Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/justbur/emacs-which-key

Emacs package that displays available keybindings in popup
https://github.com/justbur/emacs-which-key

emacs emacs-keybindings emacs-lisp emacs-packages

Last synced: 2 months ago
JSON representation

Emacs package that displays available keybindings in popup

Awesome Lists containing this project

README 

        
* which-key

  [[https://elpa.gnu.org/packages/which-key.html][https://elpa.gnu.org/packages/which-key.svg]]

  [[http://melpa.org/#/which-key][http://melpa.org/packages/which-key-badge.svg]]

  [[http://stable.melpa.org/#/which-key][file:http://stable.melpa.org/packages/which-key-badge.svg]]



** ARCHIVE NOTICE



which-key is now included in the master branch of Emacs and will likely be

released with Emacs v30. Bug reports and contributions to which-key will now be

considered through standard Emacs channels, and this repository is being

archived.



** Introduction

   =which-key= is a minor mode for Emacs that displays the key bindings

   following your currently entered incomplete command (a prefix) in a

   popup. For example, after enabling the minor mode if you enter =C-x= and wait

   for the default of 1 second the minibuffer will expand with all of the

   available key bindings that follow =C-x= (or as many as space allows given

   your settings).  This includes prefixes like =C-x 8= which are shown in a

   different face. Screenshots of what the popup will look like are included

   below. =which-key= started as a rewrite of [[https://github.com/kai2nenobu/guide-key][guide-key-mode]], but the feature

   sets have diverged to a certain extent.



** Table of Contents                                                  :TOC_3:

- [[#which-key][which-key]]

  - [[#archive-notice][ARCHIVE NOTICE]]

  - [[#introduction][Introduction]]

  - [[#install][Install]]

    - [[#melpa][MELPA]]

    - [[#manually][Manually]]

  - [[#initial-setup][Initial Setup]]

    - [[#side-window-bottom-option][Side Window Bottom Option]]

    - [[#side-window-right-option][Side Window Right Option]]

    - [[#side-window-right-then-bottom][Side Window Right then Bottom]]

    - [[#minibuffer-option][Minibuffer Option]]

  - [[#manual-activation][Manual Activation]]

  - [[#additional-commands][Additional Commands]]

  - [[#special-features-and-configuration-options][Special Features and Configuration Options]]

    - [[#popup-type-options][Popup Type Options]]

    - [[#custom-string-replacement-options][Custom String Replacement Options]]

    - [[#sorting-options][Sorting Options]]

    - [[#paging-options][Paging Options]]

    - [[#face-customization-options][Face Customization Options]]

    - [[#other-options][Other Options]]

  - [[#support-for-third-party-libraries][Support for Third-Party Libraries]]

    - [[#key-chord][Key-chord]]

    - [[#evil-operators][Evil operators]]

    - [[#god-mode][God-mode]]

  - [[#more-examples][More Examples]]

    - [[#nice-display-with-split-frame][Nice Display with Split Frame]]

  - [[#known-issues][Known Issues]]

  - [[#thanks][Thanks]]



** Install

*** MELPA

    After setting up [[http://melpa.org][MELPA]] as a repository, use =M-x package-install which-key=

    or your preferred method. You will need to call =which-key-mode= to enable

    the minor mode of course.



*** Manually

    Add which-key.el to your =load-path= and require. Something like

    #+BEGIN_SRC emacs-lisp

    (add-to-list 'load-path "path/to/which-key.el")

    (require 'which-key)

    (which-key-mode)

    #+END_SRC



** Initial Setup

   No further setup is required if you are happy with the default setup. To try

   other options, there are 3 choices of default configs that are preconfigured

   (then customize to your liking). The main choice is where you want the

   which-key buffer to display. Screenshots of the default options are shown in

   the next sections.



   In each case, we show as many key bindings as we can fit in the buffer within

   the constraints. The constraints are determined by several factors, including

   your Emacs settings, the size of the current Emacs frame, and the which-key

   settings, most of which are described below.



   There are many substitution abilities included, which are quite flexible

   (ability to use regexp for example). This makes which-key very customizable.



