lisp/org/org-indent.el

   1 ;;; org-indent.el --- Dynamic indentation for  Org-mode
   2 ;; Copyright (C) 2009-2012 Free Software Foundation, Inc.
   3 ;;
   4 ;; Author: Carsten Dominik <carsten at orgmode dot org>
   5 ;; Keywords: outlines, hypermedia, calendar, wp
   6 ;; Homepage: http://orgmode.org
   7 ;;
   8 ;; This file is part of GNU Emacs.
   9 ;;
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14 ;;
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19 ;;
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22 ;;
  23 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  24 ;;
  25 ;;; Commentary:
  26
  27 ;; This is an implementation of dynamic virtual indentation.  It works
  28 ;; by adding text properties to a buffer to make sure lines are
  29 ;; indented according to outline structure.
  30 ;;
  31 ;; The process is synchronous, toggled at every buffer modification.
  32 ;; Though, the initialization (indentation of text already in the
  33 ;; buffer), which can take a few seconds in large buffers, happens on
  34 ;; idle time.
  35 ;;
  36 ;;; Code:
  37
  38 (require 'org-macs)
  39 (require 'org-compat)
  40 (require 'org)
  41
  42 (eval-when-compile
  43   (require 'cl))
  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
  49 (defgroup org-indent nil
  50   "Options concerning dynamic virtual outline indentation."
  51   :tag "Org Indent"
  52   :group 'org)
  53
  54 (defconst org-indent-max 40
  55   "Maximum indentation in characters.")
  56 (defconst org-indent-max-levels 20
  57   "Maximum added level through virtual indentation, in characters.
  58
  59 It is computed by multiplying `org-indent-indentation-per-level'
  60 minus one by actual level of the headline minus one.")
  61
  62 (defvar org-indent-strings nil
  63   "Vector with all indentation strings.
  64 It will be set in `org-indent-initialize'.")
  65 (defvar org-indent-stars nil
  66   "Vector with all indentation star strings.
  67 It will be set in `org-indent-initialize'.")
  68 (defvar org-indent-inlinetask-first-star (org-add-props "*" '(face org-warning))
  69   "First star of inline tasks, with correct face.")
  70 (defvar org-indent-agent-timer nil
  71   "Timer running the initialize agent.")
  72 (defvar org-indent-agentized-buffers nil
  73   "List of buffers watched by the initialize agent.")
  74 (defvar org-indent-agent-resume-timer nil
  75   "Timer to reschedule agent after switching to other idle processes.")
  76 (defvar org-indent-agent-active-delay '(0 2 0)
  77   "Time to run agent before switching to other idle processes.
  78 Delay used when the buffer to initialize is current.")
  79 (defvar org-indent-agent-passive-delay '(0 0 400000)
  80   "Time to run agent before switching to other idle processes.
  81 Delay used when the buffer to initialize isn't current.")
  82 (defvar org-indent-agent-resume-delay '(0 0 100000)
  83   "Minimal time for other idle processes before switching back to agent.")
  84 (defvar org-indent-initial-marker nil
  85   "Position of initialization before interrupt.
  86 This is used locally in each buffer being initialized.")
  87 (defvar org-hide-leading-stars-before-indent-mode nil
  88   "Used locally.")
  89 (defvar org-indent-modified-headline-flag nil
  90   "Non-nil means the last deletion operated on an headline.
  91 It is modified by `org-indent-notify-modified-headline'.")
  92
  93
  94 (defcustom org-indent-boundary-char ?\   ; comment to protect space char
  95   "The end of the virtual indentation strings, a single-character string.
  96 The default is just a space, but if you wish, you can use \"|\" or so.
  97 This can be useful on a terminal window - under a windowing system,
  98 it may be prettier to customize the org-indent face."
