1 /* 2 * Copyright (C) 2017 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 android.util; 18 19 import android.annotation.TestApi; 20 import android.content.Context; 21 import android.os.SystemProperties; 22 import android.provider.Settings; 23 import android.text.TextUtils; 24 25 import java.util.HashMap; 26 import java.util.HashSet; 27 import java.util.Map; 28 import java.util.Set; 29 30 /** 31 * Util class to get feature flag information. 32 * 33 * @hide 34 */ 35 @TestApi 36 public class FeatureFlagUtils { 37 38 public static final String FFLAG_PREFIX = "sys.fflag."; 39 public static final String FFLAG_OVERRIDE_PREFIX = FFLAG_PREFIX + "override."; 40 public static final String PERSIST_PREFIX = "persist." + FFLAG_OVERRIDE_PREFIX; 41 public static final String HEARING_AID_SETTINGS = "settings_bluetooth_hearing_aid"; 42 public static final String SETTINGS_WIFITRACKER2 = "settings_wifitracker2"; 43 /** @hide */ 44 public static final String SETTINGS_DO_NOT_RESTORE_PRESERVED = 45 "settings_do_not_restore_preserved"; 46 /** @hide */ 47 public static final String SETTINGS_PROVIDER_MODEL = "settings_provider_model"; 48 /** @hide */ 49 public static final String SETTINGS_USE_NEW_BACKUP_ELIGIBILITY_RULES 50 = "settings_use_new_backup_eligibility_rules"; 51 /** @hide */ 52 public static final String SETTINGS_ENABLE_SECURITY_HUB = "settings_enable_security_hub"; 53 54 private static final Map<String, String> DEFAULT_FLAGS; 55 56 static { 57 DEFAULT_FLAGS = new HashMap<>(); 58 DEFAULT_FLAGS.put("settings_audio_switcher", "true"); 59 DEFAULT_FLAGS.put("settings_systemui_theme", "true"); DEFAULT_FLAGS.put(HEARING_AID_SETTINGS, "false")60 DEFAULT_FLAGS.put(HEARING_AID_SETTINGS, "false"); 61 DEFAULT_FLAGS.put("settings_wifi_details_datausage_header", "false"); 62 DEFAULT_FLAGS.put("settings_skip_direction_mutable", "true"); DEFAULT_FLAGS.put(SETTINGS_WIFITRACKER2, "true")63 DEFAULT_FLAGS.put(SETTINGS_WIFITRACKER2, "true"); 64 DEFAULT_FLAGS.put("settings_controller_loading_enhancement", "true"); 65 DEFAULT_FLAGS.put("settings_conditionals", "false"); 66 // This flags guards a feature introduced in R and will be removed in the next release 67 // (b/148367230). DEFAULT_FLAGS.put(SETTINGS_DO_NOT_RESTORE_PRESERVED, "true")68 DEFAULT_FLAGS.put(SETTINGS_DO_NOT_RESTORE_PRESERVED, "true"); 69 70 DEFAULT_FLAGS.put("settings_tether_all_in_one", "false"); 71 DEFAULT_FLAGS.put("settings_contextual_home", "false"); DEFAULT_FLAGS.put(SETTINGS_PROVIDER_MODEL, "true")72 DEFAULT_FLAGS.put(SETTINGS_PROVIDER_MODEL, "true"); DEFAULT_FLAGS.put(SETTINGS_USE_NEW_BACKUP_ELIGIBILITY_RULES, "true")73 DEFAULT_FLAGS.put(SETTINGS_USE_NEW_BACKUP_ELIGIBILITY_RULES, "true"); DEFAULT_FLAGS.put(SETTINGS_ENABLE_SECURITY_HUB, "true")74 DEFAULT_FLAGS.put(SETTINGS_ENABLE_SECURITY_HUB, "true"); 75 } 76 77 private static final Set<String> PERSISTENT_FLAGS; 78 static { 79 PERSISTENT_FLAGS = new HashSet<>(); 80 PERSISTENT_FLAGS.add(SETTINGS_PROVIDER_MODEL); 81 } 82 83 /** 84 * Whether or not a flag is enabled. 85 * 86 * @param feature the flag name 87 * @return true if the flag is enabled (either by default in system, or override by user) 88 */ isEnabled(Context context, String feature)89 public static boolean isEnabled(Context context, String feature) { 90 // Override precedence: 91 // Settings.Global -> sys.fflag.override.* -> static list 92 93 // Step 1: check if feature flag is set in Settings.Global. 94 String value; 95 if (context != null) { 96 value = Settings.Global.getString(context.getContentResolver(), feature); 97 if (!TextUtils.isEmpty(value)) { 98 return Boolean.parseBoolean(value); 99 } 100 } 101 102 // Step 2: check if feature flag has any override. 103 // Flag name: [persist.]sys.fflag.override.<feature> 104 value = SystemProperties.get(getSystemPropertyPrefix(feature) + feature); 105 if (!TextUtils.isEmpty(value)) { 106 return Boolean.parseBoolean(value); 107 } 108 // Step 3: check if feature flag has any default value. 109 value = getAllFeatureFlags().get(feature); 110 return Boolean.parseBoolean(value); 111 } 112 113 /** 114 * Override feature flag to new state. 115 */ setEnabled(Context context, String feature, boolean enabled)116 public static void setEnabled(Context context, String feature, boolean enabled) { 117 SystemProperties.set(getSystemPropertyPrefix(feature) + feature, 118 enabled ? "true" : "false"); 119 } 120 121 /** 122 * Returns all feature flags in their raw form. 123 */ getAllFeatureFlags()124 public static Map<String, String> getAllFeatureFlags() { 125 return DEFAULT_FLAGS; 126 } 127 getSystemPropertyPrefix(String feature)128 private static String getSystemPropertyPrefix(String feature) { 129 return PERSISTENT_FLAGS.contains(feature) ? PERSIST_PREFIX : FFLAG_OVERRIDE_PREFIX; 130 } 131 } 132