*** Side Window Bottom Option

    Popup side window on bottom. This is the current default. To restore this

    setup use



    #+BEGIN_SRC emacs-lisp

(which-key-setup-side-window-bottom)

    #+END_SRC



    [[./img/which-key-bottom.png]]



*** Side Window Right Option

    Popup side window on right. For defaults use



    #+BEGIN_SRC emacs-lisp

(which-key-setup-side-window-right)

    #+END_SRC



    Note the defaults are fairly conservative and will tend to not display on

    narrower frames. If you get a message saying which-key can't display the

    keys, try making your frame wider or adjusting the defaults related to the

    maximum width (see =M-x customize-group which-key=).



    [[./img/which-key-right.png]]



*** Side Window Right then Bottom

    This is a combination of the previous two choices. It will try to use the

    right side, but if there is no room it will switch to using the bottom,

    which is usually easier to fit keys into. This setting can be helpful if the

    size of the Emacs frame changes frequently, which might be the case if you

    are using a dynamic/tiling window manager.



    #+BEGIN_SRC emacs-lisp

    (which-key-setup-side-window-right-bottom)

    #+END_SRC



*** Minibuffer Option

    Take over the minibuffer. For the recommended configuration use



    #+BEGIN_SRC emacs-lisp

    (which-key-setup-minibuffer)

    #+END_SRC



    [[./img/which-key-minibuffer.png]]



    Note the maximum height of the minibuffer is controlled through the built-in

    variable =max-mini-window-height=. Also, the paging commands do not work

    reliably with the minibuffer option. Use the side window on the bottom

    option if you need paging.



** Manual Activation

   #+NAME: #manual-activation

   If you only want the =which-key= popup when you need it, you can try a setup

   along the following lines



   #+BEGIN_SRC emacs-lisp

     ;; Allow C-h to trigger which-key before it is done automatically

     (setq which-key-show-early-on-C-h t)

     ;; make sure which-key doesn't show normally but refreshes quickly after it is

     ;; triggered.

     (setq which-key-idle-delay 10000)

     (setq which-key-idle-secondary-delay 0.05)

     (which-key-mode)

   #+END_SRC



   This will prevent which-key from showing automatically, and allow you to use

   =C-h= in the middle of a key sequence to show the =which-key= buffer and keep

   it open for the remainder of the key sequence.



** Additional Commands

   - =which-key-show-top-level= will show most key bindings without a prefix. It

     is most and not all, because many are probably not interesting to most

     users.

   - =which-key-show-major-mode= will show the currently active major-mode

     bindings. It's similar to =C-h m= but in a which-key format. It is also

     aware of evil commands defined using =evil-define-key=.

   - =which-key-show-next-page-cycle= / =which-key-show-previous-page-cycle= will flip pages in a circle.

   - =which-key-show-next-page-no-cycle= / =which-key-show-previous-page-no-cycle= will flip pages and stop at first/last page.

   - =which-key-undo= can be used to undo the last keypress when in the middle

     of a key sequence.



** Special Features and Configuration Options

   There are more options than the ones described here. All of the configurable

   variables are available through =M-x customize-group which-key=.

*** Popup Type Options

    There are three different popup types that which-key can use by default to

    display the available keys. The variable =which-key-popup-type= decides

    which one is used.

**** minibuffer

     #+BEGIN_SRC emacs-lisp

     (setq which-key-popup-type 'minibuffer)

     #+END_SRC

     Show keys in the minibuffer.

**** side window

     #+BEGIN_SRC emacs-lisp

     (setq which-key-popup-type 'side-window)

     #+END_SRC

     Show keys in a side window. This popup type has further options:

     #+BEGIN_SRC emacs-lisp

     ;; location of which-key window. valid values: top, bottom, left, right,

     ;; or a list of any of the two. If it's a list, which-key will always try

     ;; the first location first. It will go to the second location if there is

     ;; not enough room to display any keys in the first location

     (setq which-key-side-window-location 'bottom)



     ;; max width of which-key window, when displayed at left or right.

     ;; valid values: number of columns (integer), or percentage out of current

     ;; frame's width (float larger than 0 and smaller than 1)

     (setq which-key-side-window-max-width 0.33)



     ;; max height of which-key window, when displayed at top or bottom.

