In Emacs, can we make one keystroke to do different command? - emacs

I want to make one keystroke, say C-F12, to do delete-other-windows or winner-undo. I think it's easy if I already learning Emacs Lisp programming, and set a boolean flag. That is, if previously it run delete-other-window, now it'll run winner-undo.
How do you do that in Emacs Lisp?
Thanks

Try something like this
(setq c-f12-winner-undo t)
(define-key (current-global-map) [C-f12]
(lambda()
(interactive)
(if c-f12-winner-undo
(winner-undo)
(delete-other-windows))
(setq c-f12-winner-undo (not c-f12-winner-undo))))

(defun swdev-toggle-sole-window ()
(interactive)
(if (cdr (window-list))
(delete-other-windows)
(winner-undo)))
(global-set-key (kbd "<C-f12>") 'swdev-toggle-sole-window)
The first line starts the declaration of a function called swdev-toggle-sole-window, taking no argument.
This function is declared as interactive, i.e. it can be called with M-x or through a key binding.
If the window list contains more than one element, i.e. if there is more than one window, …
… then delete other windows …
… else undo the window deletion.
Bind the function to the key C-f12.

Here's a solution using the approach taken by Emacs' recenter-top-bottom function:
(defun delete-other-window-or-winner-undo ()
"call delete-other-window on first invocation and winner-undo on subsequent invocations"
(interactive)
(if (eq this-command last-command)
(winner-undo)
(delete-other-windows)))
(global-set-key (kbd "<C-f12>") 'delete-other-window-or-winner-undo)

Related

How can I jump to a definition without being queried in Emacs?

I have a problem when using Etags in Emacs. Everytime I tap \M+. to jump to a difinition point, a query is always popping up, like:
Find tag (default function_name):
And I have to tap 'Enter' to make sure of it.
But in most cases, I find I can choose the default one. So is there any method with which I can surpress this message?
I found the reason is because:
(defun find-tag (tagname &optional next-p regexp-p)
(interactive (find-tag-interactive "Find tag: "))
...
)
Why do I have to choose a tag? Why can not the default one just be the word under the point? Can I just remove this line? (interactive), or is there a good solution?
Going shortly through a couple of defuns in the etags sources via Emacs's awesome C-h f, one can find that the default tag to search is determined via a function named find-tag-default.
This means you could just define the following function:
(defun find-tag-under-point ()
(interactive)
(find-tag (find-tag-default)))
Then you can bind this to whatever key you want via define-key or global-set-key or local-set-key.
(The interactive form is always necessary if you want a function to be a "command" which can be called with M-x or bound to a key.)
You can write your own functionality over the find-tag (or any interactive function likewise)
(defun find-tag-under-point (&optional arg)
(interactive "P")
(cond ((eq arg 9)
(let ((current-prefix-arg nil))
(call-interactively 'find-tag)))
(arg
(call-interactively 'find-tag))
(t
(find-tag (find-tag-default)))))
(global-set-key (kbd "M-.") 'find-tag-under-point)
Then hotkey C-9M-. calls find-tag (old function) as usual, but the behaviour of find-tag-under-point (new-function) by default is what you want.

Using 2 consecutive control key in Emacs [duplicate]

Let's say I bind the key to a certain function as follows:
(global-set-key (kbd "C-c =") 'function-foo)
Now, I want the key binding to work as:
After I press C-c = for the first time, if I want to repeat the function-foo, I don't need to press C-c again, but simply repeat pressing =. Then, after I call the function-foo for enough times, I can just press keys other than = (or explicitly press C-g) to quit.
How to do this?
This may be the thing you are looking for:
(defun function-foo ()
(interactive)
(do-your-thing)
(set-temporary-overlay-map
(let ((map (make-sparse-keymap)))
(define-key map (kbd "=") 'function-foo)
map)))
There's a smartrep.el package that does exactly what you need. The documentation is a bit scarce but you can get a grip of how it's supposed to be used by looking into numerous emacs configs found on github. For example (taken from here):
(require 'smartrep)
(smartrep-define-key
global-map "C-q" '(("n" . (scroll-other-window 1))
("p" . (scroll-other-window -1))
("N" . 'scroll-other-window)
("P" . (scroll-other-window '-))
("a" . (beginning-of-buffer-other-window 0))
("e" . (end-of-buffer-other-window 0))))
This is what I use. I like it because you don't have to specify the repeating key.
(require 'repeat)
(defun make-repeatable-command (cmd)
"Returns a new command that is a repeatable version of CMD.
The new command is named CMD-repeat. CMD should be a quoted
command.
This allows you to bind the command to a compound keystroke and
repeat it with just the final key. For example:
(global-set-key (kbd \"C-c a\") (make-repeatable-command 'foo))
will create a new command called foo-repeat. Typing C-c a will
just invoke foo. Typing C-c a a a will invoke foo three times,
and so on."
(fset (intern (concat (symbol-name cmd) "-repeat"))
`(lambda ,(help-function-arglist cmd) ;; arg list
,(format "A repeatable version of `%s'." (symbol-name cmd)) ;; doc string
,(interactive-form cmd) ;; interactive form
;; see also repeat-message-function
(setq last-repeatable-command ',cmd)
(repeat nil)))
(intern (concat (symbol-name cmd) "-repeat")))
You want your function-foo to use set-temporary-overlay-map.
In addition to what #juanleon suggested, which uses set-temporary-overlay-map, here is an alternative that I use quite a bit. It uses standard library repeat.el.
;; This function builds a repeatable version of its argument COMMAND.
(defun repeat-command (command)
"Repeat COMMAND."
(interactive)
(let ((repeat-previous-repeated-command command)
(last-repeatable-command 'repeat))
(repeat nil)))
Use that to define different repeatable commands. E.g.,
(defun backward-char-repeat ()
"Like `backward-char', but repeatable even on a prefix key."
(interactive)
(repeat-command 'backward-char))
Then bind such a command to a key with a repeatable suffix, e.g., C-c = (for C-c = = = =...)
See this SO post for more information.

