desktop.el 64.6 KB
Newer Older
1
;;; desktop.el --- save partial status of Emacs when killed -*- lexical-binding: t -*-
Richard M. Stallman's avatar
Richard M. Stallman committed
2

Paul Eggert's avatar
Paul Eggert committed
3
;; Copyright (C) 1993-1995, 1997, 2000-2017 Free Software Foundation,
Paul Eggert's avatar
Paul Eggert committed
4
;; Inc.
Richard M. Stallman's avatar
Richard M. Stallman committed
5 6

;; Author: Morten Welinder <terra@diku.dk>
Dave Love's avatar
Dave Love committed
7
;; Keywords: convenience
Paul Eggert's avatar
Paul Eggert committed
8
;; Favorite-brand-of-beer: None, I hate beer.
Richard M. Stallman's avatar
Richard M. Stallman committed
9 10 11

;; This file is part of GNU Emacs.

12
;; GNU Emacs is free software: you can redistribute it and/or modify
Richard M. Stallman's avatar
Richard M. Stallman committed
13
;; it under the terms of the GNU General Public License as published by
14 15
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
Richard M. Stallman's avatar
Richard M. Stallman committed
16 17 18 19 20 21 22

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
23
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
Richard M. Stallman's avatar
Richard M. Stallman committed
24 25 26

;;; Commentary:

27 28 29 30 31 32 33 34
;; Save the Desktop, i.e.,
;;	- some global variables
;; 	- the list of buffers with associated files.  For each buffer also
;;		- the major mode
;;		- the default directory
;;		- the point
;;		- the mark & mark-active
;;		- buffer-read-only
35
;;		- some local variables
36
;;	- frame and window configuration
Richard M. Stallman's avatar
Richard M. Stallman committed
37

Kenichi Handa's avatar
Kenichi Handa committed
38
;; To use this, use customize to turn on desktop-save-mode or add the
39
;; following line somewhere in your init file:
40
;;
Kenichi Handa's avatar
Kenichi Handa committed
41
;;	(desktop-save-mode 1)
42
;;
Kenichi Handa's avatar
Kenichi Handa committed
43
;; For further usage information, look at the section
Glenn Morris's avatar
Glenn Morris committed
44
;; (info "(emacs)Saving Emacs Sessions") in the GNU Emacs Manual.
Kenichi Handa's avatar
Kenichi Handa committed
45 46

;; When the desktop module is loaded, the function `desktop-kill' is
47
;; added to the `kill-emacs-hook'.  This function is responsible for
Kenichi Handa's avatar
Kenichi Handa committed
48
;; saving the desktop when Emacs is killed.  Furthermore an anonymous
49
;; function is added to the `after-init-hook'.  This function is
Kenichi Handa's avatar
Kenichi Handa committed
50
;; responsible for loading the desktop when Emacs is started.
51

52 53 54 55 56
;; Special handling.
;; -----------------
;; Variables `desktop-buffer-mode-handlers' and `desktop-minor-mode-handlers'
;; are supplied to handle special major and minor modes respectively.
;; `desktop-buffer-mode-handlers' is an alist of major mode specific functions
57
;; to restore a desktop buffer.  Elements must have the form
58
;;
59
;;    (MAJOR-MODE . RESTORE-BUFFER-FUNCTION).
60
;;
61
;; Functions listed are called by `desktop-create-buffer' when `desktop-read'
62
;; evaluates the desktop file.  Buffers with a major mode not specified here,
63 64 65
;; are restored by the default handler `desktop-restore-file-buffer'.
;; `desktop-minor-mode-handlers' is an alist of functions to restore
;; non-standard minor modes.  Elements must have the form
66
;;
67
;;    (MINOR-MODE . RESTORE-FUNCTION).
68
;;
69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85
;; Functions are called by `desktop-create-buffer' to restore minor modes.
;; Minor modes not specified here, are restored by the standard minor mode
;; function.  If you write a module that defines a major or minor mode that
;; needs a special handler, then place code like

;;    (defun foo-restore-desktop-buffer
;;    ...
;;    (add-to-list 'desktop-buffer-mode-handlers
;;                 '(foo-mode . foo-restore-desktop-buffer))

;; or

;;    (defun bar-desktop-restore
;;    ...
;;    (add-to-list 'desktop-minor-mode-handlers
;;                 '(bar-mode . bar-desktop-restore))

86 87 88 89
;; in the module itself.  The mode function must either be autoloaded,
;; or of the form "foobar-mode" and defined in library "foobar", so that
;; desktop can guess how to load its definition.
;; See the docstrings of `desktop-buffer-mode-handlers' and
90 91 92 93 94 95 96 97 98 99 100 101 102 103
;; `desktop-minor-mode-handlers' for more info.

;; Minor modes.
;; ------------
;; Conventional minor modes (see node "Minor Mode Conventions" in the elisp
;; manual) are handled in the following way:
;; When `desktop-save' saves the state of a buffer to the desktop file, it
;; saves as `desktop-minor-modes' the list of names of those variables in
;; `minor-mode-alist' that have a non-nil value.
;; When `desktop-create' restores the buffer, each of the symbols in
;; `desktop-minor-modes' is called as function with parameter 1.
;; The variables `desktop-minor-mode-table' and `desktop-minor-mode-handlers'
;; are used to handle non-conventional minor modes.  `desktop-save' uses
;; `desktop-minor-mode-table' to map minor mode variables to minor mode
104
;; functions before writing `desktop-minor-modes'.  If a minor mode has a
105 106 107 108 109 110 111 112 113
;; variable name that is different form its function name, an entry

;;    (NAME RESTORE-FUNCTION)

;; should be added to `desktop-minor-mode-table'.  If a minor mode should not
;; be restored, RESTORE-FUNCTION should be set to nil.  `desktop-create' uses
;; `desktop-minor-mode-handlers' to lookup minor modes that needs a restore
;; function different from the usual minor mode function.
;; ---------------------------------------------------------------------------
114

115 116 117 118
;; By the way: don't use desktop.el to customize Emacs -- the file .emacs
;; in your home directory is used for that.  Saving global default values
;; for buffers is an example of misuse.

