Providing a search option is essential in the Open Event Android app to make it easy for the user to see the desired results only. But sometimes it becomes difficult to implement this with a good performance if the data set is large, so providing simply a list to scroll through may not be enough and efficient. AutoCompleteTextView provides a way to search data by offering the suggestions after a user types in some initial letters of the search query.

How does it work? Actually we feed the data to an adapter which is attached to the view. So, when a user starts typing the query the suggestions starts appearing with similar names in the form of the list.

For example see above. Typing “Hall” gives the user suggestion to pick up the entry which have word “Hall” in it. Making it easier for user to search.

Let’s see how to implement it. For the first step declare the view in XML layout like this. Where our view goes by the id “map_toolbar” and white text colour for the text that will be appearing in it. Input type signifies that the autocomplete and auto correct is enabled.

<AutoCompleteTextView
       android:id="@+id/map_toolbar"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:ems="12"
       android:hint="@string/search"
       android:shadowColor="@color/white"
       android:imeOptions="actionSearch"
       android:inputType="textAutoComplete|textAutoCorrect"
       android:textColorHint="@color/white"
       android:textColor="@color/white"
/>

Now initialise the adapter in the fragment/activity with the list “searchItems” containing the information about the location. This function is in a fragment so modifying things accordingly. “textView” is the AutoCompleteTextView that we initialised. To explain this function further when a user clicks on any item from the suggestions the soft keyboard hides. You can do define desired operation here. 

Setting up AutoCompleteTextView with the locations

ArrayAdapter<String> adapter = new ArrayAdapter<>(getActivity(), android.R.layout.simple_dropdown_item_1line, searchItems);
textView.setAdapter(adapter);

textView.setOnItemClickListener((parent, view, position, id) -> {

Things you want to do on clicking the item

View mapView = getActivity().getCurrentFocus();

if (mapView != null) {
  InputMethodManager imm =     (InputMethodManager)getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
  imm.hideSoftInputFromWindow(mapView.getWindowToken(), 0);
}
});

See the complete code here to find the implementation of AutoCompleteTextView in the map fragment of Open Event Android app.