How to automatically save files on lose focus in Emacs

Question

Is it possible to configure Emacs, so that it saves all files when the emacs window loses focus?

Answer 1

I added focus hooks to Gnu Emacs 24.4.

They are called focus-in-hook and focus-out-hook.

You can add

(defun save-all ()
  (interactive)
  (save-some-buffers t))

(add-hook 'focus-out-hook 'save-all)

to your .emacs file and it should save all files on loss of focus.