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 nil
 414   "Alist of major mode specific functions to restore a desktop buffer.
 415 Functions listed are called by `desktop-create-buffer' when `desktop-read'
 416 evaluates the desktop file.  List elements must have the form
 417
 418    (MAJOR-MODE . RESTORE-BUFFER-FUNCTION).
 419
 420 Buffers with a major mode not specified here, are restored by the default
 421 handler `desktop-restore-file-buffer'.
 422
 423 Handlers are called with argument list
 424
 425    (DESKTOP-BUFFER-FILE-NAME DESKTOP-BUFFER-NAME DESKTOP-BUFFER-MISC)
 426
 427 Furthermore, they may use the following variables:
 428
 429    desktop-file-version
 430    desktop-buffer-major-mode
 431    desktop-buffer-minor-modes
 432    desktop-buffer-point
 433    desktop-buffer-mark
 434    desktop-buffer-read-only
 435    desktop-buffer-locals
 436
 437 If a handler returns a buffer, then the saved mode settings
 438 and variable values for that buffer are copied into it.
 439
 440 Modules that define a major mode that needs a special handler should contain
 441 code like
 442
 443    (defun foo-restore-desktop-buffer
 444    ...
 445    (add-to-list 'desktop-buffer-mode-handlers
 446                 '(foo-mode . foo-restore-desktop-buffer))
 447
 448 Furthermore the major mode function must be autoloaded.")
 449
 450 ;;;###autoload
 451 (put 'desktop-buffer-mode-handlers 'risky-local-variable t)
 452 (make-obsolete-variable 'desktop-buffer-handlers
 453                         'desktop-buffer-mode-handlers "22.1")
 454
 455 (defcustom desktop-minor-mode-table
 456   '((auto-fill-function auto-fill-mode)
 457     (vc-mode nil)
 458     (vc-dired-mode nil)
 459     (erc-track-minor-mode nil)
 460     (savehist-mode nil))
 461   "Table mapping minor mode variables to minor mode functions.
 462 Each entry has the form (NAME RESTORE-FUNCTION).
 463 NAME is the name of the buffer-local variable indicating that the minor
 464 mode is active.  RESTORE-FUNCTION is the function to activate the minor mode.
 465 RESTORE-FUNCTION nil means don't try to restore the minor mode.
 466 Only minor modes for which the name of the buffer-local variable
 467 and the name of the minor mode function are different have to be added to
 468 this table.  See also `desktop-minor-mode-handlers'."
 469   :type 'sexp
 470   :group 'desktop)
 471
 472 ;;;###autoload
 473 (defvar desktop-minor-mode-handlers nil
 474   "Alist of functions to restore non-standard minor modes.
 475 Functions are called by `desktop-create-buffer' to restore minor modes.
 476 List elements must have the form
 477
 478    (MINOR-MODE . RESTORE-FUNCTION).
 479
 480 Minor modes not specified here, are restored by the standard minor mode
 481 function.
 482
 483 Handlers are called with argument list
 484
 485    (DESKTOP-BUFFER-LOCALS)
 486
 487 Furthermore, they may use the following variables:
 488
 489    desktop-file-version
 490    desktop-buffer-file-name
 491    desktop-buffer-name
 492    desktop-buffer-major-mode
 493    desktop-buffer-minor-modes
 494    desktop-buffer-point
 495    desktop-buffer-mark
 496    desktop-buffer-read-only
 497    desktop-buffer-misc
 498
 499 When a handler is called, the buffer has been created and the major mode has
 500 been set, but local variables listed in desktop-buffer-locals has not yet been
 501 created and set.
 502
 503 Modules that define a minor mode that needs a special handler should contain
 504 code like
 505
 506    (defun foo-desktop-restore
 507    ...
 508    (add-to-list 'desktop-minor-mode-handlers
 509                 '(foo-mode . foo-desktop-restore))
 510
 511 Furthermore the minor mode function must be autoloaded.
 512
 513 See also `desktop-minor-mode-table'.")
 514
 515 ;;;###autoload
 516 (put 'desktop-minor-mode-handlers 'risky-local-variable t)
 517
 518 ;; ----------------------------------------------------------------------------
 519 (defvar desktop-dirname nil
 520   "The directory in which the desktop file should be saved.")
 521
 522 (defun desktop-full-file-name (&optional dirname)
 523   "Return the full name of the desktop file in DIRNAME.
 524 DIRNAME omitted or nil means use `desktop-dirname'."
 525   (expand-file-name desktop-base-file-name (or dirname desktop-dirname)))
 526
 527 (defun desktop-full-lock-name (&optional dirname)
 528   "Return the full name of the desktop lock file in DIRNAME.
 529 DIRNAME omitted or nil means use `desktop-dirname'."
 530   (expand-file-name desktop-base-lock-name (or dirname desktop-dirname)))
 531
 532 (defconst desktop-header
 533 ";; --------------------------------------------------------------------------
 534 ;; Desktop File for Emacs
 535 ;; --------------------------------------------------------------------------
 536 " "*Header to place in Desktop file.")
 537
 538 (defvar desktop-delay-hook nil
 539   "Hooks run after all buffers are loaded; intended for internal use.")
