X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/21f3d1d389c4e37dc2323062082b7c332d2aa021..1b74c4346e92c9ac1ae0575c2ad69f8d81126d7e:/lisp/winner.el

diff --git a/lisp/winner.el b/lisp/winner.el
index 15a86994c7..0fbd0221e4 100644
--- a/lisp/winner.el
+++ b/lisp/winner.el
@@ -1,11 +1,12 @@
-;;; winner.el  --- Restore window configuration or change buffer
+;;; winner.el --- Restore old window configurations
 
-;; Copyright (C) 1997 Free Software Foundation. Inc.
+;; Copyright (C) 1997, 1998, 2001, 2002, 2003, 2004,
+;;   2005 Free Software Foundation. Inc.
 
-;; Author: Ivar Rummelhoff <ivarr@ifi.uio.no>
-;; Maintainer: Ivar Rummelhoff <ivarr@ifi.uio.no>
+;; Author: Ivar Rummelhoff <ivarru@math.uio.no>
 ;; Created: 27 Feb 1997
-;; Keywords: extensions,windows
+;; Time-stamp: <2002-02-20 22:06:58 ivarru>
+;; Keywords: convenience frames
 
 ;; This file is part of GNU Emacs.
 
@@ -21,325 +22,464 @@
 
 ;; You should have received a copy of the GNU General Public License
 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
 
 ;;; Commentary:
-;; 
-;;   winner.el provides a minor mode (`winner-mode') that does
-;;   essentially two things:
-;;
-;;     1) It keeps track of changing window configurations, so that
-;;        when you wish to go back to a previous view, all you have
-;;        to do is to press C-left a couple of times.
-;;
-;;     2) It lets you switch to other buffers by pressing C-right.
-;;
-;; To use Winner mode, put this line in your .emacs file:
-;;
-;;      (add-hook 'after-init-hook (lambda () (winner-mode 1)))
-
-;; Details:
-;;
-;;   1. You may of course decide to use other bindings than those
-;;      mentioned above.  Just set these variables in your .emacs:
-;;
-;;          `winner-prev-event'
-;;          `winner-next-event'
-;;
-;;   2. When you have found the view of  your choice
-;;      (using your favourite keys), you may press ctrl-space
-;;      (`winner-max-event') to `delete-other-windows'.
-;;
-;;   3. Winner now keeps one configuration stack for each frame.
-;;
-;;
-;;
-;;                           Yours sincerely,   Ivar Rummelhoff
-;;
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-;;; Code:
-
-
 
-;;;; Variables you may want to change
+;; Winner mode is a global minor mode that records the changes in the
+;; window configuration (i.e. how the frames are partitioned into
+;; windows) so that the changes can be "undone" using the command
+;; `winner-undo'.  By default this one is bound to the key sequence
+;; ctrl-c left.  If you change your mind (while undoing), you can
+;; press ctrl-c right (calling `winner-redo').  Even though it uses
+;; some features of Emacs20.3, winner.el should also work with
+;; Emacs19.34 and XEmacs20, provided that the installed version of
+;; custom is not obsolete.
 
-(defvar winner-prev-event 'C-left
-  "Winner mode binds this event to the command `winner-previous'.")
+;; Winner mode was improved August 1998.
+;; Further improvements February 2002.
 
-(defvar winner-next-event 'C-right
-  "Winner mode binds this event to the command `winner-next'.")
-
-(defvar winner-max-event 67108896	; CTRL-space
-  "Event for deleting other windows
-after having selected a view with Winner.
-
-The normal functions of this event will also be performed.
-In the default case (CTRL-SPACE) the mark will be set.")
-
-(defvar winner-skip-buffers
-  '("*Messages*",
-    "*Compile-Log*",
-    ".newsrc-dribble",
-    "*Completions*",
-    "*Buffer list*")
-  "Exclude these buffer names
-from any \(Winner mode\) list of buffers.")
-
-(defvar winner-skip-regexps '("^ ")
-  "Exclude buffers with names matching any of these regexps.
-..from any \(Winner mode\) list of buffers.
-
-By default `winner-skip-regexps' is set to \(\"^ \"\),
-which excludes \"invisible buffers\".")
-
-
-(defvar winner-limit 50
-  "Winner will save no more than 2 * `winner-limit' window configurations.
-\(.. and no less than `winner-limit'.\)")
+;;; Code:
 
