#+TITLE: Window numbers for Emacs !

[[https://github.com/syl20bnr/spacemacs][file:https://cdn.rawgit.com/syl20bnr/spacemacs/442d025779da2f62fc86c2082703697714db6514/assets/spacemacs-badge.svg]] [[https://melpa.org/#/winum][file:https://melpa.org/packages/winum-badge.svg]] [[https://stable.melpa.org/#/winum][file:https://stable.melpa.org/packages/winum-badge.svg]]

* Contents :TOC:noexport:
- [[#introduction][Introduction]]
- [[#changelog][Changelog]]
  - [[#aug-26-2024][Aug. 26 2024]]
  - [[#sep-11-2019][Sep. 11 2019]]
  - [[#nov-15-2018][Nov. 15 2018]]
  - [[#initial-release-whats-changed-since-window-numbering][Initial release: what's changed since window-numbering]]
- [[#installation][Installation]]
  - [[#using-melpa][Using Melpa]]
  - [[#manual-installation][Manual installation]]
- [[#how-to-use][How to use]]
- [[#configuration][Configuration]]
  - [[#keybindings][Keybindings]]
  - [[#customize-options][Customize options]]
  - [[#configuration-file-example][Configuration file example]]
- [[#future-developments][Future developments]]

* Introduction

This package is a fork of the [[https://github.com/deb0ch/emacs-winum][winum]] package, which is itself a fork of the
[[https://github.com/nschum/window-numbering.el][window-numbering]] package.

Compared to winum, this fork adds support for windows having arbitrary Lisp values
as identifiers, as opposed to strictly increasing numbers. The public
API is largely the same, however, and simple numbers are still the default.

* Changelog
** Aug. 26 2024
- Added support for arbitrary Lisp objects (non-nil, compared with =equal=) as indices.
- Added customize variable =winum-auto-assign-function= to control auto-assigning behavior.
** Sep. 11 2019
- Added customize variable =winum-ignored-buffers-regexp= to ignored buffers
  based on regexps.
** Nov. 15 2018
- Added customize variable =winum-format=, a format string to configure how the
  window number appears in the mode-line

** Initial release: what's changed since window-numbering
This package brings a lot of additions to the old window-numbering:

- Number sets across multiple frames, giving a smoother experience of
  multi-screen Emacs
- 3 possible scopes: frame-local, visible frames or all frames
- =get-window-by-number= public function, needed in Spacemacs and for future
  developments.
- Unlimited window numbers
- =select-window-by-number= can now be used interactively to select a window
  using prefix arg or =read-from-minibuffer=, allowing the selection of an
  unlimited number.
- Ignore buffers by name
- =;;;###autoload= all functions that should have public visibility
- Improved =customize= integration
- Removed =window-numbering-before-assign-hook=, which just duplicated
  =window-numbering-assign-func= in a more complicated fashion
- New default key bindings under the ~C-x w~ prefix, to be compliant with Emacs
  key bindings conventions and native Emacs key bindings
- =winum-set-keymap-prefix= helper function to change the prefix more easily
- More detailed README.org
- Improved docstrings
- Simplified implementation for better readability

* Installation
** Using Melpa
The recommended way of installing =winum= is from the [[https://melpa.org/#/winum][Melpa]] package repository:

#+BEGIN_SRC emacs-lisp
M-x package-install RET winum RET
#+END_SRC

You will find instructions to setup Melpa [[https://github.com/melpa/melpa#usage][here]] if you don't have it setup yet.

Once the package is installed, you need to load and activate =winum-mode= in
your Emacs configuration:

#+BEGIN_SRC emacs-lisp
  (require 'winum)

  (winum-mode)
#+END_SRC

** Manual installation
- Clone the repo:

#+BEGIN_SRC shell
  cd /path/to/install/folder
  git clone https://github.com/deb0ch/emacs-winum
#+END_SRC

- Add the following to your Emacs configuration:

#+BEGIN_SRC emacs-lisp
  (add-to-list 'load-path "/path/to/install/folder/emacs-winum/")

  (require 'winum)

  (winum-mode)
#+END_SRC

* How to use
| Key binding | Description                                                                                 |
|-------------+---------------------------------------------------------------------------------------------|
| ~C-x w <n>~ | select window <n>, where <n> ranges from 0 to 9. A negative argument deletes the window.    |
| ~C-x w `~   | select window by index. Integer indices can be given as prefix arg, or the index will be read from minibuffer. |

- =select-window-0-or-10=

  By default, ~C-x w 0~ is bound to =select-window-0-or-10=. If window 0 is not
  assigned, it will act on the window 10 instead.