119 120 121
;; PLEASE NOTE: The kill ring can be saved as specified by the variable
;; `desktop-globals-to-save' (by default it isn't).  This may result in saving
;; things you did not mean to keep.  Use M-x desktop-clear RET.
122

123 124 125 126 127
;; Thanks to  hetrick@phys.uva.nl (Jim Hetrick)      for useful ideas.
;;            avk@rtsg.mot.com (Andrew V. Klein)     for a dired tip.
;;            chris@tecc.co.uk (Chris Boucher)       for a mark tip.
;;            f89-kam@nada.kth.se (Klas Mellbourn)   for a mh-e tip.
;;            kifer@sbkifer.cs.sunysb.edu (M. Kifer) for a bug hunt.
128
;;            treese@lcs.mit.edu (Win Treese)        for ange-ftp tips.
Glenn Morris's avatar
Glenn Morris committed
129
;;            pot@cnuce.cnr.it (Francesco Potortì)  for misc. tips.
130 131 132 133 134
;; ---------------------------------------------------------------------------
;; TODO:
;;
;; Recognize more minor modes.
;; Save mark rings.
Richard M. Stallman's avatar
Richard M. Stallman committed
135 136 137

;;; Code:

138
(require 'cl-lib)
139
(require 'frameset)
140

141
(defvar desktop-file-version "208"
Kenichi Handa's avatar
Kenichi Handa committed
142
  "Version number of desktop file format.
143 144 145 146 147 148 149 150 151
Used at desktop read to provide backward compatibility.")

(defconst desktop-native-file-version 208
  "Format version of the current desktop package, an integer.")
(defvar desktop-io-file-version nil
  "The format version of the current desktop file (an integer) or nil.")
;; Note: Historically, the version number is embedded in the entry for
;; each buffer.  It is highly inadvisable for different buffer entries
;; to have different format versions.
152

153
;; ----------------------------------------------------------------------------
154 155
;; USER OPTIONS -- settings you might want to play with.
;; ----------------------------------------------------------------------------
156 157 158 159 160

(defgroup desktop nil
  "Save status of Emacs when you exit."
  :group 'frames)

161 162
;; Maintained for backward compatibility
(define-obsolete-variable-alias 'desktop-enable 'desktop-save-mode "22.1")
Kenichi Handa's avatar
Kenichi Handa committed
163 164
;;;###autoload
(define-minor-mode desktop-save-mode
165
  "Toggle desktop saving (Desktop Save mode).
Glenn Morris's avatar
Glenn Morris committed
166 167 168
With a prefix argument ARG, enable Desktop Save mode if ARG is positive,
and disable it otherwise.  If called from Lisp, enable the mode if ARG
is omitted or nil.
169

Glenn Morris's avatar
Glenn Morris committed
170 171 172 173 174
When Desktop Save mode is enabled, the state of Emacs is saved from
one session to another.  In particular, Emacs will save the desktop when
it exits (this may prompt you; see the option `desktop-save').  The next
time Emacs starts, if this mode is active it will restore the desktop.

175 176
To manually save the desktop at any time, use the command `\\[desktop-save]'.
To load it, use `\\[desktop-read]'.
Glenn Morris's avatar
Glenn Morris committed
177 178 179 180 181 182 183

Once a desktop file exists, Emacs will auto-save it according to the
option `desktop-auto-save-timeout'.

To see all the options you can set, browse the `desktop' customization group.

For further details, see info node `(emacs)Saving Emacs Sessions'."
Kenichi Handa's avatar
Kenichi Handa committed
184
  :global t
185 186
  :group 'desktop
  (if desktop-save-mode
187 188
      (desktop-auto-save-enable)
    (desktop-auto-save-disable)))
Kenichi Handa's avatar
Kenichi Handa committed
189

190 191 192 193
(defun desktop-save-mode-off ()
  "Disable `desktop-save-mode'.  Provided for use in hooks."
  (desktop-save-mode 0))

194
(defcustom desktop-save 'ask-if-new
Lute Kamstra's avatar
Lute Kamstra committed
195
  "Specifies whether the desktop should be saved when it is killed.
Kenichi Handa's avatar
Kenichi Handa committed
196 197
A desktop is killed when the user changes desktop or quits Emacs.
Possible values are:
198 199 200 201 202 203
   t             -- always save.
   ask           -- always ask.
   ask-if-new    -- ask if no desktop file exists, otherwise just save.
   ask-if-exists -- ask if desktop file exists, otherwise don't save.
   if-exists     -- save if desktop file exists, otherwise don't save.
   nil           -- never save.
Kenichi Handa's avatar
Kenichi Handa committed
204
The desktop is never saved when `desktop-save-mode' is nil.
205
The variables `desktop-dirname' and `desktop-base-file-name'
Kenichi Handa's avatar
Kenichi Handa committed
206
determine where the desktop is saved."
207 208
  :type
  '(choice
209 210 211 212 213 214
    (const :tag "Always save" t)
    (const :tag "Always ask" ask)
    (const :tag "Ask if desktop file is new, else do save" ask-if-new)
    (const :tag "Ask if desktop file exists, else don't save" ask-if-exists)
    (const :tag "Save if desktop file exists, else don't" if-exists)
    (const :tag "Never save" nil))
215
  :group 'desktop
216
  :version "22.1")
217

