lisp/winner.el

   1 ;;; winner.el --- Restore old window configurations
   2
   3 ;; Copyright (C) 1997, 1998, 2001 Free Software Foundation. Inc.
   4
   5 ;; Author: Ivar Rummelhoff <ivarru@math.uio.no>
   6 ;; Created: 27 Feb 1997
   7 ;; Time-stamp: <2002-02-20 22:06:58 ivarru>
   8 ;; Keywords: convenience frames
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; Winner mode is a global minor mode that records the changes in the
  30 ;; window configuration (i.e. how the frames are partitioned into
  31 ;; windows) so that the changes can be "undone" using the command
  32 ;; `winner-undo'.  By default this one is bound to the key sequence
  33 ;; ctrl-x left.  If you change your mind (while undoing), you can
  34 ;; press ctrl-x right (calling `winner-redo').  Even though it uses
  35 ;; some features of Emacs20.3, winner.el should also work with
  36 ;; Emacs19.34 and XEmacs20, provided that the installed version of
  37 ;; custom is not obsolete.
  38
  39 ;; Winner mode was improved August 1998.
  40 ;; Further improvements February 2002.
  41
  42 ;;; Code:
  43
  44 (eval-when-compile
  45   (require 'cl))
  46
  47 (eval-when-compile
  48   (cond
  49    ((eq (aref (emacs-version) 0) ?X)
  50     (defmacro winner-active-region ()
  51       '(region-active-p))
  52     (defsetf winner-active-region () (store)
  53       `(if ,store (zmacs-activate-region)
  54          (zmacs-deactivate-region))))
  55    (t (defmacro winner-active-region ()
  56         'mark-active)
  57       (defsetf winner-active-region () (store)
  58         `(setq mark-active ,store)))) )
  59
  60 \f(eval-and-compile
  61   (cond
  62    ((eq (aref (emacs-version) 0) ?X)
  63     (defalias 'winner-edges 'window-pixel-edges)
  64     (defsubst winner-window-list ()
  65       (remq (minibuffer-window)
  66             (window-list nil 0))))
  67    (t (defalias 'winner-edges 'window-edges)
  68       (defsubst winner-window-list ()
  69         (window-list nil 0)))) )
  70
  71 (require 'ring)
  72
  73 (unless (fboundp 'defgroup)
  74   (defmacro defgroup (&rest rest)))
  75
  76 (defgroup winner nil
  77   "Restoring window configurations."
  78   :group 'windows)
  79
  80 (unless (fboundp 'defcustom)
  81   (defmacro defcustom (symbol &optional initvalue docs &rest rest)
  82     (list 'defvar symbol initvalue docs)))
  83
  84 ;;;###autoload
  85 (defcustom winner-mode nil
  86   "Toggle winner-mode.
  87 Setting this variable directly does not take effect;
  88 use either \\[customize] or the function `winner-mode'."
  89   :set #'(lambda (symbol value)
  90            (winner-mode (or value 0)))
  91   :initialize 'custom-initialize-default
  92   :type    'boolean
  93   :group   'winner
  94   :require 'winner)
  95
  96 (defcustom winner-dont-bind-my-keys nil
  97   "If non-nil: Do not use `winner-mode-map' in Winner mode."
  98   :type  'boolean
  99   :group 'winner)
 100
 101 (defcustom winner-ring-size 200
 102   "Maximum number of stored window configurations per frame."
 103   :type  'integer
 104   :group 'winner)
 105
 106 (defcustom winner-boring-buffers '("*Completions*")
 107   "`winner-undo' will not restore windows displaying any of these \
 108 buffers.
 109 You may want to include buffer names such as *Help*, *Apropos*,
 110 *Buffer List*, *info* and *Compile-Log*."
 111   :type '(repeat string)
 112   :group 'winner)
 113
 114
 115
 116
 117 \f;;;; Saving old configurations (internal variables and subroutines)
 118
 119
 120 ;;; Current configuration
 121
 122 ;; List the windows according to their edges.
 123 (defun winner-sorted-window-list ()
 124   (sort (winner-window-list)
 125         (lambda (x y)
 126           (loop for a in (winner-edges x)
 127                 for b in (winner-edges y)
 128                 while (= a b)
 129                 finally return (< a b)))))
 130
 131 (defun winner-win-data ()
 132   ;; Essential properties of the windows in the selected frame.
 133   (loop for win in (winner-sorted-window-list)
 134         collect (cons (winner-edges win) (window-buffer win))))
 135
 136 ;; This variable is updated with the current window configuration
 137 ;; every time it changes.
 138 (defvar winner-currents nil)
 139
 140 ;; The current configuration (+ the buffers involved).
