Small sample of the Rust/WinRT API projection https://github.com/microsoft/winrt-rs

main.rs

winrt::import!(
    dependencies
        os
    modules
        "windows.foundation"
        "windows.system.power"
);
use windows::system::power::*;

fn battery_status() -> std::string::String {
    let battery_status = PowerManager::battery_status().unwrap();
    let result = match battery_status {
        BatteryStatus::Charging => "Charging",
        BatteryStatus::Discharging => "Discharging",
        BatteryStatus::Idle => "Idle",
        BatteryStatus::NotPresent => "NotPresent",
        _ => "Unknown",
    };
    String::from(result)
}

fn energy_saver_status() -> std::string::String {
    let energy_saver_status = PowerManager::energy_saver_status().unwrap();
    let result = match energy_saver_status {
        EnergySaverStatus::On => "On",
        EnergySaverStatus::Off => "Off",
        EnergySaverStatus::Disabled => "Disabled",
        _ => "Unknown",
    };
    String::from(result)
}

fn power_supply_status() -> std::string::String {
    let power_supply_status = PowerManager::power_supply_status().unwrap();
    let result = match power_supply_status {
        PowerSupplyStatus::Adequate => "Adequate",
        PowerSupplyStatus::Inadequate => "Inadequate",
        PowerSupplyStatus::NotPresent => "NotPresent",
        _ => "Unknown",
    };
    String::from(result)
}

fn main() {
    type EvHandler = windows::foundation::EventHandler<winrt::Object>;
    PowerManager::battery_status_changed(EvHandler::new(|_sender, _args| {
        let status = battery_status();
        let msg = format!("{} - {}", "battery_status", status);
        println!("{}", msg);
        Ok({})
    }))
    .unwrap();
    PowerManager::energy_saver_status_changed(EvHandler::new(|_sender, _args| {
        let status = energy_saver_status();
        let msg = format!("{} - {}", "energy_saver_status", status);
        println!("{}", msg);
        Ok({})
    }))
    .unwrap();
    PowerManager::power_supply_status_changed(EvHandler::new(|_sender, _args| {
        let status = power_supply_status();
        let msg = format!("{} - {}", "power_supply_status", status);
        println!("{}", msg);
        Ok({})
    }))
    .unwrap();
    let status = battery_status();
    let msg = format!("{} - {}", "battery_status", status);
    println!("{}", msg);
    let status = energy_saver_status();
    let msg = format!("{} - {}", "energy_saver_status", status);
    println!("{}", msg);
    let status = power_supply_status();
    let msg = format!("{} - {}", "power_supply_status", status);
    println!("{}", msg);
    loop {}
}