-(defvar winner-mode-hook nil
-  "Functions to run whenever Winner mode is turned on.")
+(eval-when-compile
+  (require 'cl))
 
-(defvar winner-mode-leave-hook nil
-  "Functions to run whenever Winner mode is turned off.")
 
-(defvar winner-dont-bind-my-keys nil
-  "If non-nil: Do not use `winner-mode-map' in Winner mode.")
+(defmacro winner-active-region ()
+  (if (fboundp 'region-active-p)
+      '(region-active-p)
+    'mark-active))
 
+(defsetf winner-active-region () (store)
+  (if (fboundp 'zmacs-activate-region)
+      `(if ,store (zmacs-activate-region)
+	 (zmacs-deactivate-region))
+    `(setq mark-active ,store)))
 
+(defalias 'winner-edges
+  (if (featurep 'xemacs) 'window-pixel-edges 'window-edges))
+(defalias 'winner-window-list
+  (if (featurep 'xemacs)
+      (lambda () (delq (minibuffer-window) (window-list nil 0)))
+    (lambda () (window-list nil 0))))
 
-;;;; Winner mode
+(require 'ring)
 
-(eval-when-compile (require 'cl))
+(unless (fboundp 'defgroup)
+  (defmacro defgroup (&rest rest)))
 
+(defgroup winner nil
+  "Restoring window configurations."
+  :group 'windows)
 
-(defvar winner-mode nil)		; For the modeline.
-(defvar winner-mode-map nil "Keymap for Winner mode.")
+(unless (fboundp 'defcustom)
+  (defmacro defcustom (symbol &optional initvalue docs &rest rest)
+    (list 'defvar symbol initvalue docs)))
 
 ;;;###autoload
-(defun winner-mode (&optional arg)
+(defcustom winner-mode nil
   "Toggle Winner mode.
-With arg, turn Winner mode on if and only if arg is positive."
-  (interactive "P")
-  (let ((on-p (if arg (> (prefix-numeric-value arg) 0)
-		(not winner-mode))))
-    (cond
-     (on-p (let ((winner-frames-changed (frame-list)))
-	     (winner-do-save))		; Save current configurations
-	   (add-hook 'window-configuration-change-hook 'winner-save-configuration)
-	   (setq winner-mode t)
-	   (run-hooks 'winner-mode-hook))
-     (t (remove-hook 'window-configuration-change-hook 'winner-save-configuration)
-	(when winner-mode
-	  (setq winner-mode nil)
-	  (run-hooks 'winner-mode-leave-hook))))
-    (force-mode-line-update)))
-
-
-;; List of frames which have changed
-(defvar winner-frames-changed nil)
-
-;; Time to save the window configuration.
-(defun winner-save-configuration ()
-  (push (selected-frame) winner-frames-changed)
-  (add-hook 'post-command-hook 'winner-do-save))
-
-
-(defun winner-do-save ()
-  (let ((current (selected-frame)))
-    (unwind-protect
-	(do ((frames winner-frames-changed (cdr frames)))
-	    ((null frames))
-	  (unless (memq (car frames) (cdr frames))
-	    ;; Process each frame once.
-	    (select-frame (car frames))
-	    (winner-push (current-window-configuration) (car frames))))
-      (setq winner-frames-changed nil)
-      (select-frame current)
-      (remove-hook 'post-command-hook 'winner-do-save))))
+Setting this variable directly does not take effect;
+use either \\[customize] or the function `winner-mode'."
+  :set #'(lambda (symbol value) (funcall symbol (or value 0)))
+  :initialize 'custom-initialize-default
+  :type    'boolean
+  :group   'winner
+  :require 'winner)
 
