lisp/org-indent.el

   1 ;;; org-indent.el --- Dynamic indentation for Org    -*- lexical-binding: t; -*-
   2
   3 ;; Copyright (C) 2009-2017 Free Software Foundation, Inc.
   4 ;;
   5 ;; Author: Carsten Dominik <carsten at orgmode dot org>
   6 ;; Keywords: outlines, hypermedia, calendar, wp
   7 ;; Homepage: http://orgmode.org
   8 ;;
   9 ;; This file is part of GNU Emacs.
  10 ;;
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15 ;;
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20 ;;
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23 ;;
  24 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  25 ;;
  26 ;;; Commentary:
  27
  28 ;; This is an implementation of dynamic virtual indentation.  It works
  29 ;; by adding text properties to a buffer to make sure lines are
  30 ;; indented according to outline structure.
  31 ;;
  32 ;; The process is synchronous, toggled at every buffer modification.
  33 ;; Though, the initialization (indentation of text already in the
  34 ;; buffer), which can take a few seconds in large buffers, happens on
  35 ;; idle time.
  36 ;;
  37 ;;; Code:
  38
  39 (require 'org-macs)
  40 (require 'org-compat)
  41 (require 'org)
  42
  43 (require 'cl-lib)
  44
  45 (declare-function org-inlinetask-get-task-level "org-inlinetask" ())
  46 (declare-function org-inlinetask-in-task-p "org-inlinetask" ())
  47 (declare-function org-list-item-body-column "org-list" (item))
  48 (defvar org-inlinetask-show-first-star)
  49
  50 (defgroup org-indent nil
  51   "Options concerning dynamic virtual outline indentation."
  52   :tag "Org Indent"
  53   :group 'org)
  54
  55 (defvar org-indent-inlinetask-first-star (org-add-props "*" '(face org-warning))
  56   "First star of inline tasks, with correct face.")
  57 (defvar org-indent-agent-timer nil
  58   "Timer running the initialize agent.")
  59 (defvar org-indent-agentized-buffers nil
  60   "List of buffers watched by the initialize agent.")
  61 (defvar org-indent-agent-resume-timer nil
  62   "Timer to reschedule agent after switching to other idle processes.")
  63 (defvar org-indent-agent-active-delay '(0 2 0)
  64   "Time to run agent before switching to other idle processes.
  65 Delay used when the buffer to initialize is current.")
  66 (defvar org-indent-agent-passive-delay '(0 0 400000)
  67   "Time to run agent before switching to other idle processes.
  68 Delay used when the buffer to initialize isn't current.")
  69 (defvar org-indent-agent-resume-delay '(0 0 100000)
  70   "Minimal time for other idle processes before switching back to agent.")
  71 (defvar org-indent--initial-marker nil
  72   "Position of initialization before interrupt.
  73 This is used locally in each buffer being initialized.")
  74 (defvar org-hide-leading-stars-before-indent-mode nil
  75   "Used locally.")
  76 (defvar org-indent-modified-headline-flag nil
  77   "Non-nil means the last deletion operated on a headline.
  78 It is modified by `org-indent-notify-modified-headline'.")
  79
  80
  81 (defcustom org-indent-boundary-char ?\s
  82   "The end of the virtual indentation strings, a single-character string.
  83 The default is just a space, but if you wish, you can use \"|\" or so.
  84 This can be useful on a terminal window - under a windowing system,
  85 it may be prettier to customize the `org-indent' face."
  86   :group 'org-indent
  87   :type 'character)
  88
  89 (defcustom org-indent-mode-turns-off-org-adapt-indentation t
  90   "Non-nil means setting the variable `org-indent-mode' will \
  91 turn off indentation adaptation.
  92 For details see the variable `org-adapt-indentation'."
  93   :group 'org-indent
  94   :type 'boolean)
  95
  96 (defcustom org-indent-mode-turns-on-hiding-stars t
  97   "Non-nil means setting the variable `org-indent-mode' will \
  98 turn on `org-hide-leading-stars'."
  99   :group 'org-indent
 100   :type 'boolean)
 101
 102 (defcustom org-indent-indentation-per-level 2
 103   "Indentation per level in number of characters."