     ;; valid values: number of lines (integer), or percentage out of current

     ;; frame's height (float larger than 0 and smaller than 1)

     (setq which-key-side-window-max-height 0.25)

     #+END_SRC

**** frame



     #+BEGIN_SRC emacs-lisp

     (setq which-key-popup-type 'frame)

     #+END_SRC

     Show keys in a popup frame. This popup won't work very well in a terminal,

     where only one frame can be shown at any given moment. This popup type has

     further options:

     #+BEGIN_SRC emacs-lisp

     ;; max width of which-key frame: number of columns (an integer)

     (setq which-key-frame-max-width 60)



     ;; max height of which-key frame: number of lines (an integer)

     (setq which-key-frame-max-height 20)

     #+END_SRC



**** custom

     Write your own display functions! This requires you to write three

     functions, =which-key-custom-popup-max-dimensions-function=,

     =which-key-custom-show-popup-function=, and

     =which-key-custom-hide-popup-function=. Refer to the documentation for

     those variables for more information, but here is a working example (this

     is the current implementation of side-window bottom).



     #+BEGIN_SRC emacs-lisp

       (setq which-key-popup-type 'custom)

       (defun which-key-custom-popup-max-dimensions-function (ignore)

         (cons

          (which-key-height-or-percentage-to-height

           which-key-side-window-max-height)

          (frame-width)))

       (defun fit-horizonatally ()

         (let ((fit-window-to-buffer-horizontally t))

           (fit-window-to-buffer)))

       (defun which-key-custom-show-popup-function (act-popup-dim)

         (let* ((alist '((window-width . fit-horizontally)

                         (window-height . fit-window-to-buffer))))

           (if (get-buffer-window which-key--buffer)

               (display-buffer-reuse-window which-key--buffer alist)

             (display-buffer-in-major-side-window which-key--buffer

                                                  'bottom 0 alist))))

       (defun which-key-custom-hide-popup-function ()

         (when (buffer-live-p which-key--buffer)

           (quit-windows-on which-key--buffer)))

     #+END_SRC



*** Custom String Replacement Options

    #+NAME: #custom-string-replacement-options

    You can customize the way the keys show in the buffer using three different

    replacement methods. The first, keymap-based replacement, is preferred and

    will take precedence over the others. The remaining methods are still

    available, because they pre-date the first and are more flexible in what

    they can accomplish.



**** Keymap-based replacement

     Using this method, which-key can display a custom string for a key

     definition in some keymap. There are two ways to define a keymap-based

     replacement. The preferred way is to use =define-key= (or a command that

     uses =define-key= internally) with a cons cell as the definition. For

     example,



     #+BEGIN_SRC emacs-lisp

       (define-key some-map "f" '("foo" . command-foo))

       (define-key some-map "b" '("bar-prefix" . (keymap)))

       (setq my-map (make-sparse-keymap))

       (define-key some-map "b" (cons "bar-prefix" my-map))

     #+END_SRC



     binds =command-foo= to =f= in =some-map=, but also stores the string "foo"

     which which-key will extract to use to describe this command. The second

     example binds an empty keymap to =b= in =some-map= and uses "bar-prefix" to

     describe it. The last two lines replicate the functionality of the second

     line, while assigning the new keymap to the symbol =my-map= (note the use

     of =cons= to ensure that =my-map= is evaluated for =define-key=). These

     bindings are accepted by =define-key= natively (i.e., with or without

     which-key being loaded). Since many key-binding utilities use =define-key=

     internally, this functionality should be available with your favorite

     method of defining keys as well.



     The second method is to use =which-key-add-keymap-based-replacements=. The

     statement



     #+BEGIN_SRC emacs-lisp

       (define-key some-map "f" 'long-command-name-foo)

       (define-key some-map "b" some-prefix-map)

       (which-key-add-keymap-based-replacements some-map

         "f" '("foo" . long-command-name-foo)

         "b" '("bar-prefix" . (keymap)))

     #+END_SRC



     uses =define-key= to add two bindings and tells which-key to use the string

     "foo" in place of "command-foo" and the string "bar-prefix" for an empty

     prefix map. =which-key-add-keymap-based-replacements= just uses

     =define-key= to bind (or rebind) the command.



