signal handler for changing border width per layout

signal.lua

-- Arrange signal handler
for s in screen do s:connect_signal('arrange', function ()
    local clients = awful.client.visible(s)
    local layout  = awful.layout.getname(awful.layout.get(s))

    if #clients > 0 then -- Fine grained borders and floaters control
      for _, c in pairs(clients) do -- Floaters always have borders
        if c.floating or layout == 'floating' then
          c.border_width = beautiful.border_width

          -- No borders with only one visible client
        elseif #clients == 1 or layout == 'max' then
          c.border_width = 0
        else
          c.border_width = beautiful.border_width
        end
      end
    end
  end)
end