218
(defcustom desktop-auto-save-timeout auto-save-timeout
Eli Zaretskii's avatar
Eli Zaretskii committed
219 220 221
  "Number of seconds of idle time before auto-saving the desktop.
The desktop will be auto-saved when this amount of idle time have
passed after some change in the window configuration.
Glenn Morris's avatar
Glenn Morris committed
222
This applies to an existing desktop file when `desktop-save-mode' is enabled.
223
Zero or nil means disable auto-saving due to idleness."
224 225 226 227
  :type '(choice (const :tag "Off" nil)
                 (integer :tag "Seconds"))
  :set (lambda (symbol value)
         (set-default symbol value)
228 229
         (ignore-errors
	   (if (and (integerp value) (> value 0))
230 231
	       (desktop-auto-save-enable value)
	     (desktop-auto-save-disable))))
232 233 234
  :group 'desktop
  :version "24.4")

235 236 237 238 239 240 241 242 243 244 245 246 247 248
(defcustom desktop-load-locked-desktop 'ask
  "Specifies whether the desktop should be loaded if locked.
Possible values are:
   t    -- load anyway.
   nil  -- don't load.
   ask  -- ask the user.
If the value is nil, or `ask' and the user chooses not to load the desktop,
the normal hook `desktop-not-loaded-hook' is run."
  :type
  '(choice
    (const :tag "Load anyway" t)
    (const :tag "Don't load" nil)
    (const :tag "Ask the user" ask))
  :group 'desktop
249
  :version "22.2")
250

251 252 253
(define-obsolete-variable-alias 'desktop-basefilename
                                'desktop-base-file-name "22.1")

254
(defcustom desktop-base-file-name
255
  (convert-standard-filename ".emacs.desktop")
Kenichi Handa's avatar
Kenichi Handa committed
256
  "Name of file for Emacs desktop, excluding the directory part."
257 258
  :type 'file
  :group 'desktop)
Richard M. Stallman's avatar
Richard M. Stallman committed
259

260 261 262 263 264
(defcustom desktop-base-lock-name
  (convert-standard-filename ".emacs.desktop.lock")
  "Name of lock file for Emacs desktop, excluding the directory part."
  :type 'file
  :group 'desktop
265
  :version "22.2")
266

Chong Yidong's avatar
Chong Yidong committed
267
(defcustom desktop-path (list user-emacs-directory "~")
268 269 270
  "List of directories to search for the desktop file.
The base name of the file is specified in `desktop-base-file-name'."
  :type '(repeat directory)
271
  :group 'desktop
272
  :version "23.2")                      ; user-emacs-directory added
273

274
(defcustom desktop-missing-file-warning nil
275
  "If non-nil, offer to recreate the buffer of a deleted file.
276 277 278 279
Also pause for a moment to display message about errors signaled in
`desktop-buffer-mode-handlers'.

If nil, just print error messages in the message buffer."
280
  :type 'boolean
281
  :group 'desktop
282
  :version "22.1")
Richard M. Stallman's avatar
Richard M. Stallman committed
283

284
(defcustom desktop-no-desktop-file-hook nil
Kenichi Handa's avatar
Kenichi Handa committed
285
  "Normal hook run when `desktop-read' can't find a desktop file.
286
Run in the directory in which the desktop file was sought.
287
May be used to show a dired buffer."
288
  :type 'hook
289
  :group 'desktop
290
  :version "22.1")
291

292 293 294 295 296 297 298
(defcustom desktop-not-loaded-hook nil
  "Normal hook run when the user declines to re-use a desktop file.
Run in the directory in which the desktop file was found.
May be used to deal with accidental multiple Emacs jobs."
  :type 'hook
  :group 'desktop
  :options '(desktop-save-mode-off save-buffers-kill-emacs)
299
  :version "22.2")
300

301
(defcustom desktop-after-read-hook nil
Kenichi Handa's avatar
Kenichi Handa committed
302
  "Normal hook run after a successful `desktop-read'.
303
May be used to show a buffer list."
304
  :type 'hook
305
  :group 'desktop
306
  :options '(list-buffers)
307
  :version "22.1")
308 309

(defcustom desktop-save-hook nil
Kenichi Handa's avatar
Kenichi Handa committed
310
  "Normal hook run before the desktop is saved in a desktop file.
311 312 313
Run with the desktop buffer current with only the header present.
May be used to add to the desktop code or to truncate history lists,
for example."
314 315 316
  :type 'hook
  :group 'desktop)

317 318 319 320 321 322
(defcustom desktop-globals-to-save
  '(desktop-missing-file-warning
    tags-file-name
    tags-table-list
    search-ring
    regexp-search-ring
323 324
    register-alist
    file-name-history)
Kenichi Handa's avatar
Kenichi Handa committed
325 326 327 328
  "List of global variables saved by `desktop-save'.
An element may be variable name (a symbol) or a cons cell of the form
\(VAR . MAX-SIZE), which means to truncate VAR's value to at most
MAX-SIZE elements (if the value is a list) before saving the value.
329 330 331 332
Feature: Saving `kill-ring' implies saving `kill-ring-yank-pointer'."
  :type '(repeat (restricted-sexp :match-alternatives (symbolp consp)))
  :group 'desktop)

333 334 335 336 337 338 339
(defcustom desktop-globals-to-clear
  '(kill-ring
    kill-ring-yank-pointer
    search-ring
    search-ring-yank-pointer
    regexp-search-ring
    regexp-search-ring-yank-pointer)
340
  "List of global variables that `desktop-clear' will clear.
341
An element may be variable name (a symbol) or a cons cell of the form
342 343
\(VAR . FORM).  Symbols are set to nil and for cons cells VAR is set
to the value obtained by evaluating FORM."
344
  :type '(repeat (restricted-sexp :match-alternatives (symbolp consp)))
345
  :group 'desktop
346
  :version "22.1")
347

