问对于华为设备，isPowerSaveMode()总是返回false

EN

object PowerManagerCompat {

    private const val TAG = "PowerManagerCompat"

    interface PowerSaveModeChangeListener {
        /**
         * will be called when power save mode change, new state can be query via [PowerManagerCompat.isPowerSaveMode]
         */
        fun onPowerSaveModeChanged()
    }

    private val POWER_SAVE_MODE_VALUES = mapOf(
            "HUAWEI" to 4,
            "XIAOMI" to 1
    )

    private val POWER_SAVE_MODE_SETTING_NAMES = arrayOf(
            "SmartModeStatus", // huawei setting name
            "POWER_SAVE_MODE_OPEN" // xiaomi setting name
    )

    private val POWER_SAVE_MODE_CHANGE_ACTIONS = arrayOf(
            "huawei.intent.action.POWER_MODE_CHANGED_ACTION",
            "miui.intent.action.POWER_SAVE_MODE_CHANGED"
    )

    private const val monitorViaBroadcast = true

    /**
     * Monitor power save mode change, only support following devices
     * * Xiaomi
     * * Huawei
     */
    fun monitorPowerSaveModeChange(context: Context, powerSaveModeChangeListener: PowerSaveModeChangeListener) {
        if (Build.MANUFACTURER.toUpperCase(Locale.getDefault()) !in POWER_SAVE_MODE_VALUES.keys) {
            Log.w(TAG, "monitorPowerSaveModeChange: doesn't know how to monitor power save mode change for ${Build.MANUFACTURER}")
        }
        if (monitorViaBroadcast) {
            context.registerReceiver(object : BroadcastReceiver() {
                override fun onReceive(context: Context?, intent: Intent?) {
                    powerSaveModeChangeListener.onPowerSaveModeChanged()
                }
            }, IntentFilter().also {
                for (a in POWER_SAVE_MODE_CHANGE_ACTIONS) {
                    it.addAction(a)
                }
            })
        } else {
            val contentObserver = object : ContentObserver(null) {
                override fun onChange(selfChange: Boolean) {
                    super.onChange(selfChange)
                    powerSaveModeChangeListener.onPowerSaveModeChanged()
                }
            }
            for (name in POWER_SAVE_MODE_SETTING_NAMES) {
                context.contentResolver.registerContentObserver(
                        Uri.parse("content://settings/system/${name}"), false, contentObserver)
            }
        }
    }

    /**
     * Check the system is currently in power save mode
     * @see [PowerManager.isPowerSaveMode]
     */
    fun isPowerSaveMode(context: Context): Boolean {
        if (Build.MANUFACTURER.toUpperCase(Locale.getDefault()) in POWER_SAVE_MODE_VALUES.keys) {
            return isPowerSaveModeCompat(context)
        }
        val powerManager = context.getSystemService(Context.POWER_SERVICE) as? PowerManager
        return powerManager?.isPowerSaveMode ?: false
    }

    private fun isPowerSaveModeCompat(context: Context): Boolean {
        for (name in POWER_SAVE_MODE_SETTING_NAMES) {
            val mode = Settings.System.getInt(context.contentResolver, name, -1)
            if (mode != -1) {
                return POWER_SAVE_MODE_VALUES[Build.MANUFACTURER.toUpperCase(Locale.getDefault())] == mode
            }
        }
        return false
    }
}

// Manually request Power Save Mode:
public Boolean isPowerSaveMode(Context context) {
    if (Build.MANUFACTURER.equalsIgnoreCase("Huawei")) {
        return isPowerSaveModeHuawei(context);
    } else {
        return isPowerSaveModeAndroid(context);
    }
}

@TargetApi(21)
private Boolean isPowerSaveModeAndroid(Context context) {
    boolean isPowerSaveMode = false;
    if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
        if (pm != null) isPowerSaveMode = pm.isPowerSaveMode();
    }
    return isPowerSaveMode;
}

private Boolean isPowerSaveModeHuawei(Context context) {
    try {
        int value = android.provider.Settings.System.getInt(context.getContentResolver(), "SmartModeStatus");
        return (value == 4);
    } catch (Settings.SettingNotFoundException e) {
        // Setting not found?  Return standard android mechanism and hope for the best...
        return isPowerSaveModeAndroid(context);
    }
}

// Listening for changes in Power Save Mode
public void startMonitoringPowerSaveChanges(Context context) {
    if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        if (mPowerSaveChangeReceiver != null) {
            return;
        }
        // Register for PowerSaver change updates.
        mPowerSaveChangeReceiver = new PowerSaveChangeReceiver();

        // Registering the receiver
        IntentFilter filter = new IntentFilter();

        filter.addAction(PowerManager.ACTION_POWER_SAVE_MODE_CHANGED);
        // Add custom huawei action
        filter.addAction("huawei.intent.action.POWER_MODE_CHANGED_ACTION");

        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            filter.addAction(android.provider.Settings.ACTION_IGNORE_BATTERY_OPTIMIZATION_SETTINGS);
        }
        context.registerReceiver(mPowerSaveChangeReceiver, filter);
    }
}

@TargetApi(21)
class PowerSaveChangeReceiver extends BroadcastReceiver {
    public void onReceive(Context context, Intent intent) {
        boolean isPowerSaveMode = false;

        // Oh, Huawei...why don't you play by the same rules as everyone else?
        if (intent.getAction().equals("huawei.intent.action.POWER_MODE_CHANGED_ACTION")) {
            Bundle extras = intent.getExtras();
            if ((extras != null) && extras.containsKey("state")) {
                int state = intent.getExtras().getInt("state");
                isPowerSaveMode = (state == 1);  // ON=1; OFF=2
            }
        } else {
            PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
            isPowerSaveMode = pm.isPowerSaveMode();
        }
        Log.d("MyTag", "[powersavechange] isPowerSaveMode? " + isPowerSaveMode);
    }
}