1 /* 2 * Copyright (C) 2020 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.server.location.gnss; 18 19 import android.content.ContentResolver; 20 import android.content.Context; 21 import android.database.ContentObserver; 22 import android.os.Handler; 23 import android.os.Looper; 24 import android.os.UserHandle; 25 import android.provider.Settings; 26 import android.util.Log; 27 28 import com.android.internal.annotations.VisibleForTesting; 29 30 import java.util.ArrayList; 31 import java.util.List; 32 33 /** 34 * Detects denylist change and updates the denylist. 35 */ 36 class GnssSatelliteBlocklistHelper { 37 38 private static final String TAG = "GnssBlocklistHelper"; 39 private static final String BLOCKLIST_DELIMITER = ","; 40 41 private final Context mContext; 42 private final GnssSatelliteBlocklistCallback mCallback; 43 44 interface GnssSatelliteBlocklistCallback { onUpdateSatelliteBlocklist(int[] constellations, int[] svids)45 void onUpdateSatelliteBlocklist(int[] constellations, int[] svids); 46 } 47 GnssSatelliteBlocklistHelper(Context context, Looper looper, GnssSatelliteBlocklistCallback callback)48 GnssSatelliteBlocklistHelper(Context context, Looper looper, 49 GnssSatelliteBlocklistCallback callback) { 50 mContext = context; 51 mCallback = callback; 52 ContentObserver contentObserver = new ContentObserver(new Handler(looper)) { 53 @Override 54 public void onChange(boolean selfChange) { 55 updateSatelliteBlocklist(); 56 } 57 }; 58 mContext.getContentResolver().registerContentObserver( 59 Settings.Global.getUriFor( 60 Settings.Global.GNSS_SATELLITE_BLOCKLIST), 61 true, 62 contentObserver, UserHandle.USER_ALL); 63 } 64 updateSatelliteBlocklist()65 void updateSatelliteBlocklist() { 66 ContentResolver resolver = mContext.getContentResolver(); 67 String blocklist = Settings.Global.getString( 68 resolver, 69 Settings.Global.GNSS_SATELLITE_BLOCKLIST); 70 if (blocklist == null) { 71 blocklist = ""; 72 } 73 Log.i(TAG, String.format("Update GNSS satellite blocklist: %s", blocklist)); 74 75 List<Integer> blocklistValues; 76 try { 77 blocklistValues = parseSatelliteBlocklist(blocklist); 78 } catch (NumberFormatException e) { 79 Log.e(TAG, "Exception thrown when parsing blocklist string.", e); 80 return; 81 } 82 83 if (blocklistValues.size() % 2 != 0) { 84 Log.e(TAG, "blocklist string has odd number of values." 85 + "Aborting updateSatelliteBlocklist"); 86 return; 87 } 88 89 int length = blocklistValues.size() / 2; 90 int[] constellations = new int[length]; 91 int[] svids = new int[length]; 92 for (int i = 0; i < length; i++) { 93 constellations[i] = blocklistValues.get(i * 2); 94 svids[i] = blocklistValues.get(i * 2 + 1); 95 } 96 mCallback.onUpdateSatelliteBlocklist(constellations, svids); 97 } 98 99 @VisibleForTesting parseSatelliteBlocklist(String blocklist)100 static List<Integer> parseSatelliteBlocklist(String blocklist) throws NumberFormatException { 101 String[] strings = blocklist.split(BLOCKLIST_DELIMITER); 102 List<Integer> parsed = new ArrayList<>(strings.length); 103 for (String string : strings) { 104 string = string.trim(); 105 if (!"".equals(string)) { 106 int value = Integer.parseInt(string); 107 if (value < 0) { 108 throw new NumberFormatException("Negative value is invalid."); 109 } 110 parsed.add(value); 111 } 112 } 113 return parsed; 114 } 115 } 116