1 /*
2  * Copyright (C) 2019 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 package com.android.server.wifi.util;
17 
18 import android.annotation.NonNull;
19 import android.content.Context;
20 
21 import com.android.wifi.resources.R;
22 
23 /** Utilities for computations involving RSSI. */
24 public class RssiUtil {
RssiUtil()25     private RssiUtil() {}
26 
27     /** Calculate RSSI level from RSSI using overlaid RSSI level thresholds. */
calculateSignalLevel(Context context, int rssi)28     public static int calculateSignalLevel(Context context, int rssi) {
29         int[] thresholds = getRssiLevelThresholds(context);
30 
31         for (int level = 0; level < thresholds.length; level++) {
32             if (rssi < thresholds[level]) {
33                 return level;
34             }
35         }
36         return thresholds.length;
37     }
38 
39     @NonNull
getRssiLevelThresholds(Context context)40     private static int[] getRssiLevelThresholds(Context context) {
41         // getIntArray() will never return null, it will throw instead
42         return context.getResources().getIntArray(R.array.config_wifiRssiLevelThresholds);
43     }
44 }
45