how to add a prefix key to all keybindings of a specific mode?

Question

i am using a mode, but am not used to its key-bindings: some of them conflict to the emacs global ones. so, i want to add a prefix key-binding to all its existing keybindings.

for example, if my-mode defines key-binding M-] for my-mode-shot, i am looking for some ways as following:

(define-prefix-for-mode 'my-mode (kbd "C-c m"))

then the key-binding for my-mode-shot now is C-c m M-].

how should one add a prefix key-binding to all available key-bindings of a specific mode?

Answer 1

One way to move -mode's keybindings could be with something like

(let ((origmap <foo>-mode-map)
      (newmap (make-sparse-keymap)))
  (define-key newmap <prefix> origmap)
  (setq <foo>-mode-map newmap))  

But this code will fail if run before foo-mode is run. And it will have no effect if run after the mode is entered. So you'll probably have to do it within `(with-eval-after-load '-mode ...).

Also, if it's a minor mode, the above code won't have any effect either, because you additionally have to do something like (within the above let):

(setcdr (assq '<foo>-mode minor-mode-map-alist) newmap)

Answer 2

1. Define a prefix key for the mode's keymap.
2. Undefine the other keys that bother you, from that keymap.

Suppose that mode foo-mode binds key C-x o to foo-it, and you don't like that.

(define-key foo-mode-map (kbd "C-x o") nil)

And suppose you want foo-mode-map on prefix key <f9>:

(define-prefix-command 'foo-mode-map)
(define-key global-map (kbd "<f9>") 'foo-mode-map)

Answer 3

You can modify the mode's keymap directly to move all the bindings under your chosen prefix:

(setcdr my-mode-map
  `(keymap (?\C-c keymap (?m keymap . ,(cdr my-mode-map)))))