+(defcustom winner-dont-bind-my-keys nil
+  "If non-nil: Do not use `winner-mode-map' in Winner mode."
+  :type  'boolean
+  :group 'winner)
 
+(defcustom winner-ring-size 200
+  "Maximum number of stored window configurations per frame."
+  :type  'integer
+  :group 'winner)
 
+(defcustom winner-boring-buffers '("*Completions*")
+  "`winner-undo' will not restore windows displaying any of these buffers.
+You may want to include buffer names such as *Help*, *Apropos*,
+*Buffer List*, *info* and *Compile-Log*."
+  :type '(repeat string)
+  :group 'winner)
 
 
-;;;; Configuration stacks (one for each frame)
-
-
-(defvar winner-stacks nil) ; ------ " ------
-
-
-;; A stack of window configurations with some additional information.
-(defstruct (winner-stack
-	    (:constructor winner-stack-new
-			  (config &aux
-				  (data (list config))
-				  (place data))))
-  data place (count 1))
-
-
-;; Return the stack of this frame
-(defun winner-stack (frame)
-  (let ((stack (cdr (assq frame winner-stacks))))
-    (if stack (winner-stack-data stack)
-      ;; Else make new stack
-      (letf (((selected-frame) frame))
-	(let ((config (current-window-configuration)))
-	  (push (cons frame (winner-stack-new config))
-		winner-stacks)
-	  (list config))))))
-
 
 
 
-;; Push this window configuration on the right stack,
-;; but make sure the stack doesn't get too large etc...
-(defun winner-push (config frame)
-  (let ((this (cdr (assq frame winner-stacks))))
-    (if (not this) (push (cons frame (winner-stack-new config))
-			 winner-stacks)
-      (push config (winner-stack-data this))
-      (when (> (incf (winner-stack-count this)) winner-limit)
-	;; No more than 2*winner-limit configs
-	(setcdr (winner-stack-place this) nil)
-	(setf   (winner-stack-place this)
-	        (winner-stack-data  this))
-	(setf   (winner-stack-count this) 1)))))
-
-
+;;;; Saving old configurations (internal variables and subroutines)
+
+
+;;; Current configuration
+
+;; List the windows according to their edges.
+(defun winner-sorted-window-list ()
+  (sort (winner-window-list)
+        (lambda (x y)
+          (loop for a in (winner-edges x)
+                for b in (winner-edges y)
+                while (= a b)
+                finally return (< a b)))))
+
+(defun winner-win-data ()
+  ;; Essential properties of the windows in the selected frame.
+  (loop for win in (winner-sorted-window-list)
+        collect (cons (winner-edges win) (window-buffer win))))
+
+;; This variable is updated with the current window configuration
+;; every time it changes.
+(defvar winner-currents nil)
+
+;; The current configuration (+ the buffers involved).
+(defsubst winner-conf ()
+  (cons (current-window-configuration)
+        (winner-win-data)))
+
+
+;; Save current configuration.
+;; (Called below by `winner-save-old-configurations').
+(defun winner-remember ()
+  (let ((entry (assq (selected-frame) winner-currents)))
+    (if entry (setcdr entry (winner-conf))
+      (push (cons (selected-frame) (winner-conf))
+	    winner-currents))))
+
+;; Consult `winner-currents'.
+(defun winner-configuration (&optional frame)
+  (or (cdr (assq (or frame (selected-frame)) winner-currents))
+      (letf (((selected-frame) frame))
+	(winner-conf))))
 
 
 
+;;; Saved configurations
 
+;; This variable contains the window cofiguration rings.
+;; The key in this alist is the frame.
+(defvar winner-ring-alist nil)
 
+;; Find the right ring.  If it does not exist, create one.
+(defsubst winner-ring (frame)
+  (or (cdr (assq frame winner-ring-alist))
+      (let ((ring (make-ring winner-ring-size)))
+        (ring-insert ring (winner-configuration frame))
+        (push (cons frame ring) winner-ring-alist)
+        ring)))
 