  99   :group 'org-indent
 100   :set (lambda (var val)
 101          (set var val)
 102          (and org-indent-strings (org-indent-initialize)))
 103   :type 'character)
 104
 105 (defcustom org-indent-mode-turns-off-org-adapt-indentation t
 106   "Non-nil means setting the variable `org-indent-mode' will \
 107 turn off indentation adaptation.
 108 For details see the variable `org-adapt-indentation'."
 109   :group 'org-indent
 110   :type 'boolean)
 111
 112 (defcustom org-indent-mode-turns-on-hiding-stars t
 113   "Non-nil means setting the variable `org-indent-mode' will \
 114 turn on `org-hide-leading-stars'."
 115   :group 'org-indent
 116   :type 'boolean)
 117
 118 (defcustom org-indent-indentation-per-level 2
 119   "Indentation per level in number of characters."
 120   :group 'org-indent
 121   :type 'integer)
 122
 123 (defface org-indent
 124   (org-compatible-face nil nil)
 125   "Face for outline indentation.
 126 The default is to make it look like whitespace.  But you may find it
 127 useful to make it ever so slightly different."
 128   :group 'org-faces)
 129
 130 (defun org-indent-initialize ()
 131   "Initialize the indentation strings."
 132   (setq org-indent-strings (make-vector (1+ org-indent-max) nil))
 133   (setq org-indent-stars (make-vector (1+ org-indent-max) nil))
 134   (aset org-indent-strings 0 nil)
 135   (aset org-indent-stars 0 nil)
 136   (loop for i from 1 to org-indent-max do
 137         (aset org-indent-strings i
 138               (org-add-props
 139                   (concat (make-string (1- i) ?\ )
 140                           (char-to-string org-indent-boundary-char))
 141                   nil 'face 'org-indent)))
 142   (loop for i from 1 to org-indent-max-levels do
 143         (aset org-indent-stars i
 144               (org-add-props (make-string i ?*)
 145                   nil 'face 'org-hide))))
 146
 147 (defsubst org-indent-remove-properties (beg end)
 148   "Remove indentations between BEG and END."
 149   (with-silent-modifications
 150     (remove-text-properties beg end '(line-prefix nil wrap-prefix nil))))
 151
 152 ;;;###autoload
 153 (define-minor-mode org-indent-mode
 154   "When active, indent text according to outline structure.
 155
 156 Internally this works by adding `line-prefix' and `wrap-prefix'
 157 properties, after each buffer modification, on the modified zone.
 158
 159 The process is synchronous.  Though, initial indentation of
 160 buffer, which can take a few seconds on large buffers, is done
 161 during idle time." nil " Ind" nil
 162   (cond
 163    ((org-bound-and-true-p org-inhibit-startup)
 164     (setq org-indent-mode nil))
 165    ((and org-indent-mode (featurep 'xemacs))
 166     (message "org-indent-mode does not work in XEmacs - refusing to turn it on")
 167     (setq org-indent-mode nil))
 168    ((and org-indent-mode
 169          (not (org-version-check "23.1.50" "Org Indent mode" :predicate)))
 170     (message "org-indent-mode can crash Emacs 23.1 - refusing to turn it on!")
 171     (ding)
 172     (sit-for 1)
 173     (setq org-indent-mode nil))
 174    (org-indent-mode
 175     ;; mode was turned on.
 176     (org-set-local 'indent-tabs-mode nil)
 177     (or org-indent-strings (org-indent-initialize))
 178     (org-set-local 'org-indent-initial-marker (copy-marker 1))
 179     (when org-indent-mode-turns-off-org-adapt-indentation
 180       (org-set-local 'org-adapt-indentation nil))
 181     (when org-indent-mode-turns-on-hiding-stars
 182       (org-set-local 'org-hide-leading-stars-before-indent-mode
 183                      org-hide-leading-stars)
 184       (org-set-local 'org-hide-leading-stars t))
 185     (make-local-variable 'buffer-substring-filters)
 186     (add-to-list 'buffer-substring-filters
 187                  'org-indent-remove-properties-from-string)
 188     (org-add-hook 'after-change-functions 'org-indent-refresh-maybe nil 'local)
 189     (org-add-hook 'before-change-functions
 190                   'org-indent-notify-modified-headline nil 'local)
 191     (and font-lock-mode (org-restart-font-lock))
 192     (org-indent-remove-properties (point-min) (point-max))
 193     ;; Submit current buffer to initialize agent.  If it's the first
 194     ;; buffer submitted, also start the agent.  Current buffer is
 195     ;; pushed in both cases to avoid a race condition.
