I have a ListView
that gets data from a database. I applied the search filter on it, but it doesn't filter as I want. what I want is to filter with the first letter not middle or contains.
Here is the code:
public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
ListView dicList;
EditText editSearch;
ArrayAdapter<String> adapterListOfWord;
ArrayList<String> mSource = new ArrayList<String>();
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editSearch = findViewById(R.id.edit_search);
dicList = findViewById(R.id.dic_list);
adapterListOfWord = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mSource);
dicList.setAdapter(adapterListOfWord);
editSearch.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence charSequence, int start, int before, int count) {
// the problem is here, i want to search with the first letter not middle or contains.
adapterListOfWord.getFilter().filter(charSequence);
}
@Override
public void afterTextChanged(Editable s) {
}
});
}
}
I don't know how to implement and apply filterable to my project according to my codes and change the contains()
to startsWith()
to reach my goal.
I really appreciate your help.
Thanks in advance.
You need to use a customized adapter instead of the default one, and override the getFilter()
to filter the list with the String's startsWith()
method:
Adapter:
public class StartsWithArrayAdapter extends ArrayAdapter<String> implements Filterable {
private final List<String> mList = new ArrayList<>();
private List<String> mFilteredList = new ArrayList<>();
public StartsWithArrayAdapter(Context context, int textViewResourceId, ArrayList<String> list) {
super(context, textViewResourceId, list);
this.mList.addAll(list);
this.mFilteredList.addAll(list);
}
@Override
public int getCount() {
return mFilteredList.size();
}
@NonNull
@Override
public Filter getFilter() {
return new Filter() {
@Override
protected FilterResults performFiltering(CharSequence charSequence) {
String charString = charSequence.toString();
if (charString.isEmpty()) {
mFilteredList = mList;
} else {
List<String> filteredList = new ArrayList<>();
for (String listItem : mList) {
if (listItem.toLowerCase().startsWith(charString.toLowerCase())) {
filteredList.add(listItem);
}
}
mFilteredList = filteredList;
}
FilterResults filterResults = new FilterResults();
filterResults.values = mFilteredList;
return filterResults;
}
@Override
@SuppressWarnings("unchecked")
protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
mFilteredList = (ArrayList<String>) filterResults.values;
clear();
addAll(mFilteredList);
notifyDataSetChanged();
}
};
}
}
Usage in your code:
public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
StartsWithArrayAdapter adapterListOfWord;
// rest of code
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// omitted code
adapterListOfWord = new StartsWithArrayAdapter(this, android.R.layout.simple_list_item_1, mSource);
// rest of code
}
}