DBusPower #

dbus_power is a Dart library for interacting with Linux power settings over D-Bus. It exposes two backends: DBusGnomePower for the GNOME Settings Daemon (session bus, percentage based) and DBusFreedesktopPower for freedesktop's UPower (system bus, battery state and keyboard backlight).

Features #

• Get and set the screen brightness (GNOME).
• Get and set the keyboard backlight brightness (GNOME and UPower).
• Step screen brightness up and down, and toggle the keyboard backlight.
• Read battery state via UPower: charge percentage, charging state, time estimates, energy, voltage, temperature, capacity (health), and more.
• Enumerate all power devices and inspect any of them by path.
• Check whether the system is running on battery and read lid state.

Installation #

Add the package to your project using the following command:

dart pub add dbus_power

Usage #

GNOME (session bus) #

import 'package:dbus_power/dbus_power.dart';

void main() async {
  final power = DBusGnomePower();

  // Get the current screen brightness (0-100)
  final screen = await power.getScreenBrightness();
  print('Screen brightness: $screen%');

  // Set the screen brightness
  await power.setScreenBrightness(50);

  // Get and set the keyboard backlight brightness
  final keyboard = await power.getKeyboardBrightness();
  print('Keyboard brightness: $keyboard%');
  await power.setKeyboardBrightness(75);

  // Toggle the keyboard backlight on/off
  await power.keyboardToggle();

  // Close the D-Bus client connection
  await power.close();
}

UPower (system bus) #

GNOME's power daemon is a session-bus policy layer on top of freedesktop's UPower. Use DBusFreedesktopPower when you want battery information or to talk to UPower directly. Note that UPower works in raw values; the wrapper converts the keyboard backlight to/from a percentage for you.

import 'package:dbus_power/dbus_power.dart';

Future<void> main() async {
  final power = DBusFreedesktopPower();
  try {
    // Whether the system is running on battery
    print('On battery: ${await power.isOnBattery()}');

    // Battery charge percentage and state (1=charging, 2=discharging, 4=full)
    print('Battery: ${await power.getBatteryPercentage()}%');
    print('Battery state: ${await power.getBatteryState()}');
    print('Energy rate: ${await power.getEnergyRate()} W');

    // Enumerate devices and inspect a specific one by path
    final devices = await power.enumerateDevices();
    print('Devices: $devices');
    final bat = devices.firstWhere((d) => d.contains('battery_BAT'));
    print('Battery health: ${await power.getCapacity(bat)}%');
    print('Vendor/model: ${await power.getVendor(bat)} ${await power.getModel(bat)}');

    // Keyboard backlight brightness (0-100), or raw values
    print('Keyboard backlight: ${await power.getKeyboardBrightness()}%');
    await power.setKeyboardBrightness(75);
  } finally {
    // Close the D-Bus client connection
    await power.close();
  }
}

Command line #

The package ships a dbus-power executable with an interactive menu for adjusting brightness and viewing battery status:

dart pub global activate dbus_power
dbus-power

License #

This project is licensed under the MIT License.