348
(defcustom desktop-clear-preserve-buffers
Glenn Morris's avatar
Glenn Morris committed
349 350
  '("\\*scratch\\*" "\\*Messages\\*" "\\*server\\*" "\\*tramp/.+\\*"
    "\\*Warnings\\*")
Lute Kamstra's avatar
Lute Kamstra committed
351
  "List of buffers that `desktop-clear' should not delete.
352 353
Each element is a regular expression.  Buffers with a name matched by any of
these won't be deleted."
Glenn Morris's avatar
Glenn Morris committed
354
  :version "23.3"                       ; added Warnings - bug#6336
355 356
  :type '(repeat string)
  :group 'desktop)
357

358
;;;###autoload
359 360 361 362 363 364 365 366 367
(defcustom desktop-locals-to-save
  '(desktop-locals-to-save  ; Itself!  Think it over.
    truncate-lines
    case-fold-search
    case-replace
    fill-column
    overwrite-mode
    change-log-default-name
    line-number-mode
368 369 370
    column-number-mode
    size-indication-mode
    buffer-file-coding-system
371
    buffer-display-time
372
    indent-tabs-mode
373
    tab-width
374 375 376
    indicate-buffer-boundaries
    indicate-empty-lines
    show-trailing-whitespace)
Richard M. Stallman's avatar
Richard M. Stallman committed
377
  "List of local variables to save for each buffer.
378 379
The variables are saved only when they really are local.  Conventional minor
modes are restored automatically; they should not be listed here."
Kenichi Handa's avatar
Kenichi Handa committed
380 381
  :type '(repeat symbol)
  :group 'desktop)
382

383
(defcustom desktop-buffers-not-to-save "\\` "
384 385 386 387
  "Regexp identifying buffers that are to be excluded from saving.
This is in effect only for buffers that don't visit files.
To exclude buffers that visit files, use `desktop-files-not-to-save'
or `desktop-modes-not-to-save'."
388 389
  :type '(choice (const :tag "None" nil)
		 regexp)
390
  :version "24.4"		    ; skip invisible temporary buffers
391
  :group 'desktop)
Richard M. Stallman's avatar
Richard M. Stallman committed
392

Kenichi Handa's avatar
Kenichi Handa committed
393
;; Skip tramp and ange-ftp files
394
(defcustom desktop-files-not-to-save
395
  "\\(^/[^/:]*:\\|(ftp)$\\)"
396
  "Regexp identifying files whose buffers are to be excluded from saving."
397 398
  :type '(choice (const :tag "None" nil)
		 regexp)
399
  :group 'desktop)
400

401 402 403
;; We skip TAGS files to save time (tags-file-name is saved instead).
(defcustom desktop-modes-not-to-save
  '(tags-table-mode)
404 405 406 407
  "List of major modes whose buffers should not be saved."
  :type '(repeat symbol)
  :group 'desktop)

408
(defcustom desktop-restore-frames t
409 410 411
  "When non-nil, save and restore the frame and window configuration.
See related options `desktop-restore-reuses-frames',
`desktop-restore-in-current-display', and `desktop-restore-forces-onscreen'."
412 413 414 415
  :type 'boolean
  :group 'desktop
  :version "24.4")

416
(defcustom desktop-restore-in-current-display t
417 418 419 420
  "Controls how restoring of frames treats displays.
If t, restores frames into the current display.
If nil, restores frames into their original displays (if possible).
If `delete', deletes frames on other displays instead of restoring them."
421 422
  :type '(choice (const :tag "Restore in current display" t)
		 (const :tag "Restore in original display" nil)
Glenn Morris's avatar
Glenn Morris committed
423
		 (const :tag "Delete frames in other displays" delete))
424 425 426
  :group 'desktop
  :version "24.4")

427
(defcustom desktop-restore-forces-onscreen t
428 429 430 431 432 433 434
  "If t, restores frames that are fully offscreen onscreen instead.
If `all', also restores frames that are partially offscreen onscreen.

Note that checking of frame boundaries is only approximate.
It can fail to reliably detect frames whose onscreen/offscreen state
depends on a few pixels, especially near the right / bottom borders
of the screen."
435
  :type '(choice (const :tag "Only fully offscreen frames" t)
436
		 (const :tag "Also partially offscreen frames" all)
437 438 439 440
		 (const :tag "Do not force frames onscreen" nil))
  :group 'desktop
  :version "24.4")

441
(defcustom desktop-restore-reuses-frames t
442
  "If t, restoring frames reuses existing frames.
443 444
If nil, deletes existing frames.
If `keep', keeps existing frames and does not reuse them."
445 446
  :type '(choice (const :tag "Reuse existing frames" t)
		 (const :tag "Delete existing frames" nil)
447
		 (const :tag "Keep existing frames" :keep))
448 449 450
  :group 'desktop
  :version "24.4")

451
(defcustom desktop-file-name-format 'absolute
Lute Kamstra's avatar
Lute Kamstra committed
452
  "Format in which desktop file names should be saved.
453 454 455 456 457
Possible values are:
   absolute -- Absolute file name.
   tilde    -- Relative to ~.
   local    -- Relative to directory of desktop file."
  :type '(choice (const absolute) (const tilde) (const local))
458
  :group 'desktop
459
  :version "22.1")
460

461 462 463 464
(defcustom desktop-restore-eager t
  "Number of buffers to restore immediately.
Remaining buffers are restored lazily (when Emacs is idle).
If value is t, all buffers are restored immediately."
465
  :type '(choice (const t) integer)
466
  :group 'desktop
467
  :version "22.1")
468 469 470 471 472

(defcustom desktop-lazy-verbose t
  "Verbose reporting of lazily created buffers."
  :type 'boolean
  :group 'desktop
473
  :version "22.1")
474 475 476 477 478 479

(defcustom desktop-lazy-idle-delay 5
  "Idle delay before starting to create buffers.
See `desktop-restore-eager'."
  :type 'integer
  :group 'desktop
480
  :version "22.1")
481

482
;;;###autoload
483
(defvar-local desktop-save-buffer nil
484 485
  "When non-nil, save buffer status in desktop file.

