Remap “cmd”+“W” to kill-buffer in Aquamacs?

Question

In Aquamacs 3.2, I want to remap cmd+W so it will kill the current buffer instead of closing the frame. I use Aquamacs in a classic Emacs style with one window, so I close buffers far more often than I close windows.

I tried this in my .emacs to no effect.

(global-unset-key [?\s-w])
(define-key global-map [?\s-w] 'kill-buffer)

I also tried a variation on this answer but it still kills the window.

(defun kill-current-buffer ()
  (interactive)
  (kill-buffer (current-buffer)))
(global-unset-key (kbd "s-w"))
(global-set-key (kbd "s-w") 'kill-current-buffer)

I also tried putting that code into ~/Library/Preferences/Aquamacs Emacs/Preferences.el as suggested in this answer.

I've verified with describe-function that it is loaded.

kill-current-buffer is an interactive Lisp function in `.emacs'.

It is bound to s-W.

(kill-current-buffer)

Not documented.

Answer 1

There are two things going on. First, Aquamacs has remapped the Mac OS X command key to alt. So it should be (global-set-key '[(alt w)] 'kill-current-buffer).

But that gives a warning because of the second thing, osx-key-mode has defined its own osx-key-mode-map. Emacs suggests to redefine that key in that keymap with define-key.

(defun kill-current-buffer ()
  (interactive)
  (kill-buffer (current-buffer)))
(when (boundp 'osx-key-mode-map)
    (define-key osx-key-mode-map '[(alt w)] 'kill-current-buffer))