  You can rebind this to the more straightforward =select-window-0= if you
  prefer.

- =select-window-by-index=

  If you happen to have more than 10 windows, or if you want to select a window that
  doesn't have an integer index, you can use the =select-window-by-index= function, bound
  by default to ~C-x w `~.

  This function allows several ways to input the window number:

  - Use a numbered prefix argument.\\
    *Ex:* ~C-1 C-2 C-x w `~ to select window 12.
  - Use the default prefix argument to delete current window.\\
    *Ex:* ~C-u C-x w `~ to delete current window.
  - If no prefix argument is given, an un-evaluated Lisp value is read from minibuffer.

* Configuration
** Keybindings
The default prefix for key bindings is ~C-x w~ for compatibility with native
Emacs bindings.

If you don't like ~C-x w~, you can set a prefix of your choosing using the
function =winum-set-keymap-prefix=:

#+BEGIN_SRC elisp
  (winum-set-keymap-prefix (kbd "C-c"))
#+END_SRC

This function overrides the value of =winum-keymap=, so you should call it
before customization of =winum-keymap= and/or after customization of
=winum-base-map=. Its argument must be a key sequence, like the ones returned by
=kbd=.

If you prefer no to use a prefix and have even shorter bindings, you can also
override =winum-keymap= in the minor mode bindings table:

#+BEGIN_SRC emacs-lisp
  (setq winum-keymap
      (let ((map (make-sparse-keymap)))
        (define-key map (kbd "C-`") 'winum-select-window-by-index)
        (define-key map (kbd "C-²") 'winum-select-window-by-index)
        (define-key map (kbd "M-0") 'winum-select-window-0-or-10)
        (define-key map (kbd "M-1") 'winum-select-window-1)
        (define-key map (kbd "M-2") 'winum-select-window-2)
        (define-key map (kbd "M-3") 'winum-select-window-3)
        (define-key map (kbd "M-4") 'winum-select-window-4)
        (define-key map (kbd "M-5") 'winum-select-window-5)
        (define-key map (kbd "M-6") 'winum-select-window-6)
        (define-key map (kbd "M-7") 'winum-select-window-7)
        (define-key map (kbd "M-8") 'winum-select-window-8)
        map))

  (require 'winum)

  (winum-mode)
#+END_SRC

Note that it is important to set =winum-keymap= /before/ the =require=.

You can also use the more conventional =define-key= on =winum-keymap=:

#+BEGIN_SRC emacs-lisp
  (define-key winum-keymap (kbd "C-x y o l o") 'winum-select-window-by-index)
#+END_SRC

*NB:* Both ~`~ and ~²~ are mapped to =winum-select-window-by-number= by default
      to handle both =qwerty= and =azerty= keyboard layouts. If you are using a
      different kind of layout, the recommended place to map it is the key
      beside ~1~.

** Customize options
Several options are available through Emacs' Customize interface under
=convenience= > =winum=:

- =winum-scope=

  Frames affected by a number set. Choices are 'frame-local 'visible or
  'global.

  Default: 'global

- =winum-reverse-frame-list=

  If t, order frames by reverse order of creation. Has effect only when
  =winum-scope= is not 'frame-local.

  Default: =nil=

- =winum-minibuffer-auto-assign=

  If non-nil, =winum-mode= automatically assigns this index to the minibuffer.

  Default: =0=

- =winum-assign-functions=

  List of functions called for each window by `winum-mode'.

  These functions allow for deterministic assignment of numbers to windows. Each
  function is called for every window. A function should return the number to be
  assigned to a window or nil. The /first/ function to output a number for
  a given window will determine this window's number (if more than 1 function
  assigns a number a warning will be logged in the messages buffer).

  If the list is empty or if every function returns nil for a given window winum
  will proceed to automatic number assignment.

  Since this list is meant to allow custom window assignment for /mutiple/
  packages at once it should never be directly set, only added to and removed
  from.

  These functions, along with ~winum-auto-assign-0-to-minibuffer~, are the only
  way to have 0 assigned to a window.

