lisp/winner.el

   1 ;;; winner.el --- Restore old window configurations
   2
   3 ;; Copyright (C) 1997, 1998, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007 Free Software Foundation. Inc.
   5
   6 ;; Author: Ivar Rummelhoff <ivarru@math.uio.no>
   7 ;; Created: 27 Feb 1997
   8 ;; Time-stamp: <2006-02-06 15:13:57 ttn>
   9 ;; Keywords: convenience frames
  10
  11 ;; This file is part of GNU Emacs.
  12
  13 ;; GNU Emacs is free software; you can redistribute it and/or modify
  14 ;; it under the terms of the GNU General Public License as published by
  15 ;; the Free Software Foundation; either version 2, or (at your option)
  16 ;; any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  25 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  26 ;; Boston, MA 02110-1301, USA.
  27
  28 ;;; Commentary:
  29
  30 ;; Winner mode is a global minor mode that records the changes in the
  31 ;; window configuration (i.e. how the frames are partitioned into
  32 ;; windows) so that the changes can be "undone" using the command
  33 ;; `winner-undo'.  By default this one is bound to the key sequence
  34 ;; ctrl-c left.  If you change your mind (while undoing), you can
  35 ;; press ctrl-c right (calling `winner-redo').  Even though it uses
  36 ;; some features of Emacs20.3, winner.el should also work with
  37 ;; Emacs19.34 and XEmacs20, provided that the installed version of
  38 ;; custom is not obsolete.
  39
  40 ;; Winner mode was improved August 1998.
  41 ;; Further improvements February 2002.
  42
  43 ;;; Code:
  44
  45 (eval-when-compile
  46   (require 'cl))
  47
  48
  49 (defmacro winner-active-region ()
  50   (if (fboundp 'region-active-p)
  51       '(region-active-p)
  52     'mark-active))
  53
  54 (defsetf winner-active-region () (store)
  55   (if (fboundp 'zmacs-activate-region)
  56       `(if ,store (zmacs-activate-region)
  57          (zmacs-deactivate-region))
  58     `(setq mark-active ,store)))
  59
  60 (defalias 'winner-edges
  61   (if (featurep 'xemacs) 'window-pixel-edges 'window-edges))
  62 (defalias 'winner-window-list
  63   (if (featurep 'xemacs)
  64       (lambda () (delq (minibuffer-window) (window-list nil 0)))
  65     (lambda () (window-list nil 0))))
  66
  67 (require 'ring)
  68
  69 (unless (fboundp 'defgroup)
  70   (defmacro defgroup (&rest rest)))
  71
  72 (defgroup winner nil
  73   "Restoring window configurations."
  74   :group 'windows)
  75
  76 (unless (fboundp 'defcustom)
  77   (defmacro defcustom (symbol &optional initvalue docs &rest rest)
  78     (list 'defvar symbol initvalue docs)))
  79
  80 ;;;###autoload
  81 (defcustom winner-mode nil
  82   "Toggle Winner mode.
  83 Setting this variable directly does not take effect;
  84 use either \\[customize] or the function `winner-mode'."
  85   :set #'(lambda (symbol value) (funcall symbol (or value 0)))
  86   :initialize 'custom-initialize-default
  87   :type    'boolean
  88   :group   'winner
  89   :require 'winner)
  90
  91 (defcustom winner-dont-bind-my-keys nil
  92   "If non-nil: Do not use `winner-mode-map' in Winner mode."
  93   :type  'boolean
  94   :group 'winner)
  95
  96 (defcustom winner-ring-size 200
  97   "Maximum number of stored window configurations per frame."
  98   :type  'integer
  99   :group 'winner)
 100
 101 (defcustom winner-boring-buffers '("*Completions*")
 102   "`winner-undo' will not restore windows displaying any of these buffers.
 103 You may want to include buffer names such as *Help*, *Apropos*,
 104 *Buffer List*, *info* and *Compile-Log*."
 105   :type '(repeat string)
 106   :group 'winner)
 107
 108
 109
 110
 111 \f
 112 ;;;; Saving old configurations (internal variables and subroutines)
 113
 114
 115 ;;; Current configuration
 116
 117 ;; List the windows according to their edges.
 118 (defun winner-sorted-window-list ()
 119   (sort (winner-window-list)
 120         (lambda (x y)
 121           (loop for a in (winner-edges x)
 122                 for b in (winner-edges y)
 123                 while (= a b)
 124                 finally return (< a b)))))
 125
 126 (defun winner-win-data ()
 127   ;; Essential properties of the windows in the selected frame.
 128   (loop for win in (winner-sorted-window-list)
 129         collect (cons (winner-edges win) (window-buffer win))))
 130
 131 ;; This variable is updated with the current window configuration
 132 ;; every time it changes.
