Platform

Android 13

Plugin

battery_plus

Version

6.2.2

Flutter SDK

3.29.3

Steps to reproduce

This error was reported via Sentry, but I can't reproduce it on my device. This error appears to be occurring in the combination of Android 13 and the SM-A032F device. Below is the root cause observed by Sentry Seer. Please let me know if you need any more information.

Root Cause of the Issue

Flutter app's battery_plus plugin attempts to read Android's restricted psm_switch setting, causing a SecurityException on Android 12+ devices.

The application initializes a timer to periodically check the device's low power mode status.

// lib/screen/home/data/home_data.dart
  Future<void> initLowPowerModeCheckTimer() async {
    try {
      // ...
      lowPowerModeCheckTimer = Timer.periodic(1.seconds, (_) async {
        if (await battery.isInBatterySaveMode == true) showLowPowerModeDialog();
      });
    } catch (e, s) {
      await Sentry.captureException(e, stackTrace: s);
    }
  }

This function sets up a recurring check for battery save mode, which is the entry point for the problematic operation. The try-catch block here attempts to handle exceptions, but the SecurityException is still propagated.
(See lib/screen/home/data/home_data.dart)

The Flutter application invokes the isInBatterySaveMode method from the battery_plus plugin.

// packages/battery_plus/battery_plus/lib/src/method_channel_battery_plus.dart (conceptual)
class MethodChannelBattery extends BatteryPlatform {
  @override
  Future<bool> get isInBatterySaveMode async {
    final bool? isInBatterySaveMode = await _methodChannel.invokeMethod('isInBatterySaveMode');
    return isInBatterySaveMode ?? false;
  }
}

This is the Flutter-side abstraction that communicates with the native platform code. It uses a MethodChannel to send a request to the Android operating system.
(See method_channel_battery_plus.dart)

The native Android code within the battery_plus plugin attempts to read the psm_switch system setting.

// Android native code within battery_plus plugin (conceptual, based on stack trace)
// at J2.a.l(SourceFile:12)
// This line conceptually represents the plugin's call:
String psmSwitch = Settings.System.getString(context.getContentResolver(), "psm_switch");

The battery_plus plugin's Android implementation tries to determine the battery save mode status by directly querying the psm_switch setting, which is an internal Android setting.
(See SourceFile)

The Android operating system, on versions S+ (Android 12 and above), restricts access to the @hide psm_switch setting for non-system applications.

Settings key: <psm_switch> is not readable. From S+, settings keys annotated with @hide are restricted to system_server and system apps only, unless they are annotated with @Readable.

This is the core policy enforcement by the Android OS. The psm_switch setting is marked with @hide, meaning it's not part of the public API and its access is now strictly controlled for security and stability reasons.
(See Settings.java)

The Android OS throws a SecurityException because the application lacks the necessary system privileges to read the restricted setting.

java.lang.SecurityException: Settings key: <psm_switch> is not readable. From S+, settings keys annotated with @hide are restricted to system_server and system apps only, unless they are annotated with @Readable.
	at android.provider.Settings$NameValueCache.getStringForUser(Settings.java:3112)
	at android.provider.Settings$System.getStringForUser(Settings.java:3905)
	at android.provider.Settings$System.getString(Settings.java:3887)

This exception is the direct result of the Android OS denying the read operation. It clearly states the reason: the setting is restricted to system apps on Android S+ unless explicitly marked as readable.
(See Settings.java)

Code Sample

...
try {
      if (await battery.isInBatterySaveMode == true) showLowPowerModeDialog();
      lowPowerModeCheckTimer = Timer.periodic(1.seconds, (_) async {
        if (await battery.isInBatterySaveMode == true) showLowPowerModeDialog();
      });
    } catch (e, s) {
      await Sentry.captureException(e, stackTrace: s);
    }
...

await battery.isInBatterySaveMode == true <- This is where the error occurs.

Logs

I can't reproduce the error on my device. There's no issue on my end.

Flutter Doctor

I can't reproduce the error on my device. There's no issue on my end.

Checklist before submitting a bug

• I searched issues in this repository and couldn't find such bug/problem
• I Google'd a solution and I couldn't find it
• I searched on StackOverflow for a solution and I couldn't find it
• I read the README.md file of the plugin
• I'm using the latest version of the plugin
• All dependencies are up to date with flutter pub upgrade
• I did a flutter clean
• I tried running the example project