 540
 541 ;; ----------------------------------------------------------------------------
 542 ;; Desktop file conflict detection
 543 (defvar desktop-file-modtime nil
 544   "When the desktop file was last modified to the knowledge of this Emacs.
 545 Used to detect desktop file conflicts.")
 546
 547 (defun desktop-owner (&optional dirname)
 548   "Return the PID of the Emacs process that owns the desktop file in DIRNAME.
 549 Return nil if no desktop file found or no Emacs process is using it.
 550 DIRNAME omitted or nil means use `desktop-dirname'."
 551   (let (owner)
 552     (and (file-exists-p (desktop-full-lock-name dirname))
 553          (condition-case nil
 554              (with-temp-buffer
 555                (insert-file-contents-literally (desktop-full-lock-name dirname))
 556                (goto-char (point-min))
 557                (setq owner (read (current-buffer)))
 558                (integerp owner))
 559            (error nil))
 560          owner)))
 561
 562 (defun desktop-claim-lock (&optional dirname)
 563   "Record this Emacs process as the owner of the desktop file in DIRNAME.
 564 DIRNAME omitted or nil means use `desktop-dirname'."
 565   (write-region (number-to-string (emacs-pid)) nil
 566                 (desktop-full-lock-name dirname)))
 567
 568 (defun desktop-release-lock (&optional dirname)
 569   "Remove the lock file for the desktop in DIRNAME.
 570 DIRNAME omitted or nil means use `desktop-dirname'."
 571   (let ((file (desktop-full-lock-name dirname)))
 572     (when (file-exists-p file) (delete-file file))))
 573
 574 ;; ----------------------------------------------------------------------------
 575 (defun desktop-truncate (list n)
 576   "Truncate LIST to at most N elements destructively."
 577   (let ((here (nthcdr (1- n) list)))
 578     (when (consp here)
 579       (setcdr here nil))))
 580
 581 ;; ----------------------------------------------------------------------------
 582 ;;;###autoload
 583 (defun desktop-clear ()
 584   "Empty the Desktop.
 585 This kills all buffers except for internal ones and those with names matched by
 586 a regular expression in the list `desktop-clear-preserve-buffers'.
 587 Furthermore, it clears the variables listed in `desktop-globals-to-clear'."
 588   (interactive)
 589   (desktop-lazy-abort)
 590   (dolist (var desktop-globals-to-clear)
 591     (if (symbolp var)
 592         (eval `(setq-default ,var nil))
 593       (eval `(setq-default ,(car var) ,(cdr var)))))
 594   (let ((buffers (buffer-list))
 595         (preserve-regexp (concat "^\\("
 596                                  (mapconcat (lambda (regexp)
 597                                               (concat "\\(" regexp "\\)"))
 598                                             desktop-clear-preserve-buffers
 599                                             "\\|")
 600                                  "\\)$")))
 601     (while buffers
 602       (let ((bufname (buffer-name (car buffers))))
 603          (or
 604            (null bufname)
 605            (string-match preserve-regexp bufname)
 606            ;; Don't kill buffers made for internal purposes.
 607            (and (not (equal bufname "")) (eq (aref bufname 0) ?\s))
 608            (kill-buffer (car buffers))))
 609       (setq buffers (cdr buffers))))
 610   (delete-other-windows))
 611
 612 ;; ----------------------------------------------------------------------------
 613 (unless noninteractive
 614   (add-hook 'kill-emacs-hook 'desktop-kill))
 615
 616 (defun desktop-kill ()
 617   "If `desktop-save-mode' is non-nil, do what `desktop-save' says to do.
 618 If the desktop should be saved and `desktop-dirname'
 619 is nil, ask the user where to save the desktop."
 620   (when (and desktop-save-mode
 621              (let ((exists (file-exists-p (desktop-full-file-name))))
 622                (or (eq desktop-save t)
 623                    (and exists (eq desktop-save 'if-exists))
 624                    ;; If it exists, but we aren't using it, we are going
 625                    ;; to ask for a new directory below.
 626                    (and exists desktop-dirname (eq desktop-save 'ask-if-new))
 627                    (and
 628                     (or (memq desktop-save '(ask ask-if-new))
 629                         (and exists (eq desktop-save 'ask-if-exists)))
 630                     (y-or-n-p "Save desktop? ")))))
 631     (unless desktop-dirname
 632       (setq desktop-dirname
 633             (file-name-as-directory
 634              (expand-file-name
 635               (read-directory-name "Directory for desktop file: " nil nil t)))))
 636     (condition-case err
 637         (desktop-save desktop-dirname t)
 638       (file-error
 639        (unless (yes-or-no-p "Error while saving the desktop.  Ignore? ")
 640          (signal (car err) (cdr err))))))
 641   ;; If we own it, we don't anymore.
