lisp/org-indent.el

   1 ;;; org-indent.el --- Dynamic indentation for Org    -*- lexical-binding: t; -*-
   2
   3 ;; Copyright (C) 2009-2016 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 (eval-when-compile
  44   (require 'cl))
  45 (require 'cl-lib)
  46
  47 (declare-function org-inlinetask-get-task-level "org-inlinetask" ())
  48 (declare-function org-inlinetask-in-task-p "org-inlinetask" ())
  49 (declare-function org-list-item-body-column "org-list" (item))
  50 (defvar org-inlinetask-show-first-star)
  51
  52 (defgroup org-indent nil
  53   "Options concerning dynamic virtual outline indentation."
  54   :tag "Org Indent"
  55   :group 'org)
  56
  57 (defvar org-indent-inlinetask-first-star (org-add-props "*" '(face org-warning))
  58   "First star of inline tasks, with correct face.")
  59 (defvar org-indent-agent-timer nil
  60   "Timer running the initialize agent.")
  61 (defvar org-indent-agentized-buffers nil
  62   "List of buffers watched by the initialize agent.")
  63 (defvar org-indent-agent-resume-timer nil
  64   "Timer to reschedule agent after switching to other idle processes.")
  65 (defvar org-indent-agent-active-delay '(0 2 0)
  66   "Time to run agent before switching to other idle processes.
  67 Delay used when the buffer to initialize is current.")
  68 (defvar org-indent-agent-passive-delay '(0 0 400000)
  69   "Time to run agent before switching to other idle processes.
  70 Delay used when the buffer to initialize isn't current.")
  71 (defvar org-indent-agent-resume-delay '(0 0 100000)
  72   "Minimal time for other idle processes before switching back to agent.")
  73 (defvar org-indent--initial-marker nil
  74   "Position of initialization before interrupt.
  75 This is used locally in each buffer being initialized.")
  76 (defvar org-hide-leading-stars-before-indent-mode nil
  77   "Used locally.")
  78 (defvar org-indent-modified-headline-flag nil
  79   "Non-nil means the last deletion operated on a headline.
  80 It is modified by `org-indent-notify-modified-headline'.")
  81
  82
  83 (defcustom org-indent-boundary-char ?\s
  84   "The end of the virtual indentation strings, a single-character string.
  85 The default is just a space, but if you wish, you can use \"|\" or so.
  86 This can be useful on a terminal window - under a windowing system,
  87 it may be prettier to customize the `org-indent' face."
  88   :group 'org-indent
  89   :type 'character)
  90
  91 (defcustom org-indent-mode-turns-off-org-adapt-indentation t
  92   "Non-nil means setting the variable `org-indent-mode' will \
  93 turn off indentation adaptation.
  94 For details see the variable `org-adapt-indentation'."
  95   :group 'org-indent
  96   :type 'boolean)
  97
  98 (defcustom org-indent-mode-turns-on-hiding-stars t
  99   "Non-nil means setting the variable `org-indent-mode' will \
 100 turn on `org-hide-leading-stars'."
 101   :group 'org-indent
 102   :type 'boolean)
 103
 104 (defcustom org-indent-indentation-per-level 2
 105   "Indentation per level in number of characters."
 106   :group 'org-indent
 107   :type 'integer)
 108
 109 (defface org-indent '((t (:inherit org-hide)))
 110   "Face for outline indentation.
 111 The default is to make it look like whitespace.  But you may find it
 112 useful to make it ever so slightly different."
 113   :group 'org-faces)
 114
 115 (defsubst org-indent-remove-properties (beg end)
 116   "Remove indentations between BEG and END."
 117   (org-with-silent-modifications
 118    (remove-text-properties beg end '(line-prefix nil wrap-prefix nil))))
 119
 120 ;;;###autoload
 121 (define-minor-mode org-indent-mode
 122   "When active, indent text according to outline structure.
 123
 124 Internally this works by adding `line-prefix' and `wrap-prefix'
 125 properties, after each buffer modification, on the modified zone.
