ess-rdired: customize key bindings - emacs

I would like to customize the key bindings so that "n" and "p" run 'ess-rdired-next-line and 'ess-rdired-previous-line automatically by editing my .emacs
It doesn't recognize the variable ess-rdired-mode-map until I call ess-rdired from a buffer with an ESS process. I tried putting (ess-rdired) earlier in my .emacs and get the error
No ESS process is associated with this buffer now
When I call ess-rdired from an ESS buffer before using define-key as below, they key bindings work as expected.
(define-key ess-rdired-mode-map "P" 'ess-rdired-plot)
(define-key ess-rdired-mode-map "n" 'ess-rdired-next-line)
(define-key ess-rdired-mode-map "p" 'ess-rdired-previous-line)
Debugger entered--Lisp error: (void-variable ess-rdired-mode-map)

The variable isn't defined until the package is loaded, so you can just wrap your key definitions to be loaded after ess-rdired,
(with-eval-after-load 'ess-rdired
;; (define-key ...)
)

Related

Run function before keymap commands

Is there a way to advise a keymap or otherwise run a function after a keymap prefix, but before commands in the keymap?
Say I have a keymap with bindings for hideshow, but these bindings are only useful after hs-minor-mode is activated. How can I run (hs-minor-mode) after the prefix is entered, but before the functions in the map are called?
I thought making a prefix command and advising it might work, but that is an error (below).
Example:
(let ((map (define-prefix-command 'my-activate-fold 'my-fold-map)))
(define-key map "a" #'hs-hide-all)
(define-key map "s" #'hs-show-all)
(define-key map "l" #'hs-hide-level)
(global-set-key (kbd "<f6>") 'my-activate-fold))
;; error: wrong-type-argument commandp my-activate-fold
(define-advice my-activate-fold (:before (fn &rest r) "activate-hideshow")
(hs-minor-mode)
(apply fn r))
If I understand correctly, I think you may be approaching this incorrectly. For your specific question, no, there is no way to define a function which will run after a prefix key is called but before the command (an interactive function) which is bound to the key is run. However, I'm not sure that is really what your after. You can of course define commands which can wrap another command and do whatever you want. However, I'm not sure that is what you want either. You might want to state exactly what you want rather than part of what you believe is the solution to what you want.
Normal practice is for a minor mode to define a keymap and you add your mode specific key bindings to that map in a mode initialisation hook. In the case of hs-minor-mode, that is called hs-minor-mode-map. This map only exists inside buffers running hs-minro-mode and it takes precedence over the global map. So this is where you want to place your mode specific bindings. To do this, create a function which adds the bindings to the map and attach that to the hs-minor-mode-hook, which is run when hs-minor-mode is loaded.
(add-hook 'hs-minor-mode-hook (lambda ()
(define-key 'hs-minor-mode-map "a" #'hs-hide-all)
...))
The key bindings defined above will only exist if hs-minor-mode is active in the buffer. If it is not active, the keys used in the binding will either be bound to whatever the next highest map in the mode is or the global map or nothing (see the section on keymaps in the elsip manual for full details).
If what you want is to have specific hs-minor-mode bindings only exist in specific modes, then you can define those bindings in the keymap for that mode. For example, if you wanted hs-minor-mode bindings that only exist when you run hs-minor-mode in js2-mode, but not when you run hs-minor-mode in c-mode, then you can add the bindings to the js2-mode-map and load hs-minor-mode as part of the js2-mode-hook
If it is something else you are after, you need to clarify.
FWIW, you could simply advise the commands themselves:
(defun my-ensure-hs-minor-mode (&rest _args)
"Ensure `hs-minor-mode' is active."
(unless (bound-and-true-p hs-minor-mode)
(hs-minor-mode 1)))
(advice-add 'hs-hide-all :before #'my-ensure-hs-minor-mode)
(advice-add 'hs-show-all :before #'my-ensure-hs-minor-mode)
(advice-add 'hs-hide-level :before #'my-ensure-hs-minor-mode)
Your keymap then just works:
(require 'hideshow)
(let ((map (define-prefix-command 'my-activate-fold 'my-fold-map)))
(define-key map "a" #'hs-hide-all)
(define-key map "s" #'hs-show-all)
(define-key map "l" #'hs-hide-level))
(global-set-key (kbd "<f6>") 'my-activate-fold)

