implement getFilter in customAdapter that extends BaseAdapter

Question

premise: i'm newbie on Java and Android, and i've search a lot for this but i don't understand how implement getFilter in my code.

this is MainActivity (relevant code):

public void loadList() {

  /* allProd and allSpec are ArrayList<String> */
  String[] allProdString = allProd.toArray(new String[allProd.size()]);
  String[] allSpecString = allSpec.toArray(new String[allSpec.size()]);

  listViewAdapter = new ListViewAdapter(this, allProdString, allSpecString);

  listView.setAdapter(listViewAdapter);

}

this is customAdapter:

public class ListViewAdapter extends BaseAdapter {

Activity context;
String title[];
String description[];

public ListViewAdapter(Activity context, String[] title, String[] description) {

    super();
    this.context = context;
    this.title = title;
    this.description = description;
}

public int getCount() {
    return title.length;
}

public Object getItem(int position) {
    return position;
}

public long getItemId(int position) {
    return position;
}

private class ViewHolder {

    TextView txtViewTitle;
    TextView txtViewDescription;

}

public View getView(int position, View convertView, ViewGroup parent) {

    Typeface typeface = Typeface.createFromAsset(context.getAssets(), "font/Simple_Print.ttf");

    ViewHolder holder;
    LayoutInflater inflater =  context.getLayoutInflater();

    if (convertView == null) {

        convertView = inflater.inflate(R.layout.tabella_prodotti, null);
        holder = new ViewHolder();
        holder.txtViewTitle = (TextView) convertView.findViewById(R.id.titoloProd);
        holder.txtViewDescription = (TextView) convertView.findViewById(R.id.subtitoloProd);

        holder.txtViewDescription.setTypeface(typeface);
        holder.txtViewTitle.setTypeface(typeface);

        convertView.setTag(holder);
    }
    else {
        holder = (ViewHolder) convertView.getTag();
    }

    holder.txtViewTitle.setText(title [position]);
    holder.txtViewDescription.setText(description [position]);

    return convertView;

 }

}

how can I implement this function to have the ability to search within an array, and show the filtered results in the listview?

if you need any other info just ask! thanks

Answer 1

I have found a solution and share with you, I added addTextChangedListener to inputSearch in MainActivity:

inputSearch.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {

            textLength = inputSearch.getText().length();
            //allProd_sort and allSpec_sort are ArrayList for search
            allProd_sort.clear();
            allSpec_sort.clear();
            String text = inputSearch.getText().toString();

            //allProdString is the String get from ArrayList allProd
            for (int y =0; y<allProdString.length; y++) {

                  //in my case the search works only if there are min 3 characters in search
                 if (textLength <= allProdString[y].length() && textLength >=3) {

                      if (Pattern.compile(Pattern.quote(text), Pattern.CASE_INSENSITIVE)
                                .matcher(allProdString[y]).find()) {

                          allProd_sort.add(allProdString[y]);
                          allSpec_sort.add(allSpecString[y]);
                      }
                  }
               }

               String[] allProdStringSort = allProd_sort.toArray(new String[allProd_sort.size()]);
               String[] allSpecStringSort = allSpec_sort.toArray(new String[allSpec_sort.size()]);

               listView.setAdapter(new ListViewAdapter(MainActivity.this, allProdStringSort, allSpecStringSort));
            }

        @Override
        public void afterTextChanged(Editable editable) {

      }
  });

Answer 2

I think that your adapter should look like this. Also I would not recommend to instantiate objects inside getView() i.e typeface object

 public class ListViewAdapter extends BaseAdapter {
    String title[];
    String description[];
    ArrayList<String> filteredTitleList;
    ArrayList<String> filteredDescripionList;
    Typeface typeface;
    LayoutInflater inflater;

    public ListViewAdapter(Activity context, String[] title, String[] description) {
        super();
        this.context = context;
        this.title = title;
        this.description = description;

        typeface = Typeface.createFromAsset(context.getAssets(),"font/Simple_Print.ttf");

        inflater = context.getLayoutInflater();

        this.filteredTitleList = new ArrayList<String>();
        this.filteredDescripionList = new ArrayList<String>();
        applyFilter(null);
    }

    public void applyFilter(String filter){
        filteredTitleList.clear();
        filteredDescripionList.clear();

        for(int i=0; i < this.title.length; i++){
            String tempTitle = title[i];
            String tempDesc = description[i];

            if(filter == null || filter.equals("")){
                this.filteredTitleList.add(tempTitle);
                this.filteredDescripionList.add(tempDesc);
            }
            else if(tempTitle.toLowerCase().contains(filter.toLowerCase()) || tempDesc.toLowerCase().contains(filter.toLowerCase())){
                this.filteredTitleList.add(tempTitle);
                this.filteredDescripionList.add(tempDesc);
            }

        }
        this.notifyDataSetChanged();
    }

    public int getCount() {
        return filteredTitleList.size();
    }

    public Object getItem(int position) {
        return null;
    }

    public long getItemId(int position) {
        return position;
    }

    private class ViewHolder {

        TextView txtViewTitle;
        TextView txtViewDescription;

    }

    public View getView(int position, View convertView, ViewGroup parent) {

        ViewHolder holder;
        if (convertView == null) {

            convertView = inflater.inflate(R.layout.tabella_prodotti, null);
            holder = new ViewHolder();
            holder.txtViewTitle = (TextView) convertView.findViewById(R.id.titoloProd);
            holder.txtViewDescription = (TextView) convertView.findViewById(R.id.subtitoloProd);

            holder.txtViewDescription.setTypeface(typeface);
            holder.txtViewTitle.setTypeface(typeface);

            convertView.setTag(holder);
        }
        else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.txtViewTitle.setText(this.filteredTitleList.get(position));
        holder.txtViewDescription.setText(this.filteredDescriptionList.get(position));

        return convertView;

     }

    }