switch buffer settings using python-mode in emacs?

I have been using emacs for a while but not so familiar with lisp programming. Its been just couple of days I started coding Python on emacs. I found python-mode to be quite useful and I want to explore it further. I found a few emacs lips functions on internet, tewaked them a bit to make the interface userfriendly. I am trying to achieve following actions
I usually start emacs with 2 vertical windows, one with python source and other is a shell. I should be able to do following using keyboard bindings
switch between buffers (working)
execute a region (working)
but replaces the source buffer with shell buffer. I want to execute selected region in original shell buffer.
execute a line (working)
but same issue as above. when i pres say , the line should be executed in python shell without replacing any buffers. so copy the line, switch to python shell, execute line, switch back to python source buffer.
I am not able to achieve switching action above. Following is my code from my init.el file
(defun goto-python-shell ()
"Go to the python command window (start it if needed)"
(interactive)
(setq current-python-script-buffer (current-buffer))
(if (boundp 'current-python-shell-buffer)
(switch-to-buffer-other-window current-python-shell-buffer)
(py-shell))
(end-of-buffer)
)
(defun goto-python-source ()
"switch back to source window"
(interactive)
(setq current-python-shell-buffer (current-buffer))
(switch-to-buffer-other-window current-python-script-buffer)
)
(defun py-execute-statement-and-step ()
"select a statement, submit as a region and then step forward"
(interactive)
(beginning-of-line 1)
(let ((beg (point)))
(py-next-statement 1)
; if last statement.
(if (= (point) beg) (end-of-buffer ))
; (switch-to-buffer-other-window current-python-shell-buffer)
(py-execute-region beg (point))
(switch-to-buffer-other-window current-python-script-buffer)
)
)
; some key bindings
(define-key python-mode-map (quote [f9]) 'py-execute-statement-and-step)
;(define-key python-mode-map (quote [f10]) `py-execute-region)
;py-shell-switch-buffers-on-execute
(define-key python-mode-map (quote [f10]) `py-shell-switch-buffers-on-execute)
(define-key python-mode-map (quote [f11]) `py-execute-buffer)
(define-key python-mode-map (quote [f12]) `goto-python-shell)
(define-key py-shell-map (quote [f12]) `goto-python-source)
Please advice.
Also since i am new to python-mode, can someone share nice initializations for using python-mode similar to above?
thanks much for your help.
Regards,
AJ
You should take a look at the first answer to this question and customize the py-shell-switch-buffers-on-execute variable.
This way you won't need all your custom functions to make python-mode work like you want (i.e. keeping the source buffer active)
I think that you are trying to reinvent what is available in Emacs 24 (at least with evaluation stuff). Try Emacs 24. When you are editing a Python source code, you can press C-c C-c to evaluate a buffer and press C-c C-r to evaluate a region. You don't have to explicitly start a Python shell.
I don't think that there is a direct support for evaluate a line and step. You can achieve it by the keystrokes C-SPC C-n C-c C-r. Your focus will remain in the source code and there is no need to switch explicitly between the source code and the shell.
FWIW, I have been using Emacs 24 for a reasonable amount of time on a daily basis and I haven't encountered any stability issues.
following changes are working like a charm. f9 does line by line execute and f10 does region based execution. curser remains in the script window after i disabled py-shell-switch-buffers-on-execute.
(defun py-execute-statement-and-step ()
"select a statement, submit as a region and then step forward"
(interactive)
(beginning-of-line 1)
(let ((beg (point)))
(py-next-statement 1)
; if last statement.
(if (= (point) beg) (end-of-buffer ))
(py-execute-region beg (point))
(next-line)
)
)
(custom-set-variables
'(py-shell-switch-buffers-on-execute nil))
(define-key python-mode-map (quote [f9]) 'py-execute-statement-and-step)
(define-key python-mode-map (quote [f10]) `py-execute-region)

