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
17package android.util;
18
19import android.content.Context;
20import android.os.SystemProperties;
21import android.provider.Settings;
22import android.text.TextUtils;
23
24import java.util.HashMap;
25import java.util.Map;
26
27/**
28 * Util class to get feature flag information.
29 *
30 * @hide
31 */
32public 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     */
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     */
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     */
88    public static Map<String, String> getAllFeatureFlags() {
89        return DEFAULT_FLAGS;
90    }
91}
92