Android Question Change Text Size of all Items

Hi,

how can i change all Items (Button, Label, Spinner.......) Text Size in all Panels by Factor?
(what is the best way)

e.g.:
TextScaleFactor = GetDeviceLayoutValues.ApproximateScreenSize / 7 (Code from Klaus)

and then for all Items:
Item.NewTextSize = Item.OrgTextSize * TextScaleFactor

Thanks