Code completion key bindings in Emacs

When doing a M-x describe-mode in a .el file, I noticed that the Emacs-Lisp mode actually does code completion. However, lisp-complete-symbol is bound to M-TAB. In Windows, this key binding is taken by Windows for switching the active window. Most IDE's use C-SPC, but that's taken in Emacs as well. What is a good, fairly common key binding for code completion?
If you like completion of all kinds, I recommend M-/ and binding that to hippie-expand.
(global-set-key (kbd "M-/") 'hippie-expand)
It does a variety of completions, which are controlled by the variable hippie-expand-try-functions-list. In the .el files, you can set that to do the 'try-complete-lisp-symbol first to get the behavior you're asking for above, along with all the other expansions hippie-expand provides.
This would do that for you:
(add-hook 'emacs-lisp-mode-hook 'move-lisp-completion-to-front)
(defun move-lisp-completion-to-front ()
"Adjust hippie-expand-try-functions-list to have lisp completion at the front."
(make-local-variable 'hippie-expand-try-functions-list)
(setq hippie-expand-try-functions-list
(cons 'try-complete-lisp-symbol
(delq 'try-complete-lisp-symbol hippie-expand-try-functions-list)))
(setq hippie-expand-try-functions-list
(cons 'try-complete-lisp-symbol-partially
(delq 'try-complete-lisp-symbol-partially hippie-expand-try-functions-list))))
As Trey Jackson mentioned, hippie-expand is the way to go, but along with binding it to M-/, I also like having the TAB key do all my completion work for me. So I have this from the Emacs-Wiki in my .emacs file:
;;function to implement a smarter TAB (EmacsWiki)
(defun smart-tab ()
"This smart tab is minibuffer compliant: it acts as usual in
the minibuffer. Else, if mark is active, indents region. Else if
point is at the end of a symbol, expands it. Else indents the
current line."
(interactive)
(if (minibufferp)
(unless (minibuffer-complete)
(hippie-expand nil))
(if mark-active
(indent-region (region-beginning)
(region-end))
(if (looking-at "\\_>")
(hippie-expand nil)
(indent-for-tab-command)))))
(global-set-key (kbd "TAB") 'smart-tab)
You could have hippie expand settings as follows:
;;settings for hippie-expand
(setq hippie-expand-try-functions-list
'(try-complete-lisp-symbol
try-complete-lisp-symbol-partially
try-expand-dabbrev
try-expand-dabbrev-from-kill
try-expand-dabbrev-all-buffers
try-expand-line
try-complete-file-name-partially
try-complete-file-name))
C-M-i; no customization required.
I use:
(define-key function-key-map [(control tab)] [?\M-\t])
I use M-. and M-/ for the 2 completion modes - hippie-expand and the standard emacs one.
Put this in your .emacs to make Windows give Emacs the use of M-TAB:
(when (fboundp 'w32-register-hot-key) (w32-register-hot-key [M-tab]))

in Emacs, what's the best way for keyboard-escape-quit not destroy other windows?