-;;;; Selecting a window configuration
+
+;; If the same command is called several times in a row,
+;; we only save one window configuration.
+(defvar winner-last-command nil)
+
+;; Frames affected by the previous command.
+(defvar winner-last-frames nil)
+
+
+(defsubst winner-equal (a b)
+  "Check whether two Winner configurations (as produced by
+`winner-conf') are equal."
+  (equal (cdr a) (cdr b)))
+
+
+;; Save the current window configuration, if it has changed.
+;; If so return frame, otherwise return nil.
+(defun winner-insert-if-new (frame)
+  (unless (or (memq frame winner-last-frames)
+	      (eq this-command 'winner-redo))
+    (let ((conf (winner-configuration frame))
+	  (ring (winner-ring frame)))
+      (when (and (not (ring-empty-p ring))
+		 (winner-equal conf (ring-ref ring 0)))
+        ;; When the previous configuration was very similar,
+        ;; keep only the latest.
+	(ring-remove ring 0))
+      (ring-insert ring conf)
+      (push frame winner-last-frames)
+      frame)))
+
+
+
+;;; Hooks
+
+;; Frames affected by the current command.
+(defvar winner-modified-list nil)
+
+;; Called whenever the window configuration changes
+;; (a `window-configuration-change-hook').
+(defun winner-change-fun ()
+  (unless (or (memq (selected-frame) winner-modified-list)
+              (/= 0 (minibuffer-depth)))
+    (push (selected-frame) winner-modified-list)))
+
+;; A `post-command-hook' for emacsen with
+;; `window-configuration-change-hook'.
+(defun winner-save-old-configurations ()
+  (when (zerop (minibuffer-depth))
+    (unless (eq this-command winner-last-command)
+      (setq winner-last-frames nil)
+      (setq winner-last-command this-command))
+    (dolist (frame winner-modified-list)
+      (winner-insert-if-new frame))
+    (setq winner-modified-list nil)
+    (winner-remember)))
+
+;; A `minibuffer-setup-hook'.
+(defun winner-save-unconditionally ()
+  (unless (eq this-command winner-last-command)
+    (setq winner-last-frames nil)
+    (setq winner-last-command this-command))
+  (winner-insert-if-new (selected-frame))
+  (winner-remember))
+
+;; A `post-command-hook' for other emacsen.
+;; Also called by `winner-undo' before "undoing".
+(defun winner-save-conditionally ()
+  (when (zerop (minibuffer-depth))
+    (winner-save-unconditionally)))
 
 
-;; Return list of names of other buffers, excluding the current buffer
-;; and buffers specified by the user.
-(defun winner-other-buffers ()
-  (loop for buf in (buffer-list)
-	for name = (buffer-name buf)
-	unless (or (eq (current-buffer) buf)
-		   (member name winner-skip-buffers)
-		   (loop for regexp in winner-skip-regexps
-			 if (string-match regexp name) return t
-			 finally return nil))
-	collect name))
 
+
+;;;; Restoring configurations
+
+;; Works almost as `set-window-configuration',
+;; but does not change the contents or the size of the minibuffer,
+;; and tries to preserve the selected window.
+(defun winner-set-conf (winconf)
+  (let* ((miniwin  (minibuffer-window))
+         (chosen   (selected-window))
+         (minisize (window-height miniwin)))
+    (letf (((window-buffer miniwin))
+           ((window-point  miniwin)))
+      (set-window-configuration winconf))
+    (cond
+     ((window-live-p chosen) (select-window chosen))
+     ((window-minibuffer-p (selected-window))
+      (other-window 1)))
+    (when (/= minisize (window-height miniwin))
+      (letf (((selected-window) miniwin) )
+        (setf (window-height) minisize)))))
 
 
-(defun winner-select (&optional arg)
 