 126
 127 The process is synchronous.  Though, initial indentation of
 128 buffer, which can take a few seconds on large buffers, is done
 129 during idle time."
 130   nil " Ind" nil
 131   (cond
 132    (org-indent-mode
 133     ;; mode was turned on.
 134     (setq-local indent-tabs-mode nil)
 135     (setq-local org-indent--initial-marker (copy-marker 1))
 136     (when org-indent-mode-turns-off-org-adapt-indentation
 137       (setq-local org-adapt-indentation nil))
 138     (when org-indent-mode-turns-on-hiding-stars
 139       (setq-local org-hide-leading-stars-before-indent-mode
 140                   org-hide-leading-stars)
 141       (setq-local org-hide-leading-stars t))
 142     (add-hook 'filter-buffer-substring-functions
 143                   (lambda (fun start end delete)
 144                     (org-indent-remove-properties-from-string
 145                      (funcall fun start end delete)))
 146                   nil t)
 147     (add-hook 'after-change-functions 'org-indent-refresh-maybe nil 'local)
 148     (add-hook 'before-change-functions
 149                   'org-indent-notify-modified-headline nil 'local)
 150     (and font-lock-mode (org-restart-font-lock))
 151     (org-indent-remove-properties (point-min) (point-max))
 152     ;; Submit current buffer to initialize agent.  If it's the first
 153     ;; buffer submitted, also start the agent.  Current buffer is
 154     ;; pushed in both cases to avoid a race condition.
 155     (if org-indent-agentized-buffers
 156         (push (current-buffer) org-indent-agentized-buffers)
 157       (push (current-buffer) org-indent-agentized-buffers)
 158       (setq org-indent-agent-timer
 159             (run-with-idle-timer 0.2 t #'org-indent-initialize-agent))))
 160    (t
 161     ;; mode was turned off (or we refused to turn it on)
 162     (kill-local-variable 'org-adapt-indentation)
 163     (setq org-indent-agentized-buffers
 164           (delq (current-buffer) org-indent-agentized-buffers))
 165     (when (markerp org-indent--initial-marker)
 166       (set-marker org-indent--initial-marker nil))
 167     (when (boundp 'org-hide-leading-stars-before-indent-mode)
 168       (setq-local org-hide-leading-stars
 169                   org-hide-leading-stars-before-indent-mode))
 170     (remove-hook 'filter-buffer-substring-functions
 171                  (lambda (fun start end delete)
 172                    (org-indent-remove-properties-from-string
 173                     (funcall fun start end delete))))
 174     (remove-hook 'after-change-functions 'org-indent-refresh-maybe 'local)
 175     (remove-hook 'before-change-functions
 176                  'org-indent-notify-modified-headline 'local)
 177     (org-with-wide-buffer
 178      (org-indent-remove-properties (point-min) (point-max)))
 179     (and font-lock-mode (org-restart-font-lock))
 180     (redraw-display))))
 181
 182 (defun org-indent-indent-buffer ()
 183   "Add indentation properties to the accessible part of the buffer."
 184   (interactive)
 185   (if (not (derived-mode-p 'org-mode))
 186       (error "Not in Org mode")
 187     (message "Setting buffer indentation.  It may take a few seconds...")
 188     (org-indent-remove-properties (point-min) (point-max))
 189     (org-indent-add-properties (point-min) (point-max))
 190     (message "Indentation of buffer set.")))
 191
 192 (defun org-indent-remove-properties-from-string (string)
 193   "Remove indentation properties from STRING."
 194   (remove-text-properties 0 (length string)
 195                           '(line-prefix nil wrap-prefix nil) string)
 196   string)
 197
 198 (defun org-indent-initialize-agent ()
 199   "Start or resume current buffer initialization.
 200 Only buffers in `org-indent-agentized-buffers' trigger an action.
 201 When no more buffer is being watched, the agent suppress itself."
 202   (when org-indent-agent-resume-timer
 203     (cancel-timer org-indent-agent-resume-timer))
 204   (setq org-indent-agentized-buffers
 205         (cl-remove-if-not #'buffer-live-p org-indent-agentized-buffers))
 206   (cond
 207    ;; Job done:  kill agent.