 642   (when (eq (emacs-pid) (desktop-owner)) (desktop-release-lock)))
 643
 644 ;; ----------------------------------------------------------------------------
 645 (defun desktop-list* (&rest args)
 646   (if (null (cdr args))
 647       (car args)
 648     (setq args (nreverse args))
 649     (let ((value (cons (nth 1 args) (car args))))
 650       (setq args (cdr (cdr args)))
 651       (while args
 652         (setq value (cons (car args) value))
 653         (setq args (cdr args)))
 654       value)))
 655
 656 ;; ----------------------------------------------------------------------------
 657 (defun desktop-buffer-info (buffer)
 658   (set-buffer buffer)
 659   (list
 660    ;; base name of the buffer; replaces the buffer name if managed by uniquify
 661    (and (fboundp 'uniquify-buffer-base-name) (uniquify-buffer-base-name))
 662    ;; basic information
 663    (desktop-file-name (buffer-file-name) desktop-dirname)
 664    (buffer-name)
 665    major-mode
 666    ;; minor modes
 667    (let (ret)
 668      (mapc
 669       #'(lambda (minor-mode)
 670           (and (boundp minor-mode)
 671                (symbol-value minor-mode)
 672                (let* ((special (assq minor-mode desktop-minor-mode-table))
 673                       (value (cond (special (cadr special))
 674                                    ((functionp minor-mode) minor-mode))))
 675                  (when value (add-to-list 'ret value)))))
 676       (mapcar #'car minor-mode-alist))
 677      ret)
 678    ;; point and mark, and read-only status
 679    (point)
 680    (list (mark t) mark-active)
 681    buffer-read-only
 682    ;; auxiliary information
 683    (when (functionp desktop-save-buffer)
 684      (funcall desktop-save-buffer desktop-dirname))
 685    ;; local variables
 686    (let ((locals desktop-locals-to-save)
 687          (loclist (buffer-local-variables))
 688          (ll))
 689      (while locals
 690        (let ((here (assq (car locals) loclist)))
 691          (if here
 692              (setq ll (cons here ll))
 693            (when (member (car locals) loclist)
 694              (setq ll (cons (car locals) ll)))))
 695        (setq locals (cdr locals)))
 696      ll)))
 697
 698 ;; ----------------------------------------------------------------------------
 699 (defun desktop-internal-v2s (value)
 700   "Convert VALUE to a pair (QUOTE . TXT); (eval (read TXT)) gives VALUE.
 701 TXT is a string that when read and evaluated yields VALUE.
 702 QUOTE may be `may' (value may be quoted),
 703 `must' (value must be quoted), or nil (value must not be quoted)."
 704   (cond
 705     ((or (numberp value) (null value) (eq t value) (keywordp value))
 706      (cons 'may (prin1-to-string value)))
 707     ((stringp value)
 708      (let ((copy (copy-sequence value)))
 709        (set-text-properties 0 (length copy) nil copy)
 710        ;; Get rid of text properties because we cannot read them
 711        (cons 'may (prin1-to-string copy))))
 712     ((symbolp value)
 713      (cons 'must (prin1-to-string value)))
 714     ((vectorp value)
 715      (let* ((special nil)
 716             (pass1 (mapcar
 717                     (lambda (el)
 718                       (let ((res (desktop-internal-v2s el)))
 719                         (if (null (car res))
 720                             (setq special t))
 721                         res))
 722                     value)))
 723        (if special
 724            (cons nil (concat "(vector "
 725                              (mapconcat (lambda (el)
 726                                           (if (eq (car el) 'must)
 727                                               (concat "'" (cdr el))
 728                                             (cdr el)))
 729                                         pass1
 730                                         " ")
 731                              ")"))
 732          (cons 'may (concat "[" (mapconcat 'cdr pass1 " ") "]")))))
 733     ((consp value)
 734      (let ((p value)
 735            newlist
 736            use-list*
 737            anynil)
 738        (while (consp p)
 739          (let ((q.txt (desktop-internal-v2s (car p))))
 740            (or anynil (setq anynil (null (car q.txt))))
 741            (setq newlist (cons q.txt newlist)))
 742          (setq p (cdr p)))
 743        (if p
 744            (let ((last (desktop-internal-v2s p)))
 745              (or anynil (setq anynil (null (car last))))
 746              (or anynil
 747                  (setq newlist (cons '(must . ".") newlist)))
 748              (setq use-list* t)
 749              (setq newlist (cons last newlist))))
 750        (setq newlist (nreverse newlist))
 751        (if anynil
 752            (cons nil
 753                  (concat (if use-list* "(desktop-list* "  "(list ")
 754                          (mapconcat (lambda (el)
 755                                       (if (eq (car el) 'must)
 756                                           (concat "'" (cdr el))
 757                                         (cdr el)))
 758                                     newlist
 759                                     " ")
 760                          ")"))
 761          (cons 'must
 762                (concat "(" (mapconcat 'cdr newlist " ") ")")))))
 763     ((subrp value)
 764      (cons nil (concat "(symbol-function '"
 765                        (substring (prin1-to-string value) 7 -1)
 766                        ")")))
 767     ((markerp value)
 768      (let ((pos (prin1-to-string (marker-position value)))
 769            (buf (prin1-to-string (buffer-name (marker-buffer value)))))
 770        (cons nil (concat "(let ((mk (make-marker)))"
 771                          " (add-hook 'desktop-delay-hook"
 772                          " (list 'lambda '() (list 'set-marker mk "
 773                          pos " (get-buffer " buf ")))) mk)"))))
 774     (t                                   ; save as text
 775      (cons 'may "\"Unprintable entity\""))))
 776
 777 ;; ----------------------------------------------------------------------------
 778 (defun desktop-value-to-string (value)
 779   "Convert VALUE to a string that when read evaluates to the same value.