 141 (defsubst winner-conf ()
 142   (cons (current-window-configuration)
 143         (winner-win-data)))
 144
 145
 146 ;; Save current configuration.
 147 ;; (Called below by `winner-save-old-configurations').
 148 (defun winner-remember ()
 149   (let ((entry (assq (selected-frame) winner-currents)))
 150     (if entry (setcdr entry (winner-conf))
 151       (push (cons (selected-frame) (winner-conf))
 152             winner-currents))))
 153
 154 ;; Consult `winner-currents'.
 155 (defun winner-configuration (&optional frame)
 156   (or (cdr (assq (or frame (selected-frame)) winner-currents))
 157       (letf (((selected-frame) frame))
 158         (winner-conf))))
 159
 160
 161
 162 ;;; Saved configurations
 163
 164 ;; This variable contains the window cofiguration rings.
 165 ;; The key in this alist is the frame.
 166 (defvar winner-ring-alist nil)
 167
 168 ;; Find the right ring.  If it does not exist, create one.
 169 (defsubst winner-ring (frame)
 170   (or (cdr (assq frame winner-ring-alist))
 171       (progn
 172         (let ((ring (make-ring winner-ring-size)))
 173           (ring-insert ring (winner-configuration frame))
 174           (push (cons frame ring) winner-ring-alist)
 175           ring))))
 176
 177 \f;; If the same command is called several times in a row,
 178 ;; we only save one window configuration.
 179 (defvar winner-last-command nil)
 180
 181 ;; Frames affected by the previous command.
 182 (defvar winner-last-frames nil)
 183
 184
 185 (defun winner-equal (a b)
 186   "Check whether two Winner configurations (as produced by
 187 `winner-conf') are equal."
 188   (equal (cdr a) (cdr b)))
 189
 190
 191 ;; Save the current window configuration, if it has changed.
 192 ;; If so return frame, otherwise return nil.
 193 (defun winner-insert-if-new (frame)
 194   (unless (or (memq frame winner-last-frames)
 195               (eq this-command 'winner-redo))
 196     (let ((conf (winner-configuration frame))
 197           (ring (winner-ring frame)))
 198       (when (and (not (ring-empty-p ring))
 199                  (winner-equal conf (ring-ref ring 0)))
 200         ;; When the previous configuration was very similar,
 201         ;; keep only the latest.
 202         (ring-remove ring 0))
 203       (ring-insert ring conf)
 204       (push frame winner-last-frames)
 205       frame)))
 206
 207
 208
 209 ;;; Hooks
 210
 211 ;; Frames affected by the current command.
 212 (defvar winner-modified-list nil)
 213
 214 ;; Called whenever the window configuration changes
 215 ;; (a `window-configuration-change-hook').
 216 (defun winner-change-fun ()
 217   (unless (or (memq (selected-frame) winner-modified-list)
 218               (/= 0 (minibuffer-depth)))
 219     (push (selected-frame) winner-modified-list)))
 220
 221 ;; A `post-command-hook' for emacsen with
 222 ;; `window-configuration-change-hook'.
 223 (defun winner-save-old-configurations ()
 224   (when (zerop (minibuffer-depth))
 225     (unless (eq this-command winner-last-command)
 226       (setq winner-last-frames nil)
 227       (setq winner-last-command this-command))
 228     (dolist (frame winner-modified-list)
 229       (winner-insert-if-new frame))
 230     (setq winner-modified-list nil)
 231     (winner-remember)))
 232
 233 ;; A `minibuffer-setup-hook'.
 234 (defun winner-save-unconditionally ()
 235   (unless (eq this-command winner-last-command)
 236     (setq winner-last-frames nil)
 237     (setq winner-last-command this-command))
 238   (winner-insert-if-new (selected-frame))
 239   (winner-remember))
 240
 241 ;; A `post-command-hook' for other emacsen.
 242 ;; Also called by `winner-undo' before "undoing".
 243 (defun winner-save-conditionally ()
 244   (when (zerop (minibuffer-depth))
 245     (winner-save-unconditionally)))
 246
 247
 248
 249 \f;;;; Restoring configurations
 250
 251 ;; Works almost as `set-window-configuration',
 252 ;; but does not change the contents or the size of the minibuffer,
 253 ;; and tries to preserve the selected window.
 254 (defun winner-set-conf (winconf)
 255   (let* ((miniwin  (minibuffer-window))
 256          (chosen   (selected-window))
 257          (minisize (window-height miniwin)))
 258     (letf (((window-buffer miniwin))
 259            ((window-point  miniwin)))
 260       (set-window-configuration winconf))
 261     (cond
 262      ((window-live-p chosen) (select-window chosen))
 263      ((window-minibuffer-p (selected-window))
 264       (other-window 1)))
 265     (when (/= minisize (window-height miniwin))
 266       (letf (((selected-window) miniwin) )
 267         (setf (window-height) minisize)))))
 268
 269
 270
 271 (defvar winner-point-alist nil)
 272 ;; `set-window-configuration' restores old points and marks.  This is
 273 ;; not what we want, so we make a list of the "real" (i.e. new) points
 274 ;; and marks before undoing window configurations.
