BatteryBroadcastReceiver.java revision 88b27fdeac1215b26eb84c4a1bc9c2b3a0d25522 
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 com.android.settings.fuelgauge;
18
19import android.content.BroadcastReceiver;
20import android.content.Context;
21import android.content.Intent;
22import android.content.IntentFilter;
23import android.support.annotation.VisibleForTesting;
24
25import com.android.settings.Utils;
26
27/**
28 * Use this broadcastReceiver to listen to the battery change, and it will invoke
29 * {@link OnBatteryChangedListener} if any of the following happens:
30 *
31 * 1. Battery level has been changed
32 * 2. Battery status has been changed
33 */
34public class BatteryBroadcastReceiver extends BroadcastReceiver {
35
36    interface OnBatteryChangedListener {
37        void onBatteryChanged();
38    }
39
40    @VisibleForTesting
41    String mBatteryLevel;
42    @VisibleForTesting
43    String mBatteryStatus;
44    private OnBatteryChangedListener mBatteryListener;
45    private Context mContext;
46
47    public BatteryBroadcastReceiver(Context context) {
48        mContext = context;
49    }
50
51    @Override
52    public void onReceive(Context context, Intent intent) {
53        updateBatteryStatus(intent, false /* forceUpdate */);
54    }
55
56    public void setBatteryChangedListener(OnBatteryChangedListener lsn) {
57        mBatteryListener = lsn;
58    }
59
60    public void register() {
61        final Intent intent = mContext.registerReceiver(this,
62                new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
63        updateBatteryStatus(intent, true /* forceUpdate */);
64    }
65
66    public void unRegister() {
67        mContext.unregisterReceiver(this);
68    }
69
70    private void updateBatteryStatus(Intent intent, boolean forceUpdate) {
71        if (intent != null && mBatteryListener != null && Intent.ACTION_BATTERY_CHANGED.equals(
72                intent.getAction())) {
73            String batteryLevel = Utils.getBatteryPercentage(intent);
74            String batteryStatus = Utils.getBatteryStatus(
75                    mContext.getResources(), intent);
76            if (forceUpdate || !batteryLevel.equals(mBatteryLevel) || !batteryStatus.equals(
77                    mBatteryStatus)) {
78                mBatteryLevel = batteryLevel;
79                mBatteryStatus = batteryStatus;
80                mBatteryListener.onBatteryChanged();
81            }
82        }
83    }
84
85}