How to make Emacs key-bindings work in minibuffer? [duplicate]

I'm trying to redefine the keys used to navigate the history when inside several commands accepting regexps and offering C-p / C-n history navigation. I'd like to use other keys, in addition to C-p / C-n. For example when using occur or replace-regexp, C-p and C-n can be used to go to previous and next elements.
I've tried several things but can't make it work. I think I'm missing the "big picture" here.
Which mode-map do I need to modify, when and how? Everything I tried failed.
P.S: Note that I've got my own minor mode with all my keymaps as adviced here.
I'm assuming you just needed minibuffer-local-map. Subsequent definitions using keys previously assigned to that key map will trump the prior definitions. To disable a prior key assignment, then just create a new definition and set the last portion to nil instead of 'function-name.
(define-key minibuffer-local-map (kbd "<f6>") 'help-for-help)
Here is an excerpt from Emacs Trunk .../lisp/bindings.el:
(let ((map minibuffer-local-map))
(define-key map "\en" 'next-history-element)
(define-key map [next] 'next-history-element)
(define-key map [down] 'next-history-element)
(define-key map [XF86Forward] 'next-history-element)
(define-key map "\ep" 'previous-history-element)
(define-key map [prior] 'previous-history-element)
(define-key map [up] 'previous-history-element)
(define-key map [XF86Back] 'previous-history-element)
(define-key map "\es" 'next-matching-history-element)
(define-key map "\er" 'previous-matching-history-element)
;; Override the global binding (which calls indent-relative via
;; indent-for-tab-command). The alignment that indent-relative tries to
;; do doesn't make much sense here since the prompt messes it up.
(define-key map "\t" 'self-insert-command)
(define-key map [C-tab] 'file-cache-minibuffer-complete))
To add to what #lawlist said (which was to bind the key in minibuffer-local-map):
There are multiple minibuffer keymaps, depending on what is being read in the minibuffer, and how. And which of those keymaps you might want to use can depend on which Emacs version you are using.
In addition, there is also the keymap for interaction with buffer *Completions*: completion-list-mode-map.
For completion in the minibuffer, the main keymap is minibuffer-local-completion-map.
Here is a list of the minibuffer keymaps. Some of these might not be available (used) in your Emacs version.
minibuffer-local-map
minibuffer-local-ns-map
minibuffer-local-isearch-map
minibuffer-local-completion-map
minibuffer-local-must-match-map
minibuffer-local-filename-completion-map
minibuffer-local-filename-must-match-map
minibuffer-local-must-match-filename-map
In addition, you can use minibuffer-with-setup-hook (or minibuffer-setup-hook directly) to add key bindings on the fly, for the duration of a single minibuffer reading.
I will add this info, since it can be really helpful when you are manipulating minibuffer keymaps: You can use C-h M-k (command describe-keymap), from library help-fns+.el, to see all of the bindings of a given minibuffer keymap in human-readable form.

Emacs lisp key binding in shell mode not working

I have my emacs editor setup to run a shell when I press Ctrl-z. When inside of a shell buffer, I use Ctrl-z to clear the buffer by running the erase-buffer function. The code is being evaluated (when I Ctrl-h v and describe the shell-mode-map I can see that C-z is bound to clear-shell-buffer in shell mode. When I run the clear-shell-buffer with M-x the message says:
You can run the command clear-shell-buffer with <C-z>
However, when I type Ctrl-z in the shell it does not run the function or give any messages at all. Any idea why?
(defun clear-shell-buffer ()
"Clear the contents of the current buffer"
(interactive)
(erase-buffer)
;; (insert "/usr/games/fortune -a")
(comint-send-input)
)
(put 'erase-buffer 'disabled nil)
(eval-after-load 'shell
'(define-key shell-mode-map [(\C-z)] 'clear-shell-buffer))
This is happening because of the key binding being incorrect. You can verify this by doing C-h k C-z when in shell mode.
Instead of [(\C-z)], use one of these options:
[(?\C-z)]
[(control ?z)]
(kbd "C-z")
which will correctly set the key binding, and let you call the correct function with C-z
You can see a little bit of what's happening if you evaluate just the those statements. Here's the output I get for each
(define-key shell-mode-map [(\C-z)] 'clear-shell-buffer)
;;Output: (define-key shell-mode-map [(C-z)] (quote clear-shell-buffer))
(define-key shell-mode-map [(?\C-z)] 'clear-shell-buffer)
;;Output: (define-key shell-mode-map [(26)] (quote clear-shell-buffer))
You can see that the types differ for the key binding. Right now, you're passing a symbol, when you want to be passing a character code.

