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.content.Context;
20 import android.os.SystemProperties;
21 import android.provider.Settings;
22 import android.text.TextUtils;
23 
24 import java.util.HashMap;
25 import java.util.Map;
26 
27 /**
28  * Util class to get feature flag information.
29  *
30  * @hide
31  */
32 public class FeatureFlagUtils {
33 
34     public static final String FFLAG_PREFIX = "sys.fflag.";
35     public static final String FFLAG_OVERRIDE_PREFIX = FFLAG_PREFIX + "override.";
36 
37     private static final Map<String, String> DEFAULT_FLAGS;
38     static {
39         DEFAULT_FLAGS = new HashMap<>();
40         DEFAULT_FLAGS.put("settings_battery_display_app_list", "false");
41         DEFAULT_FLAGS.put("settings_zone_picker_v2", "true");
42         DEFAULT_FLAGS.put("settings_about_phone_v2", "true");
43         DEFAULT_FLAGS.put("settings_bluetooth_while_driving", "false");
44         DEFAULT_FLAGS.put("settings_data_usage_v2", "true");
45         DEFAULT_FLAGS.put("settings_audio_switcher", "true");
46         DEFAULT_FLAGS.put("settings_systemui_theme", "true");
47     }
48 
49     /**
50      * Whether or not a flag is enabled.
51      *
52      * @param feature the flag name
53      * @return true if the flag is enabled (either by default in system, or override by user)
54      */
isEnabled(Context context, String feature)55     public static boolean isEnabled(Context context, String feature) {
56         // Override precedence:
57         // Settings.Global -> sys.fflag.override.* -> static list
58 
59         // Step 1: check if feature flag is set in Settings.Global.
60         String value;
61         if (context != null) {
62             value = Settings.Global.getString(context.getContentResolver(), feature);
63             if (!TextUtils.isEmpty(value)) {
64                 return Boolean.parseBoolean(value);
65             }
66         }
67 
68         // Step 2: check if feature flag has any override. Flag name: sys.fflag.override.<feature>
69         value = SystemProperties.get(FFLAG_OVERRIDE_PREFIX + feature);
70         if (!TextUtils.isEmpty(value)) {
71             return Boolean.parseBoolean(value);
72         }
73         // Step 3: check if feature flag has any default value.
74         value = getAllFeatureFlags().get(feature);
75         return Boolean.parseBoolean(value);
76     }
77 
78     /**
79      * Override feature flag to new state.
80      */
setEnabled(Context context, String feature, boolean enabled)81     public static void setEnabled(Context context, String feature, boolean enabled) {
82         SystemProperties.set(FFLAG_OVERRIDE_PREFIX + feature, enabled ? "true" : "false");
83     }
84 
85     /**
86      * Returns all feature flags in their raw form.
87      */
getAllFeatureFlags()88     public static Map<String, String> getAllFeatureFlags() {
89         return DEFAULT_FLAGS;
90     }
91 }
92