  Example: always assign *Calculator* the number 9 and *NeoTree* the number 0:

  #+BEGIN_SRC emacs-lisp
    (defun winum-assign-9-to-calculator-8-to-flycheck-errors ()
      (cond
       ((equal (buffer-name) "*Calculator*") 9)
       ((equal (buffer-name) "*Flycheck errors*") 8)))

    (defun winum-assign-0-to-neotree ()
      (when (string-match-p (buffer-name) ".*\\*NeoTree\\*.*") 10))

    (add-to-list 'winum-assign-functions #'winum-assign-9-to-calculator-8-to-flycheck-errors)
    (add-to-list 'winum-assign-functions #'winum-assign-0-to-neotree)
  #+END_SRC

  Default: =nil=

- =winum-auto-assign-function=
  
  The function called to auto-assign indices to windows.

  This function is called after =winum-assign-functions= to automatically assign
  indices to the remaining windows. It must take in a list of windows and call
  the function =winum--assign= to assign an index to each, while avoiding
  assigning any indices already taken (stored in =winum--assigned-indices=).
  Members of this list should be tested for using `equal'.

  Default: =#'winum--auto-assign=

- =winum-auto-setup-mode-line=

  When nil, =winum-mode= will not display window numbers in the mode-line. You
  might want this to be nil if you use a package that already manages window
  numbers in the mode-line.

  Default: =t=

- =winum-format=

  Format string defining how the window number looks like in the mode-line.
  This string is passed to the =format= function along with the result of
  =winum-get-number-string=.

  Default: =" %s "=

- =winum-mode-line-position=

  The position in the mode-line =winum-mode= displays the number.

  Default: =1=

- =winum-ignored-buffers=

  List of buffers to ignore when assigning numbers.

  Default: '(" *which-key*")

- =winum-ignored-buffers-regexp=

  List of regexps for buffer names. Matching buffers will be ignored when
  assigning numbers. See [[https://www.gnu.org/software/emacs/manual/html_node/emacs/Regexps.html][Emacs' documentation on regexps]] for syntax.

  Default: '()

- face: =winum-face=

  Face used for the number in the mode-line.

** Configuration file example
Here is an example that you could put in your =.emacs=, which includes all
available winum options.

#+BEGIN_SRC emacs-lisp
  (setq winum-keymap
      (let ((map (make-sparse-keymap)))
        (define-key map (kbd "C-`") 'winum-select-window-by-index)
        (define-key map (kbd "C-²") 'winum-select-window-by-index)
        (define-key map (kbd "M-0") 'winum-select-window-0-or-10)
        (define-key map (kbd "M-1") 'winum-select-window-1)
        (define-key map (kbd "M-2") 'winum-select-window-2)
        (define-key map (kbd "M-3") 'winum-select-window-3)
        (define-key map (kbd "M-4") 'winum-select-window-4)
        (define-key map (kbd "M-5") 'winum-select-window-5)
        (define-key map (kbd "M-6") 'winum-select-window-6)
        (define-key map (kbd "M-7") 'winum-select-window-7)
        (define-key map (kbd "M-8") 'winum-select-window-8)
        map))

  (require 'winum)

  (defun winum-assign-9-to-calculator-8-to-flycheck-errors ()
    (cond
     ((equal (buffer-name) "*Calculator*") 9)
     ((equal (buffer-name) "*Flycheck errors*") 8)))

  (defun winum-assign-0-to-neotree ()
    (when (string-match-p (buffer-name) ".*\\*NeoTree\\*.*") 10))

  (add-to-list 'winum-assign-functions #'winum-assign-9-to-calculator-8-to-flycheck-errors)
  (add-to-list 'winum-assign-functions #'winum-assign-0-to-neotree)

  (set-face-attribute 'winum-face nil :weight 'bold)

  (setq window-numbering-scope            'global
        winum-reverse-frame-list          nil
        winum-minibuffer-auto-assign      0
        winum-assign-func                 'my-winum-assign-func
        winum-auto-setup-mode-line        t
        winum-format                      " %s "
        winum-mode-line-position          1
        winum-ignored-buffers             '(" *which-key*")
        winum-ignored-buffers-regexp      '(" \\*Treemacs-.*"))

  (winum-mode)
#+END_SRC

* Future developments
- send buffer to numbered window

  Send current window's buffer to window N. With prefix argument focus will
  follow.

- swap buffer with numbered window

  Same as previous, but will swap buffers instead of just sending them.

- Evilify

  Adapt the package to the famous `evil-mode` and use a leader key.

- Override native =other-window= (~C-x o~) to use window numbers

- Autocomplete read-from-minibuffer

- Things that you have thought of and I haven't :smile_cat: