device_screen_brightness 0.2.1

Control the screen brightness from Flutter. Provides getBrightness, setBrightness, incrementBrightness, decrementBrightness and streamBrightness with synchronous and compute-based async variants. Uses [...]

device_screen_brightness

A Flutter FFI plugin for reading and controlling screen brightness on Android, iOS, macOS, Windows, and Linux.

All brightness values are normalised to an integer 0–100 regardless of each platform's native range.

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Platform support

Platform	getBrightness	setBrightness	increment / decrement	streamBrightness	Notes
Android	✅	✅	✅	✅	App-level & system-level modes (see below)
iOS	✅	✅	✅	✅	UIScreen.brightness
macOS	✅	✅	✅	✅	DisplayServices (built-in Apple displays only — see below)
Linux	✅	✅	✅	✅	sysfs backlight (group video)
Windows	✅	✅	✅	✅	Physical Monitor API (dxva2)

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Installation

dependencies:
  device_screen_brightness: ^0.2.0

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Android — BrightnessMode

On Android, every brightness operation accepts an optional BrightnessMode parameter that controls what brightness is modified:

Mode	Behaviour	Permission
BrightnessMode.app	Changes WindowManager.LayoutParams.screenBrightness on the current Activity. Only affects this app; resets when the Activity is destroyed.	None
BrightnessMode.system (default)	Writes Settings.System.SCREEN_BRIGHTNESS. Affects the entire device and persists after the app is closed.	WRITE_SETTINGS

On iOS, macOS, Linux and Windows the mode parameter is ignored — the system brightness is always used.

System-level brightness — AndroidManifest.xml

If you plan to use BrightnessMode.system (the default), add the following permission to your android/app/src/main/AndroidManifest.xml:

<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <uses-permission android:name="android.permission.WRITE_SETTINGS" />
    ...
</manifest>

WRITE_SETTINGS is a special permission — it is not granted automatically at install time. Before calling setBrightness with BrightnessMode.system, check and request the permission:

// Check whether the permission has already been granted
if (!DeviceScreenBrightness.hasPermission()) {
  // Opens the system settings screen where the user can grant the permission
  DeviceScreenBrightness.requestPermission();
}

App-level brightness — no permission needed

With BrightnessMode.app no permission is required. The brightness is applied only to the current Activity window and resets when the app is closed:

// Set app-level brightness (no permission needed)
DeviceScreenBrightness.setBrightness(75, mode: BrightnessMode.app);

// Read app-level brightness (falls back to system if not set)
int level = DeviceScreenBrightness.getBrightness(mode: BrightnessMode.app);

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Usage

import 'package:device_screen_brightness/device_screen_brightness.dart';

// Read brightness (0–100)
int level = DeviceScreenBrightness.getBrightness();

// Set brightness (0–100)
DeviceScreenBrightness.setBrightness(75);

// Increment / decrement by one platform step (5)
DeviceScreenBrightness.incrementBrightness();
DeviceScreenBrightness.decrementBrightness();

// Stream — emits current value immediately, then on every change (250 ms polling)
DeviceScreenBrightness.streamBrightness().listen((value) {
  print('Brightness: $value');
});

BrightnessMode on Android

// App-level brightness (no permission needed, resets on Activity destroy)
DeviceScreenBrightness.setBrightness(80, mode: BrightnessMode.app);
int appLevel = DeviceScreenBrightness.getBrightness(mode: BrightnessMode.app);

// System-level brightness (requires WRITE_SETTINGS, persists)
DeviceScreenBrightness.setBrightness(80, mode: BrightnessMode.system);
int sysLevel = DeviceScreenBrightness.getBrightness(mode: BrightnessMode.system);

// Stream with a specific mode
DeviceScreenBrightness.streamBrightness(mode: BrightnessMode.app).listen((v) {
  print('App brightness: $v');
});

Permission helpers (Android only)

// Returns true on non-Android platforms
bool granted = DeviceScreenBrightness.hasPermission();

// Opens system settings to grant WRITE_SETTINGS; no-op on non-Android
DeviceScreenBrightness.requestPermission();

Compute variants

Every one-shot operation has a *Compute counterpart that runs on a background isolate:

int level = await DeviceScreenBrightness.getBrightnessCompute();
await DeviceScreenBrightness.setBrightnessCompute(80);
await DeviceScreenBrightness.incrementBrightnessCompute();
await DeviceScreenBrightness.decrementBrightnessCompute();

// Compute variants also accept mode:
await DeviceScreenBrightness.setBrightnessCompute(80, mode: BrightnessMode.app);

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Error handling

All failures throw a subclass of DeviceScreenBrightnessException:

Exception	When
UnsupportedOperationException	Operation not supported on the current platform
InvalidBrightnessValueException	Value outside 0–100
NativeBackendException	Native OS / driver error
PermissionDeniedException	Missing required permission (e.g. WRITE_SETTINGS)
BackendNotAvailableException	No brightness backend found (headless, VM, etc.)
BrightnessObservationException	Error while observing brightness changes

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macOS — Platform limitations

macOS support uses Apple's private DisplayServices framework. This limits brightness control to the following devices:

Device	Supported
MacBook (built-in display)	✅
iMac (built-in display)	✅
Apple Studio Display	✅
Apple Pro Display XDR	✅
Third-party external monitors (LG, Dell, Samsung…)	❌

Third-party external monitors connected via HDMI, DisplayPort, or USB-C are not supported. Any call on such a setup throws BackendNotAvailableException.

Why? macOS restricts DDC/CI brightness control to apps with special Apple entitlements. The private IOAVService API used by tools like MonitorControl and m1ddc requires root privileges or com.apple.private.* entitlements that are unavailable in standard sandboxed applications.

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Linux — Requirements

The sysfs backlight interface (/sys/class/backlight) requires write permission. On most distributions the current user must belong to the video group:

sudo usermod -aG video $USER
# Log out and back in for the change to take effect

If the user lacks write permission, setBrightness throws PermissionDeniedException.

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License

MIT