lisp/desktop.el

   1 ;;; desktop.el --- save partial status of Emacs when killed
   2
   3 ;; Copyright (C) 1993-1995, 1997, 2000-2012  Free Software Foundation, Inc.
   4
   5 ;; Author: Morten Welinder <terra@diku.dk>
   6 ;; Keywords: convenience
   7 ;; Favorite-brand-of-beer: None, I hate beer.
   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 ;; Save the Desktop, i.e.,
  27 ;;      - some global variables
  28 ;;      - the list of buffers with associated files.  For each buffer also
  29 ;;              - the major mode
  30 ;;              - the default directory
  31 ;;              - the point
  32 ;;              - the mark & mark-active
  33 ;;              - buffer-read-only
  34 ;;              - some local variables
  35
  36 ;; To use this, use customize to turn on desktop-save-mode or add the
  37 ;; following line somewhere in your .emacs file:
  38 ;;
  39 ;;      (desktop-save-mode 1)
  40 ;;
  41 ;; For further usage information, look at the section
  42 ;; (info "(emacs)Saving Emacs Sessions") in the GNU Emacs Manual.
  43
  44 ;; When the desktop module is loaded, the function `desktop-kill' is
  45 ;; added to the `kill-emacs-hook'.  This function is responsible for
  46 ;; saving the desktop when Emacs is killed.  Furthermore an anonymous
  47 ;; function is added to the `after-init-hook'.  This function is
  48 ;; responsible for loading the desktop when Emacs is started.
  49
  50 ;; Special handling.
  51 ;; -----------------
  52 ;; Variables `desktop-buffer-mode-handlers' and `desktop-minor-mode-handlers'
  53 ;; are supplied to handle special major and minor modes respectively.
  54 ;; `desktop-buffer-mode-handlers' is an alist of major mode specific functions
  55 ;; to restore a desktop buffer.  Elements must have the form
  56 ;;
  57 ;;    (MAJOR-MODE . RESTORE-BUFFER-FUNCTION).
  58 ;;
  59 ;; Functions listed are called by `desktop-create-buffer' when `desktop-read'
  60 ;; evaluates the desktop file.  Buffers with a major mode not specified here,
  61 ;; are restored by the default handler `desktop-restore-file-buffer'.
  62 ;; `desktop-minor-mode-handlers' is an alist of functions to restore
  63 ;; non-standard minor modes.  Elements must have the form
  64 ;;
  65 ;;    (MINOR-MODE . RESTORE-FUNCTION).
  66 ;;
  67 ;; Functions are called by `desktop-create-buffer' to restore minor modes.
  68 ;; Minor modes not specified here, are restored by the standard minor mode
  69 ;; function.  If you write a module that defines a major or minor mode that
  70 ;; needs a special handler, then place code like
  71
  72 ;;    (defun foo-restore-desktop-buffer
  73 ;;    ...
  74 ;;    (add-to-list 'desktop-buffer-mode-handlers
  75 ;;                 '(foo-mode . foo-restore-desktop-buffer))
  76
  77 ;; or
  78
  79 ;;    (defun bar-desktop-restore
  80 ;;    ...
  81 ;;    (add-to-list 'desktop-minor-mode-handlers
  82 ;;                 '(bar-mode . bar-desktop-restore))
  83
  84 ;; in the module itself, and make sure that the mode function is
  85 ;; autoloaded.  See the docstrings of `desktop-buffer-mode-handlers' and
  86 ;; `desktop-minor-mode-handlers' for more info.
  87
  88 ;; Minor modes.
  89 ;; ------------
  90 ;; Conventional minor modes (see node "Minor Mode Conventions" in the elisp
  91 ;; manual) are handled in the following way:
  92 ;; When `desktop-save' saves the state of a buffer to the desktop file, it
  93 ;; saves as `desktop-minor-modes' the list of names of those variables in
  94 ;; `minor-mode-alist' that have a non-nil value.
  95 ;; When `desktop-create' restores the buffer, each of the symbols in
  96 ;; `desktop-minor-modes' is called as function with parameter 1.
  97 ;; The variables `desktop-minor-mode-table' and `desktop-minor-mode-handlers'
  98 ;; are used to handle non-conventional minor modes.  `desktop-save' uses
  99 ;; `desktop-minor-mode-table' to map minor mode variables to minor mode
 100 ;; functions before writing `desktop-minor-modes'.  If a minor mode has a
 101 ;; variable name that is different form its function name, an entry
 102
 103 ;;    (NAME RESTORE-FUNCTION)
 104
 105 ;; should be added to `desktop-minor-mode-table'.  If a minor mode should not
 106 ;; be restored, RESTORE-FUNCTION should be set to nil.  `desktop-create' uses
 107 ;; `desktop-minor-mode-handlers' to lookup minor modes that needs a restore
 108 ;; function different from the usual minor mode function.
 109 ;; ---------------------------------------------------------------------------
 110
 111 ;; By the way: don't use desktop.el to customize Emacs -- the file .emacs
 112 ;; in your home directory is used for that.  Saving global default values
 113 ;; for buffers is an example of misuse.
 114
 115 ;; PLEASE NOTE: The kill ring can be saved as specified by the variable
 116 ;; `desktop-globals-to-save' (by default it isn't).  This may result in saving
 117 ;; things you did not mean to keep.  Use M-x desktop-clear RET.
 118
 119 ;; Thanks to  hetrick@phys.uva.nl (Jim Hetrick)      for useful ideas.
 120 ;;            avk@rtsg.mot.com (Andrew V. Klein)     for a dired tip.
 121 ;;            chris@tecc.co.uk (Chris Boucher)       for a mark tip.
 122 ;;            f89-kam@nada.kth.se (Klas Mellbourn)   for a mh-e tip.
 123 ;;            kifer@sbkifer.cs.sunysb.edu (M. Kifer) for a bug hunt.
 124 ;;            treese@lcs.mit.edu (Win Treese)        for ange-ftp tips.
 125 ;;            pot@cnuce.cnr.it (Francesco Potorti`)  for misc. tips.
 126 ;; ---------------------------------------------------------------------------
 127 ;; TODO:
 128 ;;
 129 ;; Save window configuration.
 130 ;; Recognize more minor modes.
 131 ;; Save mark rings.
 132
 133 ;;; Code:
 134
 135 (defvar desktop-file-version "206"
 136   "Version number of desktop file format.
 137 Written into the desktop file and used at desktop read to provide
 138 backward compatibility.")
 139
 140 ;; ----------------------------------------------------------------------------
 141 ;; USER OPTIONS -- settings you might want to play with.
 142 ;; ----------------------------------------------------------------------------
 143
 144 (defgroup desktop nil
 145   "Save status of Emacs when you exit."
 146   :group 'frames)
 147
 148 ;; Maintained for backward compatibility
 149 (define-obsolete-variable-alias 'desktop-enable 'desktop-save-mode "22.1")
 150 ;;;###autoload
 151 (define-minor-mode desktop-save-mode
 152   "Toggle desktop saving (Desktop Save mode).
 153 With a prefix argument ARG, enable Desktop Save mode if ARG is
 154 positive, and disable it otherwise.  If called from Lisp, enable
 155 the mode if ARG is omitted or nil.
 156
 157 If Desktop Save mode is enabled, the state of Emacs is saved from
 158 one session to another.  See variable `desktop-save' and function
 159 `desktop-read' for details."