     There are other methods of telling which-key to replace command names,

     which are described next. The keymap-based replacements should be the most

     performant since they use built-in functionality of emacs. However, the

     alternatives can be more flexible in telling which-key how and when to

     replace text. They can be used simultaneously, but which-key will give

     precedence to the keymap-based replacement when it exists.



**** Key-Based replacement

     Using this method, the description of a key is replaced using a string that

     you provide. Here's an example



     #+BEGIN_SRC emacs-lisp

     (which-key-add-key-based-replacements

       "C-x C-f" "find files")

     #+END_SRC



     where the first string is the key combination whose description you want to

     replace, in a form suitable for =kbd=. For that key combination, which-key

     overwrites the description with the second string, "find files". In the

     second type of entry you can restrict the replacements to a major-mode. For

     example,



     #+BEGIN_SRC emacs-lisp

     (which-key-add-major-mode-key-based-replacements 'org-mode

       "C-c C-c" "Org C-c C-c"

       "C-c C-a" "Org Attach")

     #+END_SRC



     Here the first entry is the major-mode followed by a list of the first type

     of entries. In case the same key combination is listed under a major-mode

     and by itself, the major-mode version takes precedence.



**** Key and Description replacement



     The second and third methods target the text used for the keys and the

     descriptions directly. The relevant variable is

     =which-key-replacement-alist=.  Here's an example of one of the default key

     replacements



     #+BEGIN_SRC emacs-lisp

     (push '(("<\\([[:alnum:]-]+\\)>" . nil) . ("\\1" . nil))

           which-key-replacement-alist)

     #+END_SRC



     Each element of the outer cons cell is a cons cell of the form =(KEY

     . BINDING)=. The =car= of the outer cons determines how to match key

     bindings while the =cdr= determines how those matches are replaced. See the

     docstring of =which-key-replacement-alist= for more information.



     The next example shows how to replace the description.



     #+BEGIN_SRC emacs-lisp

     (push '((nil . "left") . (nil . "lft")) which-key-replacement-alist)

     #+END_SRC



     Here is an example of using key replacement to include Unicode characters

     in the results. Unfortunately, using Unicode characters may upset the

     alignment of the which-key buffer, because Unicode characters can have

     different widths even in a monospace font and alignment is based on

     character width.



     #+BEGIN_SRC emacs-lisp

     (add-to-list 'which-key-replacement-alist '(("TAB" . nil) . ("↹" . nil)))

     (add-to-list 'which-key-replacement-alist '(("RET" . nil) . ("⏎" . nil)))

     (add-to-list 'which-key-replacement-alist '(("DEL" . nil) . ("⇤" . nil)))

     (add-to-list 'which-key-replacement-alist '(("SPC" . nil) . ("␣" . nil)))

     #+END_SRC



     The =cdr= may also be a function that receives a =cons= of the form =(KEY

     . BINDING)= and produces a =cons= of the same form. This allows for

     interesting ideas like this one suggested by [[https://github.com/pdcawley][@pdcawley]] in [[https://github.com/justbur/emacs-which-key/pull/147][PR #147]].



     #+BEGIN_SRC emacs-lisp

     (push (cons '(nil . "paredit-mode")

                 (lambda (kb)

                   (cons (car kb)

                         (if paredit-mode

                             "[x] paredit-mode"

                           "[ ] paredit-mode"))))

           which-key-replacement-alist)

     #+END_SRC



     The box will be checked if =paredit-mode= is currently active.



*** Sorting Options

    By default the output is sorted by the key in a custom order. The default

    order is to sort lexicographically within each "class" of key, where the

    classes and their order are



    =Special (SPC, TAB, ...) < Single Character (ASCII) (a, ...) < Modifier (C-, M-, ...) < Other=



    You can control the order by setting this variable. This also shows the

    other available options.