 196     (if org-indent-agentized-buffers
 197         (push (current-buffer) org-indent-agentized-buffers)
 198       (push (current-buffer) org-indent-agentized-buffers)
 199       (setq org-indent-agent-timer
 200             (run-with-idle-timer 0.2 t #'org-indent-initialize-agent))))
 201    (t
 202     ;; mode was turned off (or we refused to turn it on)
 203     (kill-local-variable 'org-adapt-indentation)
 204     (setq org-indent-agentized-buffers
 205           (delq (current-buffer) org-indent-agentized-buffers))
 206     (when (markerp org-indent-initial-marker)
 207       (set-marker org-indent-initial-marker nil))
 208     (when (boundp 'org-hide-leading-stars-before-indent-mode)
 209       (org-set-local 'org-hide-leading-stars
 210                      org-hide-leading-stars-before-indent-mode))
 211     (setq buffer-substring-filters
 212           (delq 'org-indent-remove-properties-from-string
 213                 buffer-substring-filters))
 214     (remove-hook 'after-change-functions 'org-indent-refresh-maybe 'local)
 215     (remove-hook 'before-change-functions
 216                  'org-indent-notify-modified-headline 'local)
 217     (org-with-wide-buffer
 218      (org-indent-remove-properties (point-min) (point-max)))
 219     (and font-lock-mode (org-restart-font-lock))
 220     (redraw-display))))
 221
 222 (defun org-indent-indent-buffer ()
 223   "Add indentation properties to the accessible part of the buffer."
 224   (interactive)
 225   (if (not (eq major-mode 'org-mode))
 226       (error "Not in Org mode")
 227     (message "Setting buffer indentation. It may take a few seconds...")
 228     (org-indent-remove-properties (point-min) (point-max))
 229     (org-indent-add-properties (point-min) (point-max))
 230     (message "Indentation of buffer set.")))
 231
 232 (defun org-indent-remove-properties-from-string (string)
 233   "Remove indentation properties from STRING."
 234   (remove-text-properties 0 (length string)
 235                           '(line-prefix nil wrap-prefix nil) string)
 236   string)
 237
 238 (defun org-indent-initialize-agent ()
 239   "Start or resume current buffer initialization.
 240 Only buffers in `org-indent-agentized-buffers' trigger an action.
 241 When no more buffer is being watched, the agent suppress itself."
 242   (when org-indent-agent-resume-timer
 243     (cancel-timer org-indent-agent-resume-timer))
 244   (setq org-indent-agentized-buffers
 245         (org-remove-if-not #'buffer-live-p org-indent-agentized-buffers))
 246   (cond
 247    ;; Job done:  kill agent.
 248    ((not org-indent-agentized-buffers) (cancel-timer org-indent-agent-timer))
 249    ;; Current buffer is agentized: start/resume initialization
 250    ;; somewhat aggressively.
 251    ((memq (current-buffer) org-indent-agentized-buffers)
 252     (org-indent-initialize-buffer (current-buffer)
 253                                   org-indent-agent-active-delay))
 254    ;; Else, start/resume initialization of the last agentized buffer,
 255    ;; softly.
 256    (t (org-indent-initialize-buffer (car org-indent-agentized-buffers)
 257                                     org-indent-agent-passive-delay))))
 258
 259 (defun org-indent-initialize-buffer (buffer delay)
 260   "Set virtual indentation for the buffer BUFFER, asynchronously.