 160   :global t
 161   :group 'desktop)
 162
 163 (defun desktop-save-mode-off ()
 164   "Disable `desktop-save-mode'.  Provided for use in hooks."
 165   (desktop-save-mode 0))
 166
 167 (defcustom desktop-save 'ask-if-new
 168   "Specifies whether the desktop should be saved when it is killed.
 169 A desktop is killed when the user changes desktop or quits Emacs.
 170 Possible values are:
 171    t             -- always save.
 172    ask           -- always ask.
 173    ask-if-new    -- ask if no desktop file exists, otherwise just save.
 174    ask-if-exists -- ask if desktop file exists, otherwise don't save.
 175    if-exists     -- save if desktop file exists, otherwise don't save.
 176    nil           -- never save.
 177 The desktop is never saved when `desktop-save-mode' is nil.
 178 The variables `desktop-dirname' and `desktop-base-file-name'
 179 determine where the desktop is saved."
 180   :type
 181   '(choice
 182     (const :tag "Always save" t)
 183     (const :tag "Always ask" ask)
 184     (const :tag "Ask if desktop file is new, else do save" ask-if-new)
 185     (const :tag "Ask if desktop file exists, else don't save" ask-if-exists)
 186     (const :tag "Save if desktop file exists, else don't" if-exists)
 187     (const :tag "Never save" nil))
 188   :group 'desktop
 189   :version "22.1")
 190
 191 (defcustom desktop-load-locked-desktop 'ask
 192   "Specifies whether the desktop should be loaded if locked.
 193 Possible values are:
 194    t    -- load anyway.
 195    nil  -- don't load.
 196    ask  -- ask the user.
 197 If the value is nil, or `ask' and the user chooses not to load the desktop,
 198 the normal hook `desktop-not-loaded-hook' is run."
 199   :type
 200   '(choice
 201     (const :tag "Load anyway" t)
 202     (const :tag "Don't load" nil)
 203     (const :tag "Ask the user" ask))
 204   :group 'desktop
 205   :version "22.2")
 206
 207 (define-obsolete-variable-alias 'desktop-basefilename
 208                                 'desktop-base-file-name "22.1")
 209
 210 (defcustom desktop-base-file-name
 211   (convert-standard-filename ".emacs.desktop")
 212   "Name of file for Emacs desktop, excluding the directory part."
 213   :type 'file
 214   :group 'desktop)
 215
 216 (defcustom desktop-base-lock-name
 217   (convert-standard-filename ".emacs.desktop.lock")
 218   "Name of lock file for Emacs desktop, excluding the directory part."
 219   :type 'file
 220   :group 'desktop
 221   :version "22.2")
 222
 223 (defcustom desktop-path (list "." user-emacs-directory "~")
 224   "List of directories to search for the desktop file.
 225 The base name of the file is specified in `desktop-base-file-name'."
 226   :type '(repeat directory)
 227   :group 'desktop
 228   :version "23.2")                      ; user-emacs-directory added
 229
 230 (defcustom desktop-missing-file-warning nil
 231   "If non-nil, offer to recreate the buffer of a deleted file.
 232 Also pause for a moment to display message about errors signaled in
 233 `desktop-buffer-mode-handlers'.
 234
 235 If nil, just print error messages in the message buffer."
 236   :type 'boolean
 237   :group 'desktop
 238   :version "22.1")
 239
 240 (defcustom desktop-no-desktop-file-hook nil
 241   "Normal hook run when `desktop-read' can't find a desktop file.
 242 Run in the directory in which the desktop file was sought.
 243 May be used to show a dired buffer."
 244   :type 'hook
 245   :group 'desktop
 246   :version "22.1")
 247
 248 (defcustom desktop-not-loaded-hook nil
 249   "Normal hook run when the user declines to re-use a desktop file.
 250 Run in the directory in which the desktop file was found.
 251 May be used to deal with accidental multiple Emacs jobs."
 252   :type 'hook
 253   :group 'desktop
 254   :options '(desktop-save-mode-off save-buffers-kill-emacs)
 255   :version "22.2")
 256
 257 (defcustom desktop-after-read-hook nil
 258   "Normal hook run after a successful `desktop-read'.
 259 May be used to show a buffer list."
 260   :type 'hook
 261   :group 'desktop
 262   :options '(list-buffers)
 263   :version "22.1")
 264
 265 (defcustom desktop-save-hook nil
 266   "Normal hook run before the desktop is saved in a desktop file.
 267 Run with the desktop buffer current with only the header present.
 268 May be used to add to the desktop code or to truncate history lists,
 269 for example."
 270   :type 'hook
 271   :group 'desktop)
 272
 273 (defcustom desktop-globals-to-save
 274   '(desktop-missing-file-warning
 275     tags-file-name
 276     tags-table-list
 277     search-ring
 278     regexp-search-ring
 279     register-alist
 280     file-name-history)
 281   "List of global variables saved by `desktop-save'.
 282 An element may be variable name (a symbol) or a cons cell of the form
 283 \(VAR . MAX-SIZE), which means to truncate VAR's value to at most
 284 MAX-SIZE elements (if the value is a list) before saving the value.
 285 Feature: Saving `kill-ring' implies saving `kill-ring-yank-pointer'."
 286   :type '(repeat (restricted-sexp :match-alternatives (symbolp consp)))
 287   :group 'desktop)
 288
 289 (defcustom desktop-globals-to-clear
 290   '(kill-ring
 291     kill-ring-yank-pointer
 292     search-ring
 293     search-ring-yank-pointer
 294     regexp-search-ring
 295     regexp-search-ring-yank-pointer)
 296   "List of global variables that `desktop-clear' will clear.
 297 An element may be variable name (a symbol) or a cons cell of the form
 298 \(VAR . FORM).  Symbols are set to nil and for cons cells VAR is set
 299 to the value obtained by evaluating FORM."
 300   :type '(repeat (restricted-sexp :match-alternatives (symbolp consp)))
 301   :group 'desktop
 302   :version "22.1")
 303
 304 (defcustom desktop-clear-preserve-buffers
 305   '("\\*scratch\\*" "\\*Messages\\*" "\\*server\\*" "\\*tramp/.+\\*"
 306     "\\*Warnings\\*")
 307   "List of buffers that `desktop-clear' should not delete.
 308 Each element is a regular expression.  Buffers with a name matched by any of
 309 these won't be deleted."
 310   :version "23.3"                       ; added Warnings - bug#6336
 311   :type '(repeat string)
 312   :group 'desktop)
 313
 314 ;;;###autoload
 315 (defcustom desktop-locals-to-save
 316   '(desktop-locals-to-save  ; Itself!  Think it over.
 317     truncate-lines
 318     case-fold-search
 319     case-replace
 320     fill-column
 321     overwrite-mode
 322     change-log-default-name
 323     line-number-mode
 324     column-number-mode
 325     size-indication-mode
 326     buffer-file-coding-system
 327     indent-tabs-mode
 328     tab-width
 329     indicate-buffer-boundaries
 330     indicate-empty-lines
 331     show-trailing-whitespace)
 332   "List of local variables to save for each buffer.
 333 The variables are saved only when they really are local.  Conventional minor
 334 modes are restored automatically; they should not be listed here."
 335   :type '(repeat symbol)
 336   :group 'desktop)
 337
 338 (defcustom desktop-buffers-not-to-save nil
 339   "Regexp identifying buffers that are to be excluded from saving."
