViewHolder()

if (userData.isSelected()) {
    viewholder.checkBoxPlayer.setChecked(true);
} else {
    viewholder.checkBoxPlayer.setChecked(false);
}