    #+BEGIN_SRC emacs-lisp

    ;; default

    (setq which-key-sort-order 'which-key-key-order)

    ;; same as default, except single characters are sorted alphabetically

    ;; (setq which-key-sort-order 'which-key-key-order-alpha)

    ;; same as default, except all prefix keys are grouped together at the end

    ;; (setq which-key-sort-order 'which-key-prefix-then-key-order)

    ;; same as default, except all keys from local maps shown first

    ;; (setq which-key-sort-order 'which-key-local-then-key-order)

    ;; sort based on the key description ignoring case

    ;; (setq which-key-sort-order 'which-key-description-order)

    #+END_SRC



*** Paging Options



    There are at least several prefixes that have many keys bound to them, like

    =C-x=. which-key displays as many keys as it can given your settings, but

    for these prefixes this may not be enough. The paging feature gives you the

    ability to bind a key to the function =which-key-C-h-dispatch= which will

    allow you to cycle through the pages without changing the key sequence you

    were in the middle of typing. There are two slightly different ways of doing

    this.



**** Method 1 (default): Using C-h (or =help-char=)

     This is the easiest way, and is turned on by default. Use

     #+BEGIN_SRC emacs-lisp

     (setq which-key-use-C-h-commands nil)

     #+END_SRC

     to disable the behavior (this will only take effect after toggling

     which-key-mode if it is already enabled). =C-h= can be used with any prefix

     to switch pages when there are multiple pages of keys. This changes the

     default behavior of Emacs which is to show a list of key bindings that

     apply to a prefix.  For example, if you were to type =C-x C-h= you would

     get a list of commands that follow =C-x=. This uses which-key instead to

     show those keys, and unlike the Emacs default saves the incomplete prefix

     that you just entered so that the next keystroke can complete the command.



     The commands are:

     - Cycle through the pages forward with =n= (or =C-n=)

     - Cycle backwards with =p= (or =C-p=)

     - Undo the last entered key (!) with =u= (or =C-u=)

     - Call the default command bound to =C-h=, usually

       =describe-prefix-bindings=, with =h= (or =C-h=)



  This is especially useful for those who like =helm-descbinds= but also want to

  use =C-h= as their which-key paging key.



  Note =C-h= is by default equivalent to =?= in this context.



  Note also that using =C-h= will not work with the =C-h= prefix, unless you

  make further adjustments. See Issues [[https://github.com/justbur/emacs-which-key/issues/93][#93]] and [[https://github.com/justbur/emacs-which-key/issues/175][#175]] for example.



**** Method 2: Bind your own keys



     Essentially, all you need to do for a prefix like =C-x= is the following

     which will bind == to the relevant command.



     #+BEGIN_SRC emacs-lisp

(define-key which-key-mode-map (kbd "C-x ") 'which-key-C-h-dispatch)

     #+END_SRC



     This is completely equivalent to



     #+BEGIN_SRC emacs-lisp

(setq which-key-paging-prefixes '("C-x"))

(setq which-key-paging-key "")

     #+END_SRC



     where the latter are provided for convenience if you have a lot of

     prefixes.



*** Face Customization Options

    The faces that which-key uses are

    | Face                                   | Applied To                    | Default Definition                                          |

    |----------------------------------------+-------------------------------+-------------------------------------------------------------|

    | =which-key-key-face=                   | Every key sequence            | =:inherit font-lock-constant-face=                          |

    | =which-key-separator-face=             | The separator (→)             | =:inherit font-lock-comment-face=                           |

    | =which-key-note-face=                  | Hints and notes               | =:inherit which-key-separator-face=                         |

    | =which-key-special-key-face=           | User-defined special keys     | =:inherit which-key-key-face :inverse-video t :weight bold= |

    | =which-key-group-description-face=     | Command groups (i.e, keymaps) | =:inherit font-lock-keyword-face=                           |

    | =which-key-command-description-face=   | Commands not in local-map     | =:inherit font-lock-function-name-face=                     |

    | =which-key-local-map-description-face= | Commands in local-map         | =:inherit which-key-command-description-face=               |



    The last two deserve some explanation. A command lives in one of many possible

    keymaps. You can distinguish between local maps, which depend on the buffer you

    are in, which modes are active, etc., and the global map which applies

    everywhere. It might be useful for you to distinguish between the two. One way

    to do this is to remove the default face from

    =which-key-command-description-face= like this



    #+BEGIN_SRC emacs-lisp

  (set-face-attribute 'which-key-command-description-face nil :inherit nil)

    #+END_SRC



    another is to make the local map keys appear in bold



    #+BEGIN_SRC emacs-lisp

  (set-face-attribute 'which-key-local-map-description-face nil :weight 'bold)

    #+END_SRC



    You can also use =M-x customize-face= to customize any of the above faces to

    your liking.