486 487
If the value is a function, it is called by `desktop-save' with argument
DESKTOP-DIRNAME to obtain auxiliary information to save in the desktop
488
file along with the state of the buffer for which it was called.
489

Kenichi Handa's avatar
Kenichi Handa committed
490
When file names are returned, they should be formatted using the call
491
\"(desktop-file-name FILE-NAME DESKTOP-DIRNAME)\".
492

493 494 495
Later, when `desktop-read' evaluates the desktop file, auxiliary information
is passed as the argument DESKTOP-BUFFER-MISC to functions in
`desktop-buffer-mode-handlers'.")
496
(make-obsolete-variable 'desktop-buffer-modes-to-save
497
                        'desktop-save-buffer "22.1")
498
(make-obsolete-variable 'desktop-buffer-misc-functions
499
                        'desktop-save-buffer "22.1")
500

501
;;;###autoload
Chong Yidong's avatar
Chong Yidong committed
502
(defvar desktop-buffer-mode-handlers nil
503
  "Alist of major mode specific functions to restore a desktop buffer.
504 505 506 507
Functions listed are called by `desktop-create-buffer' when `desktop-read'
evaluates the desktop file.  List elements must have the form

   (MAJOR-MODE . RESTORE-BUFFER-FUNCTION).
508 509 510 511

Buffers with a major mode not specified here, are restored by the default
handler `desktop-restore-file-buffer'.

512
Handlers are called with argument list
513

514
   (DESKTOP-BUFFER-FILE-NAME DESKTOP-BUFFER-NAME DESKTOP-BUFFER-MISC)
515 516

Furthermore, they may use the following variables:
517

518 519 520 521 522 523 524
   `desktop-file-version'
   `desktop-buffer-major-mode'
   `desktop-buffer-minor-modes'
   `desktop-buffer-point'
   `desktop-buffer-mark'
   `desktop-buffer-read-only'
   `desktop-buffer-locals'
525

526
If a handler returns a buffer, then the saved mode settings
527 528 529 530
and variable values for that buffer are copied into it.

Modules that define a major mode that needs a special handler should contain
code like
531

532 533
   (defun foo-restore-desktop-buffer
   ...
534 535
   (add-to-list \\='desktop-buffer-mode-handlers
                \\='(foo-mode . foo-restore-desktop-buffer))
536

537 538 539
The major mode function must either be autoloaded, or of the form
\"foobar-mode\" and defined in library \"foobar\", so that desktop
can guess how to load the mode's definition.")
540

541
;;;###autoload
542 543
(put 'desktop-buffer-mode-handlers 'risky-local-variable t)
(make-obsolete-variable 'desktop-buffer-handlers
544
                        'desktop-buffer-mode-handlers "22.1")
545

546 547
(defcustom desktop-minor-mode-table
  '((auto-fill-function auto-fill-mode)
548 549
    (defining-kbd-macro nil)
    (isearch-mode nil)
550
    (vc-mode nil)
551
    (vc-dired-mode nil)
552 553
    (erc-track-minor-mode nil)
    (savehist-mode nil))
554 555 556 557
  "Table mapping minor mode variables to minor mode functions.
Each entry has the form (NAME RESTORE-FUNCTION).
NAME is the name of the buffer-local variable indicating that the minor
mode is active.  RESTORE-FUNCTION is the function to activate the minor mode.
558
RESTORE-FUNCTION nil means don't try to restore the minor mode.
559
Only minor modes for which the name of the buffer-local variable
560
and the name of the minor mode function are different have to be added to
561
this table.  See also `desktop-minor-mode-handlers'."
562 563 564
  :type '(alist :key-type (symbol :tag "Minor mode")
                :value-type (list :tag "Restore function"
                                  (choice (const nil) function)))
565 566
  :group 'desktop)

567
;;;###autoload
Chong Yidong's avatar
Chong Yidong committed
568
(defvar desktop-minor-mode-handlers nil
569 570 571 572 573 574 575 576 577 578 579 580 581 582 583
  "Alist of functions to restore non-standard minor modes.
Functions are called by `desktop-create-buffer' to restore minor modes.
List elements must have the form

   (MINOR-MODE . RESTORE-FUNCTION).

Minor modes not specified here, are restored by the standard minor mode
function.

Handlers are called with argument list

   (DESKTOP-BUFFER-LOCALS)

Furthermore, they may use the following variables:

584 585 586 587 588 589 590 591 592
   `desktop-file-version'
   `desktop-buffer-file-name'
   `desktop-buffer-name'
   `desktop-buffer-major-mode'
   `desktop-buffer-minor-modes'
   `desktop-buffer-point'
   `desktop-buffer-mark'
   `desktop-buffer-read-only'
   `desktop-buffer-misc'
593 594 595 596 597 598 599 600 601 602

When a handler is called, the buffer has been created and the major mode has
been set, but local variables listed in desktop-buffer-locals has not yet been
created and set.

Modules that define a minor mode that needs a special handler should contain
code like

   (defun foo-desktop-restore
   ...
603 604
   (add-to-list \\='desktop-minor-mode-handlers
                \\='(foo-mode . foo-desktop-restore))
605

606 607 608
The minor mode function must either be autoloaded, or of the form
\"foobar-mode\" and defined in library \"foobar\", so that desktop
can guess how to load the mode's definition.
609 610 611

See also `desktop-minor-mode-table'.")

