When I program I use two screens with Emacs on both with two buffers split in each window totaling 4 open source files on screen at any one time.
I switch between buffers with C-x b and between Windows with Alt-TAB. I change the appearance of buffers when I switch between them by defining different faces for mode-line and mode-line-inactive. But how do I inactivate a buffer when I switch from the Emacs window completely to another Emacs window via Alt-TAB?
It's probably also relevant that I'm using Emacs 23.2.1 on Ubuntu 11.04 with Gnome 2.32.1.
PS: The question How to automatically save files on lose focus in Emacs is after a different goal but with the same original event of "window losing focus".
It may depend on your window manager and how it manages multiple windows, or frames, in emacs parlance. The code below works like a champ in fvwm but not always in gnome.
I map a keystroke, C-o, to go between frames, this helps when you want to go to the other frame but an alt-tab would take you through a number of superfluous apps on the way.
If you're running a single instance of emacs with two frames you could use something like the following:
(defun pgr-previous-frame ()
"go to the previous frame"
(interactive)
(pgr-switch-frame (previous-frame)))
(defun pgr-next-frame ()
"go to the next frame"
(interactive)
(pgr-switch-frame (next-frame)))
(defun pgr-switch-frame (frame)
"go to the specified frame and raise it"
;; reset the frame properties here
(select-frame frame)
(raise-frame frame)
;;change the display in some manner here
)
You could also try adding some advice to raise-frame and lower-frame haven't tried it but it's worth a try.