 104   :group 'org-indent
 105   :type 'integer)
 106
 107 (defface org-indent '((t (:inherit org-hide)))
 108   "Face for outline indentation.
 109 The default is to make it look like whitespace.  But you may find it
 110 useful to make it ever so slightly different."
 111   :group 'org-faces)
 112
 113 (defsubst org-indent-remove-properties (beg end)
 114   "Remove indentations between BEG and END."
 115   (org-with-silent-modifications
 116    (remove-text-properties beg end '(line-prefix nil wrap-prefix nil))))
 117
 118 ;;;###autoload
 119 (define-minor-mode org-indent-mode
 120   "When active, indent text according to outline structure.
 121
 122 Internally this works by adding `line-prefix' and `wrap-prefix'
 123 properties, after each buffer modification, on the modified zone.
 124
 125 The process is synchronous.  Though, initial indentation of
 126 buffer, which can take a few seconds on large buffers, is done
 127 during idle time."
 128   nil " Ind" nil
 129   (cond
 130    (org-indent-mode
 131     ;; mode was turned on.
 132     (setq-local indent-tabs-mode nil)
 133     (setq-local org-indent--initial-marker (copy-marker 1))
 134     (when org-indent-mode-turns-off-org-adapt-indentation
 135       (setq-local org-adapt-indentation nil))
 136     (when org-indent-mode-turns-on-hiding-stars
 137       (setq-local org-hide-leading-stars-before-indent-mode
 138                   org-hide-leading-stars)
 139       (setq-local org-hide-leading-stars t))
 140     (add-hook 'filter-buffer-substring-functions
 141                   (lambda (fun start end delete)
 142                     (org-indent-remove-properties-from-string
 143                      (funcall fun start end delete)))
 144                   nil t)
 145     (add-hook 'after-change-functions 'org-indent-refresh-maybe nil 'local)
 146     (add-hook 'before-change-functions
 147                   'org-indent-notify-modified-headline nil 'local)
 148     (and font-lock-mode (org-restart-font-lock))
 149     (org-indent-remove-properties (point-min) (point-max))
 150     ;; Submit current buffer to initialize agent.  If it's the first
 151     ;; buffer submitted, also start the agent.  Current buffer is
 152     ;; pushed in both cases to avoid a race condition.
 153     (if org-indent-agentized-buffers
 154         (push (current-buffer) org-indent-agentized-buffers)
 155       (push (current-buffer) org-indent-agentized-buffers)
 156       (setq org-indent-agent-timer
 157             (run-with-idle-timer 0.2 t #'org-indent-initialize-agent))))
 158    (t
 159     ;; mode was turned off (or we refused to turn it on)
 160     (kill-local-variable 'org-adapt-indentation)
 161     (setq org-indent-agentized-buffers
 162           (delq (current-buffer) org-indent-agentized-buffers))
 163     (when (markerp org-indent--initial-marker)
 164       (set-marker org-indent--initial-marker nil))
 165     (when (boundp 'org-hide-leading-stars-before-indent-mode)
 166       (setq-local org-hide-leading-stars
 167                   org-hide-leading-stars-before-indent-mode))
 168     (remove-hook 'filter-buffer-substring-functions
 169                  (lambda (fun start end delete)
 170                    (org-indent-remove-properties-from-string
 171                     (funcall fun start end delete))))
 172     (remove-hook 'after-change-functions 'org-indent-refresh-maybe 'local)
 173     (remove-hook 'before-change-functions
 174                  'org-indent-notify-modified-headline 'local)
 175     (org-with-wide-buffer
 176      (org-indent-remove-properties (point-min) (point-max)))
 177     (and font-lock-mode (org-restart-font-lock))
 178     (redraw-display))))
 179
 180 (defun org-indent-indent-buffer ()
 181   "Add indentation properties to the accessible part of the buffer."
 182   (interactive)
 183   (if (not (derived-mode-p 'org-mode))
 184       (error "Not in Org mode")
 185     (message "Setting buffer indentation.  It may take a few seconds...")
 186     (org-indent-remove-properties (point-min) (point-max))
 187     (org-indent-add-properties (point-min) (point-max))
 188     (message "Indentation of buffer set.")))
 189
 190 (defun org-indent-remove-properties-from-string (string)
 191   "Remove indentation properties from STRING."
