dotfiles/awesome/battery.lua

-- This function returns a formatted string with the current battery status. It
-- can be used to populate a text widget in the awesome window manager. Based
-- on the "Gigamo Battery Widget" found in the wiki at awesome.naquadah.org

local wibox = require("wibox")
local naughty = require("naughty")
local beautiful = require("beautiful")

local previous_percent = 0

function batteryInfo()
    local fd = io.popen('acpi | head -n 1 | cut -d ":" -f 2 | cut -d "," -f 2 | tr -d "%"')
    local percentage = fd:read('*all')
    fd:close()
    return tonumber(percentage)
end

function isCharging()
    local _,_,error = os.execute('acpi | head -n 1 | grep Discharging')
    return error ~= 0
end

function update_battery()

    local percent = batteryInfo()
    local color
    local symbol

    if percent < 15 then
        color="red"
    elseif percent < 30 then
        color="orange"
    elseif percent > 90 then
        color="green"
    else
        color="white"
    end

    if isCharging() then
        color = 'green'
        symbol = '⚡'
    else
        symbol = '%'
    end

    if previous_percent >= 15 and percent < 15 then
        naughty.notify({
            title = "Low battery...",
            text = "Battery level is lower than 15% !",
            fg="#000000",
            bg="#ff0000",
            timeout=5
        })
    end

    battery_widget:set_markup('<span color="' .. color .. '">' .. percent .. ' ' .. symbol .. '</span>')

    previous_percent = percent

end

battery_widget = wibox.widget.textbox()
battery_widget.timer = timer({timeout=5})
battery_widget.timer:connect_signal("timeout", update_battery)
battery_widget.timer:start()
update_battery()