;;; winner.el --- Restore window configuration (or switch buffer)
;; Copyright (C) 1997 Free Software Foundation. Inc.
;; Author: Ivar Rummelhoff <firstname.lastname@example.org>
;; Maintainer: Ivar Rummelhoff <email@example.com>
;; Created: 27 Feb 1997
;; Keywords: extensions, windows
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; 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.
;; Winner mode is a global minor mode that when turned on records
;; changes in window configuration. This way the changes can be
;; "undone" using the function `winner-undo'. By default this one is
;; bound to the key sequence ctrl-x left. If you change your mind
;; (while undoing), you can press ctrl-x right (calling
;; `winner-redo'). Unlike the normal undo, you may have to skip
;; through several identical window configurations in order to find
;; the one you want. This is a bug due to some techical limitations
;; in Emacs and can maybe be fixed in the future.
;; In addition to this I have added `winner-switch' which is a program
;; that switches to other buffers without disturbing Winner mode. If
;; you bind this command to a key sequence, you may step through all
;; your buffers (except the ones mentioned in `winner-skip-buffers' or
;; matched by `winner-skip-regexps'). With a numeric prefix argument
;; skip several buffers at a time.
(eval-when-compile (require 'cl))
(defvar winner-dont-bind-my-keys nil
"If non-nil: Do not use `winner-mode-map' in Winner mode.")
(defvar winner-ring-size 100
"Maximum number of stored window configurations per frame.")
"Exclude these buffer names from any \(Winner switch\) list of buffers.")
(defvar winner-skip-regexps '("^ ")
"Winner excludes buffers with names matching any of these regexps.
They are not included in any Winner mode list of buffers.
By default `winner-skip-regexps' is set to \(\"^ \"\),
which excludes \"invisible buffers\".")
(defvar winner-ring-alist nil)
(defsubst winner-ring (frame)
(or (cdr (assq frame winner-ring-alist))
(push (cons frame (make-ring winner-ring-size))
(defvar winner-modified-list nil)
(defun winner-change-fun ()
(or (memq (selected-frame) winner-modified-list)
(push (selected-frame) winner-modified-list)))
(defun winner-save-new-configurations ()
(winner-ring (car winner-modified-list))
(current-window-configuration (pop winner-modified-list)))))
(defun winner-set (conf)
(if (eq (selected-window) (minibuffer-window))
;;; Winner mode (a minor mode)
(defvar winner-mode-hook nil
"Functions to run whenever Winner mode is turned on.")
(defvar winner-mode-leave-hook nil
"Functions to run whenever Winner mode is turned off.")
(defvar winner-mode nil) ; mode variable
(defvar winner-mode-map nil "Keymap for Winner mode.")
(defun winner-mode (&optional arg)
"Toggle Winner mode.
With arg, turn Winner mode on if and only if arg is positive."
(let ((on-p (if arg (> (prefix-numeric-value arg) 0)
;; Turn mode on
(setq winner-mode t)
(add-hook 'window-configuration-change-hook 'winner-change-fun)
(add-hook 'post-command-hook 'winner-save-new-configurations)
(setq winner-modified-list (frame-list))
;; Turn mode off
(setq winner-mode nil)
;; Inspired by undo (simple.el)
(defvar winner-pending-undo-ring nil)
(defvar winner-undo-counter nil)
(defun winner-undo (arg)
"Switch back to an earlier window configuration saved by Winner mode.
In other words, \"undo\" changes in window configuration."
((not winner-mode) (error "Winner mode is turned off"))
((eq (selected-window) (minibuffer-window))
(error "No winner undo from minibuffer."))
(t (setq this-command t)
(if (eq last-command 'winner-undo)
;; This was no new window configuration after all.
(ring-remove winner-pending-undo-ring 0)
(setq winner-pending-undo-ring (winner-ring (selected-frame)))
(setq winner-undo-counter 0))
(winner-undo-more (or arg 1))
(message "Winner undo (%d)!" winner-undo-counter)
(setq this-command 'winner-undo))))
(defun winner-undo-more (count)
"Undo N window configuration changes beyond what was already undone.
Call `winner-undo-start' to get ready to undo recent changes,
then call `winner-undo-more' one or more times to undo them."
(let ((len (ring-length winner-pending-undo-ring)))
(incf winner-undo-counter count)
(if (>= winner-undo-counter len)
(error "No further window configuration undo information")
(defun winner-redo ()
"Restore a more recent window configuration saved by Winner mode."
((eq last-command 'winner-undo)
(ring-remove winner-pending-undo-ring 0)
(ring-remove winner-pending-undo-ring 0))
(or (eq (selected-window) (minibuffer-window))
(message "Winner undid undo!")))
(t (error "Previous command was not a winner-undo"))))
;;; Winner switch
(defun winner-switch-buffer-list ()
(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))
(defvar winner-switch-list nil)
(defun winner-switch (count)
"Step through your buffers without disturbing `winner-mode'.
`winner-switch' does not consider buffers mentioned in the list
`winner-skip-buffers' or matched by `winner-skip-regexps'."
(setq this-command t)
((eq last-command 'winner-switch)
(if winner-mode (ring-remove (winner-ring (selected-frame)) 0))
(mapcar 'bury-buffer winner-switch-list))
(t (setq winner-switch-list (winner-switch-buffer-list))))
(setq winner-switch-list (nthcdr count winner-switch-list))
(setq winner-switch-list (winner-switch-buffer-list))
(error "No more buffers"))
(switch-to-buffer (pop winner-switch-list))
(message (concat "Winner: [%s] "
(mapconcat 'identity winner-switch-list " "))
(setq this-command 'winner-switch))
;;;; To be evaluated when the package is loaded:
(setq winner-mode-map (make-sparse-keymap))
(define-key winner-mode-map [?\C-x left] 'winner-undo)
(define-key winner-mode-map [?\C-x right] 'winner-redo))
(unless (or (assq 'winner-mode minor-mode-map-alist)
(push (cons 'winner-mode winner-mode-map)
(unless (assq 'winner-mode minor-mode-alist)
(push '(winner-mode " Win") minor-mode-alist))
;;; winner.el ends here