 340   :type '(choice (const :tag "None" nil)
 341                  regexp)
 342   :version "23.2"                       ; set to nil
 343   :group 'desktop)
 344
 345 ;; Skip tramp and ange-ftp files
 346 (defcustom desktop-files-not-to-save
 347   "\\(^/[^/:]*:\\|(ftp)$\\)"
 348   "Regexp identifying files whose buffers are to be excluded from saving."
 349   :type '(choice (const :tag "None" nil)
 350                  regexp)
 351   :group 'desktop)
 352
 353 ;; We skip TAGS files to save time (tags-file-name is saved instead).
 354 (defcustom desktop-modes-not-to-save
 355   '(tags-table-mode)
 356   "List of major modes whose buffers should not be saved."
 357   :type '(repeat symbol)
 358   :group 'desktop)
 359
 360 (defcustom desktop-file-name-format 'absolute
 361   "Format in which desktop file names should be saved.
 362 Possible values are:
 363    absolute -- Absolute file name.
 364    tilde    -- Relative to ~.
 365    local    -- Relative to directory of desktop file."
 366   :type '(choice (const absolute) (const tilde) (const local))
 367   :group 'desktop
 368   :version "22.1")
 369
 370 (defcustom desktop-restore-eager t
 371   "Number of buffers to restore immediately.
 372 Remaining buffers are restored lazily (when Emacs is idle).
 373 If value is t, all buffers are restored immediately."
 374   :type '(choice (const t) integer)
 375   :group 'desktop
 376   :version "22.1")
 377
 378 (defcustom desktop-lazy-verbose t
 379   "Verbose reporting of lazily created buffers."
 380   :type 'boolean
 381   :group 'desktop
 382   :version "22.1")
 383
 384 (defcustom desktop-lazy-idle-delay 5
 385   "Idle delay before starting to create buffers.
 386 See `desktop-restore-eager'."
 387   :type 'integer
 388   :group 'desktop
 389   :version "22.1")
 390
 391 ;;;###autoload
 392 (defvar desktop-save-buffer nil
 393   "When non-nil, save buffer status in desktop file.
 394 This variable becomes buffer local when set.
 395
 396 If the value is a function, it is called by `desktop-save' with argument
 397 DESKTOP-DIRNAME to obtain auxiliary information to save in the desktop
 398 file along with the state of the buffer for which it was called.
 399
 400 When file names are returned, they should be formatted using the call
 401 \"(desktop-file-name FILE-NAME DESKTOP-DIRNAME)\".
 402
 403 Later, when `desktop-read' evaluates the desktop file, auxiliary information
 404 is passed as the argument DESKTOP-BUFFER-MISC to functions in
 405 `desktop-buffer-mode-handlers'.")
 406 (make-variable-buffer-local 'desktop-save-buffer)
 407 (make-obsolete-variable 'desktop-buffer-modes-to-save
 408                         'desktop-save-buffer "22.1")
 409 (make-obsolete-variable 'desktop-buffer-misc-functions
 410                         'desktop-save-buffer "22.1")
 411
 412 ;;;###autoload
 413 (defvar desktop-buffer-mode-handlers
 414   nil
 415   "Alist of major mode specific functions to restore a desktop buffer.
 416 Functions listed are called by `desktop-create-buffer' when `desktop-read'
 417 evaluates the desktop file.  List elements must have the form
 418
 419    (MAJOR-MODE . RESTORE-BUFFER-FUNCTION).
 420
 421 Buffers with a major mode not specified here, are restored by the default
 422 handler `desktop-restore-file-buffer'.
 423
 424 Handlers are called with argument list
 425
 426    (DESKTOP-BUFFER-FILE-NAME DESKTOP-BUFFER-NAME DESKTOP-BUFFER-MISC)
 427
 428 Furthermore, they may use the following variables:
 429
 430    desktop-file-version
 431    desktop-buffer-major-mode
 432    desktop-buffer-minor-modes
 433    desktop-buffer-point
 434    desktop-buffer-mark
 435    desktop-buffer-read-only
 436    desktop-buffer-locals
 437
 438 If a handler returns a buffer, then the saved mode settings
 439 and variable values for that buffer are copied into it.
 440
 441 Modules that define a major mode that needs a special handler should contain
 442 code like
 443
 444    (defun foo-restore-desktop-buffer
 445    ...
 446    (add-to-list 'desktop-buffer-mode-handlers
 447                 '(foo-mode . foo-restore-desktop-buffer))
 448
 449 Furthermore the major mode function must be autoloaded.")
 450
 451 ;;;###autoload
 452 (put 'desktop-buffer-mode-handlers 'risky-local-variable t)
 453 (make-obsolete-variable 'desktop-buffer-handlers
 454                         'desktop-buffer-mode-handlers "22.1")
 455
 456 (defcustom desktop-minor-mode-table
 457   '((auto-fill-function auto-fill-mode)
 458     (vc-mode nil)
 459     (vc-dired-mode nil)
 460     (erc-track-minor-mode nil)
 461     (savehist-mode nil))
 462   "Table mapping minor mode variables to minor mode functions.
 463 Each entry has the form (NAME RESTORE-FUNCTION).
 464 NAME is the name of the buffer-local variable indicating that the minor
 465 mode is active.  RESTORE-FUNCTION is the function to activate the minor mode.
 466 RESTORE-FUNCTION nil means don't try to restore the minor mode.
 467 Only minor modes for which the name of the buffer-local variable
 468 and the name of the minor mode function are different have to be added to
 469 this table.  See also `desktop-minor-mode-handlers'."
 470   :type 'sexp
 471   :group 'desktop)
 472
 473 ;;;###autoload
 474 (defvar desktop-minor-mode-handlers
 475   nil
 476   "Alist of functions to restore non-standard minor modes.
 477 Functions are called by `desktop-create-buffer' to restore minor modes.
 478 List elements must have the form
 479
 480    (MINOR-MODE . RESTORE-FUNCTION).
 481
 482 Minor modes not specified here, are restored by the standard minor mode
 483 function.
 484
 485 Handlers are called with argument list
 486
 487    (DESKTOP-BUFFER-LOCALS)
 488
 489 Furthermore, they may use the following variables:
 490
 491    desktop-file-version
 492    desktop-buffer-file-name
 493    desktop-buffer-name
 494    desktop-buffer-major-mode
 495    desktop-buffer-minor-modes
 496    desktop-buffer-point
 497    desktop-buffer-mark
 498    desktop-buffer-read-only
 499    desktop-buffer-misc
 500
 501 When a handler is called, the buffer has been created and the major mode has
 502 been set, but local variables listed in desktop-buffer-locals has not yet been
 503 created and set.
 504
 505 Modules that define a minor mode that needs a special handler should contain
 506 code like
 507
 508    (defun foo-desktop-restore
 509    ...
 510    (add-to-list 'desktop-minor-mode-handlers
 511                 '(foo-mode . foo-desktop-restore))
 512
 513 Furthermore the minor mode function must be autoloaded.
 514
 515 See also `desktop-minor-mode-table'.")
 516
 517 ;;;###autoload
 518 (put 'desktop-minor-mode-handlers 'risky-local-variable t)
 519
 520 ;; ----------------------------------------------------------------------------
 521 (defvar desktop-dirname nil
 522   "The directory in which the desktop file should be saved.")
 523
 524 (defun desktop-full-file-name (&optional dirname)
 525   "Return the full name of the desktop file in DIRNAME.