 780 Not all types of values are supported."
 781   (let* ((print-escape-newlines t)
 782          (float-output-format nil)
 783          (quote.txt (desktop-internal-v2s value))
 784          (quote (car quote.txt))
 785          (txt (cdr quote.txt)))
 786     (if (eq quote 'must)
 787         (concat "'" txt)
 788       txt)))
 789
 790 ;; ----------------------------------------------------------------------------
 791 (defun desktop-outvar (varspec)
 792   "Output a setq statement for variable VAR to the desktop file.
 793 The argument VARSPEC may be the variable name VAR (a symbol),
 794 or a cons cell of the form (VAR . MAX-SIZE),
 795 which means to truncate VAR's value to at most MAX-SIZE elements
 796 \(if the value is a list) before saving the value."
 797   (let (var size)
 798     (if (consp varspec)
 799         (setq var (car varspec) size (cdr varspec))
 800       (setq var varspec))
 801     (when (boundp var)
 802       (when (and (integerp size)
 803                  (> size 0)
 804                  (listp (eval var)))
 805         (desktop-truncate (eval var) size))
 806       (insert "(setq "
 807               (symbol-name var)
 808               " "
 809               (desktop-value-to-string (symbol-value var))
 810               ")\n"))))
 811
 812 ;; ----------------------------------------------------------------------------
 813 (defun desktop-save-buffer-p (filename bufname mode &rest _dummy)
 814   "Return t if buffer should have its state saved in the desktop file.
 815 FILENAME is the visited file name, BUFNAME is the buffer name, and
 816 MODE is the major mode.
 817 \n\(fn FILENAME BUFNAME MODE)"
 818   (let ((case-fold-search nil)
 819         dired-skip)
 820     (and (not (and (stringp desktop-buffers-not-to-save)
 821                    (not filename)
 822                    (string-match desktop-buffers-not-to-save bufname)))
 823          (not (memq mode desktop-modes-not-to-save))
 824          ;; FIXME this is broken if desktop-files-not-to-save is nil.
 825          (or (and filename
 826                   (stringp desktop-files-not-to-save)
 827                   (not (string-match desktop-files-not-to-save filename)))
 828              (and (eq mode 'dired-mode)
 829                   (with-current-buffer bufname
 830                     (not (setq dired-skip
 831                                (string-match desktop-files-not-to-save
 832                                              default-directory)))))
 833              (and (null filename)
 834                   (null dired-skip)     ; bug#5755
 835                   (with-current-buffer bufname desktop-save-buffer))))))
 836
 837 ;; ----------------------------------------------------------------------------
 838 (defun desktop-file-name (filename dirname)
 839   "Convert FILENAME to format specified in `desktop-file-name-format'.
 840 DIRNAME must be the directory in which the desktop file will be saved."
 841   (cond
 842     ((not filename) nil)
 843     ((eq desktop-file-name-format 'tilde)
 844      (let ((relative-name (file-relative-name (expand-file-name filename) "~")))
 845        (cond
 846          ((file-name-absolute-p relative-name) relative-name)
 847          ((string= "./" relative-name) "~/")
 848          ((string= "." relative-name) "~")
 849          (t (concat "~/" relative-name)))))
 850     ((eq desktop-file-name-format 'local) (file-relative-name filename dirname))
 851     (t (expand-file-name filename))))
 852
 853
 854 ;; ----------------------------------------------------------------------------
 855 ;;;###autoload
 856 (defun desktop-save (dirname &optional release)
 857   "Save the desktop in a desktop file.
 858 Parameter DIRNAME specifies where to save the desktop file.
 859 Optional parameter RELEASE says whether we're done with this desktop.
 860 See also `desktop-base-file-name'."
 861   (interactive "DDirectory to save desktop file in: ")
 862   (setq desktop-dirname (file-name-as-directory (expand-file-name dirname)))
 863   (save-excursion
 864     (let ((eager desktop-restore-eager)
 865           (new-modtime (nth 5 (file-attributes (desktop-full-file-name)))))
 866       (when
 867           (or (not new-modtime)         ; nothing to overwrite
 868               (equal desktop-file-modtime new-modtime)
 869               (yes-or-no-p (if desktop-file-modtime
 870                                (if (> (float-time new-modtime) (float-time desktop-file-modtime))
 871                                    "Desktop file is more recent than the one loaded.  Save anyway? "
 872                                  "Desktop file isn't the one loaded.  Overwrite it? ")
 873                              "Current desktop was not loaded from a file.  Overwrite this desktop file? "))
 874               (unless release (error "Desktop file conflict")))
 875
 876         ;; If we're done with it, release the lock.
 877         ;; Otherwise, claim it if it's unclaimed or if we created it.
