lisp/outline.el

   1 ;;; outline.el --- outline mode commands for Emacs
   2
   3 ;; Copyright (C) 1986, 1993-1995, 1997, 2000-2011
   4 ;;   Free Software Foundation, Inc.
   5
   6 ;; Maintainer: FSF
   7 ;; Keywords: outlines
   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 ;;; Commentary:
  25
  26 ;; This package is a major mode for editing outline-format documents.
  27 ;; An outline can be `abstracted' to show headers at any given level,
  28 ;; with all stuff below hidden.  See the Emacs manual for details.
  29
  30 ;;; Todo:
  31
  32 ;; - subtree-terminators
  33 ;; - better handle comments before function bodies (i.e. heading)
  34 ;; - don't bother hiding whitespace
  35
  36 ;;; Code:
  37
  38 (defvar font-lock-warning-face)
  39
  40
  41 (defgroup outlines nil
  42   "Support for hierarchical outlining."
  43   :prefix "outline-"
  44   :group 'wp)
  45
  46 (defcustom outline-regexp "[*\^L]+"
  47   "Regular expression to match the beginning of a heading.
  48 Any line whose beginning matches this regexp is considered to start a heading.
  49 Note that Outline mode only checks this regexp at the start of a line,
  50 so the regexp need not (and usually does not) start with `^'.
  51 The recommended way to set this is with a Local Variables: list
  52 in the file it applies to.  See also `outline-heading-end-regexp'."
  53   :type 'regexp
  54   :group 'outlines)
  55 ;;;###autoload(put 'outline-regexp 'safe-local-variable 'stringp)
  56
  57 (defcustom outline-heading-end-regexp "\n"
  58   "Regular expression to match the end of a heading line.
  59 You can assume that point is at the beginning of a heading when this
  60 regexp is searched for.  The heading ends at the end of the match.
  61 The recommended way to set this is with a `Local Variables:' list
  62 in the file it applies to."
  63   :type 'regexp
  64   :group 'outlines)
  65 ;;;###autoload(put 'outline-heading-end-regexp 'safe-local-variable 'stringp)
  66
  67 (defvar outline-mode-prefix-map
  68   (let ((map (make-sparse-keymap)))
  69     (define-key map "@" 'outline-mark-subtree)
  70     (define-key map "\C-n" 'outline-next-visible-heading)
  71     (define-key map "\C-p" 'outline-previous-visible-heading)
  72     (define-key map "\C-i" 'show-children)
  73     (define-key map "\C-s" 'show-subtree)
  74     (define-key map "\C-d" 'hide-subtree)
  75     (define-key map "\C-u" 'outline-up-heading)
  76     (define-key map "\C-f" 'outline-forward-same-level)
  77     (define-key map "\C-b" 'outline-backward-same-level)
  78     (define-key map "\C-t" 'hide-body)
  79     (define-key map "\C-a" 'show-all)
  80     (define-key map "\C-c" 'hide-entry)
  81     (define-key map "\C-e" 'show-entry)
  82     (define-key map "\C-l" 'hide-leaves)
  83     (define-key map "\C-k" 'show-branches)
  84     (define-key map "\C-q" 'hide-sublevels)
  85     (define-key map "\C-o" 'hide-other)
  86     (define-key map "\C-^" 'outline-move-subtree-up)
  87     (define-key map "\C-v" 'outline-move-subtree-down)
  88     (define-key map [(control ?<)] 'outline-promote)
  89     (define-key map [(control ?>)] 'outline-demote)
  90     (define-key map "\C-m" 'outline-insert-heading)
  91     ;; Where to bind outline-cycle ?
  92     map))
  93
  94 (defvar outline-mode-menu-bar-map
  95   (let ((map (make-sparse-keymap)))
  96
  97     (define-key map [hide] (cons "Hide" (make-sparse-keymap "Hide")))
  98
  99     (define-key map [hide hide-other]
 100       '(menu-item "Hide Other" hide-other
 101                   :help "Hide everything except current body and parent and top-level headings"))
 102     (define-key map [hide hide-sublevels]
 103       '(menu-item "Hide Sublevels" hide-sublevels
 104                   :help "Hide everything but the top LEVELS levels of headers, in whole buffer"))
 105     (define-key map [hide hide-subtree]
 106       '(menu-item "Hide Subtree" hide-subtree
 107                   :help "Hide everything after this heading at deeper levels"))
 108     (define-key map [hide hide-entry]
 109       '(menu-item "Hide Entry" hide-entry
 110                   :help "Hide the body directly following this heading"))
 111     (define-key map [hide hide-body]
 112       '(menu-item "Hide Body" hide-body
 113                   :help "Hide all body lines in buffer, leaving all headings visible"))
 114     (define-key map [hide hide-leaves]
 115       '(menu-item "Hide Leaves" hide-leaves
 116                   :help "Hide the body after this heading and at deeper levels"))
 117
 118     (define-key map [show] (cons "Show" (make-sparse-keymap "Show")))
 119
 120     (define-key map [show show-subtree]
 121       '(menu-item "Show Subtree" show-subtree
 122                   :help "Show everything after this heading at deeper levels"))
 123     (define-key map [show show-children]
 124       '(menu-item "Show Children" show-children
 125                   :help "Show all direct subheadings of this heading"))
 126     (define-key map [show show-branches]
 127       '(menu-item "Show Branches" show-branches
 128                   :help "Show all subheadings of this heading, but not their bodies"))
 129     (define-key map [show show-entry]
 130       '(menu-item "Show Entry" show-entry
 131                   :help "Show the body directly following this heading"))
 132     (define-key map [show show-all]
 133       '(menu-item "Show All" show-all
 134                   :help "Show all of the text in the buffer"))
 135
 136     (define-key map [headings]
 137       (cons "Headings" (make-sparse-keymap "Headings")))
 138
 139     (define-key map [headings demote-subtree]
 140       '(menu-item "Demote subtree" outline-demote
 141                   :help "Demote headings lower down the tree"))
 142     (define-key map [headings promote-subtree]
 143       '(menu-item "Promote subtree" outline-promote
 144                   :help "Promote headings higher up the tree"))
 145     (define-key map [headings move-subtree-down]
 146       '(menu-item "Move subtree down" outline-move-subtree-down
 147                   :help "Move the currrent subtree down past arg headlines of the same level"))
 148     (define-key map [headings move-subtree-up]
 149       '(menu-item "Move subtree up" outline-move-subtree-up
 150                   :help "Move the currrent subtree up past arg headlines of the same level"))
 151     (define-key map [headings copy]
 152       '(menu-item "Copy to kill ring" outline-headers-as-kill
 153                   :enable mark-active
 154                   :help "Save the visible outline headers in region at the start of the kill ring"))
 155     (define-key map [headings outline-insert-heading]
 156
 157       '(menu-item "New heading" outline-insert-heading
 158                   :help "Insert a new heading at same depth at point"))
 159     (define-key map [headings outline-backward-same-level]
 160
 161       '(menu-item "Previous Same Level" outline-backward-same-level
 162                   :help "Move backward to the arg'th subheading at same level as this one."))