 526 DIRNAME omitted or nil means use `desktop-dirname'."
 527   (expand-file-name desktop-base-file-name (or dirname desktop-dirname)))
 528
 529 (defun desktop-full-lock-name (&optional dirname)
 530   "Return the full name of the desktop lock file in DIRNAME.
 531 DIRNAME omitted or nil means use `desktop-dirname'."
 532   (expand-file-name desktop-base-lock-name (or dirname desktop-dirname)))
 533
 534 (defconst desktop-header
 535 ";; --------------------------------------------------------------------------
 536 ;; Desktop File for Emacs
 537 ;; --------------------------------------------------------------------------
 538 " "*Header to place in Desktop file.")
 539
 540 (defvar desktop-delay-hook nil
 541   "Hooks run after all buffers are loaded; intended for internal use.")
 542
 543 ;; ----------------------------------------------------------------------------
 544 ;; Desktop file conflict detection
 545 (defvar desktop-file-modtime nil
 546   "When the desktop file was last modified to the knowledge of this Emacs.
 547 Used to detect desktop file conflicts.")
 548
 549 (defun desktop-owner (&optional dirname)
 550   "Return the PID of the Emacs process that owns the desktop file in DIRNAME.
 551 Return nil if no desktop file found or no Emacs process is using it.
 552 DIRNAME omitted or nil means use `desktop-dirname'."
 553   (let (owner)
 554     (and (file-exists-p (desktop-full-lock-name dirname))
 555          (condition-case nil
 556              (with-temp-buffer
 557                (insert-file-contents-literally (desktop-full-lock-name dirname))
 558                (goto-char (point-min))
 559                (setq owner (read (current-buffer)))
 560                (integerp owner))
 561            (error nil))
 562          owner)))
 563
 564 (defun desktop-claim-lock (&optional dirname)
 565   "Record this Emacs process as the owner of the desktop file in DIRNAME.
 566 DIRNAME omitted or nil means use `desktop-dirname'."
 567   (write-region (number-to-string (emacs-pid)) nil
 568                 (desktop-full-lock-name dirname)))
 569
 570 (defun desktop-release-lock (&optional dirname)
 571   "Remove the lock file for the desktop in DIRNAME.
 572 DIRNAME omitted or nil means use `desktop-dirname'."
 573   (let ((file (desktop-full-lock-name dirname)))
 574     (when (file-exists-p file) (delete-file file))))
 575
 576 ;; ----------------------------------------------------------------------------
 577 (defun desktop-truncate (list n)
 578   "Truncate LIST to at most N elements destructively."
 579   (let ((here (nthcdr (1- n) list)))
 580     (when (consp here)
 581       (setcdr here nil))))
 582
 583 ;; ----------------------------------------------------------------------------
 584 ;;;###autoload
 585 (defun desktop-clear ()
 586   "Empty the Desktop.
 587 This kills all buffers except for internal ones and those with names matched by
 588 a regular expression in the list `desktop-clear-preserve-buffers'.
 589 Furthermore, it clears the variables listed in `desktop-globals-to-clear'."
 590   (interactive)
 591   (desktop-lazy-abort)
 592   (dolist (var desktop-globals-to-clear)
 593     (if (symbolp var)
 594         (eval `(setq-default ,var nil))
 595       (eval `(setq-default ,(car var) ,(cdr var)))))
 596   (let ((buffers (buffer-list))
 597         (preserve-regexp (concat "^\\("
 598                                  (mapconcat (lambda (regexp)
 599                                               (concat "\\(" regexp "\\)"))
 600                                             desktop-clear-preserve-buffers
 601                                             "\\|")
 602                                  "\\)$")))
 603     (while buffers
 604       (let ((bufname (buffer-name (car buffers))))
 605          (or
 606            (null bufname)
 607            (string-match preserve-regexp bufname)
 608            ;; Don't kill buffers made for internal purposes.
 609            (and (not (equal bufname "")) (eq (aref bufname 0) ?\s))
 610            (kill-buffer (car buffers))))
 611       (setq buffers (cdr buffers))))
 612   (delete-other-windows))
 613
 614 ;; ----------------------------------------------------------------------------
 615 (unless noninteractive
 616   (add-hook 'kill-emacs-hook 'desktop-kill))
 617
 618 (defun desktop-kill ()
 619   "If `desktop-save-mode' is non-nil, do what `desktop-save' says to do.
 620 If the desktop should be saved and `desktop-dirname'
 621 is nil, ask the user where to save the desktop."
 622   (when (and desktop-save-mode
 623              (let ((exists (file-exists-p (desktop-full-file-name))))
 624                (or (eq desktop-save t)
 625                    (and exists (eq desktop-save 'if-exists))
 626                    ;; If it exists, but we aren't using it, we are going
 627                    ;; to ask for a new directory below.
 628                    (and exists desktop-dirname (eq desktop-save 'ask-if-new))
 629                    (and
 630                     (or (memq desktop-save '(ask ask-if-new))
 631                         (and exists (eq desktop-save 'ask-if-exists)))
 632                     (y-or-n-p "Save desktop? ")))))
 633     (unless desktop-dirname
 634       (setq desktop-dirname
 635             (file-name-as-directory
 636              (expand-file-name
 637               (read-directory-name "Directory for desktop file: " nil nil t)))))
 638     (condition-case err
 639         (desktop-save desktop-dirname t)
 640       (file-error
 641        (unless (yes-or-no-p "Error while saving the desktop.  Ignore? ")
 642          (signal (car err) (cdr err))))))
 643   ;; If we own it, we don't anymore.
 644   (when (eq (emacs-pid) (desktop-owner)) (desktop-release-lock)))
 645
 646 ;; ----------------------------------------------------------------------------
 647 (defun desktop-list* (&rest args)
 648   (if (null (cdr args))
 649       (car args)
 650     (setq args (nreverse args))
 651     (let ((value (cons (nth 1 args) (car args))))
 652       (setq args (cdr (cdr args)))
 653       (while args
 654         (setq value (cons (car args) value))
 655         (setq args (cdr args)))
 656       value)))
 657
 658 ;; ----------------------------------------------------------------------------
 659 (defun desktop-buffer-info (buffer)
 660   (set-buffer buffer)
 661   (list
 662    ;; base name of the buffer; replaces the buffer name if managed by uniquify
 663    (and (fboundp 'uniquify-buffer-base-name) (uniquify-buffer-base-name))
 664    ;; basic information
 665    (desktop-file-name (buffer-file-name) desktop-dirname)
 666    (buffer-name)
 667    major-mode
 668    ;; minor modes
 669    (let (ret)
 670      (mapc
 671       #'(lambda (minor-mode)
 672           (and (boundp minor-mode)
 673                (symbol-value minor-mode)
 674                (let* ((special (assq minor-mode desktop-minor-mode-table))
 675                       (value (cond (special (cadr special))
 676                                    ((functionp minor-mode) minor-mode))))
 677                  (when value (add-to-list 'ret value)))))
 678       (mapcar #'car minor-mode-alist))
 679      ret)
 680    ;; point and mark, and read-only status
 681    (point)
 682    (list (mark t) mark-active)
 683    buffer-read-only
 684    ;; auxiliary information
 685    (when (functionp desktop-save-buffer)
 686      (funcall desktop-save-buffer desktop-dirname))
 687    ;; local variables
 688    (let ((locals desktop-locals-to-save)
 689          (loclist (buffer-local-variables))
 690          (ll))
 691      (while locals
 692        (let ((here (assq (car locals) loclist)))
 693          (if here
 694              (setq ll (cons here ll))
 695            (when (member (car locals) loclist)
 696              (setq ll (cons (car locals) ll)))))
 697        (setq locals (cdr locals)))
 698      ll)))
 699
 700 ;; ----------------------------------------------------------------------------
 701 (defun desktop-internal-v2s (value)
 702   "Convert VALUE to a pair (QUOTE . TXT); (eval (read TXT)) gives VALUE.