-  "Change to previous or new window configuration.
-With arg start at position 1 if arg is positive, and
-at -1 if arg is negative;  else start at position 0.
-\(For Winner to record changes in window configurations,
-Winner mode must be turned on.\)"
-  (interactive "P")
+(defvar winner-point-alist nil)
+;; `set-window-configuration' restores old points and marks.  This is
+;; not what we want, so we make a list of the "real" (i.e. new) points
+;; and marks before undoing window configurations.
+;;
+;; Format of entries: (buffer (mark . mark-active) (window . point) ..)
+
+(defun winner-make-point-alist ()
+  (letf (((current-buffer)))
+    (loop with alist
+	  for win in (winner-window-list)
+	  for entry =
+          (or (assq (window-buffer win) alist)
+              (car (push (list (set-buffer (window-buffer win))
+                               (cons (mark t) (winner-active-region)))
+                         alist)))
+	  do (push (cons win (window-point win))
+                   (cddr entry))
+	  finally return alist)))
+
+(defun winner-get-point (buf win)
+  ;; Consult (and possibly extend) `winner-point-alist'.
+  ;; Returns nil iff buf no longer exists.
+  (when (buffer-name buf)
+    (let ((entry (assq buf winner-point-alist)))
+      (cond
+       (entry
+	(or (cdr (assq win (cddr entry)))
+	    (cdr (assq nil (cddr entry)))
+	    (letf (((current-buffer) buf))
+	      (push (cons nil (point)) (cddr entry))
+	      (point))))
+       (t (letf (((current-buffer) buf))
+	    (push (list buf
+			(cons (mark t) (winner-active-region))
+			(cons nil (point)))
+		  winner-point-alist)
+	    (point)))))))
 
-  (setq arg
-	(cond
-	 ((not arg) nil)
-	 ((> (prefix-numeric-value arg) 0) winner-next-event)
-	 ((< (prefix-numeric-value arg) 0) winner-prev-event)
-	 (t nil)))
-  (if arg (push arg unread-command-events))
 