 163     (define-key map [headings outline-forward-same-level]
 164
 165       '(menu-item "Next Same Level" outline-forward-same-level
 166                   :help "Move forward to the arg'th subheading at same level as this one"))
 167     (define-key map [headings outline-previous-visible-heading]
 168
 169       '(menu-item "Previous" outline-previous-visible-heading
 170                   :help "Move to the previous heading line"))
 171     (define-key map [headings outline-next-visible-heading]
 172
 173       '(menu-item "Next" outline-next-visible-heading
 174                   :help "Move to the next visible heading line"))
 175     (define-key map [headings outline-up-heading]
 176
 177       '(menu-item "Up" outline-up-heading
 178                   :help "Move to the visible heading line of which the present line is a subheading"))
 179     map))
 180
 181 (defvar outline-minor-mode-menu-bar-map
 182   (let ((map (make-sparse-keymap)))
 183     (define-key map [outline]
 184       (cons "Outline"
 185             (nconc (make-sparse-keymap "Outline")
 186                    ;; Remove extra separator
 187                    (cdr
 188                     ;; Flatten the major mode's menus into a single menu.
 189                     (apply 'append
 190                            (mapcar (lambda (x)
 191                                      (if (consp x)
 192                                          ;; Add a separator between each
 193                                          ;; part of the unified menu.
 194                                          (cons '(--- "---") (cdr x))))
 195                                    outline-mode-menu-bar-map))))))
 196     map))
 197
 198
 199 (defvar outline-mode-map
 200   (let ((map (make-sparse-keymap)))
 201     (define-key map "\C-c" outline-mode-prefix-map)
 202     (define-key map [menu-bar] outline-mode-menu-bar-map)
 203     map))
 204
 205 (defvar outline-font-lock-keywords
 206   '(;;
 207     ;; Highlight headings according to the level.
 208     (eval . (list (concat "^\\(?:" outline-regexp "\\).+")
 209                   0 '(outline-font-lock-face) nil t)))
 210   "Additional expressions to highlight in Outline mode.")
 211
 212 (defface outline-1
 213   '((t :inherit font-lock-function-name-face))
 214   "Level 1."
 215   :group 'outlines)
 216
 217 (defface outline-2
 218   '((t :inherit font-lock-variable-name-face))
 219   "Level 2."
 220   :group 'outlines)
 221
 222 (defface outline-3
 223   '((t :inherit font-lock-keyword-face))
 224   "Level 3."
 225   :group 'outlines)
 226
 227 (defface outline-4
 228   '((t :inherit font-lock-comment-face))
 229   "Level 4."
 230   :group 'outlines)
 231
 232 (defface outline-5
 233   '((t :inherit font-lock-type-face))
 234   "Level 5."
 235   :group 'outlines)
 236
 237 (defface outline-6
 238   '((t :inherit font-lock-constant-face))
 239   "Level 6."
 240   :group 'outlines)
 241
 242 (defface outline-7
 243   '((t :inherit font-lock-builtin-face))
 244   "Level 7."
 245   :group 'outlines)
 246
 247 (defface outline-8
 248   '((t :inherit font-lock-string-face))
 249   "Level 8."
 250   :group 'outlines)
 251
 252 (defvar outline-font-lock-faces
 253   [outline-1 outline-2 outline-3 outline-4
 254    outline-5 outline-6 outline-7 outline-8])
 255
 256 ;; (defvar outline-font-lock-levels nil)
 257 ;; (make-variable-buffer-local 'outline-font-lock-levels)
 258
 259 (defun outline-font-lock-face ()
 260   ;; (save-excursion
 261   ;;   (outline-back-to-heading t)
 262   ;;   (let* ((count 0)
 263   ;;       (start-level (funcall outline-level))
 264   ;;       (level start-level)
 265   ;;       face-level)
 266   ;;     (while (not (setq face-level
 267   ;;                    (if (or (bobp) (eq level 1)) 0
 268   ;;                      (cdr (assq level outline-font-lock-levels)))))
 269   ;;    (outline-up-heading 1 t)
 270   ;;    (setq count (1+ count))
 271   ;;    (setq level (funcall outline-level)))
 272   ;;     ;; Remember for later.
 273   ;;     (unless (zerop count)
 274   ;;    (setq face-level (+ face-level count))
 275   ;;    (push (cons start-level face-level) outline-font-lock-levels))
 276   ;;     (condition-case nil
 277   ;;      (aref outline-font-lock-faces face-level)
 278   ;;    (error font-lock-warning-face))))
 279   (save-excursion
 280     (goto-char (match-beginning 0))
 281     (looking-at outline-regexp)
 282     (aref outline-font-lock-faces (% (1- (funcall outline-level)) (length outline-font-lock-faces)))))
 283
 284 (defvar outline-view-change-hook nil
 285   "Normal hook to be run after outline visibility changes.")
 286
 287 (defvar outline-mode-hook nil
 288   "*This hook is run when outline mode starts.")
 289
 290 (defvar outline-blank-line nil
 291   "*Non-nil means to leave unhidden blank line before heading.")