 703 TXT is a string that when read and evaluated yields VALUE.
 704 QUOTE may be `may' (value may be quoted),
 705 `must' (value must be quoted), or nil (value must not be quoted)."
 706   (cond
 707     ((or (numberp value) (null value) (eq t value) (keywordp value))
 708      (cons 'may (prin1-to-string value)))
 709     ((stringp value)
 710      (let ((copy (copy-sequence value)))
 711        (set-text-properties 0 (length copy) nil copy)
 712        ;; Get rid of text properties because we cannot read them
 713        (cons 'may (prin1-to-string copy))))
 714     ((symbolp value)
 715      (cons 'must (prin1-to-string value)))
 716     ((vectorp value)
 717      (let* ((special nil)
 718             (pass1 (mapcar
 719                     (lambda (el)
 720                       (let ((res (desktop-internal-v2s el)))
 721                         (if (null (car res))
 722                             (setq special t))
 723                         res))
 724                     value)))
 725        (if special
 726            (cons nil (concat "(vector "
 727                              (mapconcat (lambda (el)
 728                                           (if (eq (car el) 'must)
 729                                               (concat "'" (cdr el))
 730                                             (cdr el)))
 731                                         pass1
 732                                         " ")
 733                              ")"))
 734          (cons 'may (concat "[" (mapconcat 'cdr pass1 " ") "]")))))
 735     ((consp value)
 736      (let ((p value)
 737            newlist
 738            use-list*
 739            anynil)
 740        (while (consp p)
 741          (let ((q.txt (desktop-internal-v2s (car p))))
 742            (or anynil (setq anynil (null (car q.txt))))
 743            (setq newlist (cons q.txt newlist)))
 744          (setq p (cdr p)))
 745        (if p
 746            (let ((last (desktop-internal-v2s p)))
 747              (or anynil (setq anynil (null (car last))))
 748              (or anynil
 749                  (setq newlist (cons '(must . ".") newlist)))
 750              (setq use-list* t)
 751              (setq newlist (cons last newlist))))
 752        (setq newlist (nreverse newlist))
 753        (if anynil
 754            (cons nil
 755                  (concat (if use-list* "(desktop-list* "  "(list ")
 756                          (mapconcat (lambda (el)
 757                                       (if (eq (car el) 'must)
 758                                           (concat "'" (cdr el))
 759                                         (cdr el)))
 760                                     newlist
 761                                     " ")
 762                          ")"))
 763          (cons 'must
 764                (concat "(" (mapconcat 'cdr newlist " ") ")")))))
 765     ((subrp value)
 766      (cons nil (concat "(symbol-function '"
 767                        (substring (prin1-to-string value) 7 -1)
 768                        ")")))
 769     ((markerp value)
 770      (let ((pos (prin1-to-string (marker-position value)))
 771            (buf (prin1-to-string (buffer-name (marker-buffer value)))))
 772        (cons nil (concat "(let ((mk (make-marker)))"
 773                          " (add-hook 'desktop-delay-hook"
 774                          " (list 'lambda '() (list 'set-marker mk "
 775                          pos " (get-buffer " buf ")))) mk)"))))
 776     (t                                   ; save as text
 777      (cons 'may "\"Unprintable entity\""))))
 778
 779 ;; ----------------------------------------------------------------------------
 780 (defun desktop-value-to-string (value)
 781   "Convert VALUE to a string that when read evaluates to the same value.
 782 Not all types of values are supported."
 783   (let* ((print-escape-newlines t)
 784          (float-output-format nil)
 785          (quote.txt (desktop-internal-v2s value))
 786          (quote (car quote.txt))
 787          (txt (cdr quote.txt)))
 788     (if (eq quote 'must)
 789         (concat "'" txt)
 790       txt)))
 791
 792 ;; ----------------------------------------------------------------------------
 793 (defun desktop-outvar (varspec)
 794   "Output a setq statement for variable VAR to the desktop file.
 795 The argument VARSPEC may be the variable name VAR (a symbol),
 796 or a cons cell of the form (VAR . MAX-SIZE),
 797 which means to truncate VAR's value to at most MAX-SIZE elements
 798 \(if the value is a list) before saving the value."
 799   (let (var size)
 800     (if (consp varspec)
 801         (setq var (car varspec) size (cdr varspec))
 802       (setq var varspec))
 803     (when (boundp var)
 804       (when (and (integerp size)
 805                  (> size 0)
 806                  (listp (eval var)))
 807         (desktop-truncate (eval var) size))
 808       (insert "(setq "
 809               (symbol-name var)
 810               " "
 811               (desktop-value-to-string (symbol-value var))
 812               ")\n"))))
 813
 814 ;; ----------------------------------------------------------------------------
 815 (defun desktop-save-buffer-p (filename bufname mode &rest _dummy)
 816   "Return t if buffer should have its state saved in the desktop file.
 817 FILENAME is the visited file name, BUFNAME is the buffer name, and
 818 MODE is the major mode.
 819 \n\(fn FILENAME BUFNAME MODE)"
 820   (let ((case-fold-search nil)
 821         dired-skip)
 822     (and (not (and (stringp desktop-buffers-not-to-save)
 823                    (not filename)
 824                    (string-match desktop-buffers-not-to-save bufname)))
 825          (not (memq mode desktop-modes-not-to-save))
 826          ;; FIXME this is broken if desktop-files-not-to-save is nil.
 827          (or (and filename
 828                   (stringp desktop-files-not-to-save)
 829                   (not (string-match desktop-files-not-to-save filename)))
 830              (and (eq mode 'dired-mode)
 831                   (with-current-buffer bufname
 832                     (not (setq dired-skip
 833                                (string-match desktop-files-not-to-save
 834                                              default-directory)))))
 835              (and (null filename)
 836                   (null dired-skip)     ; bug#5755
 837                   (with-current-buffer bufname desktop-save-buffer))))))
 838
 839 ;; ----------------------------------------------------------------------------
 840 (defun desktop-file-name (filename dirname)
 841   "Convert FILENAME to format specified in `desktop-file-name-format'.
 842 DIRNAME must be the directory in which the desktop file will be saved."
 843   (cond
 844     ((not filename) nil)
 845     ((eq desktop-file-name-format 'tilde)
 846      (let ((relative-name (file-relative-name (expand-file-name filename) "~")))
 847        (cond
 848          ((file-name-absolute-p relative-name) relative-name)
 849          ((string= "./" relative-name) "~/")
 850          ((string= "." relative-name) "~")
 851          (t (concat "~/" relative-name)))))
 852     ((eq desktop-file-name-format 'local) (file-relative-name filename dirname))
 853     (t (expand-file-name filename))))
 854
 855
 856 ;; ----------------------------------------------------------------------------
 857 ;;;###autoload
 858 (defun desktop-save (dirname &optional release)
 859   "Save the desktop in a desktop file.