-  (let ((stack (winner-stack (selected-frame)))
-	(store nil)
-	(buffers (winner-other-buffers))
-	(passed nil)
-	(config (current-window-configuration))
-	(pos 0) event)
-    ;; `stack'   and `store'  are stacks of window configuration while
-    ;; `buffers' and `passed' are stacks of buffer names.
-
-    (condition-case nil
-
-	(loop
-	 (setq event (read-event))
-	 (cond
-
-	  ((eq event winner-prev-event)
-	   (cond (passed     (push (pop passed) buffers)(decf pos))
-		 ((cdr stack)(push (pop stack)  store)  (decf pos))
-		 (t (setq stack (append (nreverse store) stack))
-		    (setq store nil)
-		    (setq pos   0))))
-
-	  ((eq event winner-next-event)
-	   (cond (store   (push (pop store)   stack)  (incf pos))
-		 (buffers (push (pop buffers) passed) (incf pos))
-		 (t (setq buffers (nreverse passed))
-		    (setq passed nil)
-		    (setq pos 0))))
-
-	  ((eq event winner-max-event)
-	   ;; Delete other windows and leave.
-	   (delete-other-windows)
-	   ;; Let this change be saved.
-	   (setq pos -1)
-	   ;; Perform other actions of this event.
-	   (push event unread-command-events)
-	   (return))
-	  (t (push event unread-command-events) (return)))
-
-	 (cond
-	  ;; Display
-	  (passed (set-window-buffer (selected-window) (car passed))
-		  (message (concat "Winner\(%d\): [%s] "
-				   (mapconcat 'identity buffers " "))
-			   pos (car passed)))
-
-	  (t (set-window-configuration (car stack))
-	     (if (window-minibuffer-p (selected-window))
-		 (other-window 1))
-	     (message "Winner\(%d\)" pos))))
-
-      (quit (set-window-configuration config)
-	    (setq pos 0)))
-    (if (zerop pos)
-	;; Do not record these changes.
-	(remove-hook 'post-command-hook 'winner-do-save)
-      ;; Else update the buffer list and make sure that the displayed
-      ;; buffer is the same as the current buffer.
-      (switch-to-buffer (window-buffer)))))
-					   
-					   
-
-
-
-(defun winner-previous ()
-  "Change to previous window configuration."
-  (interactive)
-  (winner-select -1))
+;; Make sure point does not end up in the minibuffer and delete
+;; windows displaying dead or boring buffers
+;; (c.f. `winner-boring-buffers').  Return nil iff all the windows
+;; should be deleted.  Preserve correct points and marks.
+(defun winner-set (conf)
+  ;; For the format of `conf', see `winner-conf'.
+  (let* ((buffers nil)
+	 (alive
+          ;; Possibly update `winner-point-alist'
+	  (loop for buf in (mapcar 'cdr (cdr conf))
+		for pos = (winner-get-point buf nil)
+		if (and pos (not (memq buf buffers)))
+		do (push buf buffers)
+		collect pos)))
+    (winner-set-conf (car conf))
+    (let (xwins)                        ; to be deleted
+
+      ;; Restore points
+      (dolist (win (winner-sorted-window-list))
+        (unless (and (pop alive)
+                     (setf (window-point win)
+                           (winner-get-point (window-buffer win) win))
+                     (not (member (buffer-name (window-buffer win))
+                                  winner-boring-buffers)))
+          (push win xwins)))            ; delete this window
+
+      ;; Restore marks
+      (letf (((current-buffer)))
+	(loop for buf in buffers
+	      for entry = (cadr (assq buf winner-point-alist))
+	      do (progn (set-buffer buf)
+			(set-mark (car entry))
+			(setf (winner-active-region) (cdr entry)))))
+      ;; Delete windows, whose buffers are dead or boring.
+      ;; Return t if this is still a possible configuration.
+      (or (null xwins)
+	  (progn
+            (mapc 'delete-window (cdr xwins)) ; delete all but one
+            (unless (one-window-p t)
+              (delete-window (car xwins))
+              t))))))
+
+
+
+;;;; Winner mode  (a minor mode)
+
+(defcustom winner-mode-hook nil
+  "Functions to run whenever Winner mode is turned on."
+  :type 'hook
+  :group 'winner)
+
+(defcustom winner-mode-leave-hook nil
+  "Functions to run whenever Winner mode is turned off."
+  :type 'hook
+  :group 'winner)
+
+(defvar winner-mode-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map [(control c) left] 'winner-undo)
+    (define-key map [(control c) right] 'winner-redo)
+    map)
+  "Keymap for Winner mode.")
+
+;; Check if `window-configuration-change-hook' is working.
+(defun winner-hook-installed-p ()
+  (save-window-excursion
+    (let ((winner-var nil)
+	  (window-configuration-change-hook
+	   '((lambda () (setq winner-var t)))))
+      (split-window)
+      winner-var)))
 
