Let's make keyboard-quit smarter
I’ll be pretty brief today. keyboard-quit (C-g) is one of the most
used commands, but unfortunately it’s not very smart. Most annoyingly,
it doesn’t work as expected when the minibuffer is active.
Fortunately, fixing such problems (and then some) is trivial in Emacs:
(defun er-keyboard-quit ()
"Smater version of the built-in `keyboard-quit'.
The generic `keyboard-quit' does not do the expected thing when
the minibuffer is open. Whereas we want it to close the
minibuffer, even without explicitly focusing it."
(interactive)
(if (active-minibuffer-window)
(if (minibufferp)
(minibuffer-keyboard-quit)
(abort-recursive-edit))
(keyboard-quit)))
I’d suggest to just remap keyboard-quit to our improved version:
(global-set-key [remap keyboard-quit] #'er-keyboard-quit)
There are other ways to tackle this particular issue, of course,
and different people might prefer an even more complicated
version of the smarter keyboard-quit or one that does fewer
things. One of my readers suggested in the comments a similar
solution using an advice:
(define-advice keyboard-quit
(:around (quit) quit-current-context)
"Quit the current context.
When there is an active minibuffer and we are not inside it close
it. When we are inside the minibuffer use the regular
`minibuffer-keyboard-quit' which quits any active region before
exiting. When there is no minibuffer `keyboard-quit' unless we
are defining or executing a macro."
(if (active-minibuffer-window)
(if (minibufferp)
(minibuffer-keyboard-quit)
(abort-recursive-edit))
(unless (or defining-kbd-macro
executing-kbd-macro)
(funcall-interactively quit))))
This has the benefit of directly modifying the original command, so you don’t really need to rebind anything. On the other hand - advices are arguably a bit more complicated to understand and debug. Personally, I like to replace functions in my own setup with versions that I prefer, as I think this makes the modifications more obvious.
Another option is a similar function from Prot:1
(defun prot/keyboard-quit-dwim ()
"Do-What-I-Mean behaviour for a general `keyboard-quit'.
The generic `keyboard-quit' does not do the expected thing when
the minibuffer is open. Whereas we want it to close the
minibuffer, even without explicitly focusing it.
The DWIM behaviour of this command is as follows:
- When the region is active, disable it.
- When a minibuffer is open, but not focused, close the minibuffer.
- When the Completions buffer is selected, close it.
- In every other case use the regular `keyboard-quit'."
(interactive)
(cond
((region-active-p)
(keyboard-quit))
((derived-mode-p 'completion-list-mode)
(delete-completion-window))
((> (minibuffer-depth) 0)
(abort-recursive-edit))
(t
(keyboard-quit))))
I know this version of the command is quite popular in the wild, as many
people follow Prot’s work, but looking at the code of the actual keyboard-quit
it seems to me that Prot’s version is more complicated than it needs to be:
;; This executes C-g typed while Emacs is waiting for a command.
;; Quitting out of a program does not go through here;
;; that happens in the maybe_quit function at the C code level.
(defun keyboard-quit ()
"Signal a `quit' condition.
During execution of Lisp code, this character causes a quit directly.
At top-level, as an editor command, this simply beeps."
(interactive)
;; Avoid adding the region to the window selection.
(setq saved-region-selection nil)
(let (select-active-regions)
(deactivate-mark))
(if (fboundp 'kmacro-keyboard-quit)
(kmacro-keyboard-quit))
(when completion-in-region-mode
(completion-in-region-mode -1))
;; Force the next redisplay cycle to remove the "Def" indicator from
;; all the mode lines.
(if defining-kbd-macro
(force-mode-line-update t))
(setq defining-kbd-macro nil)
(let ((debug-on-quit nil))
(signal 'quit nil)))
As you can see it already handles things like the selected region and completion in region. But perhaps I’m missing what Prot was trying to achieve with his version.
Which of the three approaches do you prefer?
How would you improve er-keyboard-quit-dwim further?
That’s all I have for you today! Keep hacking!