 860 Parameter DIRNAME specifies where to save the desktop file.
 861 Optional parameter RELEASE says whether we're done with this desktop.
 862 See also `desktop-base-file-name'."
 863   (interactive "DDirectory to save desktop file in: ")
 864   (setq desktop-dirname (file-name-as-directory (expand-file-name dirname)))
 865   (save-excursion
 866     (let ((eager desktop-restore-eager)
 867           (new-modtime (nth 5 (file-attributes (desktop-full-file-name)))))
 868       (when
 869           (or (not new-modtime)         ; nothing to overwrite
 870               (equal desktop-file-modtime new-modtime)
 871               (yes-or-no-p (if desktop-file-modtime
 872                                (if (> (float-time new-modtime) (float-time desktop-file-modtime))
 873                                    "Desktop file is more recent than the one loaded.  Save anyway? "
 874                                  "Desktop file isn't the one loaded.  Overwrite it? ")
 875                              "Current desktop was not loaded from a file.  Overwrite this desktop file? "))
 876               (unless release (error "Desktop file conflict")))
 877
 878         ;; If we're done with it, release the lock.
 879         ;; Otherwise, claim it if it's unclaimed or if we created it.
 880         (if release
 881             (desktop-release-lock)
 882           (unless (and new-modtime (desktop-owner)) (desktop-claim-lock)))
 883
 884         (with-temp-buffer
 885           (insert
 886            ";; -*- mode: emacs-lisp; coding: emacs-mule; -*-\n"
 887            desktop-header
 888            ";; Created " (current-time-string) "\n"
 889            ";; Desktop file format version " desktop-file-version "\n"
 890            ";; Emacs version " emacs-version "\n")
 891           (save-excursion (run-hooks 'desktop-save-hook))
 892           (goto-char (point-max))
 893           (insert "\n;; Global section:\n")
 894           (mapc (function desktop-outvar) desktop-globals-to-save)
 895           (when (memq 'kill-ring desktop-globals-to-save)
 896             (insert
 897              "(setq kill-ring-yank-pointer (nthcdr "
 898              (int-to-string (- (length kill-ring) (length kill-ring-yank-pointer)))
 899              " kill-ring))\n"))
 900
 901           (insert "\n;; Buffer section -- buffers listed in same order as in buffer list:\n")
 902           (dolist (l (mapcar 'desktop-buffer-info (buffer-list)))
 903             (let ((base (pop l)))
 904               (when (apply 'desktop-save-buffer-p l)
 905                 (insert "("
 906                         (if (or (not (integerp eager))
 907                                 (if (zerop eager)
 908                                     nil
 909                                   (setq eager (1- eager))))
 910                             "desktop-create-buffer"
 911                           "desktop-append-buffer-args")
 912                         " "
 913                         desktop-file-version)
 914                 ;; If there's a non-empty base name, we save it instead of the buffer name
 915                 (when (and base (not (string= base "")))
 916                   (setcar (nthcdr 1 l) base))
 917                 (dolist (e l)
 918                   (insert "\n  " (desktop-value-to-string e)))
 919                 (insert ")\n\n"))))
 920
 921           (setq default-directory desktop-dirname)
 922           (let ((coding-system-for-write 'emacs-mule))
 923             (write-region (point-min) (point-max) (desktop-full-file-name) nil 'nomessage))
 924           ;; We remember when it was modified (which is presumably just now).
 925           (setq desktop-file-modtime (nth 5 (file-attributes (desktop-full-file-name)))))))))
 926
 927 ;; ----------------------------------------------------------------------------
 928 ;;;###autoload
 929 (defun desktop-remove ()
 930   "Delete desktop file in `desktop-dirname'.
 931 This function also sets `desktop-dirname' to nil."
 932   (interactive)
 933   (when desktop-dirname
 934     (let ((filename (desktop-full-file-name)))
 935       (setq desktop-dirname nil)
 936       (when (file-exists-p filename)
 937         (delete-file filename)))))
 938
 939 (defvar desktop-buffer-args-list nil
 940   "List of args for `desktop-create-buffer'.")
 941
 942 (defvar desktop-lazy-timer nil)
 943
 944 ;; ----------------------------------------------------------------------------
 945 ;;;###autoload
 946 (defun desktop-read (&optional dirname)
 947   "Read and process the desktop file in directory DIRNAME.
 948 Look for a desktop file in DIRNAME, or if DIRNAME is omitted, look in
 949 directories listed in `desktop-path'.  If a desktop file is found, it
 950 is processed and `desktop-after-read-hook' is run.  If no desktop file
 951 is found, clear the desktop and run `desktop-no-desktop-file-hook'.
 952 This function is a no-op when Emacs is running in batch mode.
 953 It returns t if a desktop file was loaded, nil otherwise."
 954   (interactive)
 955   (unless noninteractive
 956     (setq desktop-dirname
 957           (file-name-as-directory
 958            (expand-file-name
 959             (or
 960              ;; If DIRNAME is specified, use it.
 961              (and (< 0 (length dirname)) dirname)
 962              ;; Otherwise search desktop file in desktop-path.
 963              (let ((dirs desktop-path))
 964                (while (and dirs
 965                            (not (file-exists-p
 966                                  (desktop-full-file-name (car dirs)))))
 967                  (setq dirs (cdr dirs)))
 968                (and dirs (car dirs)))
 969              ;; If not found and `desktop-path' is non-nil, use its first element.
 970              (and desktop-path (car desktop-path))
 971              ;; Default: Home directory.
 972              "~"))))
 973     (if (file-exists-p (desktop-full-file-name))
 974         ;; Desktop file found, but is it already in use?
 975         (let ((desktop-first-buffer nil)
 976               (desktop-buffer-ok-count 0)
 977               (desktop-buffer-fail-count 0)
 978               (owner (desktop-owner))
 979               ;; Avoid desktop saving during evaluation of desktop buffer.
 980               (desktop-save nil))
 981           (if (and owner
 982                    (memq desktop-load-locked-desktop '(nil ask))
 983                    (or (null desktop-load-locked-desktop)
 984                        (not (y-or-n-p (format "Warning: desktop file appears to be in use by PID %s.\n\
 985 Using it may cause conflicts.  Use it anyway? " owner)))))
 986               (let ((default-directory desktop-dirname))
 987                 (setq desktop-dirname nil)
 988                 (run-hooks 'desktop-not-loaded-hook)
 989                 (unless desktop-dirname
 990                   (message "Desktop file in use; not loaded.")))
 991             (desktop-lazy-abort)
 992             ;; Evaluate desktop buffer and remember when it was modified.
 993             (load (desktop-full-file-name) t t t)
 994             (setq desktop-file-modtime (nth 5 (file-attributes (desktop-full-file-name))))
 995             ;; If it wasn't already, mark it as in-use, to bother other
 996             ;; desktop instances.
 997             (unless owner
 998               (condition-case nil
 999                   (desktop-claim-lock)
1000                 (file-error (message "Couldn't record use of desktop file")
1001                             (sit-for 1))))
1002
1003             ;; `desktop-create-buffer' puts buffers at end of the buffer list.
1004             ;; We want buffers existing prior to evaluating the desktop (and
1005             ;; not reused) to be placed at the end of the buffer list, so we
1006             ;; move them here.
1007             (mapc 'bury-buffer
1008                   (nreverse (cdr (memq desktop-first-buffer (nreverse (buffer-list))))))
1009             (switch-to-buffer (car (buffer-list)))
1010             (run-hooks 'desktop-delay-hook)
1011             (setq desktop-delay-hook nil)
1012             (run-hooks 'desktop-after-read-hook)
1013             (message "Desktop: %d buffer%s restored%s%s."