 208    ((not org-indent-agentized-buffers) (cancel-timer org-indent-agent-timer))
 209    ;; Current buffer is agentized: start/resume initialization
 210    ;; somewhat aggressively.
 211    ((memq (current-buffer) org-indent-agentized-buffers)
 212     (org-indent-initialize-buffer (current-buffer)
 213                                   org-indent-agent-active-delay))
 214    ;; Else, start/resume initialization of the last agentized buffer,
 215    ;; softly.
 216    (t (org-indent-initialize-buffer (car org-indent-agentized-buffers)
 217                                     org-indent-agent-passive-delay))))
 218
 219 (defun org-indent-initialize-buffer (buffer delay)
 220   "Set virtual indentation for the buffer BUFFER, asynchronously.
 221 Give hand to other idle processes if it takes longer than DELAY,
 222 a time value."
 223   (with-current-buffer buffer
 224     (when org-indent-mode
 225       (org-with-wide-buffer
 226        (let ((interruptp
 227               ;; Always nil unless interrupted.
 228               (catch 'interrupt
 229                 (and org-indent--initial-marker
 230                      (marker-position org-indent--initial-marker)
 231                      (equal (marker-buffer org-indent--initial-marker)
 232                             buffer)
 233                      (org-indent-add-properties org-indent--initial-marker
 234                                                 (point-max)
 235                                                 delay)
 236                      nil))))
 237          (move-marker org-indent--initial-marker interruptp)
 238          ;; Job is complete: un-agentize buffer.
 239          (unless interruptp
 240            (setq org-indent-agentized-buffers
 241                  (delq buffer org-indent-agentized-buffers))))))))
 242
 243 (defun org-indent-set-line-properties (level indentation &optional heading)
 244   "Set prefix properties on current line an move to next one.
 245
 246 LEVEL is the current level of heading.  INDENTATION is the
 247 expected indentation when wrapping line.
 248
 249 When optional argument HEADING is non-nil, assume line is at
 250 a heading.  Moreover, if is is `inlinetask', the first star will
 251 have `org-warning' face."
 252   (let* ((stars (if (<= level 1) ""
 253                   (make-string (* (1- org-indent-indentation-per-level)
 254                                   (1- level))
 255                                ?*)))
 256          (line
 257           (cond
 258            ((and (org-bound-and-true-p org-inlinetask-show-first-star)
 259                  (eq heading 'inlinetask))
 260             (concat org-indent-inlinetask-first-star
 261                     (org-add-props (substring stars 1) nil 'face 'org-hide)))
 262            (heading (org-add-props stars nil 'face 'org-hide))
 263            (t (concat (org-add-props (concat stars (make-string level ?*))
 264                           nil 'face 'org-indent)
 265                       (and (> level 0)
 266                            (char-to-string org-indent-boundary-char))))))
 267          (wrap
 268           (org-add-props
 269               (concat stars
 270                       (make-string level ?*)
 271                       (if heading " "
 272                         (make-string (+ indentation (min level 1)) ?\s)))
 273               nil 'face 'org-indent)))
 274     ;; Add properties down to the next line to indent empty lines.
 275     (add-text-properties (line-beginning-position) (line-beginning-position 2)
 276                          `(line-prefix ,line wrap-prefix ,wrap)))
 277   (forward-line))
 278
 279 (defun org-indent-add-properties (beg end &optional delay)
 280   "Add indentation properties between BEG and END.
 281
 282 When DELAY is non-nil, it must be a time value.  In that case,
 283 the process is asynchronous and can be interrupted, either by
 284 user request, or after DELAY.  This is done by throwing the
 285 `interrupt' tag along with the buffer position where the process
 286 stopped."
 287   (save-match-data
 288     (org-with-wide-buffer
 289      (goto-char beg)
 290      (beginning-of-line)
 291      ;; Initialize prefix at BEG, according to current entry's level.
