Globally override key binding in Emacs

Question

How can I set a key binding that globally overrides and takes precedence over all other bindings for that key? I want to override all major/minor mode maps and make sure my

Answer 1

I don't think you can. That is roughly equivalent to saying that you want to define a global variable that cannot be hidden by local variable declarations in functions. Scope just doesn't work that way.

However, there might be a way to write an elisp function to go through the mode list and reassign it in every single one for you.

Answer 2

If you want to "always use the keybinds in the map, unless I explicitly override them for a specific mode-map", and assuming you are using scottfrazier's approach, you want:

(defun locally-override (key cmd)
  (unless (local-variable-p 'my-keys-minor-mode-map)
    (set (make-variable-buffer-local 'my-keys-minor-mode-map)
         (make-sparse-keymap))
    (set-keymap-parent my-keys-minor-mode-map 
                       (default-value 'my-keys-minor-mode-map)))
  (define-key my-keys-minor-mode-map key cmd))

So

(locally-override "\C-i" nil)

should remove the "\C-i" binding from the minor mode in the current buffer only. Warning: this is completely untested, but seems like the right approach. The point of setting the parent rather than just coping the global value of my-keys-minor-mode-map is so any later changes to the global value are automatically reflected in the local value.

Answer 3

Install use-package, eval and you're done:

(require 'bind-key)
(bind-key* "C-i" 'some-function)

Answer 4

I found this question while searching for "emacs undefine org mode keybindings", because I wanted to unbind the existing C-c C-b behavior to allow my global map to bury-buffer to work in an org buffer.

This ended up being the simplest solution for me:

(add-hook 'org-mode-hook
      (lambda ()
        (local-unset-key (kbd "C-c C-b"))))

Answer 5

Although scottfrazer's answer is exactly what you asked for, I will mention for posterity another solution.

From The Emacs Manual:

"Don't define C-c letter as a key in Lisp programs. Sequences consisting of C-c and a letter (either upper or lower case) are reserved for users; they are the only sequences reserved for users, so do not block them."

If you bind your personal global bindings to C-c plus a letter, then you "should" be safe. However, this is merely a convention, and any mode is still able to override your bindings.

Answer 6

I use a minor mode for all my "override" key bindings:

(defvar my-keys-minor-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map (kbd "C-i") 'some-function)
    map)
  "my-keys-minor-mode keymap.")

(define-minor-mode my-keys-minor-mode
  "A minor mode so that my key settings override annoying major modes."
  :init-value t
  :lighter " my-keys")

(my-keys-minor-mode 1)

This has the added benefit of being able to turn off all my modifications in one fell swoop (just disable the minor mode) in case someone else is driving the keyboard or if I need to see what a default key binding does.

Note that you may need to turn this off in the minibuffer:

(defun my-minibuffer-setup-hook ()
  (my-keys-minor-mode 0))

(add-hook 'minibuffer-setup-hook 'my-minibuffer-setup-hook)