Files
emacs/lisp/indent-guide/indent-guide.el
2025-06-22 17:08:08 +02:00

331 lines
12 KiB
EmacsLisp

;;; indent-guide.el --- show vertical lines to guide indentation
;; Copyright (C) 2013- zk_phi
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2 of the License, or
;; (at your option) any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with this program; if not, write to the Free Software
;; Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
;; Author: zk_phi
;; URL: http://hins11.yu-yake.com/
;; Package-Version: 20210115.400
;; Package-Revision: d388c3387781
;;; Commentary:
;; Require this script
;;
;; (require 'indent-guide)
;;
;; and call command "M-x indent-guide-mode".
;; If you want to enable indent-guide-mode automatically,
;; call "indent-guide-global-mode" function.
;;
;; (indent-guide-global-mode)
;; Column lines are propertized with "indent-guide-face". So you may
;; configure this face to make guides more pretty in your colorscheme.
;;
;; (set-face-background 'indent-guide-face "dimgray")
;;
;; You may also change the character for guides.
;;
;; (setq indent-guide-char ":")
;;; Change Log:
;; 1.0.0 first released
;; 1.0.1 cleaned and optimized code
;; works better for the file without trailing-whitespaces
;; 1.0.2 modified behavior for lines with only whitespaces
;; 1.0.3 Allow custom indent guide char
;; 1.0.4 disabled in org-indent-mode
;; 1.0.5 faster update of indent-guide (especially for huge files)
;; 1.1.0 work with tab-indented files
;; 1.1.1 turned into minor-mode
;; 1.1.2 an infinite-loop bug fix
;; 1.1.3 changed behavior for blank lines
;; 2.0.0 rewrite almost everything
;; 2.0.1 improve blank-line and tab handling
;; 2.0.2 fixed bug that sometimes newline gets invisible
;; 2.0.3 added indent-guide-global-mode
;; 2.1.0 now lines are not drawn over the cursor
;; 2.1.1 work better with blank lines
;; 2.1.2 fixed bug in empty files
;; 2.1.3 better bob and eob handling
;; 2.1.4 use "display" property instead of "before-string"
;; (now works better with hl-line and linum)
;; 2.1.5 add "indent-guide-inhibit-modes"
;; 2.1.6 add option "indent-guide-recursive"
;; 2.2.0 add option "indent-guide-threshold"
;; 2.3.0 use regexp search to find the beginning of level
;; 2.3.1 add option "indent-guide-lispy-modes"
;;; Code:
(require 'cl-lib)
(defconst indent-guide-version "2.3.1")
;; * customs
(defgroup indent-guide nil
"Show vertical lines to guide indentation."
:group 'environment)
(defcustom indent-guide-char "|"
"Character used as vertical line."
:type 'string
:group 'indent-guide)
(defcustom indent-guide-inhibit-modes
'(tabulated-list-mode
special-mode
dired-mode
eww-mode
eshell-mode
Custom-mode)
"List of major-modes in which indent-guide should be turned off."
:type '(repeat symbol)
:group 'indent-guide)
(defcustom indent-guide-recursive nil
"When non-nil, draw multiple guide lines recursively."
:type 'boolean
:group 'indent-guide)
(defcustom indent-guide-delay nil
"When a positive number, rendering guide lines is delayed DELAY
seconds."
:type 'number
:group 'indent-guide)
(defcustom indent-guide-threshold -1
"Guide lines are drawn only when the column number is over this
value."
:type 'number
:group 'indent-guide)
(defcustom indent-guide-lispy-modes
'(lisp-mode emacs-lisp-mode scheme-mode
lisp-interaction-mode gauche-mode scheme-mode
clojure-mode racket-mode egison-mode)
"List of lisp-like language modes, in which the last brace of
blocks are NOT placed at beginning of line."
:type '(repeat symbol)
:group 'indent-guide)
(defface indent-guide-face '((t (:foreground "#535353" :slant normal)))
"Face used to indent guide lines."
:group 'indent-guide)
;; * variables
(defvar indent-guide--timer-object nil)
;; * utilities
(defun indent-guide--active-overlays ()
"Return the list of all overlays created by indent-guide."
(delq nil
(mapcar
(lambda (ov)
(and (eq (overlay-get ov 'category) 'indent-guide) ov))
(overlays-in (point-min) (point-max)))))
(defun indent-guide--indentation-candidates (level)
"*Internal function for `indent-guide--beginning-of-level'."
(cond ((<= level 0)
(list ""))
((>= level tab-width)
(let ((ntabs (/ level tab-width))
(nspaces (mod level tab-width)))
(cons (concat (make-string ntabs ?\t)
(make-string nspaces ?\s))
(cons (make-string level ?\s)
(indent-guide--indentation-candidates (1- level))))))
(t
(cons (make-string level ?\s)
(indent-guide--indentation-candidates (1- level))))))
(defun indent-guide--beginning-of-level ()
"Move to the beginning of current indentation level and return
the point. When no such points are found, just return nil."