 878         (if release
 879             (desktop-release-lock)
 880           (unless (and new-modtime (desktop-owner)) (desktop-claim-lock)))
 881
 882         (with-temp-buffer
 883           (insert
 884            ";; -*- mode: emacs-lisp; coding: emacs-mule; -*-\n"
 885            desktop-header
 886            ";; Created " (current-time-string) "\n"
 887            ";; Desktop file format version " desktop-file-version "\n"
 888            ";; Emacs version " emacs-version "\n")
 889           (save-excursion (run-hooks 'desktop-save-hook))
 890           (goto-char (point-max))
 891           (insert "\n;; Global section:\n")
 892           (mapc (function desktop-outvar) desktop-globals-to-save)
 893           (when (memq 'kill-ring desktop-globals-to-save)
 894             (insert
 895              "(setq kill-ring-yank-pointer (nthcdr "
 896              (int-to-string (- (length kill-ring) (length kill-ring-yank-pointer)))
 897              " kill-ring))\n"))
 898
 899           (insert "\n;; Buffer section -- buffers listed in same order as in buffer list:\n")
 900           (dolist (l (mapcar 'desktop-buffer-info (buffer-list)))
 901             (let ((base (pop l)))
 902               (when (apply 'desktop-save-buffer-p l)
 903                 (insert "("
 904                         (if (or (not (integerp eager))
 905                                 (if (zerop eager)
 906                                     nil
 907                                   (setq eager (1- eager))))
 908                             "desktop-create-buffer"
 909                           "desktop-append-buffer-args")
 910                         " "
 911                         desktop-file-version)
 912                 ;; If there's a non-empty base name, we save it instead of the buffer name
 913                 (when (and base (not (string= base "")))
 914                   (setcar (nthcdr 1 l) base))
 915                 (dolist (e l)
 916                   (insert "\n  " (desktop-value-to-string e)))
 917                 (insert ")\n\n"))))
 918
 919           (setq default-directory desktop-dirname)
 920           (let ((coding-system-for-write 'emacs-mule))
 921             (write-region (point-min) (point-max) (desktop-full-file-name) nil 'nomessage))
 922           ;; We remember when it was modified (which is presumably just now).
 923           (setq desktop-file-modtime (nth 5 (file-attributes (desktop-full-file-name)))))))))
 924
 925 ;; ----------------------------------------------------------------------------
 926 ;;;###autoload
 927 (defun desktop-remove ()
 928   "Delete desktop file in `desktop-dirname'.
 929 This function also sets `desktop-dirname' to nil."
 930   (interactive)
 931   (when desktop-dirname
 932     (let ((filename (desktop-full-file-name)))
 933       (setq desktop-dirname nil)
 934       (when (file-exists-p filename)
 935         (delete-file filename)))))
 936
 937 (defvar desktop-buffer-args-list nil
 938   "List of args for `desktop-create-buffer'.")
 939
 940 (defvar desktop-lazy-timer nil)
 941
 942 ;; ----------------------------------------------------------------------------
 943 ;;;###autoload
 944 (defun desktop-read (&optional dirname)
 945   "Read and process the desktop file in directory DIRNAME.
 946 Look for a desktop file in DIRNAME, or if DIRNAME is omitted, look in
 947 directories listed in `desktop-path'.  If a desktop file is found, it
 948 is processed and `desktop-after-read-hook' is run.  If no desktop file
 949 is found, clear the desktop and run `desktop-no-desktop-file-hook'.
 950 This function is a no-op when Emacs is running in batch mode.
 951 It returns t if a desktop file was loaded, nil otherwise."
 952   (interactive)
 953   (unless noninteractive
 954     (setq desktop-dirname
 955           (file-name-as-directory
 956            (expand-file-name
 957             (or
 958              ;; If DIRNAME is specified, use it.
 959              (and (< 0 (length dirname)) dirname)
 960              ;; Otherwise search desktop file in desktop-path.
 961              (let ((dirs desktop-path))
 962                (while (and dirs
 963                            (not (file-exists-p
 964                                  (desktop-full-file-name (car dirs)))))
 965                  (setq dirs (cdr dirs)))
 966                (and dirs (car dirs)))
 967              ;; If not found and `desktop-path' is non-nil, use its first element.
 968              (and desktop-path (car desktop-path))
 969              ;; Default: .emacs.d.
 970              user-emacs-directory))))
 971     (if (file-exists-p (desktop-full-file-name))
 972         ;; Desktop file found, but is it already in use?
 973         (let ((desktop-first-buffer nil)
 974               (desktop-buffer-ok-count 0)
 975               (desktop-buffer-fail-count 0)
 976               (owner (desktop-owner))
 977               ;; Avoid desktop saving during evaluation of desktop buffer.
 978               (desktop-save nil))
 979           (if (and owner
 980                    (memq desktop-load-locked-desktop '(nil ask))
 981                    (or (null desktop-load-locked-desktop)
 982                        (daemonp)
 983                        (not (y-or-n-p (format "Warning: desktop file appears to be in use by PID %s.\n\
 984 Using it may cause conflicts.  Use it anyway? " owner)))))
 985               (let ((default-directory desktop-dirname))
 986                 (setq desktop-dirname nil)
 987                 (run-hooks 'desktop-not-loaded-hook)
 988                 (unless desktop-dirname
 989                   (message "Desktop file in use; not loaded.")))
 990             (desktop-lazy-abort)
 991             ;; Evaluate desktop buffer and remember when it was modified.
 992             (load (desktop-full-file-name) t t t)
 993             (setq desktop-file-modtime (nth 5 (file-attributes (desktop-full-file-name))))
 994             ;; If it wasn't already, mark it as in-use, to bother other
 995             ;; desktop instances.