 292
 293 ;;;###autoload
 294 (define-derived-mode outline-mode text-mode "Outline"
 295   "Set major mode for editing outlines with selective display.
 296 Headings are lines which start with asterisks: one for major headings,
 297 two for subheadings, etc.  Lines not starting with asterisks are body lines.
 298
 299 Body text or subheadings under a heading can be made temporarily
 300 invisible, or visible again.  Invisible lines are attached to the end
 301 of the heading, so they move with it, if the line is killed and yanked
 302 back.  A heading with text hidden under it is marked with an ellipsis (...).
 303
 304 Commands:\\<outline-mode-map>
 305 \\[outline-next-visible-heading]   outline-next-visible-heading      move by visible headings
 306 \\[outline-previous-visible-heading]   outline-previous-visible-heading
 307 \\[outline-forward-same-level]   outline-forward-same-level        similar but skip subheadings
 308 \\[outline-backward-same-level]   outline-backward-same-level
 309 \\[outline-up-heading]   outline-up-heading                 move from subheading to heading
 310
 311 \\[hide-body]   make all text invisible (not headings).
 312 \\[show-all]    make everything in buffer visible.
 313 \\[hide-sublevels]  make only the first N levels of headers visible.
 314
 315 The remaining commands are used when point is on a heading line.
 316 They apply to some of the body or subheadings of that heading.
 317 \\[hide-subtree]   hide-subtree make body and subheadings invisible.
 318 \\[show-subtree]   show-subtree make body and subheadings visible.
 319 \\[show-children]   show-children       make direct subheadings visible.
 320                  No effect on body, or subheadings 2 or more levels down.
 321                  With arg N, affects subheadings N levels down.
 322 \\[hide-entry]     make immediately following body invisible.
 323 \\[show-entry]     make it visible.
 324 \\[hide-leaves]    make body under heading and under its subheadings invisible.
 325                      The subheadings remain visible.
 326 \\[show-branches]  make all subheadings at all levels visible.
 327
 328 The variable `outline-regexp' can be changed to control what is a heading.
 329 A line is a heading if `outline-regexp' matches something at the
 330 beginning of the line.  The longer the match, the deeper the level.
 331
 332 Turning on outline mode calls the value of `text-mode-hook' and then of
 333 `outline-mode-hook', if they are non-nil."
 334   (make-local-variable 'line-move-ignore-invisible)
 335   (setq line-move-ignore-invisible t)
 336   ;; Cause use of ellipses for invisible text.
 337   (add-to-invisibility-spec '(outline . t))
 338   (set (make-local-variable 'paragraph-start)
 339        (concat paragraph-start "\\|\\(?:" outline-regexp "\\)"))
 340   ;; Inhibit auto-filling of header lines.
 341   (set (make-local-variable 'auto-fill-inhibit-regexp) outline-regexp)
 342   (set (make-local-variable 'paragraph-separate)
 343        (concat paragraph-separate "\\|\\(?:" outline-regexp "\\)"))
 344   (set (make-local-variable 'font-lock-defaults)
 345        '(outline-font-lock-keywords t nil nil backward-paragraph))
 346   (setq imenu-generic-expression
 347         (list (list nil (concat "^\\(?:" outline-regexp "\\).*$") 0)))
 348   (add-hook 'change-major-mode-hook 'show-all nil t))
 349
 350 (defcustom outline-minor-mode-prefix "\C-c@"
 351   "Prefix key to use for Outline commands in Outline minor mode.
 352 The value of this variable is checked as part of loading Outline mode.
 353 After that, changing the prefix key requires manipulating keymaps."
 354   :type 'string
 355   :group 'outlines)
 356
 357 ;;;###autoload
 358 (define-minor-mode outline-minor-mode
 359   "Toggle Outline minor mode.
 360 With arg, turn Outline minor mode on if arg is positive, off otherwise.
 361 See the command `outline-mode' for more information on this mode."
 362   nil " Outl" (list (cons [menu-bar] outline-minor-mode-menu-bar-map)
 363                     (cons outline-minor-mode-prefix outline-mode-prefix-map))
 364   :group 'outlines
 365   (if outline-minor-mode
 366       (progn
 367         ;; Turn off this mode if we change major modes.
 368         (add-hook 'change-major-mode-hook
 369                   (lambda () (outline-minor-mode -1))
 370                   nil t)
 371         (set (make-local-variable 'line-move-ignore-invisible) t)
 372         ;; Cause use of ellipses for invisible text.
 373         (add-to-invisibility-spec '(outline . t)))
 374     (setq line-move-ignore-invisible nil)
 375     ;; Cause use of ellipses for invisible text.
 376     (remove-from-invisibility-spec '(outline . t))
 377     ;; When turning off outline mode, get rid of any outline hiding.
 378     (show-all)))
 379 \f
 380 (defvar outline-level 'outline-level
 381   "*Function of no args to compute a header's nesting level in an outline.
 382 It can assume point is at the beginning of a header line and that the match
 383 data reflects the `outline-regexp'.")
 384 ;;;###autoload(put 'outline-level 'risky-local-variable t)
 385
 386 (defvar outline-heading-alist ()
 387   "Alist associating a heading for every possible level.
 388 Each entry is of the form (HEADING . LEVEL).
 389 This alist is used two ways: to find the heading corresponding to
 390 a given level and to find the level of a given heading.
 391 If a mode or document needs several sets of outline headings (for example
 392 numbered and unnumbered sections), list them set by set and sorted by level
 393 within each set.  For example in texinfo mode:
 394
 395      (setq outline-heading-alist
 396       '((\"@chapter\" . 2) (\"@section\" . 3) (\"@subsection\" . 4)
 397            (\"@subsubsection\" . 5)
 398         (\"@unnumbered\" . 2) (\"@unnumberedsec\" . 3)
 399            (\"@unnumberedsubsec\" . 4)  (\"@unnumberedsubsubsec\" . 5)
 400         (\"@appendix\" . 2) (\"@appendixsec\" . 3)...
 401            (\"@appendixsubsec\" . 4) (\"@appendixsubsubsec\" . 5) ..))
 402
 403 Instead of sorting the entries in each set, you can also separate the
 404 sets with nil.")