 261 Give hand to other idle processes if it takes longer than DELAY,
 262 a time value."
 263   (with-current-buffer buffer
 264     (when org-indent-mode
 265       (org-with-wide-buffer
 266        (let ((interruptp
 267               ;; Always nil unless interrupted.
 268               (catch 'interrupt
 269                 (and org-indent-initial-marker
 270                      (marker-position org-indent-initial-marker)
 271                      (org-indent-add-properties org-indent-initial-marker
 272                                                 (point-max)
 273                                                 delay)
 274                      nil))))
 275          (move-marker org-indent-initial-marker interruptp)
 276          ;; Job is complete: un-agentize buffer.
 277          (unless interruptp
 278            (setq org-indent-agentized-buffers
 279                  (delq buffer org-indent-agentized-buffers))))))))
 280
 281 (defsubst org-indent-set-line-properties (l w h)
 282   "Set prefix properties on current line an move to next one.
 283
 284 Prefix properties `line-prefix' and `wrap-prefix' in current line
 285 are set to, respectively, length L and W.
 286
 287 If H is non-nil, `line-prefix' will be starred.  If H is
 288 `inline', the first star will have `org-warning' face.
 289
 290 Assume point is at beginning of line."
 291   (let ((line (cond
 292                ((eq 'inline h)
 293                 (let ((stars (aref org-indent-stars
 294                                    (min l org-indent-max-levels))))
 295                   (and stars
 296                        (concat org-indent-inlinetask-first-star
 297                                (substring stars 1)))))
 298                (h (aref org-indent-stars
 299                         (min l org-indent-max-levels)))
 300                (t (aref org-indent-strings
 301                         (min l org-indent-max)))))
 302         (wrap (aref org-indent-strings (min w org-indent-max))))
 303     ;; Add properties down to the next line to indent empty lines.
 304     (add-text-properties (point) (min (1+ (point-at-eol)) (point-max))
 305                          `(line-prefix ,line wrap-prefix ,wrap)))
 306   (forward-line 1))
 307
 308 (defun org-indent-add-properties (beg end &optional delay)
 309   "Add indentation properties between BEG and END.
 310
 311 When DELAY is non-nil, it must be a time value.  In that case,
 312 the process is asynchronous and can be interrupted, either by
 313 user request, or after DELAY.  This is done by throwing the
 314 `interrupt' tag along with the buffer position where the process
 315 stopped."
 316   (save-match-data
 317     (org-with-wide-buffer
 318      (goto-char beg)
 319      (beginning-of-line)
 320      ;; 1. Initialize prefix at BEG.  This is done by storing two
 321      ;;    variables: INLINE-PF and PF, representing respectively
 322      ;;    length of current `line-prefix' when line is inside an
 323      ;;    inline task or not.
 324      (let* ((case-fold-search t)
 325             (limited-re (org-get-limited-outline-regexp))
 326             (added-ind-per-lvl (1- org-indent-indentation-per-level))
 327             (pf (save-excursion
 328                   (and (ignore-errors (let ((outline-regexp limited-re))
 329                                         (org-back-to-heading t)))
 330                        (+ (* org-indent-indentation-per-level
 331                              (- (match-end 0) (match-beginning 0) 2)) 2))))
 332             (pf-inline (and (featurep 'org-inlinetask)
 333                             (org-inlinetask-in-task-p)
 334                             (+ (* org-indent-indentation-per-level
 335                                   (1- (org-inlinetask-get-task-level))) 2)))
 336             (time-limit (and delay (time-add (current-time) delay))))
 337        ;; 2. For each line, set `line-prefix' and `wrap-prefix'
 338        ;;    properties depending on the type of line (headline,
 339        ;;    inline task, item or other).
 340        (with-silent-modifications
 341          (while (and (<= (point) end) (not (eobp)))
 342            (cond
 343             ;; When in asynchronous mode, check if interrupt is
 344             ;; required.
