A simple clock with LGI (Lua + GTK)

GtkClock.lua

--[[--
 @desc	    A simple clock with LGI (Lua + GTK)
 @author    Díaz Urbaneja Víctor Eduardo Diex <victor.vector008@gmail.com>
 @date      23.02.2021 03:57:22 -04
]]

-- I require the LGI libraries
local lgi = require('lgi')
local Gtk = lgi.require('Gtk', '3.0')
local GLib = lgi.require('GLib', '2.0')
local Pango = lgi.require('Pango', '1.0')

-- I declare my variables
local current_time
-- I change the font size
local font_size = Pango.attr_scale_new(3)

-- I create the list of attributes
local attrlist = Pango.AttrList()
-- I add the attribute
attrlist:insert(
	font_size
)

-- I create the main window
local window = Gtk.Window {
	title = 'A simple clock with LGI (Lua + GTK)',
	width = 400,
	height = 400,
	window_position = Gtk.WindowPosition.CENTER,
	{
		Gtk.Label {
			id = 'time',
			visible = true,
			can_focus = false,
			label = '00:00:00',
			attributes = attrlist
		}
	},
	on_destroy = function()
		Gtk.main_quit()
	end
}

-- This loop will update the label with the current time every 1 second.
GLib.timeout_add_seconds(GLib.PRIORITY_DEFAULT, 1,
	function ()
		current_time = os.date('%H:%M:%S', os.time())
		window.child.time.label = current_time
		return true
	end
)

window:show_all()
Gtk.main()