lisp/winner.el

   1 ;;; winner.el --- Restore old window configurations
   2
   3 ;; Copyright (C) 1997, 1998, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007, 2008 Free Software Foundation. Inc.
   5
   6 ;; Author: Ivar Rummelhoff <ivarru@math.uio.no>
   7 ;; Created: 27 Feb 1997
   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 3, 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., 51 Franklin Street, Fifth Floor,
  25 ;; Boston, MA 02110-1301, 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-c left.  If you change your mind (while undoing), you can
  34 ;; press ctrl-c 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
  48 (defmacro winner-active-region ()
  49   (if (fboundp 'region-active-p)
  50       '(region-active-p)
  51     'mark-active))
  52
  53 (defsetf winner-active-region () (store)
  54   (if (fboundp 'zmacs-activate-region)
  55       `(if ,store (zmacs-activate-region)
  56          (zmacs-deactivate-region))
  57     `(setq mark-active ,store)))
  58
  59 (defalias 'winner-edges
  60   (if (featurep 'xemacs) 'window-pixel-edges 'window-edges))
  61 (defalias 'winner-window-list
  62   (if (featurep 'xemacs)
  63       (lambda () (delq (minibuffer-window) (window-list nil 0)))
  64     (lambda () (window-list nil 0))))
  65
  66 (require 'ring)
  67
  68 (unless (fboundp 'defgroup)
  69   (defmacro defgroup (&rest rest)))
  70
  71 (defgroup winner nil
  72   "Restoring window configurations."
  73   :group 'windows)
  74
  75 (unless (fboundp 'defcustom)
  76   (defmacro defcustom (symbol &optional initvalue docs &rest rest)
  77     (list 'defvar symbol initvalue docs)))
  78
  79 ;;;###autoload
  80 (defcustom winner-mode nil
  81   "Toggle Winner mode.
  82 Setting this variable directly does not take effect;
  83 use either \\[customize] or the function `winner-mode'."
  84   :set #'(lambda (symbol value) (funcall symbol (or value 0)))
  85   :initialize 'custom-initialize-default
  86   :type    'boolean
  87   :group   'winner
  88   :require 'winner)
  89
  90 (defcustom winner-dont-bind-my-keys nil
  91   "If non-nil: Do not use `winner-mode-map' in Winner mode."
  92   :type  'boolean
  93   :group 'winner)
  94
  95 (defcustom winner-ring-size 200
  96   "Maximum number of stored window configurations per frame."
  97   :type  'integer
  98   :group 'winner)
  99
 100 (defcustom winner-boring-buffers '("*Completions*")
 101   "`winner-undo' will not restore windows displaying any of these buffers.
 102 You may want to include buffer names such as *Help*, *Apropos*,
 103 *Buffer List*, *info* and *Compile-Log*."
 104   :type '(repeat string)
 105   :group 'winner)
 106
 107
 108
 109
 110 \f
 111 ;;;; Saving old configurations (internal variables and subroutines)
 112
 113
 114 ;;; Current configuration
 115
 116 ;; List the windows according to their edges.
 117 (defun winner-sorted-window-list ()
 118   (sort (winner-window-list)
 119         (lambda (x y)
 120           (loop for a in (winner-edges x)
 121                 for b in (winner-edges y)
 122                 while (= a b)
 123                 finally return (< a b)))))
 124
 125 (defun winner-win-data ()
 126   ;; Essential properties of the windows in the selected frame.
 127   (loop for win in (winner-sorted-window-list)
 128         collect (cons (winner-edges win) (window-buffer win))))
 129
 130 ;; This variable is updated with the current window configuration
 131 ;; every time it changes.
 132 (defvar winner-currents nil)
 133
 134 ;; The current configuration (+ the buffers involved).
 135 (defsubst winner-conf ()
 136   (cons (current-window-configuration)
 137         (winner-win-data)))
 138
 139
 140 ;; Save current configuration.
 141 ;; (Called below by `winner-save-old-configurations').
 142 (defun winner-remember ()
 143   (let ((entry (assq (selected-frame) winner-currents)))
 144     (if entry (setcdr entry (winner-conf))
 145       (push (cons (selected-frame) (winner-conf))
 146             winner-currents))))
 147
 148 ;; Consult `winner-currents'.
 149 (defun winner-configuration (&optional frame)
 150   (or (cdr (assq (or frame (selected-frame)) winner-currents))
 151       (letf (((selected-frame) frame))
 152         (winner-conf))))
 153
 154
 155
 156 ;;; Saved configurations
 157
 158 ;; This variable contains the window cofiguration rings.