 292      (let* ((case-fold-search t)
 293             (limited-re (org-get-limited-outline-regexp))
 294             (level (or (org-current-level) 0))
 295             (time-limit (and delay (time-add (current-time) delay))))
 296        ;; For each line, set `line-prefix' and `wrap-prefix'
 297        ;; properties depending on the type of line (headline, inline
 298        ;; task, item or other).
 299        (org-with-silent-modifications
 300         (while (and (<= (point) end) (not (eobp)))
 301           (cond
 302            ;; When in asynchronous mode, check if interrupt is
 303            ;; required.
 304            ((and delay (input-pending-p)) (throw 'interrupt (point)))
 305            ;; In asynchronous mode, take a break of
 306            ;; `org-indent-agent-resume-delay' every DELAY to avoid
 307            ;; blocking any other idle timer or process output.
 308            ((and delay (time-less-p time-limit (current-time)))
 309             (setq org-indent-agent-resume-timer
 310                   (run-with-idle-timer
 311                    (time-add (current-idle-time) org-indent-agent-resume-delay)
 312                    nil #'org-indent-initialize-agent))
 313             (throw 'interrupt (point)))
 314            ;; Headline or inline task.
 315            ((looking-at org-outline-regexp)
 316             (let* ((nstars (- (match-end 0) (match-beginning 0) 1))
 317                    (type (or (looking-at-p limited-re) 'inlinetask)))
 318               (org-indent-set-line-properties nstars 0 type)
 319               ;; At an headline, define new value for LEVEL.
 320               (unless (eq type 'inlinetask) (setq level nstars))))
 321            ;; List item: `wrap-prefix' is set where body starts.
 322            ((org-at-item-p)
 323             (org-indent-set-line-properties
 324              level (org-list-item-body-column (point))))
 325            ;; Regular line.
 326            (t
 327             (org-indent-set-line-properties level (org-get-indentation))))))))))
 328
 329 (defun org-indent-notify-modified-headline (beg end)
 330   "Set `org-indent-modified-headline-flag' depending on context.
 331
 332 BEG and END are the positions of the beginning and end of the
 333 range of deleted text.
 334
 335 This function is meant to be called by `before-change-functions'.
 336 Flag will be non-nil if command is going to modify or delete an
 337 headline."
 338   (when org-indent-mode
 339     (setq org-indent-modified-headline-flag
 340           (org-with-wide-buffer
 341            (goto-char beg)
 342            (save-match-data
 343              (or (and (org-at-heading-p) (< beg (match-end 0)))
 344                  (re-search-forward
 345                   (org-with-limited-levels org-outline-regexp-bol) end t)))))))
 346
 347 (defun org-indent-refresh-maybe (beg end _)
 348   "Refresh indentation properties in an adequate portion of buffer.
 349 BEG and END are the positions of the beginning and end of the
 350 range of inserted text.  DUMMY is an unused argument.
 351
 352 This function is meant to be called by `after-change-functions'."
 353   (when org-indent-mode
 354     (save-match-data
 355       ;; If a headline was modified or inserted, set properties until
 356       ;; next headline.
 357       (org-with-wide-buffer
 358        (if (or org-indent-modified-headline-flag
 359                (save-excursion
 360                  (goto-char beg)
 361                  (beginning-of-line)
 362                  (re-search-forward
 363                   (org-with-limited-levels org-outline-regexp-bol) end t)))
 364            (let ((end (save-excursion
 365                         (goto-char end)
 366                         (org-with-limited-levels (outline-next-heading))
 367                         (point))))
 368              (setq org-indent-modified-headline-flag nil)
 369              (org-indent-add-properties beg end))
 370          ;; Otherwise, only set properties on modified area.
 371          (org-indent-add-properties beg end))))))
 372
 373 (provide 'org-indent)
 374
 375 ;; Local variables:
 376 ;; generated-autoload-file: "org-loaddefs.el"
 377 ;; End:
 378
 379 ;;; org-indent.el ends here