battery.lua (for awesome wm - awful)

---------------------------------------------------------------------------
-- @author jesus <ask@jesus.now>
-- @copyright 0 Jesus
-- @release v0.0.0
---------------------------------------------------------------------------

local setmetatable = setmetatable
local os = os
local textbox = require("wibox.widget.textbox")
local capi = { timer = timer }

--- Battery widget.
-- awful.widget.battery
local battery = { mt = {} }

function battery:percentage()
    -- 'echo "scale=4; $(cat /sys/class/power_supply/BAT0/energy_now) / $(cat /sys/class/power_supply/BAT0/energy_full)" | bc'
    local file_now = io.open('/sys/class/power_supply/BAT0/energy_now', 'r')
    local energy_now = file_now:read '*all'
    file_now:close()

    local file_full = io.open('/sys/class/power_supply/BAT0/energy_full', 'r')
    local energy_full = file_full:read '*all'
    file_full:close()

    return energy_now / energy_full
end

function battery:status()
    local file_status = io.open('/sys/class/power_supply/BAT0/status', 'r')
    local status = file_status:read '*all'
    file_status:close()

    return status
end

function battery:decimal()
    return math.floor(battery:percentage() * 10000) / 10000
end

--- Create a battery widget. It draws the current battery percentage in a textbox.
-- @param timeout How often update the time. Default is 60.
-- @return A textbox widget.
function battery.new(timeout)

    local timeout = timeout or 1

    local w = textbox()
    local timer = capi.timer { timeout = timeout }
    timer:connect_signal("timeout", function()
        local status = battery:status()
        local decimal = battery:decimal()
        --text = text .. status
        local ts = ""
        if status == "Charging\n" then
            if decimal > 0.95 then
                ts = " <span color=\"#00FFFF\">+</span> "
            else
                ts = " <span color=\"#00FF00\">+</span> "
            end
        else
            if decimal < 0.15 then
                ts = " <span color=\"#FF0000\">-</span> "
            else
                ts = " <span color=\"#FFFF00\">-</span> "
            end
        end

        w:set_markup(decimal .. ts)
    end)
    timer:start()
    timer:emit_signal("timeout")
    return w
end

function battery.mt:__call(...)
    return battery.new(...)
end

return setmetatable(battery, battery.mt)

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