Built with the idea of large data and not wanting to re-instantiate data after pulling form a database. Easily changed to support more efficient filtering based on previous results

Asynchronous Cursor Filter

import android.database.Cursor;
import android.database.CursorWrapper;
import android.os.AsyncTask;
import android.util.Log;

// todo optimize this to not filter through entire array for continuous entries or deletions
public class FilterableGuestCursor extends CursorWrapper {
    public static String TAG = FilterableGuestCursor.class.getSimpleName();
    FilterListener mFilterListener;
    private String filter;
    private int[] index;
    private int filterCount;
    private int count = 0;
    private int pos = 0;

    public FilterableGuestCursor(Cursor cursor, String filter, FilterListener mFilterListener) {
        super(cursor);
        this.mFilterListener = mFilterListener;
        this.filter = filter.toLowerCase();
        this.filterCount = this.count = super.getCount();
        this.index = new int[this.count];
        for (int i = 0; i < this.count; i++) {
            this.index[i] = i;
        }
    }

    public void refreshFilter(String filter) {
        this.filter = filter.toLowerCase();
        new FilterTask().execute();
    }

    private void populateFilterIndex() {

        if (!this.filter.equals("")) {
            this.count = super.getCount();
            this.index = new int[this.count];
            this.pos = 0;
            for (int i = 0; i < this.count; i++) {
                Log.d(TAG, "Cursor Index:" + i + ", Array Index :" + pos);
                super.moveToPosition(i);
                String fullName = this.getString(#insert cursor column matching here);
                if (fullName.toLowerCase().contains(filter))
                    this.index[this.pos++] = i;
            }
            this.filterCount = this.pos;
            super.moveToFirst();
        }
        else {
            this.filterCount = this.count = super.getCount();
            this.index = new int[this.count];
            for (int i = 0; i < this.count; i++) {
                this.index[i] = i;
            }
        }
    }

    @Override
    public boolean move(int offset) {
        return this.moveToPosition(this.pos + offset);
    }

    @Override
    public boolean moveToNext() {
        return this.moveToPosition(this.pos + 1);
    }

    @Override
    public boolean moveToPrevious() {
        return this.moveToPosition(this.pos - 1);
    }

    @Override
    public boolean moveToFirst() {
        return this.moveToPosition(0);
    }

    @Override
    public boolean moveToLast() {
        return this.moveToPosition(this.filterCount - 1);
    }

    @Override
    public boolean moveToPosition(int position) {
        if (position >= this.filterCount || position < 0)
            return false;
        this.pos = position;
        return super.moveToPosition(this.index[position]);
    }

    @Override
    public int getCount() {
        return this.filterCount;
    }

    @Override
    public int getPosition() {
        return this.pos;
    }


    public interface FilterListener{
        public void onFiltered();
    }

    public class FilterTask extends AsyncTask<Void, Void, Void> {

        @Override
        protected Void doInBackground(Void... aVoid) {
            populateFilterIndex();
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            mFilterListener.onFiltered();
        }

    }

}