612
;;;###autoload
613 614
(put 'desktop-minor-mode-handlers 'risky-local-variable t)

615 616
;; ----------------------------------------------------------------------------
(defvar desktop-dirname nil
Kenichi Handa's avatar
Kenichi Handa committed
617
  "The directory in which the desktop file should be saved.")
Richard M. Stallman's avatar
Richard M. Stallman committed
618

619 620 621 622 623
(defun desktop-full-file-name (&optional dirname)
  "Return the full name of the desktop file in DIRNAME.
DIRNAME omitted or nil means use `desktop-dirname'."
  (expand-file-name desktop-base-file-name (or dirname desktop-dirname)))

624 625 626 627 628
(defun desktop-full-lock-name (&optional dirname)
  "Return the full name of the desktop lock file in DIRNAME.
DIRNAME omitted or nil means use `desktop-dirname'."
  (expand-file-name desktop-base-lock-name (or dirname desktop-dirname)))

Richard M. Stallman's avatar
Richard M. Stallman committed
629
(defconst desktop-header
630 631 632
";; --------------------------------------------------------------------------
;; Desktop File for Emacs
;; --------------------------------------------------------------------------
Richard M. Stallman's avatar
Richard M. Stallman committed
633
" "*Header to place in Desktop file.")
634 635 636

(defvar desktop-delay-hook nil
  "Hooks run after all buffers are loaded; intended for internal use.")
637

638 639 640 641
(defvar desktop-file-checksum nil
  "Checksum of the last auto-saved contents of the desktop file.
Used to avoid writing contents unchanged between auto-saves.")

642
(defvar desktop-saved-frameset nil
643 644
  "Saved state of all frames.
Only valid during frame saving & restoring; intended for internal use.")
645

646 647 648 649 650 651
;; ----------------------------------------------------------------------------
;; Desktop file conflict detection
(defvar desktop-file-modtime nil
  "When the desktop file was last modified to the knowledge of this Emacs.
Used to detect desktop file conflicts.")

652 653 654 655 656 657 658 659 660 661 662 663
(defvar desktop-var-serdes-funs
  (list (list
	 'mark-ring
	 (lambda (mr)
	   (mapcar #'marker-position mr))
	 (lambda (mr)
	   (mapcar #'copy-marker mr))))
  "Table of serialization/deserialization functions for variables.
Each record is a list of form: (var serializer deserializer).
These records can be freely reordered, deleted, or new ones added.
However, for compatibility, don't modify the functions for existing records.")

664 665 666 667
(defun desktop-owner (&optional dirname)
  "Return the PID of the Emacs process that owns the desktop file in DIRNAME.
Return nil if no desktop file found or no Emacs process is using it.
DIRNAME omitted or nil means use `desktop-dirname'."
668 669 670 671 672 673 674 675 676
  (let (owner
	(file (desktop-full-lock-name dirname)))
    (and (file-exists-p file)
	 (ignore-errors
	   (with-temp-buffer
	     (insert-file-contents-literally file)
	     (goto-char (point-min))
	     (setq owner (read (current-buffer)))
	     (integerp owner)))
677 678 679 680 681 682 683 684 685 686 687 688 689 690
	 owner)))

(defun desktop-claim-lock (&optional dirname)
  "Record this Emacs process as the owner of the desktop file in DIRNAME.
DIRNAME omitted or nil means use `desktop-dirname'."
  (write-region (number-to-string (emacs-pid)) nil
		(desktop-full-lock-name dirname)))

(defun desktop-release-lock (&optional dirname)
  "Remove the lock file for the desktop in DIRNAME.
DIRNAME omitted or nil means use `desktop-dirname'."
  (let ((file (desktop-full-lock-name dirname)))
    (when (file-exists-p file) (delete-file file))))

691
;; ----------------------------------------------------------------------------
Kenichi Handa's avatar
Kenichi Handa committed
692
(defun desktop-truncate (list n)
693
  "Truncate LIST to at most N elements destructively."
Kenichi Handa's avatar
Kenichi Handa committed
694
  (let ((here (nthcdr (1- n) list)))
695 696
    (when (consp here)
      (setcdr here nil))))
697

698
;; ----------------------------------------------------------------------------
699
;;;###autoload
700 701
(defun desktop-clear ()
  "Empty the Desktop.
702 703
This kills all buffers except for internal ones and those with names matched by
a regular expression in the list `desktop-clear-preserve-buffers'.
704 705 706 707
Furthermore, it clears the variables listed in `desktop-globals-to-clear'.
When called interactively and `desktop-restore-frames' is non-nil, it also
deletes all frames except the selected one (and its minibuffer frame,
if different)."
Richard M. Stallman's avatar
Richard M. Stallman committed
708
  (interactive)
709
  (desktop-lazy-abort)
710
  (setq desktop-io-file-version nil)
711 712
  (dolist (var desktop-globals-to-clear)
    (if (symbolp var)
Mark Oteiza's avatar
Mark Oteiza committed
713 714
	(set-default var nil)
      (set-default var (eval (cdr var)))))
715
  (let ((preserve-regexp (concat "^\\("
716 717 718 719 720
                                 (mapconcat (lambda (regexp)
                                              (concat "\\(" regexp "\\)"))
                                            desktop-clear-preserve-buffers
                                            "\\|")
                                 "\\)$")))
721 722
    (dolist (buffer (buffer-list))
      (let ((bufname (buffer-name buffer)))
723
	(unless (or (eq (aref bufname 0) ?\s) ;; Don't kill internal buffers
724 725
		    (string-match-p preserve-regexp bufname))
	  (kill-buffer buffer)))))
726
  (delete-other-windows)
727 728 729 730 731
  (when (and desktop-restore-frames
	     ;; Non-interactive calls to desktop-clear happen before desktop-read
	     ;; which already takes care of frame restoration and deletion.
	     (called-interactively-p 'any))
    (let* ((this (selected-frame))
Paul Eggert's avatar
Paul Eggert committed
732
	   (mini (window-frame (minibuffer-window this)))) ; in case they differ
733
      (dolist (frame (sort (frame-list) #'frameset-minibufferless-first-p))
734 735 736
	(condition-case err
	    (unless (or (eq frame this)
			(eq frame mini)
737 738 739 740
                        ;; Don't delete daemon's initial frame, or
                        ;; we'll never be able to close the last
                        ;; client's frame (Bug#26912).
                        (if (daemonp) (not (frame-parameter frame 'client)))
741 742 743
			(frame-parameter frame 'desktop-dont-clear))
	      (delete-frame frame))
	  (error
744
	   (delay-warning 'desktop (error-message-string err))))))))
745

