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0. 介绍

主要介绍UI位置和基本函数入口，其中耗电详情与power_profile.xml息息相关

1. UI 界面

2. 源码

2.1 设置界面入口

PowerUsageSummary->getPreferenceScreenResId()

package com.android.settings.fuelgauge;/** * Displays a list of apps and subsystems that consume power, ordered by how much power was * consumed since the last time it was unplugged. */public class PowerUsageSummary extends PowerUsageBase implements        AnomalyDialogListener, OnLongClickListener, OnClickListener {
       @Override    protected int getPreferenceScreenResId() {        return R.xml.power_usage_summary;    }

2.2 UI 布局

R.xml.power_usage_summary

   
    "充满电（
    
     ^1
    前）后的应用用电量"
       
   

上述即 key 为 app_list 为耗电详情列表

2.3 耗电详情 app_list

PowerUsageSummary.java

private static final String KEY_APP_LIST = "app_list";    @Override    public void onCreate(Bundle icicle) {        super.onCreate(icicle);        ...        mAppListGroup = (PreferenceGroup) findPreference(KEY_APP_LIST);

2.4 耗电数据填充

• PowerUsageSummary->refreshAppListGroup， 显示耗电详情
• PowerUsageSummary->addNotAvailableMessage, 显示没有电池使用数据

private void refreshAppListGroup() {        ...        mAppListGroup.addPreference(notAvailable);        ...    }    private void addNotAvailableMessage() {        final String NOT_AVAILABLE = "not_available";        Preference notAvailable = getCachedPreference(NOT_AVAILABLE);        if (notAvailable == null) {            notAvailable = new Preference(getPrefContext());            notAvailable.setKey(NOT_AVAILABLE);            // 
   
    "没有电池使用数据。"
               notAvailable.setTitle(R.string.power_usage_not_available);            mAppListGroup.addPreference(notAvailable);        }    }

2.5 refreshAppListGroup 数据处理

2.5.1 条件判断-功耗参考文件

PowerUsageSummary->refreshAppListGroup

// 是否使用假数据    private static final boolean USE_FAKE_DATA = false;    // 背光电流的最小值    private static final int MIN_AVERAGE_POWER_THRESHOLD_MILLI_AMP = 10;    private void refreshAppListGroup() {        // 获取背光亮度功率        final double averagePower = powerProfile.getAveragePower(PowerProfile.POWER_SCREEN_FULL);        if (averagePower >= MIN_AVERAGE_POWER_THRESHOLD_MILLI_AMP || USE_FAKE_DATA) {            // 这里要求平均电流需要大于 10, 要求我们需要配置 power_profile.xml 文件的电流数据            // frameworks\base\core\res\res\xml\power_profile.xml 厂商根据功耗电流进行配置，否则该项数据始终为无            final List
   
     usageList = getCoalescedUsageList(                    USE_FAKE_DATA ? getFakeStats() : mStatsHelper.getUsageList());        }
   

小知识

文件路径在于:frameworks\base\core\java\com\android\internal\os\PowerProfile.java文件路径:frameworks\base\core\res\res\xml\power_profile.xml    /**     * Power consumption at full backlight brightness. If the backlight is at     * 50% brightness, then this should be multiplied by 0.5     */    public static final String POWER_SCREEN_FULL = "screen.full";    
   
    0.1
     
   

2.5.2 功耗文件，获取假数据

PowerUsageSummary-> getFakeStats()

private static List
   
     getFakeStats() {        ArrayList
    
      stats = new ArrayList<>();        float use = 5;        for (DrainType type : DrainType.values()) {            if (type == DrainType.APP) {                continue;            }            stats.add(new BatterySipper(type, null, use));            use += 5;        }        for (int i = 0; i < 100; i++) {            stats.add(new BatterySipper(DrainType.APP,                    new FakeUid(Process.FIRST_APPLICATION_UID + i), use));        }        stats.add(new BatterySipper(DrainType.APP,                new FakeUid(0), use));        // Simulate dex2oat process.        BatterySipper sipper = new BatterySipper(DrainType.APP,                new FakeUid(UserHandle.getSharedAppGid(Process.FIRST_APPLICATION_UID)), 10.0f);        sipper.packageWithHighestDrain = "dex2oat";        stats.add(sipper);        sipper = new BatterySipper(DrainType.APP,                new FakeUid(UserHandle.getSharedAppGid(Process.FIRST_APPLICATION_UID + 1)), 10.0f);        sipper.packageWithHighestDrain = "dex2oat";        stats.add(sipper);        sipper = new BatterySipper(DrainType.APP,                new FakeUid(UserHandle.getSharedAppGid(Process.LOG_UID)), 9.0f);        stats.add(sipper);        return stats;    }
    
   

2.5.3 功耗文件，获取功耗数据

frameworks/base/core/java/com/android/internal/os/BatteryStatsHelper.java

BatteryStatsHelper->getUsageList()

/**     * List of apps using power.     */    private final List
   
     mUsageList = new ArrayList<>();    public List
    
      getUsageList() {        return mUsageList;    }    public void refreshStats(int statsType, SparseArray
     
       asUsers, long rawRealtimeUs, long rawUptimeUs) {        ...        mUsageList.add(index, bs);        ...    }