| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * 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 com.android.textclassifier.ulp; |
| |
| import android.content.Context; |
| import android.icu.util.ULocale; |
| import android.location.Address; |
| import android.location.Geocoder; |
| import android.location.Location; |
| import android.location.LocationManager; |
| import android.telephony.TelephonyManager; |
| import com.android.textclassifier.TcLog; |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.base.Preconditions; |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.concurrent.TimeUnit; |
| import javax.annotation.Nullable; |
| |
| final class LocationSignalProvider { |
| private static final String TAG = "LocationSignalProvider"; |
| |
| private static final long EXPIRATION_TIME = TimeUnit.DAYS.toMillis(1); |
| private final LocationManager locationManager; |
| private final TelephonyManager telephonyManager; |
| private final Geocoder geocoder; |
| private final Object lock = new Object(); |
| |
| private String cachedLanguageTag = null; |
| private long lastModifiedTime; |
| |
| LocationSignalProvider(Context context) { |
| this( |
| context.getSystemService(LocationManager.class), |
| context.getSystemService(TelephonyManager.class), |
| new Geocoder(context)); |
| } |
| |
| @VisibleForTesting |
| LocationSignalProvider( |
| LocationManager locationManager, TelephonyManager telephonyManager, Geocoder geocoder) { |
| this.locationManager = Preconditions.checkNotNull(locationManager); |
| this.telephonyManager = Preconditions.checkNotNull(telephonyManager); |
| this.geocoder = Preconditions.checkNotNull(geocoder); |
| } |
| |
| /** |
| * Deduces the language by using user's current location as a signal and returns a BCP 47 language |
| * code. |
| */ |
| @Nullable |
| String detectLanguageTag() { |
| synchronized (lock) { |
| if ((System.currentTimeMillis() - lastModifiedTime) < EXPIRATION_TIME) { |
| return cachedLanguageTag; |
| } |
| cachedLanguageTag = detectLanguageCodeInternal(); |
| lastModifiedTime = System.currentTimeMillis(); |
| return cachedLanguageTag; |
| } |
| } |
| |
| @Nullable |
| private String detectLanguageCodeInternal() { |
| String currentCountryCode = detectCurrentCountryCode(); |
| if (currentCountryCode == null) { |
| return null; |
| } |
| return toLanguageTag(currentCountryCode); |
| } |
| |
| @Nullable |
| private String detectCurrentCountryCode() { |
| String networkCountryCode = telephonyManager.getNetworkCountryIso(); |
| if (networkCountryCode != null) { |
| return networkCountryCode; |
| } |
| return detectCurrentCountryFromLocationManager(); |
| } |
| |
| @Nullable |
| private String detectCurrentCountryFromLocationManager() { |
| Location location = locationManager.getLastKnownLocation(LocationManager.PASSIVE_PROVIDER); |
| if (location == null) { |
| return null; |
| } |
| try { |
| List<Address> addresses = |
| geocoder.getFromLocation( |
| location.getLatitude(), location.getLongitude(), /*maxResults=*/ 1); |
| if (addresses != null && !addresses.isEmpty()) { |
| return addresses.get(0).getCountryCode(); |
| } |
| } catch (IOException e) { |
| TcLog.e(TAG, "Failed to call getFromLocation: ", e); |
| return null; |
| } |
| return null; |
| } |
| |
| @Nullable |
| private static String toLanguageTag(String countryTag) { |
| ULocale locale = new ULocale.Builder().setRegion(countryTag).build(); |
| locale = ULocale.addLikelySubtags(locale); |
| return locale.getLanguage(); |
| } |
| } |