1014                      desktop-buffer-ok-count
1015                      (if (= 1 desktop-buffer-ok-count) "" "s")
1016                      (if (< 0 desktop-buffer-fail-count)
1017                          (format ", %d failed to restore" desktop-buffer-fail-count)
1018                        "")
1019                      (if desktop-buffer-args-list
1020                          (format ", %d to restore lazily"
1021                                  (length desktop-buffer-args-list))
1022                        ""))
1023             ;; Bury the *Messages* buffer to not reshow it when burying
1024             ;; the buffer we switched to above.
1025             (when (buffer-live-p (get-buffer "*Messages*"))
1026               (bury-buffer "*Messages*"))
1027             ;; Clear all windows' previous and next buffers, these have
1028             ;; been corrupted by the `switch-to-buffer' calls in
1029             ;; `desktop-restore-file-buffer' (bug#11556).  This is a
1030             ;; brute force fix and should be replaced by a more subtle
1031             ;; strategy eventually.
1032             (walk-window-tree (lambda (window)
1033                                 (set-window-prev-buffers window nil)
1034                                 (set-window-next-buffers window nil)))
1035             t))
1036       ;; No desktop file found.
1037       (desktop-clear)
1038       (let ((default-directory desktop-dirname))
1039         (run-hooks 'desktop-no-desktop-file-hook))
1040       (message "No desktop file.")
1041       nil)))
1042
1043 ;; ----------------------------------------------------------------------------
1044 ;; Maintained for backward compatibility
1045 ;;;###autoload
1046 (defun desktop-load-default ()
1047   "Load the `default' start-up library manually.
1048 Also inhibit further loading of it."
1049   (unless inhibit-default-init          ; safety check
1050     (load "default" t t)
1051     (setq inhibit-default-init t)))
1052 (make-obsolete 'desktop-load-default
1053                'desktop-save-mode "22.1")
1054
1055 ;; ----------------------------------------------------------------------------
1056 ;;;###autoload
1057 (defun desktop-change-dir (dirname)
1058   "Change to desktop saved in DIRNAME.
1059 Kill the desktop as specified by variables `desktop-save-mode' and
1060 `desktop-save', then clear the desktop and load the desktop file in
1061 directory DIRNAME."
1062   (interactive "DChange to directory: ")
1063   (setq dirname (file-name-as-directory (expand-file-name dirname desktop-dirname)))
1064   (desktop-kill)
1065   (desktop-clear)
1066   (desktop-read dirname))
1067
1068 ;; ----------------------------------------------------------------------------
1069 ;;;###autoload
1070 (defun desktop-save-in-desktop-dir ()
1071   "Save the desktop in directory `desktop-dirname'."
1072   (interactive)
1073   (if desktop-dirname
1074       (desktop-save desktop-dirname)
1075     (call-interactively 'desktop-save))
1076   (message "Desktop saved in %s" (abbreviate-file-name desktop-dirname)))
1077
1078 ;; ----------------------------------------------------------------------------
1079 ;;;###autoload
1080 (defun desktop-revert ()
1081   "Revert to the last loaded desktop."
1082   (interactive)
1083   (unless desktop-dirname
1084     (error "Unknown desktop directory"))
1085   (unless (file-exists-p (desktop-full-file-name))
1086     (error "No desktop file found"))
1087   (desktop-clear)
1088   (desktop-read desktop-dirname))
1089
1090 (defvar desktop-buffer-major-mode)
1091 (defvar desktop-buffer-locals)
1092 (defvar auto-insert)  ; from autoinsert.el
1093 ;; ----------------------------------------------------------------------------
1094 (defun desktop-restore-file-buffer (buffer-filename
1095                                     _buffer-name
1096                                     _buffer-misc)
1097   "Restore a file buffer."
1098   (when buffer-filename
1099     (if (or (file-exists-p buffer-filename)
1100             (let ((msg (format "Desktop: File \"%s\" no longer exists."
1101                                buffer-filename)))
1102               (if desktop-missing-file-warning
1103                   (y-or-n-p (concat msg " Re-create buffer? "))
1104                 (message "%s" msg)
1105                 nil)))
1106         (let* ((auto-insert nil) ; Disable auto insertion
1107                (coding-system-for-read
1108                 (or coding-system-for-read
1109                     (cdr (assq 'buffer-file-coding-system
1110                                desktop-buffer-locals))))
1111                (buf (find-file-noselect buffer-filename)))
1112           (condition-case nil
1113               (switch-to-buffer buf)
1114             (error (pop-to-buffer buf)))
1115           (and (not (eq major-mode desktop-buffer-major-mode))
1116                (functionp desktop-buffer-major-mode)
1117                (funcall desktop-buffer-major-mode))
1118           buf)
1119       nil)))
1120
1121 (defun desktop-load-file (function)
1122   "Load the file where auto loaded FUNCTION is defined."
1123   (when function
1124     (let ((fcell (and (fboundp function) (symbol-function function))))
1125       (when (and (listp fcell)
1126                  (eq 'autoload (car fcell)))
1127         (load (cadr fcell))))))
1128
1129 ;; ----------------------------------------------------------------------------
1130 ;; Create a buffer, load its file, set its mode, ...;
1131 ;; called from Desktop file only.
1132
1133 ;; Just to silence the byte compiler.
1134
1135 (defvar desktop-first-buffer)          ; Dynamically bound in `desktop-read'
1136
1137 ;; Bound locally in `desktop-read'.
1138 (defvar desktop-buffer-ok-count)
1139 (defvar desktop-buffer-fail-count)
1140
1141 (defun desktop-create-buffer
1142     (file-version
1143      buffer-filename
1144      buffer-name
1145      buffer-majormode
1146      buffer-minormodes
1147      buffer-point
1148      buffer-mark
1149      buffer-readonly
1150      buffer-misc
1151      &optional
1152      buffer-locals)
1153
1154   (let ((desktop-file-version       file-version)
1155         (desktop-buffer-file-name   buffer-filename)
1156         (desktop-buffer-name        buffer-name)
1157         (desktop-buffer-major-mode  buffer-majormode)
1158         (desktop-buffer-minor-modes buffer-minormodes)
1159         (desktop-buffer-point       buffer-point)
1160         (desktop-buffer-mark        buffer-mark)
1161         (desktop-buffer-read-only   buffer-readonly)
1162         (desktop-buffer-misc        buffer-misc)
1163         (desktop-buffer-locals      buffer-locals))
1164     ;; To make desktop files with relative file names possible, we cannot
1165     ;; allow `default-directory' to change. Therefore we save current buffer.
1166     (save-current-buffer
1167       ;; Give major mode module a chance to add a handler.
1168       (desktop-load-file desktop-buffer-major-mode)
1169       (let ((buffer-list (buffer-list))
1170             (result
1171              (condition-case-unless-debug err
1172                  (funcall (or (cdr (assq desktop-buffer-major-mode
1173                                          desktop-buffer-mode-handlers))
1174                               'desktop-restore-file-buffer)
1175                           desktop-buffer-file-name
1176                           desktop-buffer-name
1177                           desktop-buffer-misc)
1178                (error
1179                 (message "Desktop: Can't load buffer %s: %s"
1180                          desktop-buffer-name
1181                          (error-message-string err))
1182                 (when desktop-missing-file-warning (sit-for 1))
1183                 nil))))
1184         (if (bufferp result)
1185             (setq desktop-buffer-ok-count (1+ desktop-buffer-ok-count))
1186           (setq desktop-buffer-fail-count (1+ desktop-buffer-fail-count))
1187           (setq result nil))
1188         ;; Restore buffer list order with new buffer at end. Don't change
1189         ;; the order for old desktop files (old desktop module behavior).