 405 (make-variable-buffer-local 'outline-heading-alist)
 406
 407 ;; This used to count columns rather than characters, but that made ^L
 408 ;; appear to be at level 2 instead of 1.  Columns would be better for
 409 ;; tab handling, but the default regexp doesn't use tabs, and anyone
 410 ;; who changes the regexp can also redefine the outline-level variable
 411 ;; as appropriate.
 412 (defun outline-level ()
 413   "Return the depth to which a statement is nested in the outline.
 414 Point must be at the beginning of a header line.
 415 This is actually either the level specified in `outline-heading-alist'
 416 or else the number of characters matched by `outline-regexp'."
 417   (or (cdr (assoc (match-string 0) outline-heading-alist))
 418       (- (match-end 0) (match-beginning 0))))
 419
 420 (defun outline-next-preface ()
 421   "Skip forward to just before the next heading line.
 422 If there's no following heading line, stop before the newline
 423 at the end of the buffer."
 424   (if (re-search-forward (concat "\n\\(?:" outline-regexp "\\)")
 425                          nil 'move)
 426       (goto-char (match-beginning 0)))
 427   (if (and (bolp) (or outline-blank-line (eobp)) (not (bobp)))
 428       (forward-char -1)))
 429
 430 (defun outline-next-heading ()
 431   "Move to the next (possibly invisible) heading line."
 432   (interactive)
 433   ;; Make sure we don't match the heading we're at.
 434   (if (and (bolp) (not (eobp))) (forward-char 1))
 435   (if (re-search-forward (concat "^\\(?:" outline-regexp "\\)")
 436                          nil 'move)
 437       (goto-char (match-beginning 0))))
 438
 439 (defun outline-previous-heading ()
 440   "Move to the previous (possibly invisible) heading line."
 441   (interactive)
 442   (re-search-backward (concat "^\\(?:" outline-regexp "\\)")
 443                       nil 'move))
 444
 445 (defsubst outline-invisible-p (&optional pos)
 446   "Non-nil if the character after point is invisible."
 447   (get-char-property (or pos (point)) 'invisible))
 448
 449 (defun outline-back-to-heading (&optional invisible-ok)
 450   "Move to previous heading line, or beg of this line if it's a heading.
 451 Only visible heading lines are considered, unless INVISIBLE-OK is non-nil."
 452   (beginning-of-line)
 453   (or (outline-on-heading-p invisible-ok)
 454       (let (found)
 455         (save-excursion
 456           (while (not found)
 457             (or (re-search-backward (concat "^\\(?:" outline-regexp "\\)")
 458                                     nil t)
 459                 (error "before first heading"))
 460             (setq found (and (or invisible-ok (not (outline-invisible-p)))
 461                              (point)))))
 462         (goto-char found)
 463         found)))
 464
 465 (defun outline-on-heading-p (&optional invisible-ok)
 466   "Return t if point is on a (visible) heading line.
 467 If INVISIBLE-OK is non-nil, an invisible heading line is ok too."
 468   (save-excursion
 469     (beginning-of-line)
 470     (and (bolp) (or invisible-ok (not (outline-invisible-p)))
 471          (looking-at outline-regexp))))
 472
 473 (defun outline-insert-heading ()
 474   "Insert a new heading at same depth at point."
 475   (interactive)
 476   (let ((head (save-excursion
 477                 (condition-case nil
 478                     (outline-back-to-heading)
 479                   (error (outline-next-heading)))
 480                 (if (eobp)
 481                     (or (caar outline-heading-alist) "")
 482                   (match-string 0)))))
 483     (unless (or (string-match "[ \t]\\'" head)
 484                 (not (string-match (concat "\\`\\(?:" outline-regexp "\\)")
 485                                    (concat head " "))))
 486       (setq head (concat head " ")))
 487     (unless (bolp) (end-of-line) (newline))
 488     (insert head)
 489     (unless (eolp)
 490       (save-excursion (newline-and-indent)))
 491     (run-hooks 'outline-insert-heading-hook)))
 492
 493 (defun outline-invent-heading (head up)
 494   (save-match-data
 495     ;; Let's try to invent one by repeating or deleting the last char.
 496     (let ((new-head (if up (substring head 0 -1)
 497                       (concat head (substring head -1)))))
 498       (if (string-match (concat "\\`\\(?:" outline-regexp "\\)")
 499                         new-head)
 500           ;; Why bother checking that it is indeed higher/lower level ?
 501           new-head
 502         ;; Didn't work, so ask what to do.
 503         (read-string (format "%s heading for `%s': "
 504                              (if up "Parent" "Demoted") head)
 505                      head nil nil t)))))
 506
 507 (defun outline-promote (&optional which)
 508   "Promote headings higher up the tree.
 509 If transient-mark-mode is on, and mark is active, promote headings in
 510 the region (from a Lisp program, pass `region' for WHICH).  Otherwise:
 511 without prefix argument, promote current heading and all headings in the
 512 subtree (from a Lisp program, pass `subtree' for WHICH); with prefix
 513 argument, promote just the current heading (from a Lisp program, pass
 514 nil for WHICH, or do not pass any argument)."
 515   (interactive
 516    (list (if (and transient-mark-mode mark-active) 'region
 517            (outline-back-to-heading)
 518            (if current-prefix-arg nil 'subtree))))
 519   (cond
 520    ((eq which 'region)
 521     (outline-map-region 'outline-promote (region-beginning) (region-end)))
 522    (which
 523     (outline-map-region 'outline-promote
 524                         (point)
 525                         (save-excursion (outline-get-next-sibling) (point))))
 526    (t
 527     (outline-back-to-heading t)
 528     (let* ((head (match-string-no-properties 0))
 529            (level (save-match-data (funcall outline-level)))
 530            (up-head (or (outline-head-from-level (1- level) head)
 531                         ;; Use the parent heading, if it is really
 532                         ;; one level less.
 533                         (save-excursion
 534                           (save-match-data
 535                             (outline-up-heading 1 t)
 536                             (and (= (1- level) (funcall outline-level))
 537                                  (match-string-no-properties 0))))
 538                         ;; Bummer!! There is no lower level heading.