 159 ;; The key in this alist is the frame.
 160 (defvar winner-ring-alist nil)
 161
 162 ;; Find the right ring.  If it does not exist, create one.
 163 (defsubst winner-ring (frame)
 164   (or (cdr (assq frame winner-ring-alist))
 165       (let ((ring (make-ring winner-ring-size)))
 166         (ring-insert ring (winner-configuration frame))
 167         (push (cons frame ring) winner-ring-alist)
 168         ring)))
 169
 170 \f
 171 ;; If the same command is called several times in a row,
 172 ;; we only save one window configuration.
 173 (defvar winner-last-command nil)
 174
 175 ;; Frames affected by the previous command.
 176 (defvar winner-last-frames nil)
 177
 178
 179 (defsubst winner-equal (a b)
 180   "Check whether two Winner configurations (as produced by
 181 `winner-conf') are equal."
 182   (equal (cdr a) (cdr b)))
 183
 184
 185 ;; Save the current window configuration, if it has changed.
 186 ;; If so return frame, otherwise return nil.
 187 (defun winner-insert-if-new (frame)
 188   (unless (or (memq frame winner-last-frames)
 189               (eq this-command 'winner-redo))
 190     (let ((conf (winner-configuration frame))
 191           (ring (winner-ring frame)))
 192       (when (and (not (ring-empty-p ring))
 193                  (winner-equal conf (ring-ref ring 0)))
 194         ;; When the previous configuration was very similar,
 195         ;; keep only the latest.
 196         (ring-remove ring 0))
 197       (ring-insert ring conf)
 198       (push frame winner-last-frames)
 199       frame)))
 200
 201
 202
 203 ;;; Hooks
 204
 205 ;; Frames affected by the current command.
 206 (defvar winner-modified-list nil)
 207
 208 ;; Called whenever the window configuration changes
 209 ;; (a `window-configuration-change-hook').
 210 (defun winner-change-fun ()
 211   (unless (or (memq (selected-frame) winner-modified-list)
 212               (/= 0 (minibuffer-depth)))
 213     (push (selected-frame) winner-modified-list)))
 214
 215 ;; A `post-command-hook' for emacsen with
 216 ;; `window-configuration-change-hook'.
 217 (defun winner-save-old-configurations ()
 218   (when (zerop (minibuffer-depth))
 219     (unless (eq this-command winner-last-command)
 220       (setq winner-last-frames nil)
 221       (setq winner-last-command this-command))
 222     (dolist (frame winner-modified-list)
 223       (winner-insert-if-new frame))
 224     (setq winner-modified-list nil)
 225     (winner-remember)))
 226
 227 ;; A `minibuffer-setup-hook'.
 228 (defun winner-save-unconditionally ()
 229   (unless (eq this-command winner-last-command)
 230     (setq winner-last-frames nil)
 231     (setq winner-last-command this-command))
 232   (winner-insert-if-new (selected-frame))
 233   (winner-remember))
 234
 235 ;; A `post-command-hook' for other emacsen.
 236 ;; Also called by `winner-undo' before "undoing".
 237 (defun winner-save-conditionally ()
 238   (when (zerop (minibuffer-depth))
 239     (winner-save-unconditionally)))
 240
 241
 242
 243 \f
 244 ;;;; Restoring configurations
 245
 246 ;; Works almost as `set-window-configuration',
 247 ;; but does not change the contents or the size of the minibuffer,
 248 ;; and tries to preserve the selected window.
 249 (defun winner-set-conf (winconf)
 250   (let* ((miniwin  (minibuffer-window))
 251          (chosen   (selected-window))
 252          (minisize (window-height miniwin)))
 253     (letf (((window-buffer miniwin))
 254            ((window-point  miniwin)))
 255       (set-window-configuration winconf))
 256     (cond
 257      ((window-live-p chosen) (select-window chosen))
 258      ((window-minibuffer-p (selected-window))
 259       (other-window 1)))
 260     (when (/= minisize (window-height miniwin))
 261       (letf (((selected-window) miniwin) )
 262         (setf (window-height) minisize)))))
 263
 264
 265
 266 (defvar winner-point-alist nil)
 267 ;; `set-window-configuration' restores old points and marks.  This is
 268 ;; not what we want, so we make a list of the "real" (i.e. new) points
 269 ;; and marks before undoing window configurations.
 270 ;;
 271 ;; Format of entries: (buffer (mark . mark-active) (window . point) ..)