*** Other Options

    #+NAME: #other-options

    The options below are also available through customize. Their defaults are

    shown.



    #+BEGIN_SRC emacs-lisp

      ;; Set the time delay (in seconds) for the which-key popup to appear. A value of

      ;; zero might cause issues so a non-zero value is recommended.

      (setq which-key-idle-delay 1.0)



      ;; Set the maximum length (in characters) for key descriptions (commands or

      ;; prefixes). Descriptions that are longer are truncated and have ".." added.

      ;; This can also be a float (fraction of available width) or a function.

      (setq which-key-max-description-length 27)



      ;; Use additional padding between columns of keys. This variable specifies the

      ;; number of spaces to add to the left of each column.

      (setq which-key-add-column-padding 0)



      ;; The maximum number of columns to display in the which-key buffer. nil means

      ;; don't impose a maximum.

      (setq which-key-max-display-columns nil)



      ;; Set the separator used between keys and descriptions. Change this setting to

      ;; an ASCII character if your font does not show the default arrow. The second

      ;; setting here allows for extra padding for Unicode characters. which-key uses

      ;; characters as a means of width measurement, so wide Unicode characters can

      ;; throw off the calculation.

      (setq which-key-separator " → " )

      (setq which-key-unicode-correction 3)



      ;; Set the prefix string that will be inserted in front of prefix commands

      ;; (i.e., commands that represent a sub-map).

      (setq which-key-prefix-prefix "+" )



      ;; Set the special keys. These are automatically truncated to one character and

      ;; have which-key-special-key-face applied. Disabled by default. An example

      ;; setting is

      ;; (setq which-key-special-keys '("SPC" "TAB" "RET" "ESC" "DEL"))

      (setq which-key-special-keys nil)



      ;; Show the key prefix on the left, top, or bottom (nil means hide the prefix).

      ;; The prefix consists of the keys you have typed so far. which-key also shows

      ;; the page information along with the prefix.

      (setq which-key-show-prefix 'left)



      ;; Set to t to show the count of keys shown vs. total keys in the mode line.

      (setq which-key-show-remaining-keys nil)

    #+END_SRC

** Support for Third-Party Libraries

   Some support is provided for third-party libraries which don't use standard

   methods of looking up commands. Some of these need to be enabled

   explicitly. This code includes some hacks, so please report any problems.

*** Key-chord

    Enabled by default.

*** Evil operators

    Evil motions and text objects following an operator like =d= are not all

    looked up in a standard way. Support is controlled through

    =which-key-allow-evil-operators= which should be non-nil if evil is loaded

    before which-key and through =which-key-show-operator-state-maps= which

    needs to be enabled explicitly because it is more of a hack. The former

    allows for the inner and outer text object maps to show, while the latter

    shows motions as well.

*** God-mode

    Call =(which-key-enable-god-mode-support)= after loading god-mode to enable

    support for god-mode key sequences. This is new and experimental, so please

    report any issues.

** More Examples

*** Nice Display with Split Frame

    Unlike guide-key, which-key looks good even if the frame is split into

    several windows.

    #+CAPTION: which-key in a frame with 3 horizontal splits

    [[./img/which-key-right-split.png]]



    #+CAPTION: which-key in a frame with 2 vertical splits

    [[./img/which-key-bottom-split.png]]

** Known Issues

   - A few users have reported crashes related to which-key popups when quitting

     a key sequence with =C-g=. A possible fix is discussed in [[https://github.com/justbur/emacs-which-key/issues/130][this issue]].

** Thanks

   Special thanks to

   - [[https://github.com/bmag][@bmag]] for helping with the initial development and finding many bugs.

   - [[https://github/iqbalansari][@iqbalansari]] who among other things adapted the code to make

     =which-key-show-top-level= possible.