emacs - error: Key sequence

I am getting errors when I try to add this to my ~/.emacs file:
(define-key evil-normal-state-map "ss" 'split-window-vertically)
I get this error:
error: Key sequence s s starts with non-prefix key s
The problem is that there is already a command bound to s (specifically, evil-substitute), which means you could not get to you ss binding because the first s would invoke evil-substitute. You can undefine the s by setting it to nil and then bind ss as you already have it:
(define-key evil-normal-state-map "s" nil)
(define-key evil-normal-state-map "ss" 'split-window-vertically)
(If you want to know what commands are bound to which keys, you can use M-x describe-key SOMEKEY or C-h k SOMEKEY.)

emacs, python-mode.el define-key map assignment

When I load the python-mode.el file in emacs, I don't get any of the key bindings specified.
I started playing with the file and noticed that when I change:
(define-key map [(control c)(\#)] 'py-comment-region)
to:
(define-key global-map [(control c)(\#)] 'py-comment-region)
it works fine.
I went to look where the define the map variable and saw:
(defvar py-shell-map nil
"Keymap used in *Python* shell buffers.")
;; used by py-completion-at-point, the way of python.el
(defvar python-shell-map
(let ((map (copy-keymap comint-mode-map)))
(define-key map [tab] 'py-shell-complete)
(define-key map "\C-c-" 'py-up-exception)
(define-key map "\C-c=" 'py-down-exception)
map)
"Keymap used in *Python* shell buffers.")
Is the 'map' variable defined alright? Should I do some changes to my init file? I assume that this file works to everybody else, so why I need to change the 'map' variable to 'global-map' for it to work in my computer?
I'm running in a virtual machine if that's of any help.
The code you quoted in which you believe map is defined is not actually the relevant portion of the code. It is a different keymap used for a python shell, and it's not the one used when you edit a python file in Emacs.
The line you're editing appears in python-mode inside the following code block:
(defvar python-mode-map)
(setq python-mode-map
(let ((map (make-sparse-keymap)))
;; electric keys
(define-key map [(:)] 'py-electric-colon)
(define-key map [(\#)] 'py-electric-comment)
...
As you can see the variable map is first initialized as a "sparse keymap", then certain key-bindings get defined in that map, and finally the map is set as the value of python-mode-map. The latter is the keymap used in a buffer that is in python-mode.
So the keybindings should work - but of course only in a buffer that is in python-mode. To activate python-mode in a buffer, type M-x python-mode. This works only after the file python-mode.el has been loaded.
You can check if your current buffer is in python-mode in two ways:
your mode line should display the letters "Py"
type M-: ENTER major-mode ENTER -> this should print "python-mode" to the minibuffer
Each major mode and some minor modes have their own keymap, which is overlaid on the global keymap (which is global-map). When you press a key, Emacs tries to find a binding for that key in the overlaid keymaps, falling back to "more global" ones until it gets to the global-map. This is why global-map works and map doesn't.
In lisp, let is used to bind local variables. The map variable doesn't exist outside of the let (or maybe it does, but it's probably not the one you want). Read the documentation for let and defvar (e.g. C-h f defvar).
You need to figure out which keymap is being used in the major mode, and use define-key on that. In this case, (define-key python-mode-map (kbd "C-c #") 'py-comment-region) will probably work. N.B. I do not use python-mode.el, but looking at the source it seems like it uses python-mode-map as the keymap variable. The other keymaps are for auxiliary buffers.