-(defun winner-next ()
-  "Change to new window configuration."
+
+;;;###autoload
+(defun winner-mode (&optional arg)
+  "Toggle Winner mode.
+With arg, turn Winner mode on if and only if arg is positive."
+  (interactive "P")
+  (let ((on-p (if arg (> (prefix-numeric-value arg) 0)
+		(not winner-mode))))
+    (cond
+     ;; Turn mode on
+     (on-p
+      (setq winner-mode t)
+      (cond
+       ((winner-hook-installed-p)
+	(add-hook 'window-configuration-change-hook 'winner-change-fun)
+      (add-hook 'post-command-hook 'winner-save-old-configurations))
+       (t (add-hook 'post-command-hook 'winner-save-conditionally)))
+      (add-hook 'minibuffer-setup-hook 'winner-save-unconditionally)
+      (setq winner-modified-list (frame-list))
+      (winner-save-old-configurations)
+      (run-hooks 'winner-mode-hook)
+      (when (interactive-p) (message "Winner mode enabled")))
+     ;; Turn mode off
+     (winner-mode
+      (setq winner-mode nil)
+      (remove-hook 'window-configuration-change-hook 'winner-change-fun)
+      (remove-hook 'post-command-hook 'winner-save-old-configurations)
+      (remove-hook 'post-command-hook 'winner-save-conditionally)
+      (remove-hook 'minibuffer-setup-hook 'winner-save-unconditionally)
+      (run-hooks 'winner-mode-leave-hook)
+      (when (interactive-p) (message "Winner mode disabled"))))))
+
+;; Inspired by undo (simple.el)
+
+(defvar winner-undo-frame nil)
+
+(defvar winner-pending-undo-ring nil
+  "The ring currently used by `winner-undo'.")
+(defvar winner-undo-counter nil)
+(defvar winner-undone-data  nil) ; There confs have been passed.
+
+(defun winner-undo ()
+  "Switch back to an earlier window configuration saved by Winner mode.
+In other words, \"undo\" changes in window configuration."
   (interactive)
-  (winner-select 1))
-
-
+  (cond
+   ((not winner-mode) (error "Winner mode is turned off"))
+   (t (unless (and (eq last-command 'winner-undo)
+ 		   (eq winner-undo-frame (selected-frame)))
+	(winner-save-conditionally)     ; current configuration->stack
+ 	(setq winner-undo-frame (selected-frame))
+ 	(setq winner-point-alist (winner-make-point-alist))
+ 	(setq winner-pending-undo-ring (winner-ring (selected-frame)))
+ 	(setq winner-undo-counter 0)
+ 	(setq winner-undone-data (list (winner-win-data))))
+      (incf winner-undo-counter)	; starting at 1
+      (when (and (winner-undo-this)
+ 		 (not (window-minibuffer-p (selected-window))))
+ 	(message "Winner undo (%d / %d)"
+ 		 winner-undo-counter
+ 		 (1- (ring-length winner-pending-undo-ring)))))))
 
 
-;;;; To be evaluated when the package is loaded:
 
-(unless winner-mode-map
-  (setq winner-mode-map (make-sparse-keymap))
-  (define-key winner-mode-map (vector winner-prev-event) 'winner-previous)
-  (define-key winner-mode-map (vector winner-next-event) 'winner-next))
+
+(defun winner-undo-this ()		; The heart of winner undo.
+  (loop
+   (cond
+    ((>= winner-undo-counter (ring-length winner-pending-undo-ring))
+     (message "No further window configuration undo information")
+     (return nil))
+
+    ((and				; If possible configuration
+      (winner-set (ring-ref winner-pending-undo-ring
+ 			    winner-undo-counter))
+                                        ; .. and new configuration
+      (let ((data (winner-win-data)))
+ 	(and (not (member data winner-undone-data))
+ 	     (push data winner-undone-data))))
+     (return t))			; .. then everything is fine.
+    (t ;; Otherwise, discharge it (and try the next one).
+     (ring-remove winner-pending-undo-ring winner-undo-counter)))))
+
+
+(defun winner-redo ()			; If you change your mind.
+  "Restore a more recent window configuration saved by Winner mode."
+  (interactive)
+  (cond
+   ((eq last-command 'winner-undo)
+    (winner-set
+     (if (zerop (minibuffer-depth))
+         (ring-remove winner-pending-undo-ring 0)
+       (ring-ref winner-pending-undo-ring 0)))
+    (unless (eq (selected-window) (minibuffer-window))
+      (message "Winner undid undo")))
+   (t (error "Previous command was not a `winner-undo'"))))
+
+;;; To be evaluated when the package is loaded:
 
 (unless (or (assq 'winner-mode minor-mode-map-alist)
 	    winner-dont-bind-my-keys)
   (push (cons 'winner-mode winner-mode-map)
 	minor-mode-map-alist))
 
-(unless (assq 'winner-mode minor-mode-alist)
-  (push '(winner-mode " Win") minor-mode-alist))
-
 (provide 'winner)
-
+;; arch-tag: 686d1c1b-010e-42ca-a192-b5685112418f
 ;;; winner.el ends here