1190         (unless (< desktop-file-version 206)
1191           (mapc 'bury-buffer buffer-list)
1192           (when result (bury-buffer result)))
1193         (when result
1194           (unless (or desktop-first-buffer (< desktop-file-version 206))
1195             (setq desktop-first-buffer result))
1196           (set-buffer result)
1197           (unless (equal (buffer-name) desktop-buffer-name)
1198             (rename-buffer desktop-buffer-name t))
1199           ;; minor modes
1200           (cond ((equal '(t) desktop-buffer-minor-modes) ; backwards compatible
1201                  (auto-fill-mode 1))
1202                 ((equal '(nil) desktop-buffer-minor-modes) ; backwards compatible
1203                  (auto-fill-mode 0))
1204                 (t
1205                  (dolist (minor-mode desktop-buffer-minor-modes)
1206                    ;; Give minor mode module a chance to add a handler.
1207                    (desktop-load-file minor-mode)
1208                    (let ((handler (cdr (assq minor-mode desktop-minor-mode-handlers))))
1209                      (if handler
1210                          (funcall handler desktop-buffer-locals)
1211                        (when (functionp minor-mode)
1212                          (funcall minor-mode 1)))))))
1213           ;; Even though point and mark are non-nil when written by
1214           ;; `desktop-save', they may be modified by handlers wanting to set
1215           ;; point or mark themselves.
1216           (when desktop-buffer-point
1217             (goto-char
1218              (condition-case err
1219                  ;; Evaluate point.  Thus point can be something like
1220                  ;; '(search-forward ...
1221                  (eval desktop-buffer-point)
1222                (error (message "%s" (error-message-string err)) 1))))
1223           (when desktop-buffer-mark
1224             (if (consp desktop-buffer-mark)
1225                 (progn
1226                   (set-mark (car desktop-buffer-mark))
1227                   (setq mark-active (car (cdr desktop-buffer-mark))))
1228               (set-mark desktop-buffer-mark)))
1229           ;; Never override file system if the file really is read-only marked.
1230           (when desktop-buffer-read-only (setq buffer-read-only desktop-buffer-read-only))
1231           (while desktop-buffer-locals
1232             (let ((this (car desktop-buffer-locals)))
1233               (if (consp this)
1234                   ;; an entry of this form `(symbol . value)'
1235                   (progn
1236                     (make-local-variable (car this))
1237                     (set (car this) (cdr this)))
1238                 ;; an entry of the form `symbol'
1239                 (make-local-variable this)
1240                 (makunbound this)))
1241             (setq desktop-buffer-locals (cdr desktop-buffer-locals))))))))
1242
1243 ;; ----------------------------------------------------------------------------
1244 ;; Backward compatibility -- update parameters to 205 standards.
1245 (defun desktop-buffer (buffer-filename buffer-name buffer-majormode
1246                        mim pt mk ro tl fc cfs cr buffer-misc)
1247   (desktop-create-buffer 205 buffer-filename buffer-name
1248                          buffer-majormode (cdr mim) pt mk ro
1249                          buffer-misc
1250                          (list (cons 'truncate-lines tl)
1251                                (cons 'fill-column fc)
1252                                (cons 'case-fold-search cfs)
1253                                (cons 'case-replace cr)
1254                                (cons 'overwrite-mode (car mim)))))
1255
1256 (defun desktop-append-buffer-args (&rest args)
1257   "Append ARGS at end of `desktop-buffer-args-list'.
1258 ARGS must be an argument list for `desktop-create-buffer'."
1259   (setq desktop-buffer-args-list (nconc desktop-buffer-args-list (list args)))
1260   (unless desktop-lazy-timer
1261     (setq desktop-lazy-timer
1262           (run-with-idle-timer desktop-lazy-idle-delay t 'desktop-idle-create-buffers))))
1263
1264 (defun desktop-lazy-create-buffer ()
1265   "Pop args from `desktop-buffer-args-list', create buffer and bury it."
1266   (when desktop-buffer-args-list
1267     (let* ((remaining (length desktop-buffer-args-list))
1268            (args (pop desktop-buffer-args-list))
1269            (buffer-name (nth 2 args))
1270            (msg (format "Desktop lazily opening %s (%s remaining)..."
1271                             buffer-name remaining)))
1272       (when desktop-lazy-verbose
1273         (message "%s" msg))
1274       (let ((desktop-first-buffer nil)
1275             (desktop-buffer-ok-count 0)
1276             (desktop-buffer-fail-count 0))
1277         (apply 'desktop-create-buffer args)
1278         (run-hooks 'desktop-delay-hook)
1279         (setq desktop-delay-hook nil)
1280         (bury-buffer (get-buffer buffer-name))
1281         (when desktop-lazy-verbose
1282           (message "%s%s" msg (if (> desktop-buffer-ok-count 0) "done" "failed")))))))
1283
1284 (defun desktop-idle-create-buffers ()
1285   "Create buffers until the user does something, then stop.
1286 If there are no buffers left to create, kill the timer."
1287   (let ((repeat 1))
1288     (while (and repeat desktop-buffer-args-list)
1289       (save-window-excursion
1290         (desktop-lazy-create-buffer))
1291       (setq repeat (sit-for 0.2))
1292     (unless desktop-buffer-args-list
1293       (cancel-timer desktop-lazy-timer)
1294       (setq desktop-lazy-timer nil)
1295       (message "Lazy desktop load complete")
1296       (sit-for 3)
1297       (message "")))))
1298
1299 (defun desktop-lazy-complete ()
1300   "Run the desktop load to completion."
1301   (interactive)
1302   (let ((desktop-lazy-verbose t))
1303     (while desktop-buffer-args-list
1304       (save-window-excursion
1305         (desktop-lazy-create-buffer)))
1306     (message "Lazy desktop load complete")))
1307
1308 (defun desktop-lazy-abort ()
1309   "Abort lazy loading of the desktop."
1310   (interactive)
1311   (when desktop-lazy-timer
1312     (cancel-timer desktop-lazy-timer)
1313     (setq desktop-lazy-timer nil))
1314   (when desktop-buffer-args-list
1315     (setq desktop-buffer-args-list nil)
1316     (when (called-interactively-p 'interactive)
1317       (message "Lazy desktop load aborted"))))
1318
1319 ;; ----------------------------------------------------------------------------
1320 ;; When `desktop-save-mode' is non-nil and "--no-desktop" is not specified on the
1321 ;; command line, we do the rest of what it takes to use desktop, but do it
1322 ;; after finishing loading the init file.
1323 ;; We cannot use `command-switch-alist' to process "--no-desktop" because these
1324 ;; functions are processed after `after-init-hook'.
1325 (add-hook
1326   'after-init-hook
1327   (lambda ()
1328     (let ((key "--no-desktop"))
1329       (when (member key command-line-args)
1330         (setq command-line-args (delete key command-line-args))
1331         (setq desktop-save-mode nil)))
1332     (when desktop-save-mode
1333       (desktop-read)
1334       (setq inhibit-startup-screen t))))
1335
1336 (provide 'desktop)
1337
1338 ;;; desktop.el ends here