GeoDataClient.getAutocompletePredictions - Canceling/Ignoring Previous Requests

Question

Android SDK https://developers.google.com/places/android-sdk/autocomplete (Look for Get place predictions programmatically)

GeoDataClient.getAutocompletePredictions() - I would like to ignore responses that are not the last request... autoComplete typing for example: 'New'->'New Y'->'New Yo'

3 Responses - but I want to catch only the last one.. (Not Using RX)

// Submit the query to the autocomplete API and retrieve a PendingResult that will
   // contain the results when the query completes.
   Task<AutocompletePredictionBufferResponse> results =
           geoDataClient.getAutocompletePredictions(constraint, bounds, typeFilter);
   results.addOnSuccessListener(autocompletePredictions -> {
       if (autoCompletePredictionsListener != null) {
           autoCompletePredictionsListener.onAutoCompleteSuccess(autocompletePredictions);
       }
//****Here I want to ignore(or cancel somewhere before) previous requests
       autocompletePredictions.release();
   });

iOS SDK - Solved By Google Developers https://developers.google.com/places/ios-sdk/reference/interface_g_m_s_autocomplete_fetcher

The delegate will only be called with prediction results if those predictions are for the text supplied in the most recent call to sourceTextHasChanged.

Answer 1

Had a similar need recently and this was what I did to achieve the desired result

// create a class-scope variable to track the most recent query
private String lastQuery;
private GeoDataClient geoDataClient;

// wrap the geoDataClient.getAutocompletePredictions in a class to associate the prediction results with the query that triggered the call
class AutocompletePredictor {
    String query;

    AutocompletePredictor(String query) {
        this.query = query;
    }

    Task<AutocompletePredictionBufferResponse> getPredictions(LatLngBounds bounds, AutocompleteFilter typeFilter) {
        return geoDataClient.getAutocompletePredictions(query, bounds, typeFilter);
    }
}

// modify your method that triggers the autocomplete filter
void filterAutocomplete(String constraint) {
    // update lastQuery every time this method is called
    lastQuery = constraint;

    // Submit the query to the autocomplete API and retrieve a PendingResult that will contain the results when the query completes.
    final AutocompletePredictor predictor = new AutocompletePredictor(constraint);
    Task<AutocompletePredictionBufferResponse> results = predictor.getPredictions(bounds, typeFilter);

    results.addOnSuccessListener(autocompletePredictions -> {
        // checks if the query for this filter is same as the most recent query issued to this method
        if (autoCompletePredictionsListener != null && predictor.query.equals(lastQuery)) {
            autoCompletePredictionsListener.onAutoCompleteSuccess(autocompletePredictions);
        }

        autocompletePredictions.release();
    });
}

Edit: Delay calls when user is typing...
Instead of calling the autocomplete method each time the content of the EditText changes (which can be every time the user types a character), schedule the autocomplete call to wait for a period of time before actually executing. If the EditText content changes again before the waiting period elapses, cancel the previous schedule and re-schedule.

editText.addTextChangedListener(new TextWatcher() {
    int delayMilliseconds = 500;
    Handler handler = new Handler();

    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {}

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {}

    @Override
    public void afterTextChanged(Editable editable) {
        final String constraint = editable.toString();

        // remove all delayed/pending tasks set in the last 500 milliseconds
        handler.removeCallbacksAndMessages(null);

        // setup a new delayed task to execute after 500 milliseconds
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                filterAutocomplete(constraint);
            }
        }, delayMilliseconds);
    }
});