I'm trying to implement filtering of a ListView which is uses a custom object adapter, but I can't find any useful samples. The included code is very simplified, so no- keep in mind I can't use an regular ArrayAdapter. I have a EditText above the ListView, and when the user enters text in the EditText widget I would like to filter the ListView by the text written in the EditText. Any suggestions would be much appreciated!
Here is the snippet from the activity class:
public class management_objects extends Activity {
private static List<User> UserList;
private EfficientAdapter adapter = null;
private ListView objectListView = null;
private EditText SearchText = null;
private static class EfficientAdapter extends BaseAdapter implements Filterable{
private LayoutInflater mInflater;
public EfficientAdapter(Context context) {
mInflater = LayoutInflater.from(context);
}
public int getCount() {
return UserList.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.imagelayout_2lines, null);
holder = new ViewHolder();
holder.text = (TextView) convertView.findViewById(R.id.managementObjectText);
holder.subtext = (TextView) convertView.findViewById(R.id.managementObjectSubText);
holder.icon = (ImageView) convertView.findViewById(R.id.managementObjectIcon);
convertView.setTag(holder);
}
else {
holder = (ViewHolder) convertView.getTag();
}
holder.text.setText(UserList.get(position).getFirstName());
holder.subtext.setText(UserList.get(position).getLastName());
holder.icon.setImageResource(R.drawable.user);
return convertView;
}
static class ViewHolder {
TextView text;
TextView subtext;
ImageView icon;
}
@Override
public Filter getFilter() {
return null;
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.adobjectlist);
Bundle extras = getIntent().getExtras();
SearchText = (EditText) findViewById(R.id.SearchBox);
SearchText.addTextChangedListener(filterTextWatcher);
objectListView = (ListView) findViewById(R.id.ObjectList);
objectListView.setOnItemClickListener(Item_Click);
adapter = new EfficientAdapter(this);
ComputerName = extras.getString("COMPUTER_NAME");
//Get User list from webservice
ShowUsers();
}
Here is The User class:
public class User {
private int UserId;
private String FirstName;
private String LastName;
public int getUserId() {
return UserId;
}
public void setUserId(int UserId) {
this.UserId = UserId;
}
public String getFirstName() {
return FirstName;
}
public void setFirstName(String FirstName) {
this.FirstName = FirstName;
}
public String getLastName() {
return LastName;
}
public void setLastName(String LastName) {
this.LastName = LastName;
}
}
You need to do a few things:
1) In your activity, register for a text change listener on your EditText that contains the value the user enters:
mSearchValue.addTextChangedListener(searchTextWatcher);
2) Create your searchTextWatcher and have it do something:
private TextWatcher searchTextWatcher = new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// ignore
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
// ignore
}
@Override
public void afterTextChanged(Editable s) {
Log.d(Constants.TAG, "*** Search value changed: " + s.toString());
adapter.getFilter().filter(s.toString());
}
};
3) Override getFilter() in your custom adapter and have it filter the results and notify the listview that the dataset has changed.
@Override
public Filter getFilter() {
return new Filter() {
@SuppressWarnings("unchecked")
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
Log.d(Constants.TAG, "**** PUBLISHING RESULTS for: " + constraint);
myData = (List<MyDataType>) results.values;
MyCustomAdapter.this.notifyDataSetChanged();
}
@Override
protected FilterResults performFiltering(CharSequence constraint) {
Log.d(Constants.TAG, "**** PERFORM FILTERING for: " + constraint);
List<MyDataType> filteredResults = getFilteredResults(constraint);
FilterResults results = new FilterResults();
results.values = filteredResults;
return results;
}
};
}