 539                         (outline-invent-heading head 'up))))
 540
 541       (unless (rassoc level outline-heading-alist)
 542         (push (cons head level) outline-heading-alist))
 543
 544       (replace-match up-head nil t)))))
 545
 546 (defun outline-demote (&optional which)
 547   "Demote headings lower down the tree.
 548 If transient-mark-mode is on, and mark is active, demote headings in
 549 the region (from a Lisp program, pass `region' for WHICH).  Otherwise:
 550 without prefix argument, demote current heading and all headings in the
 551 subtree (from a Lisp program, pass `subtree' for WHICH); with prefix
 552 argument, demote just the current heading (from a Lisp program, pass
 553 nil for WHICH, or do not pass any argument)."
 554   (interactive
 555    (list (if (and transient-mark-mode mark-active) 'region
 556            (outline-back-to-heading)
 557            (if current-prefix-arg nil 'subtree))))
 558   (cond
 559    ((eq which 'region)
 560     (outline-map-region 'outline-demote (region-beginning) (region-end)))
 561    (which
 562     (outline-map-region 'outline-demote
 563                         (point)
 564                         (save-excursion (outline-get-next-sibling) (point))))
 565    (t
 566     (let* ((head (match-string-no-properties 0))
 567            (level (save-match-data (funcall outline-level)))
 568            (down-head
 569             (or (outline-head-from-level (1+ level) head)
 570                 (save-excursion
 571                   (save-match-data
 572                     (while (and (progn (outline-next-heading) (not (eobp)))
 573                                 (<= (funcall outline-level) level)))
 574                     (when (eobp)
 575                       ;; Try again from the beginning of the buffer.
 576                       (goto-char (point-min))
 577                       (while (and (progn (outline-next-heading) (not (eobp)))
 578                                   (<= (funcall outline-level) level))))
 579                     (unless (eobp)
 580                       (looking-at outline-regexp)
 581                       (match-string-no-properties 0))))
 582                 ;; Bummer!! There is no higher-level heading in the buffer.
 583                 (outline-invent-heading head nil))))
 584
 585       (unless (rassoc level outline-heading-alist)
 586         (push (cons head level) outline-heading-alist))
 587       (replace-match down-head nil t)))))
 588
 589 (defun outline-head-from-level (level head &optional alist)
 590   "Get new heading with level LEVEL from ALIST.
 591 If there are no such entries, return nil.
 592 ALIST defaults to `outline-heading-alist'.
 593 Similar to (car (rassoc LEVEL ALIST)).
 594 If there are several different entries with same new level, choose
 595 the one with the smallest distance to the association of HEAD in the alist.
 596 This makes it possible for promotion to work in modes with several
 597 independent sets of headings (numbered, unnumbered, appendix...)"
 598   (unless alist (setq alist outline-heading-alist))
 599   (let ((l (rassoc level alist))
 600         ll h hl l2 l2l)
 601     (cond
 602      ((null l) nil)
 603      ;; If there's no HEAD after L, any other entry for LEVEL after L
 604      ;; can't be much better than L.
 605      ((null (setq h (assoc head (setq ll (memq l alist))))) (car l))
 606      ;; If there's no other entry for LEVEL, just keep L.
 607      ((null (setq l2 (rassoc level (cdr ll)))) (car l))
 608      ;; Now we have L, L2, and H: see if L2 seems better than L.
 609      ;; If H is after L2, L2 is better.
 610      ((memq h (setq l2l (memq l2 (cdr ll))))
 611       (outline-head-from-level level head l2l))
 612      ;; Now we have H between L and L2.
 613      ;; If there's a separator between L and H, prefer L2.
 614      ((memq h (memq nil ll))
 615       (outline-head-from-level level head l2l))
 616      ;; If there's a separator between L2 and H, prefer L.
 617      ((memq l2 (memq nil (setq hl (memq h ll)))) (car l))
 618      ;; No separator between L and L2, check the distance.
 619      ((< (* 2 (length hl)) (+ (length ll) (length l2l)))
 620       (outline-head-from-level level head l2l))
 621      ;; If all else fails, just keep L.
 622      (t (car l)))))
 623
 624 (defun outline-map-region (fun beg end)
 625   "Call FUN for every heading between BEG and END.
 626 When FUN is called, point is at the beginning of the heading and
 627 the match data is set appropriately."
 628   (save-excursion
 629     (setq end (copy-marker end))
 630     (goto-char beg)
 631     (when (re-search-forward (concat "^\\(?:" outline-regexp "\\)") end t)
 632       (goto-char (match-beginning 0))
 633       (funcall fun)
 634       (while (and (progn
 635                     (outline-next-heading)
 636                     (< (point) end))
 637                   (not (eobp)))
 638         (funcall fun)))))
 639
 640 ;; Vertical tree motion
 641
 642 (defun outline-move-subtree-up (&optional arg)
 643   "Move the currrent subtree up past ARG headlines of the same level."
 644   (interactive "p")
 645   (outline-move-subtree-down (- arg)))
 646
 647 (defun outline-move-subtree-down (&optional arg)
 648   "Move the currrent subtree down past ARG headlines of the same level."
 649   (interactive "p")
 650   (let ((movfunc (if (> arg 0) 'outline-get-next-sibling
 651                    'outline-get-last-sibling))
 652         (ins-point (make-marker))
 653         (cnt (abs arg))
 654         beg end folded)
 655     ;; Select the tree
 656     (outline-back-to-heading)
 657     (setq beg (point))
 658     (save-match-data
 659       (save-excursion (outline-end-of-heading)
 660                       (setq folded (outline-invisible-p)))
 661       (outline-end-of-subtree))
 662     (if (= (char-after) ?\n) (forward-char 1))
 663     (setq end (point))
 664     ;; Find insertion point, with error handling
 665     (goto-char beg)
 666     (while (> cnt 0)
 667       (or (funcall movfunc)
 668           (progn (goto-char beg)
 669                  (error "Cannot move past superior level")))
 670       (setq cnt (1- cnt)))
 671     (if (> arg 0)
 672         ;; Moving forward - still need to move over subtree
 673         (progn (outline-end-of-subtree)
 674                (if (= (char-after) ?\n) (forward-char 1))))
 675     (move-marker ins-point (point))
 676     (insert (delete-and-extract-region beg end))
 677     (goto-char ins-point)
 678     (if folded (hide-subtree))
 679     (move-marker ins-point nil)))
 680
 681 (defun outline-end-of-heading ()
 682   (if (re-search-forward outline-heading-end-regexp nil 'move)
 683       (forward-char -1)))
 684
 685 (defun outline-next-visible-heading (arg)
 686   "Move to the next visible heading line.