 133 (defvar winner-currents nil)
 134
 135 ;; The current configuration (+ the buffers involved).
 136 (defsubst winner-conf ()
 137   (cons (current-window-configuration)
 138         (winner-win-data)))
 139
 140
 141 ;; Save current configuration.
 142 ;; (Called below by `winner-save-old-configurations').
 143 (defun winner-remember ()
 144   (let ((entry (assq (selected-frame) winner-currents)))
 145     (if entry (setcdr entry (winner-conf))
 146       (push (cons (selected-frame) (winner-conf))
 147             winner-currents))))
 148
 149 ;; Consult `winner-currents'.
 150 (defun winner-configuration (&optional frame)
 151   (or (cdr (assq (or frame (selected-frame)) winner-currents))
 152       (letf (((selected-frame) frame))
 153         (winner-conf))))
 154
 155
 156
 157 ;;; Saved configurations
 158
 159 ;; This variable contains the window cofiguration rings.
 160 ;; The key in this alist is the frame.
 161 (defvar winner-ring-alist nil)
 162
 163 ;; Find the right ring.  If it does not exist, create one.
 164 (defsubst winner-ring (frame)
 165   (or (cdr (assq frame winner-ring-alist))
 166       (let ((ring (make-ring winner-ring-size)))
 167         (ring-insert ring (winner-configuration frame))
 168         (push (cons frame ring) winner-ring-alist)
 169         ring)))
 170
 171 \f
 172 ;; If the same command is called several times in a row,
 173 ;; we only save one window configuration.
 174 (defvar winner-last-command nil)
 175
 176 ;; Frames affected by the previous command.
 177 (defvar winner-last-frames nil)
 178
 179
 180 (defsubst winner-equal (a b)
 181   "Check whether two Winner configurations (as produced by
 182 `winner-conf') are equal."
 183   (equal (cdr a) (cdr b)))
 184
 185
 186 ;; Save the current window configuration, if it has changed.
 187 ;; If so return frame, otherwise return nil.
 188 (defun winner-insert-if-new (frame)
 189   (unless (or (memq frame winner-last-frames)
 190               (eq this-command 'winner-redo))
 191     (let ((conf (winner-configuration frame))
 192           (ring (winner-ring frame)))
 193       (when (and (not (ring-empty-p ring))
 194                  (winner-equal conf (ring-ref ring 0)))
 195         ;; When the previous configuration was very similar,
 196         ;; keep only the latest.
 197         (ring-remove ring 0))
 198       (ring-insert ring conf)
 199       (push frame winner-last-frames)
 200       frame)))
 201
 202
 203
 204 ;;; Hooks
 205
 206 ;; Frames affected by the current command.
 207 (defvar winner-modified-list nil)
 208
 209 ;; Called whenever the window configuration changes
 210 ;; (a `window-configuration-change-hook').
 211 (defun winner-change-fun ()
 212   (unless (or (memq (selected-frame) winner-modified-list)
 213               (/= 0 (minibuffer-depth)))
 214     (push (selected-frame) winner-modified-list)))
 215
 216 ;; A `post-command-hook' for emacsen with
 217 ;; `window-configuration-change-hook'.
 218 (defun winner-save-old-configurations ()
 219   (when (zerop (minibuffer-depth))
 220     (unless (eq this-command winner-last-command)
 221       (setq winner-last-frames nil)
 222       (setq winner-last-command this-command))
 223     (dolist (frame winner-modified-list)
 224       (winner-insert-if-new frame))
 225     (setq winner-modified-list nil)
 226     (winner-remember)))
 227
 228 ;; A `minibuffer-setup-hook'.
 229 (defun winner-save-unconditionally ()
 230   (unless (eq this-command winner-last-command)
 231     (setq winner-last-frames nil)
 232     (setq winner-last-command this-command))
 233   (winner-insert-if-new (selected-frame))
 234   (winner-remember))
 235
 236 ;; A `post-command-hook' for other emacsen.
 237 ;; Also called by `winner-undo' before "undoing".
 238 (defun winner-save-conditionally ()
 239   (when (zerop (minibuffer-depth))
 240     (winner-save-unconditionally)))
 241
 242
 243
 244 \f
 245 ;;;; Restoring configurations
 246
 247 ;; Works almost as `set-window-configuration',
 248 ;; but does not change the contents or the size of the minibuffer,
 249 ;; and tries to preserve the selected window.