746
;; ----------------------------------------------------------------------------
Juanma Barranquero's avatar
Juanma Barranquero committed
747 748
(unless noninteractive
  (add-hook 'kill-emacs-hook 'desktop-kill))
749

Richard M. Stallman's avatar
Richard M. Stallman committed
750
(defun desktop-kill ()
Kenichi Handa's avatar
Kenichi Handa committed
751
  "If `desktop-save-mode' is non-nil, do what `desktop-save' says to do.
752 753
If the desktop should be saved and `desktop-dirname'
is nil, ask the user where to save the desktop."
754 755 756
  (when (and desktop-save-mode
             (let ((exists (file-exists-p (desktop-full-file-name))))
               (or (eq desktop-save t)
757 758 759 760
                   (and exists (eq desktop-save 'if-exists))
		   ;; If it exists, but we aren't using it, we are going
		   ;; to ask for a new directory below.
                   (and exists desktop-dirname (eq desktop-save 'ask-if-new))
761 762 763 764
                   (and
                    (or (memq desktop-save '(ask ask-if-new))
                        (and exists (eq desktop-save 'ask-if-exists)))
                    (y-or-n-p "Save desktop? ")))))
765 766
    (unless desktop-dirname
      (setq desktop-dirname
767 768
            (file-name-as-directory
             (expand-file-name
769
	      (read-directory-name "Directory for desktop file: " nil nil t)))))
770
    (condition-case err
771
	(desktop-save desktop-dirname t)
772
      (file-error
773
       (unless (yes-or-no-p "Error while saving the desktop.  Ignore? ")
774 775 776
	 (signal (car err) (cdr err))))))
  ;; If we own it, we don't anymore.
  (when (eq (emacs-pid) (desktop-owner)) (desktop-release-lock)))
777

778
;; ----------------------------------------------------------------------------
779
(defun desktop-list* (&rest args)
780
  (and args (apply #'cl-list* args)))
781

782 783
;; ----------------------------------------------------------------------------
(defun desktop-buffer-info (buffer)
784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801
  "Return information describing BUFFER.
This function is not pure, as BUFFER is made current with
`set-buffer'.

Returns a list of all the necessary information to recreate the
buffer, which is (in order):

    `uniquify-buffer-base-name';
    `buffer-file-name';
    `buffer-name';
    `major-mode';
    list of minor-modes,;
    `point';
    `mark';
    `buffer-read-only';
    auxiliary information given by `desktop-save-buffer';
    local variables;
    auxiliary information given by `desktop-var-serdes-funs'."
802
  (set-buffer buffer)
803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842
  `(
    ;; base name of the buffer; replaces the buffer name if managed by uniquify
    ,(and (fboundp 'uniquify-buffer-base-name) (uniquify-buffer-base-name))
    ;; basic information
    ,(desktop-file-name (buffer-file-name) desktop-dirname)
    ,(buffer-name)
    ,major-mode
    ;; minor modes
    ,(let (ret)
       (dolist (minor-mode (mapcar #'car minor-mode-alist) ret)
         (and (boundp minor-mode)
              (symbol-value minor-mode)
              (let* ((special (assq minor-mode desktop-minor-mode-table))
                     (value (cond (special (cadr special))
                                  ((functionp minor-mode) minor-mode))))
                (when value (cl-pushnew value ret))))))
    ;; point and mark, and read-only status
    ,(point)
    ,(list (mark t) mark-active)
    ,buffer-read-only
    ;; auxiliary information
    ,(when (functionp desktop-save-buffer)
       (funcall desktop-save-buffer desktop-dirname))
    ;; local variables
    ,(let ((loclist (buffer-local-variables))
           (ll nil))
       (dolist (local desktop-locals-to-save)
         (let ((here (assq local loclist)))
           (cond (here
                  (push here ll))
                 ((member local loclist)
                  (push local ll)))))
       ll)
   ,@(when (>= desktop-io-file-version 208)
       (list
        (mapcar (lambda (record)
                  (let ((var (car record)))
                    (list var
                          (funcall (cadr record) (symbol-value var)))))
                desktop-var-serdes-funs)))))
843