 275 ;;
 276 ;; Format of entries: (buffer (mark . mark-active) (window . point) ..)
 277
 278 (defun winner-make-point-alist ()
 279   (letf (((current-buffer)))
 280     (loop with alist
 281           for win in (winner-window-list)
 282           for entry =
 283           (or (assq (window-buffer win) alist)
 284               (car (push (list (set-buffer (window-buffer win))
 285                                (cons (mark t) (winner-active-region)))
 286                          alist)))
 287           do (push (cons win (window-point win))
 288                    (cddr entry))
 289           finally return alist)))
 290
 291 (defun winner-get-point (buf win)
 292   ;; Consult (and possibly extend) `winner-point-alist'.
 293   ;; Returns nil iff buf no longer exists.
 294   (when (buffer-name buf)
 295     (let ((entry (assq buf winner-point-alist)))
 296       (cond
 297        (entry
 298         (or (cdr (assq win (cddr entry)))
 299             (cdr (assq nil (cddr entry)))
 300             (letf (((current-buffer) buf))
 301               (push (cons nil (point)) (cddr entry))
 302               (point))))
 303        (t (letf (((current-buffer) buf))
 304             (push (list buf
 305                         (cons (mark t) (winner-active-region))
 306                         (cons nil (point)))
 307                   winner-point-alist)
 308             (point)))))))
 309
 310 \f;; Make sure point does not end up in the minibuffer and delete
 311 ;; windows displaying dead or boring buffers
 312 ;; (c.f. `winner-boring-buffers').  Return nil iff all the windows
 313 ;; should be deleted.  Preserve correct points and marks.
 314 (defun winner-set (conf)
 315   ;; For the format of `conf', see `winner-conf'.
 316   (let* ((buffers nil)
 317          (alive
 318           ;; Possibly update `winner-point-alist'
 319           (loop for buf in (mapcar 'cdr (cdr conf))
 320                 for pos = (winner-get-point buf nil)
 321                 if (and pos (not (memq buf buffers)))
 322                 do (push buf buffers)
 323                 collect pos)))
 324     (winner-set-conf (car conf))
 325     (let (xwins)                        ; to be deleted
 326
 327       ;; Restore points
 328       (dolist (win (winner-sorted-window-list))
 329         (unless (and (pop alive)
 330                      (setf (window-point win)
 331                            (winner-get-point (window-buffer win) win))
 332                      (not (member (buffer-name (window-buffer win))
 333                                   winner-boring-buffers)))
 334           (push win xwins)))            ; delete this window
 335
 336       ;; Restore marks
 337       (letf (((current-buffer)))
 338         (loop for buf in buffers
 339               for entry = (cadr (assq buf winner-point-alist))
 340               do (progn (set-buffer buf)
 341                         (set-mark (car entry))
 342                         (setf (winner-active-region) (cdr entry)))))
 343       ;; Delete windows, whose buffers are dead or boring.
 344       ;; Return t if this is still a possible configuration.
 345       (or (null xwins)
 346           (progn
 347             (mapc 'delete-window (cdr xwins)) ; delete all but one
 348             (unless (one-window-p t)
 349               (delete-window (car xwins))
 350               t))))))
 351
 352
 353
 354 ;;;; Winner mode  (a minor mode)
 355
 356 (defcustom winner-mode-hook nil
 357   "Functions to run whenever Winner mode is turned on."
 358   :type 'hook
 359   :group 'winner)
 360
 361 (defcustom winner-mode-leave-hook nil
 362   "Functions to run whenever Winner mode is turned off."
 363   :type 'hook
 364   :group 'winner)
 365
 366 (defvar winner-mode-map nil "Keymap for Winner mode.")
 367
 368 ;; Check if `window-configuration-change-hook' is working.
 369 (defun winner-hook-installed-p ()
 370   (save-window-excursion
 371     (let ((winner-var nil)
 372           (window-configuration-change-hook
 373            '((lambda () (setq winner-var t)))))
 374       (split-window)
 375       winner-var)))
 376
 377 \f
 378 ;;;###autoload
 379 (defun winner-mode (&optional arg)
 380   "Toggle Winner mode.
