Any change in the Label.font, Label.fontstyle and Label.fontsize properties results in an automatic resizing of the Label so that the content is displayed correctly
Label.fontsize read/write property
Get or set the Label font size, a number that represent the font size in pixels.
Example
local ui = require "ui"
-- create a simple label
local win = ui.Window("Label.fontsize sample", 640, 200)
local label = ui.Label(win, "", 200, 70)
label.fontsize = 16
label.text = label.font.." font, "..label.fontsize.."px"
win:show()
-- update the user interface until the user closes the Window
repeat
ui.update()
until not win.visible