Java tutorial
/* * Copyright (C) 2015 Google Inc. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package tw.geodoer.mGeoInfo.controller; import com.google.android.gms.common.api.GoogleApiClient; import com.google.android.gms.common.api.PendingResult; import com.google.android.gms.common.api.Status; import com.google.android.gms.location.places.AutocompleteFilter; import com.google.android.gms.location.places.AutocompletePrediction; import com.google.android.gms.location.places.AutocompletePredictionBuffer; import com.google.android.gms.location.places.Places; import com.google.android.gms.maps.model.LatLngBounds; import android.content.Context; import android.support.v4.app.FragmentActivity; import android.widget.ArrayAdapter; import android.widget.Filter; import android.widget.Filterable; import android.widget.Toast; import java.util.ArrayList; import java.util.Iterator; import java.util.concurrent.TimeUnit; public class PlaceAutocompleteAdapter extends ArrayAdapter<PlaceAutocompleteAdapter.PlaceAutocomplete> implements Filterable { private static final String TAG = "PlaceAutocompleteAdapter"; /** * Current results returned by this adapter. */ private ArrayList<PlaceAutocomplete> mResultList; /** * Handles autocomplete requests. */ private GoogleApiClient mGoogleApiClient; /** * The bounds used for Places Geo Data autocomplete API requests. */ private LatLngBounds mBounds; /** * The autocomplete filter used to restrict queries to a specific set of place types. */ private AutocompleteFilter mPlaceFilter; /** * Initializes with a resource for text rows and autocomplete query bounds. * * @see ArrayAdapter#ArrayAdapter(Context, int) */ public PlaceAutocompleteAdapter(Context context, int resource, GoogleApiClient googleApiClient, LatLngBounds bounds, AutocompleteFilter filter) { super(context, resource); mGoogleApiClient = googleApiClient; mBounds = bounds; mPlaceFilter = filter; } /** * Sets the GoogleApiClient to use for autocomplete queries. * Autocomplete queries are suspended when the client is set to null. * Ensure that the client has successfully connected, contains the {@link Places#GEO_DATA_API} * API and is available for queries, otherwise API access will be disabled when it is set here. */ public void setGoogleApiClient(GoogleApiClient googleApiClient) { if (googleApiClient == null || !googleApiClient.isConnected()) { mGoogleApiClient = null; } else { mGoogleApiClient = googleApiClient; } } /** * Sets the bounds for all subsequent queries. */ public void setBounds(LatLngBounds bounds) { mBounds = bounds; } /** * Returns the number of results received in the last autocomplete query. */ @Override public int getCount() { return mResultList.size(); } /** * Returns an item from the last autocomplete query. */ @Override public PlaceAutocomplete getItem(int position) { return mResultList.get(position); } /** * Returns the filter for the current set of autocomplete results. */ @Override public Filter getFilter() { Filter filter = new Filter() { @Override protected FilterResults performFiltering(CharSequence constraint) { FilterResults results = new FilterResults(); // Skip the autocomplete query if no constraints are given. if (constraint != null) { // Query the autocomplete API for the (constraint) search string. mResultList = getAutocomplete(constraint); if (mResultList != null) { // The API successfully returned results. results.values = mResultList; results.count = mResultList.size(); } } return results; } @Override protected void publishResults(CharSequence constraint, FilterResults results) { if (results != null && results.count > 0) { // The API returned at least one result, update the data. notifyDataSetChanged(); } else { // The API did not return any results, invalidate the data set. notifyDataSetInvalidated(); } } }; return filter; } private ArrayList<PlaceAutocomplete> getAutocomplete(CharSequence constraint) { if (mGoogleApiClient.isConnected()) { // Log.i(TAG, "Starting autocomplete query for: " + constraint); // Submit the query to the autocomplete API and retrieve a PendingResult that will // contain the results when the query completes. PendingResult<AutocompletePredictionBuffer> results = Places.GeoDataApi .getAutocompletePredictions(mGoogleApiClient, constraint.toString(), mBounds, mPlaceFilter); // This method should have been called off the main UI thread. Block and wait for at most 60s // for a result from the API. AutocompletePredictionBuffer autocompletePredictions = results.await(60, TimeUnit.SECONDS); // Confirm that the query completed successfully, otherwise return null final Status status = autocompletePredictions.getStatus(); if (!status.isSuccess()) { Toast.makeText(getContext(), "Error contacting API: " + status.toString(), Toast.LENGTH_SHORT) .show(); // Log.e(TAG, "Error getting autocomplete prediction API call: " + status.toString()); autocompletePredictions.release(); return null; } // Log.i(TAG, "Query completed. Received " + autocompletePredictions.getCount() // + " predictions."); // Copy the results into our own data structure, because we can't hold onto the buffer. // AutocompletePrediction objects encapsulate the API response (place ID and description). Iterator<AutocompletePrediction> iterator = autocompletePredictions.iterator(); ArrayList resultList = new ArrayList<>(autocompletePredictions.getCount()); while (iterator.hasNext()) { AutocompletePrediction prediction = iterator.next(); // Get the details of this prediction and copy it into a new PlaceAutocomplete object. resultList.add(new PlaceAutocomplete(prediction.getPlaceId(), prediction.getDescription())); } // Release the buffer now that all data has been copied. autocompletePredictions.release(); return resultList; } // Log.e(TAG, "Google API client is not connected for autocomplete query."); return null; } /** * Holder for Places Geo Data Autocomplete API results. */ public class PlaceAutocomplete { public CharSequence placeId; public CharSequence description; PlaceAutocomplete(CharSequence placeId, CharSequence description) { this.placeId = placeId; this.description = description; } @Override public String toString() { return description.toString(); } } }