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      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 PIXEL_WALLPAPER_CATEGORY_SWITCH =
     43             "settings_pixel_wallpaper_category_switch";
     44     public static final String DYNAMIC_SYSTEM = "settings_dynamic_system";
     45 
     46     private static final Map<String, String> DEFAULT_FLAGS;
     47 
     48     static {
     49         DEFAULT_FLAGS = new HashMap<>();
     50         DEFAULT_FLAGS.put("settings_audio_switcher", "true");
     51         DEFAULT_FLAGS.put("settings_mobile_network_v2", "true");
     52         DEFAULT_FLAGS.put("settings_network_and_internet_v2", "true");
     53         DEFAULT_FLAGS.put("settings_systemui_theme", "true");
     54         DEFAULT_FLAGS.put(DYNAMIC_SYSTEM, "false");
     55         DEFAULT_FLAGS.put(SEAMLESS_TRANSFER, "false");
     56         DEFAULT_FLAGS.put(HEARING_AID_SETTINGS, "false");
     57         DEFAULT_FLAGS.put(SCREENRECORD_LONG_PRESS, "false");
     58         DEFAULT_FLAGS.put(PIXEL_WALLPAPER_CATEGORY_SWITCH, "false");
     59         DEFAULT_FLAGS.put("settings_wifi_details_datausage_header", "false");
     60     }
     61 
     62     /**
     63      * Whether or not a flag is enabled.
     64      *
     65      * @param feature the flag name
     66      * @return true if the flag is enabled (either by default in system, or override by user)
     67      */
     68     public static boolean isEnabled(Context context, String feature) {
     69         // Override precedence:
     70         // Settings.Global -> sys.fflag.override.* -> static list
     71 
     72         // Step 1: check if feature flag is set in Settings.Global.
     73         String value;
     74         if (context != null) {
     75             value = Settings.Global.getString(context.getContentResolver(), feature);
     76             if (!TextUtils.isEmpty(value)) {
     77                 return Boolean.parseBoolean(value);
     78             }
     79         }
     80 
     81         // Step 2: check if feature flag has any override. Flag name: sys.fflag.override.<feature>
     82         value = SystemProperties.get(FFLAG_OVERRIDE_PREFIX + feature);
     83         if (!TextUtils.isEmpty(value)) {
     84             return Boolean.parseBoolean(value);
     85         }
     86         // Step 3: check if feature flag has any default value.
     87         value = getAllFeatureFlags().get(feature);
     88         return Boolean.parseBoolean(value);
     89     }
     90 
     91     /**
     92      * Override feature flag to new state.
     93      */
     94     public static void setEnabled(Context context, String feature, boolean enabled) {
     95         SystemProperties.set(FFLAG_OVERRIDE_PREFIX + feature, enabled ? "true" : "false");
     96     }
     97 
     98     /**
     99      * Returns all feature flags in their raw form.
    100      */
    101     public static Map<String, String> getAllFeatureFlags() {
    102         return DEFAULT_FLAGS;
    103     }
    104 }
    105