 250 (defun winner-set-conf (winconf)
 251   (let* ((miniwin  (minibuffer-window))
 252          (chosen   (selected-window))
 253          (minisize (window-height miniwin)))
 254     (letf (((window-buffer miniwin))
 255            ((window-point  miniwin)))
 256       (set-window-configuration winconf))
 257     (cond
 258      ((window-live-p chosen) (select-window chosen))
 259      ((window-minibuffer-p (selected-window))
 260       (other-window 1)))
 261     (when (/= minisize (window-height miniwin))
 262       (letf (((selected-window) miniwin) )
 263         (setf (window-height) minisize)))))
 264
 265
 266
 267 (defvar winner-point-alist nil)
 268 ;; `set-window-configuration' restores old points and marks.  This is
 269 ;; not what we want, so we make a list of the "real" (i.e. new) points
 270 ;; and marks before undoing window configurations.
 271 ;;
 272 ;; Format of entries: (buffer (mark . mark-active) (window . point) ..)
 273
 274 (defun winner-make-point-alist ()
 275   (letf (((current-buffer)))
 276     (loop with alist
 277           for win in (winner-window-list)
 278           for entry =
 279           (or (assq (window-buffer win) alist)
 280               (car (push (list (set-buffer (window-buffer win))
 281                                (cons (mark t) (winner-active-region)))
 282                          alist)))
 283           do (push (cons win (window-point win))
 284                    (cddr entry))
 285           finally return alist)))
 286
 287 (defun winner-get-point (buf win)
 288   ;; Consult (and possibly extend) `winner-point-alist'.
 289   ;; Returns nil iff buf no longer exists.
 290   (when (buffer-name buf)
 291     (let ((entry (assq buf winner-point-alist)))
 292       (cond
 293        (entry
 294         (or (cdr (assq win (cddr entry)))
 295             (cdr (assq nil (cddr entry)))
 296             (letf (((current-buffer) buf))
 297               (push (cons nil (point)) (cddr entry))
 298               (point))))
 299        (t (letf (((current-buffer) buf))
 300             (push (list buf
 301                         (cons (mark t) (winner-active-region))
 302                         (cons nil (point)))
 303                   winner-point-alist)
 304             (point)))))))
 305
 306 \f
 307 ;; Make sure point does not end up in the minibuffer and delete
 308 ;; windows displaying dead or boring buffers
 309 ;; (c.f. `winner-boring-buffers').  Return nil iff all the windows
 310 ;; should be deleted.  Preserve correct points and marks.
 311 (defun winner-set (conf)
 312   ;; For the format of `conf', see `winner-conf'.
 313   (let* ((buffers nil)
 314          (alive
 315           ;; Possibly update `winner-point-alist'
 316           (loop for buf in (mapcar 'cdr (cdr conf))
 317                 for pos = (winner-get-point buf nil)
 318                 if (and pos (not (memq buf buffers)))
 319                 do (push buf buffers)
 320                 collect pos)))
 321     (winner-set-conf (car conf))
 322     (let (xwins)                        ; to be deleted
 323
 324       ;; Restore points
 325       (dolist (win (winner-sorted-window-list))
 326         (unless (and (pop alive)
 327                      (setf (window-point win)
 328                            (winner-get-point (window-buffer win) win))
 329                      (not (member (buffer-name (window-buffer win))
 330                                   winner-boring-buffers)))
 331           (push win xwins)))            ; delete this window
 332
 333       ;; Restore marks
 334       (letf (((current-buffer)))
 335         (loop for buf in buffers
 336               for entry = (cadr (assq buf winner-point-alist))
 337               do (progn (set-buffer buf)
 338                         (set-mark (car entry))
 339                         (setf (winner-active-region) (cdr entry)))))
 340       ;; Delete windows, whose buffers are dead or boring.
 341       ;; Return t if this is still a possible configuration.
 342       (or (null xwins)
 343           (progn
 344             (mapc 'delete-window (cdr xwins)) ; delete all but one
 345             (unless (one-window-p t)
 346               (delete-window (car xwins))
 347               t))))))
 348
 349
 350
 351 ;;;; Winner mode  (a minor mode)
 352
 353 (defcustom winner-mode-hook nil
 354   "Functions to run whenever Winner mode is turned on."
 355   :type 'hook
 356   :group 'winner)
 357
 358 (defcustom winner-mode-leave-hook nil
 359   "Functions to run whenever Winner mode is turned off."
 360   :type 'hook
 361   :group 'winner)
 362
 363 (defvar winner-mode-map
 364   (let ((map (make-sparse-keymap)))
 365     (define-key map [(control c) left] 'winner-undo)
 366     (define-key map [(control c) right] 'winner-redo)
 367     map)
 368   "Keymap for Winner mode.")
 369
 370 ;; Check if `window-configuration-change-hook' is working.
 371 (defun winner-hook-installed-p ()
 372   (save-window-excursion
 373     (let ((winner-var nil)
 374           (window-configuration-change-hook
 375            '((lambda () (setq winner-var t)))))
 376       (split-window)
 377       winner-var)))
 378
 379 \f
 380 ;;;###autoload
 381 (defun winner-mode (&optional arg)
 382   "Toggle Winner mode.
