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.Map;
27 
28 /**
29  * Util class to get feature flag information.
30  *
31  * @hide
32  */
33 @TestApi
34 public class FeatureFlagUtils {
35 
36     public static final String FFLAG_PREFIX = "sys.fflag.";
37     public static final String FFLAG_OVERRIDE_PREFIX = FFLAG_PREFIX + "override.";
38     public static final String PERSIST_PREFIX = "persist." + FFLAG_OVERRIDE_PREFIX;
39     public static final String SEAMLESS_TRANSFER = "settings_seamless_transfer";
40     public static final String HEARING_AID_SETTINGS = "settings_bluetooth_hearing_aid";
41     public static final String SCREENRECORD_LONG_PRESS = "settings_screenrecord_long_press";
42     public static final String DYNAMIC_SYSTEM = "settings_dynamic_system";
43     public static final String SETTINGS_WIFITRACKER2 = "settings_wifitracker2";
44     public static final String SETTINGS_FUSE_FLAG = "settings_fuse";
45     /** @hide */
46     public static final String SETTINGS_DO_NOT_RESTORE_PRESERVED =
47             "settings_do_not_restore_preserved";
48 
49     private static final Map<String, String> DEFAULT_FLAGS;
50 
51     static {
52         DEFAULT_FLAGS = new HashMap<>();
53         DEFAULT_FLAGS.put("settings_audio_switcher", "true");
54         DEFAULT_FLAGS.put("settings_systemui_theme", "true");
DEFAULT_FLAGS.put(SETTINGS_FUSE_FLAG, "true")55         DEFAULT_FLAGS.put(SETTINGS_FUSE_FLAG, "true");
DEFAULT_FLAGS.put(DYNAMIC_SYSTEM, "false")56         DEFAULT_FLAGS.put(DYNAMIC_SYSTEM, "false");
DEFAULT_FLAGS.put(SEAMLESS_TRANSFER, "false")57         DEFAULT_FLAGS.put(SEAMLESS_TRANSFER, "false");
DEFAULT_FLAGS.put(HEARING_AID_SETTINGS, "false")58         DEFAULT_FLAGS.put(HEARING_AID_SETTINGS, "false");
DEFAULT_FLAGS.put(SCREENRECORD_LONG_PRESS, "false")59         DEFAULT_FLAGS.put(SCREENRECORD_LONG_PRESS, "false");
60         DEFAULT_FLAGS.put("settings_wifi_details_datausage_header", "false");
61         DEFAULT_FLAGS.put("settings_skip_direction_mutable", "true");
DEFAULT_FLAGS.put(SETTINGS_WIFITRACKER2, "true")62         DEFAULT_FLAGS.put(SETTINGS_WIFITRACKER2, "true");
63         DEFAULT_FLAGS.put("settings_controller_loading_enhancement", "true");
64         DEFAULT_FLAGS.put("settings_conditionals", "false");
65         // This flags guards a feature introduced in R and will be removed in the next release
66         // (b/148367230).
DEFAULT_FLAGS.put(SETTINGS_DO_NOT_RESTORE_PRESERVED, "true")67         DEFAULT_FLAGS.put(SETTINGS_DO_NOT_RESTORE_PRESERVED, "true");
68 
69         DEFAULT_FLAGS.put("settings_tether_all_in_one", "false");
70     }
71 
72     /**
73      * Whether or not a flag is enabled.
74      *
75      * @param feature the flag name
76      * @return true if the flag is enabled (either by default in system, or override by user)
77      */
isEnabled(Context context, String feature)78     public static boolean isEnabled(Context context, String feature) {
79         // Override precedence:
80         // Settings.Global -> sys.fflag.override.* -> static list
81 
82         // Step 1: check if feature flag is set in Settings.Global.
83         String value;
84         if (context != null) {
85             value = Settings.Global.getString(context.getContentResolver(), feature);
86             if (!TextUtils.isEmpty(value)) {
87                 return Boolean.parseBoolean(value);
88             }
89         }
90 
91         // Step 2: check if feature flag has any override. Flag name: sys.fflag.override.<feature>
92         value = SystemProperties.get(FFLAG_OVERRIDE_PREFIX + feature);
93         if (!TextUtils.isEmpty(value)) {
94             return Boolean.parseBoolean(value);
95         }
96         // Step 3: check if feature flag has any default value.
97         value = getAllFeatureFlags().get(feature);
98         return Boolean.parseBoolean(value);
99     }
100 
101     /**
102      * Override feature flag to new state.
103      */
setEnabled(Context context, String feature, boolean enabled)104     public static void setEnabled(Context context, String feature, boolean enabled) {
105         SystemProperties.set(FFLAG_OVERRIDE_PREFIX + feature, enabled ? "true" : "false");
106     }
107 
108     /**
109      * Returns all feature flags in their raw form.
110      */
getAllFeatureFlags()111     public static Map<String, String> getAllFeatureFlags() {
112         return DEFAULT_FLAGS;
113     }
114 }
115