RStudio, we can be friend, right?
This elisp project seeks for .Rproj file in the current directory or the base directory of your current developing R package. And then set indentation of ESS according to the .Rproj file. Useful for ESS users surviving in this RStudio-dominant world.
Download ess_rproj.el somewhere. Put this into your configuration file.
(load-file "ess_rproj.el")
(add-hook 'ess-mode-hook #'ess-rproj)