 996             (unless owner
 997               (condition-case nil
 998                   (desktop-claim-lock)
 999                 (file-error (message "Couldn't record use of desktop file")
1000                             (sit-for 1))))
1001
1002             ;; `desktop-create-buffer' puts buffers at end of the buffer list.
1003             ;; We want buffers existing prior to evaluating the desktop (and
1004             ;; not reused) to be placed at the end of the buffer list, so we
1005             ;; move them here.
1006             (mapc 'bury-buffer
1007                   (nreverse (cdr (memq desktop-first-buffer (nreverse (buffer-list))))))
1008             (switch-to-buffer (car (buffer-list)))
1009             (run-hooks 'desktop-delay-hook)
1010             (setq desktop-delay-hook nil)
1011             (run-hooks 'desktop-after-read-hook)
1012             (message "Desktop: %d buffer%s restored%s%s."
1013                      desktop-buffer-ok-count
1014                      (if (= 1 desktop-buffer-ok-count) "" "s")
1015                      (if (< 0 desktop-buffer-fail-count)
1016                          (format ", %d failed to restore" desktop-buffer-fail-count)
1017                        "")
1018                      (if desktop-buffer-args-list
1019                          (format ", %d to restore lazily"
1020                                  (length desktop-buffer-args-list))
1021                        ""))
1022             ;; Bury the *Messages* buffer to not reshow it when burying
1023             ;; the buffer we switched to above.
1024             (when (buffer-live-p (get-buffer "*Messages*"))
1025               (bury-buffer "*Messages*"))
1026             ;; Clear all windows' previous and next buffers, these have
1027             ;; been corrupted by the `switch-to-buffer' calls in
1028             ;; `desktop-restore-file-buffer' (bug#11556).  This is a
1029             ;; brute force fix and should be replaced by a more subtle
1030             ;; strategy eventually.
1031             (walk-window-tree (lambda (window)
1032                                 (set-window-prev-buffers window nil)
1033                                 (set-window-next-buffers window nil)))
1034             t))
1035       ;; No desktop file found.
1036       (desktop-clear)
1037       (let ((default-directory desktop-dirname))
1038         (run-hooks 'desktop-no-desktop-file-hook))
1039       (message "No desktop file.")
1040       nil)))
1041
1042 ;; ----------------------------------------------------------------------------
1043 ;; Maintained for backward compatibility
1044 ;;;###autoload
1045 (defun desktop-load-default ()
1046   "Load the `default' start-up library manually.
1047 Also inhibit further loading of it."
1048   (unless inhibit-default-init          ; safety check
1049     (load "default" t t)
1050     (setq inhibit-default-init t)))
1051 (make-obsolete 'desktop-load-default
1052                'desktop-save-mode "22.1")
1053
1054 ;; ----------------------------------------------------------------------------
1055 ;;;###autoload
1056 (defun desktop-change-dir (dirname)
1057   "Change to desktop saved in DIRNAME.
1058 Kill the desktop as specified by variables `desktop-save-mode' and
1059 `desktop-save', then clear the desktop and load the desktop file in
1060 directory DIRNAME."
1061   (interactive "DChange to directory: ")
1062   (setq dirname (file-name-as-directory (expand-file-name dirname desktop-dirname)))
1063   (desktop-kill)
1064   (desktop-clear)
1065   (desktop-read dirname))
1066
1067 ;; ----------------------------------------------------------------------------
1068 ;;;###autoload
1069 (defun desktop-save-in-desktop-dir ()
1070   "Save the desktop in directory `desktop-dirname'."
1071   (interactive)
1072   (if desktop-dirname
1073       (desktop-save desktop-dirname)
1074     (call-interactively 'desktop-save))
1075   (message "Desktop saved in %s" (abbreviate-file-name desktop-dirname)))
1076
1077 ;; ----------------------------------------------------------------------------
1078 ;;;###autoload
1079 (defun desktop-revert ()
1080   "Revert to the last loaded desktop."
1081   (interactive)
1082   (unless desktop-dirname
1083     (error "Unknown desktop directory"))
1084   (unless (file-exists-p (desktop-full-file-name))
1085     (error "No desktop file found"))
1086   (desktop-clear)
1087   (desktop-read desktop-dirname))
1088
1089 (defvar desktop-buffer-major-mode)
1090 (defvar desktop-buffer-locals)
1091 (defvar auto-insert)  ; from autoinsert.el
1092 ;; ----------------------------------------------------------------------------
1093 (defun desktop-restore-file-buffer (buffer-filename
1094                                     _buffer-name
1095                                     _buffer-misc)
1096   "Restore a file buffer."
1097   (when buffer-filename
1098     (if (or (file-exists-p buffer-filename)
1099             (let ((msg (format "Desktop: File \"%s\" no longer exists."
1100                                buffer-filename)))
1101               (if desktop-missing-file-warning
1102                   (y-or-n-p (concat msg " Re-create buffer? "))
1103                 (message "%s" msg)
1104                 nil)))
1105         (let* ((auto-insert nil) ; Disable auto insertion
1106                (coding-system-for-read
1107                 (or coding-system-for-read
1108                     (cdr (assq 'buffer-file-coding-system
1109                                desktop-buffer-locals))))
1110                (buf (find-file-noselect buffer-filename)))
1111           (condition-case nil
1112               (switch-to-buffer buf)
1113             (error (pop-to-buffer buf)))
1114           (and (not (eq major-mode desktop-buffer-major-mode))
1115                (functionp desktop-buffer-major-mode)
1116                (funcall desktop-buffer-major-mode))
1117           buf)
1118       nil)))
1119
1120 (defun desktop-load-file (function)
1121   "Load the file where auto loaded FUNCTION is defined."