 687 With argument, repeats or can move backward if negative.
 688 A heading line is one that starts with a `*' (or that
 689 `outline-regexp' matches)."
 690   (interactive "p")
 691   (if (< arg 0)
 692       (beginning-of-line)
 693     (end-of-line))
 694   (let (found-heading-p)
 695     (while (and (not (bobp)) (< arg 0))
 696       (while (and (not (bobp))
 697                   (setq found-heading-p
 698                         (re-search-backward
 699                          (concat "^\\(?:" outline-regexp "\\)")
 700                          nil 'move))
 701                   (outline-invisible-p)))
 702       (setq arg (1+ arg)))
 703     (while (and (not (eobp)) (> arg 0))
 704       (while (and (not (eobp))
 705                   (setq found-heading-p
 706                         (re-search-forward
 707                          (concat "^\\(?:" outline-regexp "\\)")
 708                          nil 'move))
 709                   (outline-invisible-p (match-beginning 0))))
 710       (setq arg (1- arg)))
 711     (if found-heading-p (beginning-of-line))))
 712
 713 (defun outline-previous-visible-heading (arg)
 714   "Move to the previous heading line.
 715 With argument, repeats or can move forward if negative.
 716 A heading line is one that starts with a `*' (or that
 717 `outline-regexp' matches)."
 718   (interactive "p")
 719   (outline-next-visible-heading (- arg)))
 720
 721 (defun outline-mark-subtree ()
 722   "Mark the current subtree in an outlined document.
 723 This puts point at the start of the current subtree, and mark at the end."
 724   (interactive)
 725   (let ((beg))
 726     (if (outline-on-heading-p)
 727         ;; we are already looking at a heading
 728         (beginning-of-line)
 729       ;; else go back to previous heading
 730       (outline-previous-visible-heading 1))
 731     (setq beg (point))
 732     (outline-end-of-subtree)
 733     (push-mark (point) nil t)
 734     (goto-char beg)))
 735 \f
 736
 737 (defvar outline-isearch-open-invisible-function nil
 738   "Function called if `isearch' finishes in an invisible overlay.
 739 The function is called with the overlay as its only argument.
 740 If nil, `show-entry' is called to reveal the invisible text.")
 741
 742 (put 'outline 'reveal-toggle-invisible 'outline-reveal-toggle-invisible)
 743 (defun outline-flag-region (from to flag)
 744   "Hide or show lines from FROM to TO, according to FLAG.
 745 If FLAG is nil then text is shown, while if FLAG is t the text is hidden."
 746   (remove-overlays from to 'invisible 'outline)
 747   (when flag
 748     ;; We use `front-advance' here because the invisible text begins at the
 749     ;; very end of the heading, before the newline, so text inserted at FROM
 750     ;; belongs to the heading rather than to the entry.
 751     (let ((o (make-overlay from to nil 'front-advance)))
 752       (overlay-put o 'invisible 'outline)
 753       (overlay-put o 'isearch-open-invisible
 754                    (or outline-isearch-open-invisible-function
 755                        'outline-isearch-open-invisible))))
 756   ;; Seems only used by lazy-lock.  I.e. obsolete.
 757   (run-hooks 'outline-view-change-hook))
 758
 759 (defun outline-reveal-toggle-invisible (o hidep)
 760   (save-excursion
 761     (goto-char (overlay-start o))
 762     (if hidep
 763         ;; When hiding the area again, we could just clean it up and let
 764         ;; reveal do the rest, by simply doing:
 765         ;; (remove-overlays (overlay-start o) (overlay-end o)
 766         ;;                  'invisible 'outline)
 767         ;;
 768         ;; That works fine as long as everything is in sync, but if the
 769         ;; structure of the document is changed while revealing parts of it,
 770         ;; the resulting behavior can be ugly.  I.e. we need to make
 771         ;; sure that we hide exactly a subtree.
 772         (progn
 773           (let ((end (overlay-end o)))
 774             (delete-overlay o)
 775             (while (progn
 776                      (hide-subtree)
 777                      (outline-next-visible-heading 1)
 778                      (and (not (eobp)) (< (point) end))))))
 779
 780       ;; When revealing, we just need to reveal sublevels.  If point is
 781       ;; inside one of the sublevels, reveal will call us again.
 782       ;; But we need to preserve the original overlay.
 783       (let ((o1 (copy-overlay o)))
 784         (overlay-put o 'invisible nil)  ;Show (most of) the text.
 785         (while (progn
 786                  (show-entry)
 787                  (show-children)
 788                  ;; Normally just the above is needed.
 789                  ;; But in odd cases, the above might fail to show anything.
 790                  ;; To avoid an infinite loop, we have to make sure that
 791                  ;; *something* gets shown.
 792                  (and (equal (overlay-start o) (overlay-start o1))
 793                       (< (point) (overlay-end o))
 794                       (= 0 (forward-line 1)))))
 795         ;; If still nothing was shown, just kill the damn thing.
 796         (when (equal (overlay-start o) (overlay-start o1))
 797           ;; I've seen it happen at the end of buffer.
 798           (delete-overlay o1))))))
 799
 800 ;; Function to be set as an outline-isearch-open-invisible' property
 801 ;; to the overlay that makes the outline invisible (see
 802 ;; `outline-flag-region').
 803 (defun outline-isearch-open-invisible (_overlay)
 804   ;; We rely on the fact that isearch places point on the matched text.
 805   (show-entry))
 806 \f
 807 (defun hide-entry ()
 808   "Hide the body directly following this heading."
