How to authorize an AutoCompleteTextView field to make a limited change to the available options?

Question

I'm trying to make my autoCategory_book variable only allow changing the value change for the options provided by category_book not allowing user input, the problem is that the field is closed for any change, leaving the value shown totally static for the change.

How do I authorize the autoCategory_bookto change to just the category_book options, that's my question.

Got it, simulate a Spinner in autoCategory_book to change the current option to another option.

• The line blocking the field is this one, located in BookAdapter.java.

    autoCategory_book.setKeyListener(null);

• string.xml

    <string-array name="category_book">
                <item> Self help </item>
                <item> Biography </item>
                <item> Education </item>
                <item> Science fiction </item>
                <item> Manual </item>
                <item> Literature </item>
                <item> Romance </item>
            </string-array> 

  

• BookAdapter.java

    public class ViewHolder extends RecyclerView.ViewHolder{
            
            AutoCompleteTextView autoCategory_book;
            String[] Category_book;

            public ViewHolder(@NonNull View itemView) {
                super(itemView);
                
                autoCategory_book = itemView.findViewById(R.id.autoCategory_book);
                autoCategory_book.setKeyListener(null);
                Category_book = itemView.getResources().getStringArray(R.array.category_book);
                ArrayAdapter<String> adapter = new ArrayAdapter<>(itemView.getContext(),android.R.layout.simple_list_item_1, Category_book);
                autoCategory_book.setThreshold(0);
                autoCategory_book.setAdapter(adapter);

                autoCategory_book.setOnFocusChangeListener((v, hasFocus) -> {
                    if (hasFocus) {
                        autoCategory_book.showDropDown();
                    }
                });

            }
    }