1 /* 2 * Copyright (C) 2014 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.example.android.wearable.geofencing; 18 19 import static com.example.android.wearable.geofencing.Constants.INVALID_FLOAT_VALUE; 20 import static com.example.android.wearable.geofencing.Constants.INVALID_INT_VALUE; 21 import static com.example.android.wearable.geofencing.Constants.INVALID_LONG_VALUE; 22 import static com.example.android.wearable.geofencing.Constants.KEY_EXPIRATION_DURATION; 23 import static com.example.android.wearable.geofencing.Constants.KEY_LATITUDE; 24 import static com.example.android.wearable.geofencing.Constants.KEY_LONGITUDE; 25 import static com.example.android.wearable.geofencing.Constants.KEY_PREFIX; 26 import static com.example.android.wearable.geofencing.Constants.KEY_RADIUS; 27 import static com.example.android.wearable.geofencing.Constants.KEY_TRANSITION_TYPE; 28 29 import android.content.Context; 30 import android.content.SharedPreferences; 31 32 /** 33 * Storage for geofence values, implemented in SharedPreferences. 34 */ 35 public class SimpleGeofenceStore { 36 37 // The SharedPreferences object in which geofences are stored. 38 private final SharedPreferences mPrefs; 39 // The name of the SharedPreferences. 40 private static final String SHARED_PREFERENCES = "SharedPreferences"; 41 42 /** 43 * Create the SharedPreferences storage with private access only. 44 */ 45 public SimpleGeofenceStore(Context context) { 46 mPrefs = context.getSharedPreferences(SHARED_PREFERENCES, Context.MODE_PRIVATE); 47 } 48 49 /** 50 * Returns a stored geofence by its id, or returns null if it's not found. 51 * @param id The ID of a stored geofence. 52 * @return A SimpleGeofence defined by its center and radius, or null if the ID is invalid. 53 */ 54 public SimpleGeofence getGeofence(String id) { 55 // Get the latitude for the geofence identified by id, or INVALID_FLOAT_VALUE if it doesn't 56 // exist (similarly for the other values that follow). 57 double lat = mPrefs.getFloat(getGeofenceFieldKey(id, KEY_LATITUDE), 58 INVALID_FLOAT_VALUE); 59 double lng = mPrefs.getFloat(getGeofenceFieldKey(id, KEY_LONGITUDE), 60 INVALID_FLOAT_VALUE); 61 float radius = mPrefs.getFloat(getGeofenceFieldKey(id, KEY_RADIUS), 62 INVALID_FLOAT_VALUE); 63 long expirationDuration = 64 mPrefs.getLong(getGeofenceFieldKey(id, KEY_EXPIRATION_DURATION), 65 INVALID_LONG_VALUE); 66 int transitionType = mPrefs.getInt(getGeofenceFieldKey(id, KEY_TRANSITION_TYPE), 67 INVALID_INT_VALUE); 68 // If none of the values is incorrect, return the object. 69 if (lat != INVALID_FLOAT_VALUE 70 && lng != INVALID_FLOAT_VALUE 71 && radius != INVALID_FLOAT_VALUE 72 && expirationDuration != INVALID_LONG_VALUE 73 && transitionType != INVALID_INT_VALUE) { 74 return new SimpleGeofence(id, lat, lng, radius, expirationDuration, transitionType); 75 } 76 // Otherwise, return null. 77 return null; 78 } 79 80 /** 81 * Save a geofence. 82 * @param geofence The SimpleGeofence with the values you want to save in SharedPreferences. 83 */ 84 public void setGeofence(String id, SimpleGeofence geofence) { 85 // Get a SharedPreferences editor instance. Among other things, SharedPreferences 86 // ensures that updates are atomic and non-concurrent. 87 SharedPreferences.Editor prefs = mPrefs.edit(); 88 // Write the Geofence values to SharedPreferences. 89 prefs.putFloat(getGeofenceFieldKey(id, KEY_LATITUDE), (float) geofence.getLatitude()); 90 prefs.putFloat(getGeofenceFieldKey(id, KEY_LONGITUDE), (float) geofence.getLongitude()); 91 prefs.putFloat(getGeofenceFieldKey(id, KEY_RADIUS), geofence.getRadius()); 92 prefs.putLong(getGeofenceFieldKey(id, KEY_EXPIRATION_DURATION), 93 geofence.getExpirationDuration()); 94 prefs.putInt(getGeofenceFieldKey(id, KEY_TRANSITION_TYPE), 95 geofence.getTransitionType()); 96 // Commit the changes. 97 prefs.commit(); 98 } 99 100 /** 101 * Remove a flattened geofence object from storage by removing all of its keys. 102 */ 103 public void clearGeofence(String id) { 104 SharedPreferences.Editor prefs = mPrefs.edit(); 105 prefs.remove(getGeofenceFieldKey(id, KEY_LATITUDE)); 106 prefs.remove(getGeofenceFieldKey(id, KEY_LONGITUDE)); 107 prefs.remove(getGeofenceFieldKey(id, KEY_RADIUS)); 108 prefs.remove(getGeofenceFieldKey(id, KEY_EXPIRATION_DURATION)); 109 prefs.remove(getGeofenceFieldKey(id, KEY_TRANSITION_TYPE)); 110 prefs.commit(); 111 } 112 113 /** 114 * Given a Geofence object's ID and the name of a field (for example, KEY_LATITUDE), return 115 * the key name of the object's values in SharedPreferences. 116 * @param id The ID of a Geofence object. 117 * @param fieldName The field represented by the key. 118 * @return The full key name of a value in SharedPreferences. 119 */ 120 private String getGeofenceFieldKey(String id, String fieldName) { 121 return KEY_PREFIX + "_" + id + "_" + fieldName; 122 } 123 124 } 125
