Image list view filter

package com.example.imagelistfilter;

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

/**
 * 
 * @author huyletran84@gmail.com
 * 
 */
public class MainActivity extends Activity {

	public ArrayList<FootballPlayer> listDatas = new ArrayList<MainActivity.FootballPlayer>();
	public ArrayList<FootballPlayer> listBackupDatas = new ArrayList<MainActivity.FootballPlayer>();
	public FootballPlayerAdapter adapter;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		String[] userNames = new String[] { "Ronaldo", "Zidance", "Cong Vinh",
				"Huynh Duc", "Gerrard", "Nagatomo", "Messi", "Minh Phuong",
				"neymar" };
		int[] playerDrawableResourceIds = new int[] { R.drawable.ronaldo,
				R.drawable.zindance, R.drawable.congvinh, R.drawable.huynhduc,
				R.drawable.gerrard, R.drawable.nagatomo, R.drawable.messi,
				R.drawable.minhphuong, R.drawable.neymar };

		// Prepare dummy data
		for (int i = 0; i < playerDrawableResourceIds.length; i++) {
			FootballPlayer footballPlayer = new FootballPlayer();
			footballPlayer.name = userNames[i];
			footballPlayer.imageResourceId = playerDrawableResourceIds[i];
			listDatas.add(footballPlayer);
			listBackupDatas.add(footballPlayer);
		}

		ListView lv = (ListView) findViewById(R.id.lv);
		adapter = new FootballPlayerAdapter();
		lv.setAdapter(adapter);

		EditText filter = (EditText) findViewById(R.id.filter_text);
		filter.addTextChangedListener(new TextWatcher() {

			@Override
			public void onTextChanged(CharSequence s, int arg1, int arg2,
					int arg3) {
				adapter.getFilter().filter(s.toString());
			}

			@Override
			public void beforeTextChanged(CharSequence arg0, int arg1,
					int arg2, int arg3) {
			}

			@Override
			public void afterTextChanged(Editable arg0) {

			}
		});

	}

	private class FootballPlayerAdapter extends BaseAdapter implements
			Filterable {
		private PlayerFilter playerFilter;

		@Override
		public int getCount() {
			return listDatas.size();
		}

		public Filter getFilter() {
			if (playerFilter == null)
				playerFilter = new PlayerFilter();
			return playerFilter;
		}

		@Override
		public FootballPlayer getItem(int position) {
			return listDatas.get(position);
		}

		@Override
		public long getItemId(int position) {
			return 0;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			PlayerViewHolder holder;
			if (convertView == null) {
				convertView = (ViewGroup) LayoutInflater.from(
						getApplicationContext()).inflate(
						R.layout.football_player_item, null);
				holder = new PlayerViewHolder();
				holder.name = (TextView) convertView
						.findViewById(R.id.player_name);
				holder.thumb = (ImageView) convertView
						.findViewById(R.id.player_thumbnail);
				convertView.setTag(holder);
			} else {
				holder = (PlayerViewHolder) convertView.getTag();
			}
			holder.name.setText(getItem(position).name);
			holder.thumb.setImageResource(getItem(position).imageResourceId);
			return convertView;
		}

	}

	private class PlayerFilter extends Filter {
		@Override
		protected FilterResults performFiltering(CharSequence constraint) {
			FilterResults results = new FilterResults();
			// We implement here the filter logic
			ArrayList<FootballPlayer> filters = new ArrayList<FootballPlayer>();
			if (constraint == null || constraint.length() == 0) {
				// No filter implemented we return all the list
				for (FootballPlayer player : listBackupDatas) {
					filters.add(player);
				}
				results.values = filters;
				results.count = filters.size();
			} else {
				// We perform filtering operation
				for (FootballPlayer row : listBackupDatas) {
					if (((FootballPlayer) row).name.toUpperCase().startsWith(
							constraint.toString().toUpperCase())) {
						filters.add(row);
					}
				}
				results.values = filters;
				results.count = filters.size();
			}
			return results;
		}

		@Override
		protected void publishResults(CharSequence constraint,
				FilterResults results) {
			if (results.count == 0) {
				listDatas.clear();
				adapter.notifyDataSetChanged();
			} else {
				listDatas.clear();
				ArrayList<FootballPlayer> resultList = (ArrayList<FootballPlayer>) results.values;
				for (FootballPlayer row : resultList) {
					listDatas.add(row);
				}
				adapter.notifyDataSetChanged();
			}
		}
	}

	private static class PlayerViewHolder {
		public ImageView thumb;
		public TextView name;
	}

	public class FootballPlayer {
		/** Keep the id of resource file which is player's thumbnail. */
		public int imageResourceId;
		/** Player name. */
		public String name;
	}
}