 272
 273 (defun winner-make-point-alist ()
 274   (letf (((current-buffer)))
 275     (loop with alist
 276           for win in (winner-window-list)
 277           for entry =
 278           (or (assq (window-buffer win) alist)
 279               (car (push (list (set-buffer (window-buffer win))
 280                                (cons (mark t) (winner-active-region)))
 281                          alist)))
 282           do (push (cons win (window-point win))
 283                    (cddr entry))
 284           finally return alist)))
 285
 286 (defun winner-get-point (buf win)
 287   ;; Consult (and possibly extend) `winner-point-alist'.
 288   ;; Returns nil if buf no longer exists.
 289   (when (buffer-name buf)
 290     (let ((entry (assq buf winner-point-alist)))
 291       (cond
 292        (entry
 293         (or (cdr (assq win (cddr entry)))
 294             (cdr (assq nil (cddr entry)))
 295             (letf (((current-buffer) buf))
 296               (push (cons nil (point)) (cddr entry))
 297               (point))))
 298        (t (letf (((current-buffer) buf))
 299             (push (list buf
 300                         (cons (mark t) (winner-active-region))
 301                         (cons nil (point)))
 302                   winner-point-alist)
 303             (point)))))))
 304
 305 \f
 306 ;; Make sure point does not end up in the minibuffer and delete
 307 ;; windows displaying dead or boring buffers
 308 ;; (c.f. `winner-boring-buffers').  Return nil if all the windows
 309 ;; should be deleted.  Preserve correct points and marks.
 310 (defun winner-set (conf)
 311   ;; For the format of `conf', see `winner-conf'.
 312   (let* ((buffers nil)
 313          (alive
 314           ;; Possibly update `winner-point-alist'
 315           (loop for buf in (mapcar 'cdr (cdr conf))
 316                 for pos = (winner-get-point buf nil)
 317                 if (and pos (not (memq buf buffers)))
 318                 do (push buf buffers)
 319                 collect pos)))
 320     (winner-set-conf (car conf))
 321     (let (xwins)                        ; to be deleted
 322
 323       ;; Restore points
 324       (dolist (win (winner-sorted-window-list))
 325         (unless (and (pop alive)
 326                      (setf (window-point win)
 327                            (winner-get-point (window-buffer win) win))
 328                      (not (member (buffer-name (window-buffer win))
 329                                   winner-boring-buffers)))
 330           (push win xwins)))            ; delete this window
 331
 332       ;; Restore marks
 333       (letf (((current-buffer)))
 334         (loop for buf in buffers
 335               for entry = (cadr (assq buf winner-point-alist))
 336               do (progn (set-buffer buf)
 337                         (set-mark (car entry))
 338                         (setf (winner-active-region) (cdr entry)))))
 339       ;; Delete windows, whose buffers are dead or boring.
 340       ;; Return t if this is still a possible configuration.
 341       (or (null xwins)
 342           (progn
 343             (mapc 'delete-window (cdr xwins)) ; delete all but one
 344             (unless (one-window-p t)
 345               (delete-window (car xwins))
 346               t))))))
 347
 348
 349
 350 ;;;; Winner mode  (a minor mode)
 351
 352 (defcustom winner-mode-hook nil
 353   "Functions to run whenever Winner mode is turned on."
 354   :type 'hook
 355   :group 'winner)
 356
 357 (defcustom winner-mode-leave-hook nil
 358   "Functions to run whenever Winner mode is turned off."
 359   :type 'hook
 360   :group 'winner)
 361
 362 (defvar winner-mode-map
 363   (let ((map (make-sparse-keymap)))
 364     (define-key map [(control c) left] 'winner-undo)
 365     (define-key map [(control c) right] 'winner-redo)
 366     map)
 367   "Keymap for Winner mode.")
 368
 369 ;; Check if `window-configuration-change-hook' is working.
 370 (defun winner-hook-installed-p ()
 371   (save-window-excursion
 372     (let ((winner-var nil)
 373           (window-configuration-change-hook
 374            '((lambda () (setq winner-var t)))))
 375       (split-window)
 376       winner-var)))
 377
 378 \f
 379 ;;;###autoload
 380 (defun winner-mode (&optional arg)
 381   "Toggle Winner mode.