 381 With arg, turn Winner mode on if and only if arg is positive."
 382   (interactive "P")
 383   (let ((on-p (if arg (> (prefix-numeric-value arg) 0)
 384                 (not winner-mode))))
 385     (cond
 386      ;; Turn mode on
 387      (on-p
 388       (setq winner-mode t)
 389       (cond
 390        ((winner-hook-installed-p)
 391         (add-hook 'window-configuration-change-hook 'winner-change-fun)
 392         (add-hook 'post-command-hook 'winner-save-old-configurations))
 393        (t (add-hook 'post-command-hook 'winner-save-conditionally)))
 394       (add-hook 'minibuffer-setup-hook 'winner-save-unconditionally)
 395       (setq winner-modified-list (frame-list))
 396       (winner-save-old-configurations)
 397       (run-hooks 'winner-mode-hook)
 398       (when (interactive-p) (message "Winner mode enabled")))
 399      ;; Turn mode off
 400      (winner-mode
 401       (setq winner-mode nil)
 402       (remove-hook 'window-configuration-change-hook 'winner-change-fun)
 403       (remove-hook 'post-command-hook 'winner-save-old-configurations)
 404       (remove-hook 'post-command-hook 'winner-save-conditionally)
 405       (remove-hook 'minibuffer-setup-hook 'winner-save-unconditionally)
 406       (run-hooks 'winner-mode-leave-hook)
 407       (when (interactive-p) (message "Winner mode disabled"))))))
 408
 409 ;; Inspired by undo (simple.el)
 410
 411 (defvar winner-undo-frame nil)
 412
 413 (defvar winner-pending-undo-ring nil
 414   "The ring currently used by winner undo.")
 415 (defvar winner-undo-counter nil)
 416 (defvar winner-undone-data  nil) ; There confs have been passed.
 417
 418 (defun winner-undo ()
 419   "Switch back to an earlier window configuration saved by Winner mode.
 420 In other words, \"undo\" changes in window configuration."
 421   (interactive)
 422   (cond
 423    ((not winner-mode) (error "Winner mode is turned off"))
 424    (t (unless (and (eq last-command 'winner-undo)
 425                    (eq winner-undo-frame (selected-frame)))
 426         (winner-save-conditionally)     ; current configuration->stack
 427         (setq winner-undo-frame (selected-frame))
 428         (setq winner-point-alist (winner-make-point-alist))
 429         (setq winner-pending-undo-ring (winner-ring (selected-frame)))
 430         (setq winner-undo-counter 0)
 431         (setq winner-undone-data (list (winner-win-data))))
 432       (incf winner-undo-counter)        ; starting at 1
 433       (when (and (winner-undo-this)
 434                  (not (window-minibuffer-p (selected-window))))
 435         (message "Winner undo (%d / %d)"
 436                  winner-undo-counter
 437                  (1- (ring-length winner-pending-undo-ring)))))))
 438
 439
 440
 441 \f(defun winner-undo-this ()             ; The heart of winner undo.
 442   (loop
 443    (cond
 444     ((>= winner-undo-counter (ring-length winner-pending-undo-ring))
 445      (message "No further window configuration undo information")
 446      (return nil))
 447
 448     ((and                               ; If possible configuration
 449       (winner-set (ring-ref winner-pending-undo-ring
 450                             winner-undo-counter))
 451                                         ; .. and new configuration
 452       (let ((data (winner-win-data)))
 453         (and (not (member data winner-undone-data))
 454              (push data winner-undone-data))))
 455      (return t))                        ; .. then everything is fine.
 456     (t ;; Otherwise, discharge it (and try the next one).
 457      (ring-remove winner-pending-undo-ring winner-undo-counter)))))
 458
 459
 460 (defun winner-redo ()                   ; If you change your mind.
 461   "Restore a more recent window configuration saved by Winner mode."
 462   (interactive)
 463   (cond
 464    ((eq last-command 'winner-undo)
 465     (winner-set
 466      (if (zerop (minibuffer-depth))
 467          (ring-remove winner-pending-undo-ring 0)
 468        (ring-ref winner-pending-undo-ring 0)))
 469     (unless (eq (selected-window) (minibuffer-window))
 470       (message "Winner undid undo")))
 471    (t (error "Previous command was not a winner-undo"))))
 472
 473 ;;; To be evaluated when the package is loaded:
 474
 475 (unless winner-mode-map
 476   (setq winner-mode-map (make-sparse-keymap))
 477   (define-key winner-mode-map [(control x) left] 'winner-undo)
 478   (define-key winner-mode-map [(control x) right] 'winner-redo))
 479
 480 (unless (or (assq 'winner-mode minor-mode-map-alist)
 481             winner-dont-bind-my-keys)
 482   (push (cons 'winner-mode winner-mode-map)
 483         minor-mode-map-alist))
 484
 485 (provide 'winner)
 486
 487 ;;; winner.el ends here