EDIT: I understand there is keyboard-quit (which is normally bound to C-g); but I'm more interested to know about how one deals with editing functions that come with Emacs (like in this case). I run into this kind of situations from time to time when I want to change just a little bit of some build-in functions.
In emacs, when you hit M-ESC ESC (or ESC three times), you can get out of a lots of situations like transient-mark, etc. But I habitually hit the escape key (I actually remap this to a single hit of the escape key) more than I intended, and that ends up killing my windows configuration, which is quite annoying. The function keyboard-escape-quit is defined in simple.el:
(defun keyboard-escape-quit ()
"Exit the current \"mode\" (in a generalized sense of the word).
This command can exit an interactive command such as `query-replace',
can clear out a prefix argument or a region,
can get out of the minibuffer or other recursive edit,
cancel the use of the current buffer (for special-purpose buffers),
or go back to just one window (by deleting all but the selected window)."
(interactive)
(cond ((eq last-command 'mode-exited) nil)
((> (minibuffer-depth) 0)
(abort-recursive-edit))
(current-prefix-arg
nil)
((and transient-mark-mode mark-active)
(deactivate-mark))
((> (recursion-depth) 0)
(exit-recursive-edit))
(buffer-quit-function
(funcall buffer-quit-function))
((not (one-window-p t))
(delete-other-windows))
((string-match "^ \\*" (buffer-name (current-buffer)))
(bury-buffer))))
And I can see that I don't want the lines:
((not (one-window-p t))
(delete-other-windows))
But what is the best way to modify this function? I can see only two ways: 1) modify simple.el 2) copy this function to my .emacs file and do the modifications there. Both ways are not really good; ideally I would like to see something on the line of defadvice, but I can't see how I can do it in this case.
You could use around advice and redefine the offending function to do what you want (i.e. one-window-p should always return t):
(defadvice keyboard-escape-quit (around my-keyboard-escape-quit activate)
(let (orig-one-window-p)
(fset 'orig-one-window-p (symbol-function 'one-window-p))
(fset 'one-window-p (lambda (&optional nomini all-frames) t))
(unwind-protect
ad-do-it
(fset 'one-window-p (symbol-function 'orig-one-window-p)))))
This kind of acts like a (let ...) but has to be more complicated because you need to override a function for a limited scope instead of a variable.
I usually find that 'keyboard-quit (C-g) works to get out of all of those situations.
However, if you really want to have a variant of this function, I think that copying to your .emacs file (and renaming, I usually usa a prefix of bp) and making the edits there is probably the best option.
EDIT, in response to edit: In general, whenever I want an edited version of an emacs function, I either write it myself, or copy it to my .emacs, rename it bp-whotever and then do appropriate edits.
The downside of this is that my .emacs is HUGE, and probably extra-crufty with ancient functions that are nolonger used... the upside is that whenever I need to write something new, I've got tons of sample code to look at...
Here's another, simpler piece of advice that takes advantage of the fact that keyboard-escape-quit calls buffer-quit-function before closing windows:
(defadvice keyboard-escape-quit
(around keyboard-escape-quit-dont-close-windows activate)
(let ((buffer-quit-function (lambda () ())))
ad-do-it))
Works with Emacs 25.1. (I originally used #scottfrazer's advice, but it's unhappy in 25.1. Haven't bothered debugging yet.)
A single press of the Escape key, by default, acts as a Meta prefix key; that is, a keybinding which involves the Meta key.
Triple-pressing the Escape key will run keyboard-escape-quit, which is like keyboard-quit but with more of a "do what I mean" behaviour.
This code may help with your use case. You can use this in your Emacs init file:
;;; esc always quits
(define-key minibuffer-local-map [escape] 'minibuffer-keyboard-quit)
(define-key minibuffer-local-ns-map [escape] 'minibuffer-keyboard-quit)
(define-key minibuffer-local-completion-map [escape] 'minibuffer-keyboard-quit)
(define-key minibuffer-local-must-match-map [escape] 'minibuffer-keyboard-quit)
(define-key minibuffer-local-isearch-map [escape] 'minibuffer-keyboard-quit)
(global-set-key [escape] 'keyboard-quit)
I'm more interested to know about how one deals with editing functions that come with Emacs (like in this case). I run into this kind of situations from time to time when I want to change just a little bit of some build-in functions.
This is exactly the purpose for which I created the library el-patch. You would put this in your init-file:
(el-patch-defun keyboard-escape-quit ()
"Exit the current \"mode\" (in a generalized sense of the word).
This command can exit an interactive command such as `query-replace',
can clear out a prefix argument or a region,
can get out of the minibuffer or other recursive edit,
cancel the use of the current buffer (for special-purpose buffers),
or go back to just one window (by deleting all but the selected window)."
(interactive)
(cond ((eq last-command 'mode-exited) nil)
((> (minibuffer-depth) 0)
(abort-recursive-edit))
(current-prefix-arg
nil)
((and transient-mark-mode mark-active)
(deactivate-mark))
((> (recursion-depth) 0)
(exit-recursive-edit))
(buffer-quit-function
(funcall buffer-quit-function))
(el-patch-remove
((not (one-window-p t))
(delete-other-windows)))
((string-match "^ \\*" (buffer-name (current-buffer)))
(bury-buffer))))
Here's a new way using cl-lib instead of cl which is now deprecated:
;; Make it so keyboard-escape-quit doesn't delete-other-windows
(defadvice keyboard-escape-quit
(around keyboard-escape-quit-dont-delete-other-windows activate)
(cl-letf (((symbol-function 'delete-other-windows)
(lambda () nil)))
ad-do-it))
You'll need to make sure prior to it you have called:
(require 'cl-lib)