 809   (interactive)
 810   (save-excursion
 811     (outline-back-to-heading)
 812     (outline-end-of-heading)
 813     (outline-flag-region (point) (progn (outline-next-preface) (point)) t)))
 814
 815 (defun show-entry ()
 816   "Show the body directly following this heading.
 817 Show the heading too, if it is currently invisible."
 818   (interactive)
 819   (save-excursion
 820     (outline-back-to-heading t)
 821     (outline-flag-region (1- (point))
 822                          (progn (outline-next-preface) (point)) nil)))
 823
 824 (defun hide-body ()
 825   "Hide all body lines in buffer, leaving all headings visible."
 826   (interactive)
 827   (hide-region-body (point-min) (point-max)))
 828
 829 (defun hide-region-body (start end)
 830   "Hide all body lines in the region, but not headings."
 831   ;; Nullify the hook to avoid repeated calls to `outline-flag-region'
 832   ;; wasting lots of time running `lazy-lock-fontify-after-outline'
 833   ;; and run the hook finally.
 834   (let (outline-view-change-hook)
 835     (save-excursion
 836       (save-restriction
 837         (narrow-to-region start end)
 838         (goto-char (point-min))
 839         (if (outline-on-heading-p)
 840             (outline-end-of-heading)
 841           (outline-next-preface))
 842         (while (not (eobp))
 843           (outline-flag-region (point)
 844                                (progn (outline-next-preface) (point)) t)
 845           (unless (eobp)
 846             (forward-char (if (looking-at "\n\n") 2 1))
 847             (outline-end-of-heading))))))
 848   (run-hooks 'outline-view-change-hook))
 849
 850 (defun show-all ()
 851   "Show all of the text in the buffer."
 852   (interactive)
 853   (outline-flag-region (point-min) (point-max) nil))
 854
 855 (defun hide-subtree ()
 856   "Hide everything after this heading at deeper levels."
 857   (interactive)
 858   (outline-flag-subtree t))
 859
 860 (defun hide-leaves ()
 861   "Hide the body after this heading and at deeper levels."
 862   (interactive)
 863   (save-excursion
 864     (outline-back-to-heading)
 865 ;; Turned off to fix bug reported by Otto Maddox on 22 Nov 2005.
 866 ;;    (outline-end-of-heading)
 867     (hide-region-body (point) (progn (outline-end-of-subtree) (point)))))
 868
 869 (defun show-subtree ()
 870   "Show everything after this heading at deeper levels."
 871   (interactive)
 872   (outline-flag-subtree nil))
 873
 874 (defun outline-show-heading ()
 875   "Show the current heading and move to its end."
 876   (outline-flag-region (- (point)
 877                           (if (bobp) 0
 878                             (if (and outline-blank-line
 879                                      (eq (char-before (1- (point))) ?\n))
 880                                 2 1)))
 881                        (progn (outline-end-of-heading) (point))
 882                        nil))
 883
 884 (defun hide-sublevels (levels)
 885   "Hide everything but the top LEVELS levels of headers, in whole buffer."
 886   (interactive (list
 887                 (cond
 888                  (current-prefix-arg (prefix-numeric-value current-prefix-arg))
 889                  ((save-excursion (beginning-of-line)
 890                                   (looking-at outline-regexp))
 891                   (funcall outline-level))
 892                  (t 1))))
 893   (if (< levels 1)
 894       (error "Must keep at least one level of headers"))
 895   (save-excursion
 896     (let* (outline-view-change-hook
 897            (beg (progn
 898                   (goto-char (point-min))
 899                   ;; Skip the prelude, if any.
 900                   (unless (outline-on-heading-p t) (outline-next-heading))
 901                   (point)))
 902            (end (progn
 903                   (goto-char (point-max))
 904                   ;; Keep empty last line, if available.
 905                   (if (bolp) (1- (point)) (point)))))
 906       (if (< end beg)
 907           (setq beg (prog1 end (setq end beg))))
 908       ;; First hide everything.
 909       (outline-flag-region beg end t)
 910       ;; Then unhide the top level headers.
 911       (outline-map-region
 912        (lambda ()
 913          (if (<= (funcall outline-level) levels)
 914              (outline-show-heading)))
 915        beg end)
 916       ;; Finally unhide any trailing newline.
 917       (goto-char (point-max))
 918       (if (and (bolp) (not (bobp)) (outline-invisible-p (1- (point))))
 919           (outline-flag-region (1- (point)) (point) nil))))
 920   (run-hooks 'outline-view-change-hook))
 921
 922 (defun hide-other ()
 923   "Hide everything except current body and parent and top-level headings."
 924   (interactive)
 925   (hide-sublevels 1)
 926   (let (outline-view-change-hook)
 927     (save-excursion
 928       (outline-back-to-heading t)
 929       (show-entry)
 930       (while (condition-case nil (progn (outline-up-heading 1 t) (not (bobp)))
 931                (error nil))
 932         (outline-flag-region (1- (point))
 933                              (save-excursion (forward-line 1) (point))
 934                              nil))))
 935   (run-hooks 'outline-view-change-hook))
 936
 937 (defun outline-toggle-children ()
 938   "Show or hide the current subtree depending on its current state."
 939   (interactive)
 940   (save-excursion
 941     (outline-back-to-heading)
 942     (if (not (outline-invisible-p (line-end-position)))
 943         (hide-subtree)
 944       (show-children)
 945       (show-entry))))
 946
 947 (defun outline-flag-subtree (flag)
 948   (save-excursion
 949     (outline-back-to-heading)
 950     (outline-end-of-heading)
 951     (outline-flag-region (point)
 952                           (progn (outline-end-of-subtree) (point))
 953                           flag)))
 954
 955 (defun outline-end-of-subtree ()
 956   (outline-back-to-heading)
 957   (let ((first t)
 958         (level (funcall outline-level)))
 959     (while (and (not (eobp))
 960                 (or first (> (funcall outline-level) level)))
 961       (setq first nil)
 962       (outline-next-heading))
 963     (if (and (bolp) (not (eolp)))
 964         ;; We stopped at a nonempty line (the next heading).