 382 With arg, turn Winner mode on if and only if arg is positive."
 383   (interactive "P")
 384   (let ((on-p (if arg (> (prefix-numeric-value arg) 0)
 385                 (not winner-mode))))
 386     (cond
 387      ;; Turn mode on
 388      (on-p
 389       (setq winner-mode t)
 390       (cond
 391        ((winner-hook-installed-p)
 392         (add-hook 'window-configuration-change-hook 'winner-change-fun)
 393       (add-hook 'post-command-hook 'winner-save-old-configurations))
 394        (t (add-hook 'post-command-hook 'winner-save-conditionally)))
 395       (add-hook 'minibuffer-setup-hook 'winner-save-unconditionally)
 396       (setq winner-modified-list (frame-list))
 397       (winner-save-old-configurations)
 398       (run-hooks 'winner-mode-hook)
 399       (when (interactive-p) (message "Winner mode enabled")))
 400      ;; Turn mode off
 401      (winner-mode
 402       (setq winner-mode nil)
 403       (remove-hook 'window-configuration-change-hook 'winner-change-fun)
 404       (remove-hook 'post-command-hook 'winner-save-old-configurations)
 405       (remove-hook 'post-command-hook 'winner-save-conditionally)
 406       (remove-hook 'minibuffer-setup-hook 'winner-save-unconditionally)
 407       (run-hooks 'winner-mode-leave-hook)
 408       (when (interactive-p) (message "Winner mode disabled"))))))
 409
 410 ;; Inspired by undo (simple.el)
 411
 412 (defvar winner-undo-frame nil)
 413
 414 (defvar winner-pending-undo-ring nil
 415   "The ring currently used by `winner-undo'.")
 416 (defvar winner-undo-counter nil)
 417 (defvar winner-undone-data  nil) ; There confs have been passed.
 418
 419 (defun winner-undo ()
 420   "Switch back to an earlier window configuration saved by Winner mode.
 421 In other words, \"undo\" changes in window configuration."
 422   (interactive)
 423   (cond
 424    ((not winner-mode) (error "Winner mode is turned off"))
 425    (t (unless (and (eq last-command 'winner-undo)
 426                    (eq winner-undo-frame (selected-frame)))
 427         (winner-save-conditionally)     ; current configuration->stack
 428         (setq winner-undo-frame (selected-frame))
 429         (setq winner-point-alist (winner-make-point-alist))
 430         (setq winner-pending-undo-ring (winner-ring (selected-frame)))
 431         (setq winner-undo-counter 0)
 432         (setq winner-undone-data (list (winner-win-data))))
 433       (incf winner-undo-counter)        ; starting at 1
 434       (when (and (winner-undo-this)
 435                  (not (window-minibuffer-p (selected-window))))
 436         (message "Winner undo (%d / %d)"
 437                  winner-undo-counter
 438                  (1- (ring-length winner-pending-undo-ring)))))))
 439
 440
 441
 442 \f
 443 (defun winner-undo-this ()              ; The heart of winner undo.
 444   (loop
 445    (cond
 446     ((>= winner-undo-counter (ring-length winner-pending-undo-ring))
 447      (message "No further window configuration undo information")
 448      (return nil))
 449
 450     ((and                               ; If possible configuration
 451       (winner-set (ring-ref winner-pending-undo-ring
 452                             winner-undo-counter))
 453                                         ; .. and new configuration
 454       (let ((data (winner-win-data)))
 455         (and (not (member data winner-undone-data))
 456              (push data winner-undone-data))))
 457      (return t))                        ; .. then everything is fine.
 458     (t ;; Otherwise, discharge it (and try the next one).
 459      (ring-remove winner-pending-undo-ring winner-undo-counter)))))
 460
 461
 462 (defun winner-redo ()                   ; If you change your mind.
 463   "Restore a more recent window configuration saved by Winner mode."
 464   (interactive)
 465   (cond
 466    ((eq last-command 'winner-undo)
 467     (winner-set
 468      (if (zerop (minibuffer-depth))
 469          (ring-remove winner-pending-undo-ring 0)
 470        (ring-ref winner-pending-undo-ring 0)))
 471     (unless (eq (selected-window) (minibuffer-window))
 472       (message "Winner undid undo")))
 473    (t (error "Previous command was not a `winner-undo'"))))
 474
 475 ;;; To be evaluated when the package is loaded:
 476
 477 (unless (or (assq 'winner-mode minor-mode-map-alist)
 478             winner-dont-bind-my-keys)
 479   (push (cons 'winner-mode winner-mode-map)
 480         minor-mode-map-alist))
 481
 482 (provide 'winner)
 483 ;; arch-tag: 686d1c1b-010e-42ca-a192-b5685112418f
 484 ;;; winner.el ends here