Use this in your adapter:

private ArrayList<WordFolder> actualdata = new ArrayList<WordFolder>();
    private ArrayList<WordFolder> orignallist= new ArrayList<>();

WordAdapter(Context context, ArrayList<WordFolder> word){
        super(context, 0, word);

         this.actualdata=new ArrayList<WordFolder>();
        this.orignallist=new ArrayList<WordFolder>();
        actualdata.addAll(word);//use this to set up your view
        orignallist.addAll(word);


    }


public void filterData(String query){
        query=query.toLowerCase();
 
        actualdata.clear();
        if(query.isEmpty()){
            actualdata.addAll(orignallist);
        }
        else {
            ArrayList<WordFolder> newlist = new ArrayList<>();
            for(WordFolder gd: orignallist) {

                if ((gd.getTitle().contains(query))  ) {
                    newlist.add(gd);
                }
            }

            if(newlist.size()> 0){

                actualdata.addAll(newlist);
            }

        }

        notifyDataSetChanged();
    }

Then change in your mainclass itemAdapter.getfilter() to itemAdapter.filterData("your query")

Now it should work

Hello guys I want to implement a Search interface on my Toolbar to search items in my GridView. However it appears on my Toolbar but when I click the search icon and start typing, nothing pops up. I’m lost on where the issue currently is. I use a custom adapter so I believe there is it bit more work into it.

Here is my custom ArrayAdapter class (WordAdapter). Focus the stuff after the getView() function since I believe that’s the most relevant part of the class. I also added some global variables such as ArrayList<> list and listFull since I believe I needed some copy of my entire item list but honestly I wasn’t sure on how to go about that.

    //variable responsible for making checkbox visible or not
    private boolean displayCheckBox;
    private ArrayList<WordFolder> original_list;
    private ArrayList<WordFolder> new_list;

    //constructor - it takes the context and the list of words
    WordAdapter(Context context, ArrayList<WordFolder> word){
        super(context, 0, word);

        //creating a copy of the ArrayList containing all the folders name
        original_list = new ArrayList<>(word);
        new_list = new ArrayList<>(word);

    }

    //sets the visibility of the checkBox
    public void setCheckBoxVisibility(boolean visible){
        this.displayCheckBox = visible;
    }


    @Override
    public View getView(int position, View convertView, ViewGroup parent){
        View listItemView = convertView;
        if(listItemView == null){
            listItemView = LayoutInflater.from(getContext()).inflate(R.layout.folder_view, parent, false);
        }

        //getting the checkBox view id
        CheckBox checkBox = (CheckBox) listItemView.findViewById(R.id.check_box);
        checkBox.setVisibility(displayCheckBox ? View.VISIBLE : View.GONE);


        //Getting the current word
        final WordFolder currentWord = getItem(position);

        //making the 3 text view to match our word_folder.xml
        TextView date_created = (TextView) listItemView.findViewById(R.id.date_created);

        TextView title = (TextView) listItemView.findViewById(R.id.title);

        TextView desc = (TextView) listItemView.findViewById(R.id.desc);

        //using the setText to get the text and set it in the textView
        date_created.setText(currentWord.getDateCreated());

        title.setText(currentWord.getTitle());

        desc.setText(currentWord.getTitleDesc());

        //call automatically when checkbox is changed
        checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener(){

            @Override
            //compound button = the view of the button
            //b = the new state of the checkbox
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                //set the value of the checkbox to the CurrentWord
                currentWord.setChecked(b);
            }
        });

        return listItemView;

    }
    
    @NonNull
    @Override
    public Filter getFilter() {
        Filter filter = new Filter() {
            @Override
            protected FilterResults performFiltering(CharSequence charSequence) {

                FilterResults filterResults = new FilterResults();

                if (charSequence == null || charSequence.length() == 0) {
                    filterResults.count = original_list.size();
                    filterResults.values = original_list;
                } else {
                    String searchStr = charSequence.toString().toLowerCase();
                    ArrayList<WordFolder> results = new ArrayList<>();
                    for (WordFolder item : original_list) {
                        if (item.getTitle().contains(searchStr)) {
                            results.add(item);
                        }
                        filterResults.count = results.size();
                        filterResults.values = results;
                    }
                }

                //new list which contains only filtered items
                ArrayList<WordFolder> filteredList = new ArrayList<>();
                if(charSequence == null || charSequence.length() == 0){
                    filteredList.addAll(original_list);
                }
                else{
                    String filterPattern = charSequence.toString().toLowerCase().trim();

                    for(WordFolder item : original_list){
                        if(item.getTitle().toLowerCase().contains(filterPattern)){
                            filteredList.add(item);
                        }
                    }
                }

                FilterResults results = new FilterResults();
                results.values = filteredList;
                return results;
            }

            @Override
            protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
                new_list.clear();
                new_list.addAll((ArrayList) filterResults.values);
                notifyDataSetChanged();

            }
        };
        return filter;
    }
}

Here is the part of the code in my MainActivity that I created the Search interface for reference. Btw itemadapter is the name of my custom adapter variable

    public boolean onCreateOptionsMenu(Menu menu) {
        // initialize menu inflater
        MenuInflater inflater = getMenuInflater();
        if(whichToolbar == 0){
            //inflate menu
            inflater.inflate(R.menu.menu_search, menu);
            SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
            SearchView searchView = (SearchView) menu.findItem(R.id.search).getActionView();
            searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
            searchView.setIconifiedByDefault(false);
            //initialize menu item
            MenuItem searchItem = menu.findItem(R.id.search);));
            searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
                @Override
                public boolean onQueryTextSubmit(String s) {
                    itemAdapter.getFilter().filter(s);
                    return true;
                }

                @Override
                public boolean onQueryTextChange(String newText) {
                    itemAdapter.getFilter().filter(newText);
                    return true;
                }
            });
            searchView.setOnCloseListener(new SearchView.OnCloseListener() {
                @Override
                public boolean onClose() {
                    itemAdapter.getFilter().filter("");
                    return false;
                }
            });
             
        }
        else{
            inflater.inflate(R.menu.delete_menu, menu);
        }
        return true;
    }

I updated this since question hasn’t been answered. I’ve been following and watching Youtube videos (not just 1 vid) and the android developer guide about this and made sure the code was “working” and yet my search bar does not do anything at the moment.