Path: news2.funet.fi!news.funet.fi!news.cs.hut.fi!news.clinet.fi!uunet!in1.uu.net!207.22.81.9!europa.clark.net!208.134.241.18!infeed1.internetmci.com!newsfeed.internetmci.com!news1.best.com!nntp2.ba.best.com!not-for-mail From: Bob Glickstein Newsgroups: gnu.emacs.sources Subject: winhist-mode v3.0 (was Re: winhist-mode v2.1 (was Re: winhist-mode v1.0)) Date: 23 Jul 1997 22:00:24 -0700 Organization: Interpost, Mill Valley, CA Lines: 153 Message-ID: References: Reply-To: Bob Glickstein NNTP-Posting-Host: zoger.ipost.com X-Attribution: BG X-Newsreader: Gnus v5.5/Emacs 20.0 Xref: news2.funet.fi gnu.emacs.sources:6228 Here's yet another new version of winhist-mode. (And remember, it doesn't work in Emacs 19.x, but Emacs 20.x should be available soon.) This version maintains separate window histories for each frame, and eschews the problematic use of post-command-hook for an idle-timer-based approach suggested by the new paren.el. Enjoy! ;;; winhist.el --- window configuration history ;; Copyright 1997 Bob Glickstein. ;; Author: Bob Glickstein ;; Maintainer: Bob Glickstein ;; Version: 3.0 ;; This file is not part of GNU Emacs. ;; This file 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. ;; This program 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, send e-mail to ;; this program's maintainer or write to the Free Software Foundation, ;; Inc., 59 Temple Place, Suite 330; Boston, MA 02111-1307, USA. ;;; Plug: ;; Check out my book, "Writing GNU Emacs Extensions," from O'Reilly ;; and Associates. ;;; Commentary: ;; `winhist-mode' is a global mode that records every change to the ;; window configuration in a "ring" (like the yank ring or the mark ;; ring). It is then possible to step backward and forward through ;; the history of window configurations. I find this to be valuable ;; for restoring mental context when working on a complex project. ;; This works imperfectly because of vagaries in the way buffers and ;; windows are connected and manipulated by various packages. In ;; particular, sometimes several consecutive window configurations in ;; the history may seem to be identical. But it's better than ;; nothing, and I also like it better than some packages that require ;; you to remember to save and possibly name a window configuration ;; before restoring it. ;; To use this package, add ;; (require 'winhist) ;; (winhist-mode 1) ;; to your .emacs. You should then bind keysequences to the commands ;; `winhist-backward' and `winhist-forward'. I prefer: ;; (global-set-key "\M-B" 'winhist-backward) ;; (global-set-key "\M-F" 'winhist-forward) ;;; Code: (require 'ring) (defvar winhist-timer nil) (defvar winhist-delay .125 "*Seconds after Emacs becomes idle before recording window configuration.") (defvar winhist-frames nil "Alist of the form ((frame . (ring . index)) ...).") (defvar winhist-ring-size 100 "*How many window configurations to automatically remember.") (defvar winhist-mode nil) (defvar winhist-traversing nil) (defvar winhist-changed nil) ;; This function goes in window-configuration-change-hook. (defsubst winhist-notice-change () (setq winhist-changed (selected-frame))) ;; This function goes in post-command-hook. (defun winhist-maybe-record-configuration () (if (and winhist-changed winhist-mode (not winhist-traversing) (not (window-minibuffer-p (selected-window)))) (let ((entry (assq winhist-changed winhist-frames))) (unless entry (setq entry (cons winhist-changed (cons (make-ring winhist-ring-size) 0)) winhist-frames (cons entry winhist-frames))) (ring-insert (car (cdr entry)) (current-window-configuration)) (setcdr (cdr entry) 0))) (setq winhist-changed nil) (setq winhist-traversing nil)) (defun winhist-traverse (&optional n) "Move backward through the window configuration history by N entries." (interactive "p") (let ((entry (assq (selected-frame) winhist-frames)) ring index conf) (unless entry (error "No window history for this frame.")) (setq ring (car (cdr entry)) index (+ n (cdr (cdr entry))) conf (ring-ref ring index) winhist-traversing t) (setcdr (cdr entry) index) (when conf (set-window-configuration conf) (message "Window history: %d" index)))) (defalias 'winhist-backward 'winhist-traverse) (defsubst winhist-forward (&optional n) "Move forward through the window configuration history by N entries." (interactive "p") (winhist-traverse (- n))) (defun winhist-mode (&optional arg) "Toggle recording of window configuration changes. With optional ARG, turn winhist-mode on iff positive, off otherwise. The number of window configurations that are memorized is controlled by `winhist-ring-size'. To traverse the window configuration history, use \\[winhist-backward] and \\[winhist-forward]." (interactive "P") (setq winhist-mode (if (null arg) (not winhist-mode) (> (prefix-numeric-value arg) 0))) (when winhist-timer (cancel-timer winhist-timer) (setq winhist-timer nil)) (if winhist-mode (if (boundp 'window-configuration-change-hook) (progn (add-hook 'window-configuration-change-hook 'winhist-notice-change) (setq winhist-timer (run-with-idle-timer winhist-delay t 'winhist-maybe-record-configuration))) (progn (setq winhist-mode nil) (error "This version of Emacs does not have `window-configuration-change-hook'"))) (setq winhist-frames nil) (remove-hook 'window-configuration-change-hook 'winhist-notice-change))) (provide 'winhist) ;;; winhist.el ends here