Filtering ListView with custom (object) adapter

Question

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;     } } 

Answer 1

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;             }         };     }