[Lua + Gtk 3] Switches between enabling/disabling the CSD

GtkToggleCSD.lua

local lgi = require("lgi")
local Gtk = lgi.Gtk
local GObject = lgi.GObject
local Example = lgi.package("Example")

Example:class("App", Gtk.Application)
Example:class("Header", Gtk.HeaderBar)
Example:class("Window", Gtk.ApplicationWindow)

function Example.App:_init( ... )
  self.application_id = "org.example.Gtk"
end

function Example.App:do_startup( ... )
  self._parent.do_startup(self)
end

function Example.App:do_activate( ... )
  local Window = Example.Window({ title = "CSD Disabled" })
  local Btn    = Gtk.Button({
    label   = "Toggle CSD",
    visible = true,
    expand  = false,
    halign  = Gtk.Align.CENTER,
    valign  = Gtk.Align.CENTER
  })

  local App = self

  function ToggleCSD(self)
    App:hold()
    App:remove_window(Window)

    Window:destroy()

    if Window.has_csd then
      Window = Example.Window({ title = "CSD Disabled" })
      Window.has_csd = false
    else
      Window = Example.Window()
      Window:set_titlebar(Example.Header({ title = "CSD Enabled" }))
      Window.has_csd = true
    end

    Window:add(Gtk.Button({
      label   = "Toggle CSD",
      visible = true,
      expand  = false,
      halign  = Gtk.Align.CENTER,
      valign  = Gtk.Align.CENTER,
      on_clicked = ToggleCSD
    }))

    Window:present()
    App:add_window(Window)
    App:release()
  end

  Btn.on_clicked = ToggleCSD
  Window:add(Btn)
  Window:present()
  self:add_window(Window)
end

function Example.Header:_init( ... )
  self.decoration_layout = ":close"
  self.show_close_button = true
  self.visible = true
  self.id = "header"
end

function Example.Window:_class_init(Class)
  function Class:set_property(id, value, pspec)
    if id == 1 then
      self.priv.has_csd = value:get_boolean()
    else
      GObject.OBJECT_WARN_INVALID_PROPERTY_ID(self, id, pspec)
    end
  end

  function Class:get_property(id, value, pspec)
    if id == 1 then
      value:set_boolean(self.priv.has_csd)
    else
      GObject.OBJECT_WARN_INVALID_PROPERTY_ID(self, id, pspec)
    end
  end

  Class:install_property(1, GObject.ParamSpecBoolean(
    "has-csd",
    "Has CSD",
    "Holds the CSD status (enabled/disabled) of the window",
    false,
    { "READWRITE" }
  ))
end

function Example.Window:_init( ... )
  self.window_position = Gtk.WindowPosition.CENTER
  self.width_request = 600
  self.height_request = 400
  self.border_width = 80
  self.title = "CSD Disabled"
end

return Example.App():run(arg)