1122   (when function
1123     (let ((fcell (and (fboundp function) (symbol-function function))))
1124       (when (and (listp fcell)
1125                  (eq 'autoload (car fcell)))
1126         (load (cadr fcell))))))
1127
1128 ;; ----------------------------------------------------------------------------
1129 ;; Create a buffer, load its file, set its mode, ...;
1130 ;; called from Desktop file only.
1131
1132 ;; Just to silence the byte compiler.
1133
1134 (defvar desktop-first-buffer)          ; Dynamically bound in `desktop-read'
1135
1136 ;; Bound locally in `desktop-read'.
1137 (defvar desktop-buffer-ok-count)
1138 (defvar desktop-buffer-fail-count)
1139
1140 (defun desktop-create-buffer
1141     (file-version
1142      buffer-filename
1143      buffer-name
1144      buffer-majormode
1145      buffer-minormodes
1146      buffer-point
1147      buffer-mark
1148      buffer-readonly
1149      buffer-misc
1150      &optional
1151      buffer-locals)
1152
1153   (let ((desktop-file-version       file-version)
1154         (desktop-buffer-file-name   buffer-filename)
1155         (desktop-buffer-name        buffer-name)
1156         (desktop-buffer-major-mode  buffer-majormode)
1157         (desktop-buffer-minor-modes buffer-minormodes)
1158         (desktop-buffer-point       buffer-point)
1159         (desktop-buffer-mark        buffer-mark)
1160         (desktop-buffer-read-only   buffer-readonly)
1161         (desktop-buffer-misc        buffer-misc)
1162         (desktop-buffer-locals      buffer-locals))
1163     ;; To make desktop files with relative file names possible, we cannot
1164     ;; allow `default-directory' to change. Therefore we save current buffer.
1165     (save-current-buffer
1166       ;; Give major mode module a chance to add a handler.
1167       (desktop-load-file desktop-buffer-major-mode)
1168       (let ((buffer-list (buffer-list))
1169             (result
1170              (condition-case-unless-debug err
1171                  (funcall (or (cdr (assq desktop-buffer-major-mode
1172                                          desktop-buffer-mode-handlers))
1173                               'desktop-restore-file-buffer)
1174                           desktop-buffer-file-name
1175                           desktop-buffer-name
1176                           desktop-buffer-misc)
1177                (error
1178                 (message "Desktop: Can't load buffer %s: %s"
1179                          desktop-buffer-name
1180                          (error-message-string err))
1181                 (when desktop-missing-file-warning (sit-for 1))
1182                 nil))))
1183         (if (bufferp result)
1184             (setq desktop-buffer-ok-count (1+ desktop-buffer-ok-count))
1185           (setq desktop-buffer-fail-count (1+ desktop-buffer-fail-count))
1186           (setq result nil))
1187         ;; Restore buffer list order with new buffer at end. Don't change
1188         ;; the order for old desktop files (old desktop module behavior).
1189         (unless (< desktop-file-version 206)
1190           (mapc 'bury-buffer buffer-list)
1191           (when result (bury-buffer result)))
1192         (when result
1193           (unless (or desktop-first-buffer (< desktop-file-version 206))
1194             (setq desktop-first-buffer result))
1195           (set-buffer result)
1196           (unless (equal (buffer-name) desktop-buffer-name)
1197             (rename-buffer desktop-buffer-name t))
1198           ;; minor modes
1199           (cond ((equal '(t) desktop-buffer-minor-modes) ; backwards compatible
1200                  (auto-fill-mode 1))
1201                 ((equal '(nil) desktop-buffer-minor-modes) ; backwards compatible
1202                  (auto-fill-mode 0))
1203                 (t
1204                  (dolist (minor-mode desktop-buffer-minor-modes)
1205                    ;; Give minor mode module a chance to add a handler.
1206                    (desktop-load-file minor-mode)
1207                    (let ((handler (cdr (assq minor-mode desktop-minor-mode-handlers))))
1208                      (if handler
1209                          (funcall handler desktop-buffer-locals)
1210                        (when (functionp minor-mode)
1211                          (funcall minor-mode 1)))))))
1212           ;; Even though point and mark are non-nil when written by
1213           ;; `desktop-save', they may be modified by handlers wanting to set
1214           ;; point or mark themselves.
1215           (when desktop-buffer-point
1216             (goto-char
1217              (condition-case err
1218                  ;; Evaluate point.  Thus point can be something like
1219                  ;; '(search-forward ...
1220                  (eval desktop-buffer-point)
1221                (error (message "%s" (error-message-string err)) 1))))
1222           (when desktop-buffer-mark
1223             (if (consp desktop-buffer-mark)
1224                 (progn
1225                   (set-mark (car desktop-buffer-mark))
1226                   (setq mark-active (car (cdr desktop-buffer-mark))))
1227               (set-mark desktop-buffer-mark)))
1228           ;; Never override file system if the file really is read-only marked.