844
;; ----------------------------------------------------------------------------
845 846 847
(defun desktop--v2s (value)
  "Convert VALUE to a pair (QUOTE . SEXP); (eval SEXP) gives VALUE.
SEXP is an sexp that when evaluated yields VALUE.
Richard M. Stallman's avatar
Richard M. Stallman committed
848
QUOTE may be `may' (value may be quoted),
849
`must' (value must be quoted), or nil (value must not be quoted)."
850
  (cond
851
    ((or (numberp value) (null value) (eq t value) (keywordp value))
852
     (cons 'may value))
853 854 855
    ((stringp value)
     (let ((copy (copy-sequence value)))
       (set-text-properties 0 (length copy) nil copy)
856 857
       ;; Get rid of text properties because we cannot read them.
       (cons 'may copy)))
858
    ((symbolp value)
859
     (cons 'must value))
860
    ((vectorp value)
861 862
     (let* ((pass1 (mapcar #'desktop--v2s value))
	    (special (assq nil pass1)))
863
       (if special
864 865 866 867 868 869
	   (cons nil `(vector
                       ,@(mapcar (lambda (el)
                                   (if (eq (car el) 'must)
                                       `',(cdr el) (cdr el)))
                                 pass1)))
	 (cons 'may `[,@(mapcar #'cdr pass1)]))))
870 871 872
    ((consp value)
     (let ((p value)
	   newlist
873
	   use-list*)
874
       (while (consp p)
875 876
	 (let ((q.sexp (desktop--v2s (car p))))
           (push q.sexp newlist))
877
	 (setq p (cdr p)))
878 879 880 881 882
       (when p
         (let ((last (desktop--v2s p)))
           (setq use-list* t)
           (push last newlist)))
       (if (assq nil newlist)
883
	   (cons nil
884 885 886 887 888
		 `(,(if use-list* 'desktop-list* 'list)
                   ,@(mapcar (lambda (el)
                               (if (eq (car el) 'must)
                                   `',(cdr el) (cdr el)))
                             (nreverse newlist))))
889
	 (cons 'must
890 891 892
	       `(,@(mapcar #'cdr
                           (nreverse (if use-list* (cdr newlist) newlist)))
                 ,@(if use-list* (cdar newlist)))))))
893
    ((subrp value)
894 895
     (cons nil `(symbol-function
                 ',(intern-soft (substring (prin1-to-string value) 7 -1)))))
896
    ((markerp value)
897 898 899 900 901 902 903 904 905 906
     (let ((pos (marker-position value))
	   (buf (buffer-name (marker-buffer value))))
       (cons nil
             `(let ((mk (make-marker)))
                (add-hook 'desktop-delay-hook
                          `(lambda ()
                             (set-marker ,mk ,,pos (get-buffer ,,buf))))
                mk))))
    (t                                  ; Save as text.
     (cons 'may "Unprintable entity"))))
907

908
;; ----------------------------------------------------------------------------
Kenichi Handa's avatar
Kenichi Handa committed
909
(defun desktop-value-to-string (value)
Richard M. Stallman's avatar
Richard M. Stallman committed
910 911
  "Convert VALUE to a string that when read evaluates to the same value.
Not all types of values are supported."
912
  (let* ((print-escape-newlines t)
913 914
	 (print-length nil)
	 (print-level nil)
915
	 (float-output-format nil)
916 917
	 (quote.sexp (desktop--v2s value))
	 (quote (car quote.sexp))
918 919
	 (print-quoted t)
	 (txt (prin1-to-string (cdr quote.sexp))))
920 921 922
    (if (eq quote 'must)
	(concat "'" txt)
      txt)))
923

924
;; ----------------------------------------------------------------------------
925 926 927
(defun desktop-outvar (varspec)
  "Output a setq statement for variable VAR to the desktop file.
The argument VARSPEC may be the variable name VAR (a symbol),
928
or a cons cell of the form (VAR . MAX-SIZE),
929 930 931 932 933 934
which means to truncate VAR's value to at most MAX-SIZE elements
\(if the value is a list) before saving the value."
  (let (var size)
    (if (consp varspec)
	(setq var (car varspec) size (cdr varspec))
      (setq var varspec))
935 936 937 938 939 940 941 942 943 944
    (when (boundp var)
      (when (and (integerp size)
		 (> size 0)
		 (listp (eval var)))
	(desktop-truncate (eval var) size))
      (insert "(setq "
	      (symbol-name var)
	      " "
	      (desktop-value-to-string (symbol-value var))
	      ")\n"))))
945

946
;; ----------------------------------------------------------------------------
947
(defun desktop-save-buffer-p (filename bufname mode &rest _dummy)
948
  "Return t if buffer should have its state saved in the desktop file.
949
FILENAME is the visited file name, BUFNAME is the buffer name, and
950 951
MODE is the major mode.
\n\(fn FILENAME BUFNAME MODE)"
Glenn Morris's avatar
Glenn Morris committed
952
  (let ((case-fold-search nil)
953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971
	(no-regexp-to-check (not (stringp desktop-files-not-to-save)))
	dired-skip)
    (and (or filename
	     (not (stringp desktop-buffers-not-to-save))
	     (not (string-match-p desktop-buffers-not-to-save bufname)))
	 (not (memq mode desktop-modes-not-to-save))
	 (or (and filename
		  (or no-regexp-to-check
		      (not (string-match-p desktop-files-not-to-save filename))))
	     (and (memq mode '(dired-mode vc-dir-mode))
		  (or no-regexp-to-check
		      (not (setq dired-skip
				 (with-current-buffer bufname
				   (string-match-p desktop-files-not-to-save
						   default-directory))))))
	     (and (null filename)
		  (null dired-skip)  ; bug#5755
		  (with-current-buffer bufname desktop-save-buffer)))
	 t)))
972

973
;; ----------------------------------------------------------------------------
974 975 976 977 978 979 980 981 982 983 984 985 986 987
(defun desktop-file-name (filename dirname)
  "Convert FILENAME to format specified in `desktop-file-name-format'.
DIRNAME must be the directory in which the desktop file will be saved."
  (cond
    ((not filename) nil)
    ((eq desktop-file-name-format 'tilde)
     (let ((relative-name (file-relative-name (expand-file-name filename) "~")))
       (cond
         ((file-name-absolute-p relative-name) relative-name)
         ((string= "./" relative-name) "~/")
         ((string= "." relative-name) "~")
         (t (concat "~/" relative-name)))))
    ((eq desktop-file-name-format 'local) (file-relative-name filename dirname))
    (t (expand-file-name filename))))
988

Miles Bader's avatar
Miles Bader committed