 192   (remove-text-properties 0 (length string)
 193                           '(line-prefix nil wrap-prefix nil) string)
 194   string)
 195
 196 (defun org-indent-initialize-agent ()
 197   "Start or resume current buffer initialization.
 198 Only buffers in `org-indent-agentized-buffers' trigger an action.
 199 When no more buffer is being watched, the agent suppress itself."
 200   (when org-indent-agent-resume-timer
 201     (cancel-timer org-indent-agent-resume-timer))
 202   (setq org-indent-agentized-buffers
 203         (cl-remove-if-not #'buffer-live-p org-indent-agentized-buffers))
 204   (cond
 205    ;; Job done:  kill agent.
 206    ((not org-indent-agentized-buffers) (cancel-timer org-indent-agent-timer))
 207    ;; Current buffer is agentized: start/resume initialization
 208    ;; somewhat aggressively.
 209    ((memq (current-buffer) org-indent-agentized-buffers)
 210     (org-indent-initialize-buffer (current-buffer)
 211                                   org-indent-agent-active-delay))
 212    ;; Else, start/resume initialization of the last agentized buffer,
 213    ;; softly.
 214    (t (org-indent-initialize-buffer (car org-indent-agentized-buffers)
 215                                     org-indent-agent-passive-delay))))
 216
 217 (defun org-indent-initialize-buffer (buffer delay)
 218   "Set virtual indentation for the buffer BUFFER, asynchronously.
 219 Give hand to other idle processes if it takes longer than DELAY,
 220 a time value."
 221   (with-current-buffer buffer
 222     (when org-indent-mode
 223       (org-with-wide-buffer
 224        (let ((interruptp
 225               ;; Always nil unless interrupted.
 226               (catch 'interrupt
 227                 (and org-indent--initial-marker
 228                      (marker-position org-indent--initial-marker)
 229                      (equal (marker-buffer org-indent--initial-marker)
 230                             buffer)
 231                      (org-indent-add-properties org-indent--initial-marker
 232                                                 (point-max)
 233                                                 delay)
 234                      nil))))
 235          (move-marker org-indent--initial-marker interruptp)
 236          ;; Job is complete: un-agentize buffer.
 237          (unless interruptp
 238            (setq org-indent-agentized-buffers
 239                  (delq buffer org-indent-agentized-buffers))))))))
 240
 241 (defun org-indent-set-line-properties (level indentation &optional heading)
 242   "Set prefix properties on current line an move to next one.
 243
 244 LEVEL is the current level of heading.  INDENTATION is the
 245 expected indentation when wrapping line.
 246
 247 When optional argument HEADING is non-nil, assume line is at
 248 a heading.  Moreover, if is is `inlinetask', the first star will
 249 have `org-warning' face."
 250   (let* ((stars (if (<= level 1) ""
 251                   (make-string (* (1- org-indent-indentation-per-level)
 252                                   (1- level))
 253                                ?*)))
 254          (line
 255           (cond
 256            ((and (bound-and-true-p org-inlinetask-show-first-star)
 257                  (eq heading 'inlinetask))
 258             (concat org-indent-inlinetask-first-star
 259                     (org-add-props (substring stars 1) nil 'face 'org-hide)))
 260            (heading (org-add-props stars nil 'face 'org-hide))
 261            (t (concat (org-add-props (concat stars (make-string level ?*))
 262                           nil 'face 'org-indent)
 263                       (and (> level 0)
 264                            (char-to-string org-indent-boundary-char))))))
 265          (wrap
 266           (org-add-props
 267               (concat stars
 268                       (make-string level ?*)
 269                       (if heading " "
 270                         (make-string (+ indentation (min level 1)) ?\s)))
 271               nil 'face 'org-indent)))
 272     ;; Add properties down to the next line to indent empty lines.
 273     (add-text-properties (line-beginning-position) (line-beginning-position 2)
 274                          `(line-prefix ,line wrap-prefix ,wrap)))
 275   (forward-line))
 276
 277 (defun org-indent-add-properties (beg end &optional delay)
 278   "Add indentation properties between BEG and END.
 279
 280 When DELAY is non-nil, it must be a time value.  In that case,
 281 the process is asynchronous and can be interrupted, either by
 282 user request, or after DELAY.  This is done by throwing the
 283 `interrupt' tag along with the buffer position where the process
 284 stopped."