(back-to-indentation)
(let* ((base-level (if (not (eolp))
(current-column)
(max (save-excursion
(skip-chars-forward "\s\t\n")
(current-column))
(save-excursion
(skip-chars-backward "\s\t\n")
(back-to-indentation)
(current-column)))))
(candidates (indent-guide--indentation-candidates (1- base-level)))
(regex (concat "^" (regexp-opt candidates t) "[^\s\t\n]")))
(unless (zerop base-level)
(and (search-backward-regexp regex nil t)
(goto-char (match-end 1))))))
;; * generate guides
(defun indent-guide--make-overlay (line col)
"draw line at (line, col)"
(let (diff string ov prop)
(save-excursion
;; try to goto (line, col)
(goto-char (point-min))
(forward-line (1- line))
(move-to-column col)
;; calculate difference from the actual col
(setq diff (- col (current-column)))
;; make overlay or not
(cond ((and (eolp) (<= 0 diff)) ; the line is too short
;; <-line-width-> <-diff->
;; [] |
(if (setq ov (cl-some
(lambda (ov)
(when (eq (overlay-get ov 'category) 'indent-guide)
ov))
(overlays-in (point) (point))))
;; we already have an overlay here => append to the existing overlay
;; (important when "recursive" is enabled)
(setq string (let ((str (overlay-get ov 'before-string)))
(concat str
(make-string (- diff (length str)) ?\s)
(propertize indent-guide-char 'face 'indent-guide-face)))
prop 'before-string)
(setq string (concat (make-string diff ?\s)
(propertize indent-guide-char 'face 'indent-guide-face))
prop 'before-string
ov (make-overlay (point) (point)))))
((< diff 0) ; the column is inside a tab
;; <---tab-width-->
;; <-(- diff)->
;; | []
(if (setq ov (cl-some
(lambda (ov)
(when (eq (overlay-get ov 'category) 'indent-guide)
ov))
(overlays-in (1- (point)) (point))))
;; we already have an overlay here => modify the existing overlay
;; (important when "recursive" is enabled)
(setq string (let ((str (overlay-get ov 'display)))
(aset str (+ 1 tab-width diff) ?|)
str)
prop 'display)
(setq string (concat (make-string (+ tab-width diff) ?\s)
(propertize indent-guide-char 'face 'indent-guide-face)
(make-string (1- (- diff)) ?\s))
prop 'display
ov (make-overlay (point) (1- (point))))))
((looking-at "\t") ; okay but looking at tab
;; <-tab-width->
;; [|]
(setq string (concat (propertize indent-guide-char 'face 'indent-guide-face)
(make-string (1- tab-width) ?\s))
prop 'display
ov (make-overlay (point) (1+ (point)))))
(t ; okay and looking at a space
(setq string (propertize indent-guide-char 'face 'indent-guide-face)
prop 'display
ov (make-overlay (point) (1+ (point))))))
(when ov
(overlay-put ov 'category 'indent-guide)
(overlay-put ov prop string)))))
(defun indent-guide-show ()
(interactive)
(unless (or (indent-guide--active-overlays)
(active-minibuffer-window))
(let ((win-start (window-start))
(win-end (window-end nil t))
line-col line-start line-end)
;; decide line-col, line-start
(save-excursion
(indent-guide--beginning-of-level)
(setq line-col (current-column)
line-start (max (1+ (line-number-at-pos))
(line-number-at-pos win-start)))
;; if recursive draw is enabled and (line-col > 0), recurse
;; into lower level.
(when (and indent-guide-recursive (> line-col 0))
(indent-guide-show)))
(when (> line-col indent-guide-threshold)
;; decide line-end
(save-excursion
(while (and (progn (back-to-indentation)
(or (< line-col (current-column)) (eolp)))
(forward-line 1)
(not (eobp))
(<= (point) win-end)))
(cond ((< line-col (current-column))
(setq line-end (line-number-at-pos)))
((not (memq major-mode indent-guide-lispy-modes))
(setq line-end (1- (line-number-at-pos))))
(t
(skip-chars-backward "\s\t\n")
(setq line-end (line-number-at-pos)))))
;; draw line
(dotimes (tmp (- (1+ line-end) line-start))
(indent-guide--make-overlay (+ line-start tmp) line-col))
(remove-overlays (point) (point) 'category 'indent-guide)))))
(defun indent-guide-remove ()
(dolist (ov (indent-guide--active-overlays))
(delete-overlay ov)))
;; * minor-mode
(defun indent-guide-post-command-hook ()
(if (null indent-guide-delay)
(indent-guide-show)
(when (null indent-guide--timer-object)
(setq indent-guide--timer-object
(run-with-idle-timer indent-guide-delay nil
(lambda ()
(indent-guide-show)
(setq indent-guide--timer-object nil)))))))
(defun indent-guide-pre-command-hook ()
;; some commands' behavior may affected by indent-guide overlays, so
;; remove all overlays in pre-command-hook.
(indent-guide-remove))
;;;###autoload
(define-minor-mode indent-guide-mode
"show vertical lines to guide indentation"
:init-value nil
:lighter " ing"
:global nil
(if indent-guide-mode
(progn
(add-hook 'pre-command-hook 'indent-guide-pre-command-hook nil t)
(add-hook 'post-command-hook 'indent-guide-post-command-hook nil t))
(remove-hook 'pre-command-hook 'indent-guide-pre-command-hook t)
(remove-hook 'post-command-hook 'indent-guide-post-command-hook t)))
;;;###autoload
(define-globalized-minor-mode indent-guide-global-mode
indent-guide-mode
(lambda ()
(unless (cl-some 'derived-mode-p indent-guide-inhibit-modes)
(indent-guide-mode 1))))
;; * provide
(provide 'indent-guide)
;;; indent-guide.el ends here