 965         (progn
 966           ;; Go to end of line before heading
 967           (forward-char -1)
 968           (if (and outline-blank-line (bolp))
 969               ;; leave blank line before heading
 970               (forward-char -1))))))
 971 \f
 972 (defun show-branches ()
 973   "Show all subheadings of this heading, but not their bodies."
 974   (interactive)
 975   (show-children 1000))
 976
 977 (defun show-children (&optional level)
 978   "Show all direct subheadings of this heading.
 979 Prefix arg LEVEL is how many levels below the current level should be shown.
 980 Default is enough to cause the following heading to appear."
 981   (interactive "P")
 982   (setq level
 983         (if level (prefix-numeric-value level)
 984           (save-excursion
 985             (outline-back-to-heading)
 986             (let ((start-level (funcall outline-level)))
 987               (outline-next-heading)
 988               (if (eobp)
 989                   1
 990                 (max 1 (- (funcall outline-level) start-level)))))))
 991   (let (outline-view-change-hook)
 992     (save-excursion
 993       (outline-back-to-heading)
 994       (setq level (+ level (funcall outline-level)))
 995       (outline-map-region
 996        (lambda ()
 997          (if (<= (funcall outline-level) level)
 998              (outline-show-heading)))
 999        (point)
1000        (progn (outline-end-of-subtree)
1001               (if (eobp) (point-max) (1+ (point)))))))
1002   (run-hooks 'outline-view-change-hook))
1003
1004 \f
1005
1006 (defun outline-up-heading (arg &optional invisible-ok)
1007   "Move to the visible heading line of which the present line is a subheading.
1008 With argument, move up ARG levels.
1009 If INVISIBLE-OK is non-nil, also consider invisible lines."
1010   (interactive "p")
1011   (and (eq this-command 'outline-up-heading)
1012        (or (eq last-command 'outline-up-heading) (push-mark)))
1013   (outline-back-to-heading invisible-ok)
1014   (let ((start-level (funcall outline-level)))
1015     (when (<= start-level 1)
1016       (error "Already at top level of the outline"))
1017     (while (and (> start-level 1) (> arg 0) (not (bobp)))
1018       (let ((level start-level))
1019         (while (not (or (< level start-level) (bobp)))
1020           (if invisible-ok
1021               (outline-previous-heading)
1022             (outline-previous-visible-heading 1))
1023           (setq level (funcall outline-level)))
1024         (setq start-level level))
1025       (setq arg (- arg 1))))
1026   (looking-at outline-regexp))
1027
1028 (defun outline-forward-same-level (arg)
1029   "Move forward to the ARG'th subheading at same level as this one.
1030 Stop at the first and last subheadings of a superior heading."
1031   (interactive "p")
1032   (outline-back-to-heading)
1033   (while (> arg 0)
1034     (let ((point-to-move-to (save-excursion
1035                               (outline-get-next-sibling))))
1036       (if point-to-move-to
1037           (progn
1038             (goto-char point-to-move-to)
1039             (setq arg (1- arg)))
1040         (progn
1041           (setq arg 0)
1042           (error "No following same-level heading"))))))
1043
1044 (defun outline-get-next-sibling ()
1045   "Move to next heading of the same level, and return point.
1046 If there is no such heading, return nil."
1047   (let ((level (funcall outline-level)))
1048     (outline-next-visible-heading 1)
1049     (while (and (not (eobp)) (> (funcall outline-level) level))
1050       (outline-next-visible-heading 1))
1051     (if (or (eobp) (< (funcall outline-level) level))
1052         nil
1053       (point))))
1054
1055 (defun outline-backward-same-level (arg)
1056   "Move backward to the ARG'th subheading at same level as this one.
1057 Stop at the first and last subheadings of a superior heading."
1058   (interactive "p")
1059   (outline-back-to-heading)
1060   (while (> arg 0)
1061     (let ((point-to-move-to (save-excursion
1062                               (outline-get-last-sibling))))
1063       (if point-to-move-to
1064           (progn
1065             (goto-char point-to-move-to)
1066             (setq arg (1- arg)))
1067         (progn
1068           (setq arg 0)
1069           (error "No previous same-level heading"))))))
1070
1071 (defun outline-get-last-sibling ()
1072   "Move to previous heading of the same level, and return point.
1073 If there is no such heading, return nil."
1074   (let ((opoint (point))
1075         (level (funcall outline-level)))
1076     (outline-previous-visible-heading 1)
1077     (when (and (/= (point) opoint) (outline-on-heading-p))
1078       (while (and (> (funcall outline-level) level)
1079                   (not (bobp)))
1080         (outline-previous-visible-heading 1))
1081       (if (< (funcall outline-level) level)
1082           nil
1083         (point)))))
1084 \f
1085 (defun outline-headers-as-kill (beg end)
1086   "Save the visible outline headers in region at the start of the kill ring.
1087
1088 Text shown between the headers isn't copied.  Two newlines are
1089 inserted between saved headers.  Yanking the result may be a
1090 convenient way to make a table of contents of the buffer."
1091   (interactive "r")
1092   (save-excursion
1093     (save-restriction
1094       (narrow-to-region beg end)
1095       (goto-char (point-min))
1096       (let ((buffer (current-buffer))
1097             start end)
1098         (with-temp-buffer
1099           (with-current-buffer buffer
1100             ;; Boundary condition: starting on heading:
1101             (when (outline-on-heading-p)
1102               (outline-back-to-heading)
1103               (setq start (point)
1104                     end (progn (outline-end-of-heading)
1105                                (point)))
1106               (insert-buffer-substring buffer start end)
1107               (insert "\n\n")))
1108           (let ((temp-buffer (current-buffer)))
1109             (with-current-buffer buffer
1110               (while (outline-next-heading)
1111                 (unless (outline-invisible-p)
1112                   (setq start (point)
1113                         end (progn (outline-end-of-heading) (point)))
1114                   (with-current-buffer temp-buffer
1115                     (insert-buffer-substring buffer start end)
1116                     (insert "\n\n"))))))
1117           (kill-new (buffer-string)))))))
1118
1119 (provide 'outline)
1120 (provide 'noutline)
1121
1122 ;;; outline.el ends here