 285   (save-match-data
 286     (org-with-wide-buffer
 287      (goto-char beg)
 288      (beginning-of-line)
 289      ;; Initialize prefix at BEG, according to current entry's level.
 290      (let* ((case-fold-search t)
 291             (limited-re (org-get-limited-outline-regexp))
 292             (level (or (org-current-level) 0))
 293             (time-limit (and delay (time-add (current-time) delay))))
 294        ;; For each line, set `line-prefix' and `wrap-prefix'
 295        ;; properties depending on the type of line (headline, inline
 296        ;; task, item or other).
 297        (org-with-silent-modifications
 298         (while (and (<= (point) end) (not (eobp)))
 299           (cond
 300            ;; When in asynchronous mode, check if interrupt is
 301            ;; required.
 302            ((and delay (input-pending-p)) (throw 'interrupt (point)))
 303            ;; In asynchronous mode, take a break of
 304            ;; `org-indent-agent-resume-delay' every DELAY to avoid
 305            ;; blocking any other idle timer or process output.
 306            ((and delay (time-less-p time-limit (current-time)))
 307             (setq org-indent-agent-resume-timer
 308                   (run-with-idle-timer
 309                    (time-add (current-idle-time) org-indent-agent-resume-delay)
 310                    nil #'org-indent-initialize-agent))
 311             (throw 'interrupt (point)))
 312            ;; Headline or inline task.
 313            ((looking-at org-outline-regexp)
 314             (let* ((nstars (- (match-end 0) (match-beginning 0) 1))
 315                    (type (or (looking-at-p limited-re) 'inlinetask)))
 316               (org-indent-set-line-properties nstars 0 type)
 317               ;; At an headline, define new value for LEVEL.
 318               (unless (eq type 'inlinetask) (setq level nstars))))
 319            ;; List item: `wrap-prefix' is set where body starts.
 320            ((org-at-item-p)
 321             (org-indent-set-line-properties
 322              level (org-list-item-body-column (point))))
 323            ;; Regular line.
 324            (t
 325             (org-indent-set-line-properties level (org-get-indentation))))))))))
 326
 327 (defun org-indent-notify-modified-headline (beg end)
 328   "Set `org-indent-modified-headline-flag' depending on context.
 329
 330 BEG and END are the positions of the beginning and end of the
 331 range of deleted text.
 332
 333 This function is meant to be called by `before-change-functions'.
 334 Flag will be non-nil if command is going to modify or delete an
 335 headline."
 336   (when org-indent-mode
 337     (setq org-indent-modified-headline-flag
 338           (org-with-wide-buffer
 339            (goto-char beg)
 340            (save-match-data
 341              (or (and (org-at-heading-p) (< beg (match-end 0)))
 342                  (re-search-forward
 343                   (org-with-limited-levels org-outline-regexp-bol) end t)))))))
 344
 345 (defun org-indent-refresh-maybe (beg end _)
 346   "Refresh indentation properties in an adequate portion of buffer.
 347 BEG and END are the positions of the beginning and end of the
 348 range of inserted text.  DUMMY is an unused argument.
 349
 350 This function is meant to be called by `after-change-functions'."
 351   (when org-indent-mode
 352     (save-match-data
 353       ;; If a headline was modified or inserted, set properties until
 354       ;; next headline.
 355       (org-with-wide-buffer
 356        (if (or org-indent-modified-headline-flag
 357                (save-excursion
 358                  (goto-char beg)
 359                  (beginning-of-line)
 360                  (re-search-forward
 361                   (org-with-limited-levels org-outline-regexp-bol) end t)))
 362            (let ((end (save-excursion
 363                         (goto-char end)
 364                         (org-with-limited-levels (outline-next-heading))
 365                         (point))))
 366              (setq org-indent-modified-headline-flag nil)
 367              (org-indent-add-properties beg end))
 368          ;; Otherwise, only set properties on modified area.
 369          (org-indent-add-properties beg end))))))
 370
 371 (provide 'org-indent)
 372
 373 ;; Local variables:
 374 ;; generated-autoload-file: "org-loaddefs.el"
 375 ;; End:
 376
 377 ;;; org-indent.el ends here