public class DataAdapter extends BaseAdapter {

    private List<Data> dataList;
    private Context context;

    public DataAdapter(Context context, List<Data> dataList) {
        this.context = context;
        this.dataList = dataList;
    }

    public void addData(List<Data> newDataList) {
        if (dataList == null)
            dataList = new ArrayList<Data>();

        dataList.addAll(newDataList);
        notifyDataSetChanged();
    }

    @Override
    public int getCount() {
        return (dataList != null ? dataList.size() : 0);
    }

    @Override
    public Object getItem(int position) {
        return dataList.get(position);
    }

    static class ViewHolder {
        public TextView nameTextView;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        final DataAdapter.ViewHolder holder;

        if (convertView == null) {
            holder = new DataAdapter.ViewHolder();

            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(R.layout.list_item, parent, false);
            holder.nameTextView = (TextView) convertView.findViewById(R.id.txt_name);

            convertView.setTag(holder);

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

        final Data data = dataList.get(position);
        if (data != null) {
        //set text
        }

        }

        return convertView;
    }


    @Override
    public int getViewTypeCount() {
        return 0;
    }

    @Override
    public int getItemViewType(int position) {
        return position;
    }

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