 345             ((and delay (input-pending-p)) (throw 'interrupt (point)))
 346             ;; In asynchronous mode, take a break of
 347             ;; `org-indent-agent-resume-delay' every DELAY to avoid
 348             ;; blocking any other idle timer or process output.
 349             ((and delay (time-less-p time-limit (current-time)))
 350              (setq org-indent-agent-resume-timer
 351                    (run-with-idle-timer
 352                     (time-add (current-idle-time)
 353                               org-indent-agent-resume-delay)
 354                     nil #'org-indent-initialize-agent))
 355              (throw 'interrupt (point)))
 356             ;; Headline or inline task.
 357             ((looking-at org-outline-regexp)
 358              (let* ((nstars (- (match-end 0) (match-beginning 0) 1))
 359                     (line (* added-ind-per-lvl (1- nstars)))
 360                     (wrap (+ line (1+ nstars))))
 361                (cond
 362                 ;; Headline: new value for PF.
 363                 ((looking-at limited-re)
 364                  (org-indent-set-line-properties line wrap t)
 365                  (setq pf wrap))
 366                 ;; End of inline task: PF-INLINE is now nil.
 367                 ((looking-at "\\*+ end[ \t]*$")
 368                  (org-indent-set-line-properties line wrap 'inline)
 369                  (setq pf-inline nil))
 370                 ;; Start of inline task.  Determine if it contains
 371                 ;; text, or if it is only one line long.  Set
 372                 ;; PF-INLINE accordingly.
 373                 (t (org-indent-set-line-properties line wrap 'inline)
 374                    (setq pf-inline (and (org-inlinetask-in-task-p) wrap))))))
 375             ;; List item: `wrap-prefix' is set where body starts.
 376             ((org-at-item-p)
 377              (let* ((line (or pf-inline pf 0))
 378                     (wrap (+ (org-list-item-body-column (point)) line)))
 379                (org-indent-set-line-properties line wrap nil)))
 380             ;; Normal line: use PF-INLINE, PF or nil as prefixes.
 381             (t (let* ((line (or pf-inline pf 0))
 382                       (wrap (+ line (org-get-indentation))))
 383                  (org-indent-set-line-properties line wrap nil))))))))))
 384
 385 (defun org-indent-notify-modified-headline (beg end)
 386   "Set `org-indent-modified-headline-flag' depending on context.
 387
 388 BEG and END are the positions of the beginning and end of the
 389 range of deleted text.
 390
 391 This function is meant to be called by `before-change-functions'.
 392 Flag will be non-nil if command is going to modify or delete an
 393 headline."
 394   (when org-indent-mode
 395     (setq org-indent-modified-headline-flag
 396           (save-excursion
 397             (goto-char beg)
 398             (save-match-data
 399               (or (and (org-at-heading-p) (< beg (match-end 0)))
 400                   (re-search-forward org-outline-regexp-bol end t)))))))
 401
 402 (defun org-indent-refresh-maybe (beg end dummy)
 403   "Refresh indentation properties in an adequate portion of buffer.
 404 BEG and END are the positions of the beginning and end of the
 405 range of inserted text.  DUMMY is an unused argument.
 406
 407 This function is meant to be called by `after-change-functions'."
 408   (when org-indent-mode
 409     (save-match-data
 410       ;; If an headline was modified or inserted, set properties until
 411       ;; next headline.
 412       (if (or org-indent-modified-headline-flag
 413               (save-excursion
 414                 (goto-char beg)
 415                 (re-search-forward org-outline-regexp-bol end t)))
 416         (let ((end (save-excursion
 417                      (goto-char end)
 418                      (org-with-limited-levels (outline-next-heading))
 419                      (point))))
 420           (setq org-indent-modified-headline-flag nil)
 421           (org-indent-add-properties beg end))
 422         ;; Otherwise, only set properties on modified area.
 423         (org-indent-add-properties beg end)))))
 424
 425 (provide 'org-indent)
 426
 427 ;;; org-indent.el ends here