 383 With arg, turn Winner mode on if and only if arg is positive."
 384   (interactive "P")
 385   (let ((on-p (if arg (> (prefix-numeric-value arg) 0)
 386                 (not winner-mode))))
 387     (cond
 388      ;; Turn mode on
 389      (on-p
 390       (setq winner-mode t)
 391       (cond
 392        ((winner-hook-installed-p)
 393         (add-hook 'window-configuration-change-hook 'winner-change-fun)
 394       (add-hook 'post-command-hook 'winner-save-old-configurations))
 395        (t (add-hook 'post-command-hook 'winner-save-conditionally)))
 396       (add-hook 'minibuffer-setup-hook 'winner-save-unconditionally)
 397       (setq winner-modified-list (frame-list))
 398       (winner-save-old-configurations)
 399       (run-hooks 'winner-mode-hook)
 400       (when (interactive-p) (message "Winner mode enabled")))
 401      ;; Turn mode off
 402      (winner-mode
 403       (setq winner-mode nil)
 404       (remove-hook 'window-configuration-change-hook 'winner-change-fun)
 405       (remove-hook 'post-command-hook 'winner-save-old-configurations)
 406       (remove-hook 'post-command-hook 'winner-save-conditionally)
 407       (remove-hook 'minibuffer-setup-hook 'winner-save-unconditionally)
 408       (run-hooks 'winner-mode-leave-hook)
 409       (when (interactive-p) (message "Winner mode disabled"))))))
 410
 411 ;; Inspired by undo (simple.el)
 412
 413 (defvar winner-undo-frame nil)
 414
 415 (defvar winner-pending-undo-ring nil
 416   "The ring currently used by `winner-undo'.")
 417 (defvar winner-undo-counter nil)
 418 (defvar winner-undone-data  nil) ; There confs have been passed.
 419
 420 (defun winner-undo ()
 421   "Switch back to an earlier window configuration saved by Winner mode.
 422 In other words, \"undo\" changes in window configuration."
 423   (interactive)
 424   (cond
 425    ((not winner-mode) (error "Winner mode is turned off"))
 426    (t (unless (and (eq last-command 'winner-undo)
 427                    (eq winner-undo-frame (selected-frame)))
 428         (winner-save-conditionally)     ; current configuration->stack
 429         (setq winner-undo-frame (selected-frame))
 430         (setq winner-point-alist (winner-make-point-alist))
 431         (setq winner-pending-undo-ring (winner-ring (selected-frame)))
 432         (setq winner-undo-counter 0)
 433         (setq winner-undone-data (list (winner-win-data))))
 434       (incf winner-undo-counter)        ; starting at 1
 435       (when (and (winner-undo-this)
 436                  (not (window-minibuffer-p (selected-window))))
 437         (message "Winner undo (%d / %d)"
 438                  winner-undo-counter
 439                  (1- (ring-length winner-pending-undo-ring)))))))
 440
 441
 442
 443 \f
 444 (defun winner-undo-this ()              ; The heart of winner undo.
 445   (loop
 446    (cond
 447     ((>= winner-undo-counter (ring-length winner-pending-undo-ring))
 448      (message "No further window configuration undo information")
 449      (return nil))
 450
 451     ((and                               ; If possible configuration
 452       (winner-set (ring-ref winner-pending-undo-ring
 453                             winner-undo-counter))
 454                                         ; .. and new configuration
 455       (let ((data (winner-win-data)))
 456         (and (not (member data winner-undone-data))
 457              (push data winner-undone-data))))
 458      (return t))                        ; .. then everything is fine.
 459     (t ;; Otherwise, discharge it (and try the next one).
 460      (ring-remove winner-pending-undo-ring winner-undo-counter)))))
 461
 462
 463 (defun winner-redo ()                   ; If you change your mind.
 464   "Restore a more recent window configuration saved by Winner mode."
 465   (interactive)
 466   (cond
 467    ((eq last-command 'winner-undo)
 468     (winner-set
 469      (if (zerop (minibuffer-depth))
 470          (ring-remove winner-pending-undo-ring 0)
 471        (ring-ref winner-pending-undo-ring 0)))
 472     (unless (eq (selected-window) (minibuffer-window))
 473       (message "Winner undid undo")))
 474    (t (error "Previous command was not a `winner-undo'"))))
 475
 476 ;;; To be evaluated when the package is loaded:
 477
 478 (unless (or (assq 'winner-mode minor-mode-map-alist)
 479             winner-dont-bind-my-keys)
 480   (push (cons 'winner-mode winner-mode-map)
 481         minor-mode-map-alist))
 482
 483 (provide 'winner)
 484 ;; arch-tag: 686d1c1b-010e-42ca-a192-b5685112418f
 485 ;;; winner.el ends here