1229           (when desktop-buffer-read-only (setq buffer-read-only desktop-buffer-read-only))
1230           (while desktop-buffer-locals
1231             (let ((this (car desktop-buffer-locals)))
1232               (if (consp this)
1233                   ;; an entry of this form `(symbol . value)'
1234                   (progn
1235                     (make-local-variable (car this))
1236                     (set (car this) (cdr this)))
1237                 ;; an entry of the form `symbol'
1238                 (make-local-variable this)
1239                 (makunbound this)))
1240             (setq desktop-buffer-locals (cdr desktop-buffer-locals))))))))
1241
1242 ;; ----------------------------------------------------------------------------
1243 ;; Backward compatibility -- update parameters to 205 standards.
1244 (defun desktop-buffer (buffer-filename buffer-name buffer-majormode
1245                        mim pt mk ro tl fc cfs cr buffer-misc)
1246   (desktop-create-buffer 205 buffer-filename buffer-name
1247                          buffer-majormode (cdr mim) pt mk ro
1248                          buffer-misc
1249                          (list (cons 'truncate-lines tl)
1250                                (cons 'fill-column fc)
1251                                (cons 'case-fold-search cfs)
1252                                (cons 'case-replace cr)
1253                                (cons 'overwrite-mode (car mim)))))
1254
1255 (defun desktop-append-buffer-args (&rest args)
1256   "Append ARGS at end of `desktop-buffer-args-list'.
1257 ARGS must be an argument list for `desktop-create-buffer'."
1258   (setq desktop-buffer-args-list (nconc desktop-buffer-args-list (list args)))
1259   (unless desktop-lazy-timer
1260     (setq desktop-lazy-timer
1261           (run-with-idle-timer desktop-lazy-idle-delay t 'desktop-idle-create-buffers))))
1262
1263 (defun desktop-lazy-create-buffer ()
1264   "Pop args from `desktop-buffer-args-list', create buffer and bury it."
1265   (when desktop-buffer-args-list
1266     (let* ((remaining (length desktop-buffer-args-list))
1267            (args (pop desktop-buffer-args-list))
1268            (buffer-name (nth 2 args))
1269            (msg (format "Desktop lazily opening %s (%s remaining)..."
1270                             buffer-name remaining)))
1271       (when desktop-lazy-verbose
1272         (message "%s" msg))
1273       (let ((desktop-first-buffer nil)
1274             (desktop-buffer-ok-count 0)
1275             (desktop-buffer-fail-count 0))
1276         (apply 'desktop-create-buffer args)
1277         (run-hooks 'desktop-delay-hook)
1278         (setq desktop-delay-hook nil)
1279         (bury-buffer (get-buffer buffer-name))
1280         (when desktop-lazy-verbose
1281           (message "%s%s" msg (if (> desktop-buffer-ok-count 0) "done" "failed")))))))
1282
1283 (defun desktop-idle-create-buffers ()
1284   "Create buffers until the user does something, then stop.
1285 If there are no buffers left to create, kill the timer."
1286   (let ((repeat 1))
1287     (while (and repeat desktop-buffer-args-list)
1288       (save-window-excursion
1289         (desktop-lazy-create-buffer))
1290       (setq repeat (sit-for 0.2))
1291     (unless desktop-buffer-args-list
1292       (cancel-timer desktop-lazy-timer)
1293       (setq desktop-lazy-timer nil)
1294       (message "Lazy desktop load complete")
1295       (sit-for 3)
1296       (message "")))))
1297
1298 (defun desktop-lazy-complete ()
1299   "Run the desktop load to completion."
1300   (interactive)
1301   (let ((desktop-lazy-verbose t))
1302     (while desktop-buffer-args-list
1303       (save-window-excursion
1304         (desktop-lazy-create-buffer)))
1305     (message "Lazy desktop load complete")))
1306
1307 (defun desktop-lazy-abort ()
1308   "Abort lazy loading of the desktop."
1309   (interactive)
1310   (when desktop-lazy-timer
1311     (cancel-timer desktop-lazy-timer)
1312     (setq desktop-lazy-timer nil))
1313   (when desktop-buffer-args-list
1314     (setq desktop-buffer-args-list nil)
1315     (when (called-interactively-p 'interactive)
1316       (message "Lazy desktop load aborted"))))
1317
1318 ;; ----------------------------------------------------------------------------
1319 ;; When `desktop-save-mode' is non-nil and "--no-desktop" is not specified on the
1320 ;; command line, we do the rest of what it takes to use desktop, but do it
1321 ;; after finishing loading the init file.
1322 ;; We cannot use `command-switch-alist' to process "--no-desktop" because these
1323 ;; functions are processed after `after-init-hook'.
1324 (add-hook
1325   'after-init-hook
1326   (lambda ()
1327     (let ((key "--no-desktop"))
1328       (when (member key command-line-args)
1329         (setq command-line-args (delete key command-line-args))
1330         (setq desktop-save-mode nil)))
1331     (when desktop-save-mode
1332       (desktop-read)
1333       (setq inhibit-startup-screen t))))
1334
1335 (provide 'desktop)
1336
1337 ;;; desktop.el ends here