lisp/scroll-all.el

   1 ;;; scroll-all.el -- scroll all buffers together minor mode
   2
   3 ;; Copyright (C) 1997 Free Software Foundation, Inc.
   4
   5 ;; Author: Gary D. Foster <Gary.Foster@corp.sun.com>
   6 ;; Keywords: scroll crisp brief lock
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;; Commentary
  26 ;;    This mode allows multiple buffers to be 'locked' so that scrolling
  27 ;;    up or down lines in any buffer causes all the buffers to mirror
  28 ;;    the scrolling.  It hooks into the post-command-hook to check for
  29 ;;    potential scrolling commands and if we're locked, mirrors them in all
  30 ;;    windows.  This allows us to grab line-at-a-time scrolling as well as
  31 ;;    screen-at-a-time scrolling, and doesn't remap any of the keyboard
  32 ;;    commands to do it.
  33
  34 ;; You can enable and disable this mode with the 'scroll-all-mode' command.
  35
  36 ;; Suggestions/ideas from:
  37 ;;    Rick Macdonald <rickm@vsl.com>
  38 ;;    Anders Lindgren <andersl@csd.uu.se>
  39
  40 (defvar running-xemacs (string-match "XEmacs\\|Lucid" emacs-version))
  41 (defvar scroll-all-mode nil
  42   "Track status of scroll locking.")
  43 (if running-xemacs
  44     (add-minor-mode 'scroll-all-mode " *SL*")
  45   (or (assq 'scroll-all-mode-mode minor-mode-alist)
  46       (setq minor-mode-alist
  47             (cons '(scroll-all-mode-mode " *SL*") minor-mode-alist))))
  48
  49 (defun scroll-all-scroll-down-all (arg)
  50   "Scroll down all visible windows."
  51   (interactive "P")
  52   (let ((num-windows (count-windows))
  53         (count 1))
  54     (if (> num-windows 1)
  55         ( progn (other-window 1)
  56                 (while (< count num-windows)
  57                   (if (not (eq (point) (point-max)))
  58                       (progn (call-interactively 'next-line)))
  59                   (other-window 1)
  60                   (setq count (1+ count)))))))
  61
  62 (defun scroll-all-scroll-up-all (arg)
  63   "Scroll up all visible windows."
  64   (interactive "P")
  65   (let ((num-windows (count-windows))
  66         (count 1))
  67     (if (> num-windows 1)
  68         ( progn (other-window 1)
  69                 (while (< count num-windows)
  70                   (if (not (eq (point) (point-min)))
  71                       (progn (call-interactively 'previous-line)))
  72                   (other-window 1)
  73                   (setq count (1+ count)))))))
  74
  75 (defun scroll-all-page-down-all (arg)
  76   "Page down in all visible windows."
  77   (interactive "P")
  78   (let ((num-windows (count-windows))
  79         (count 1))
  80     (if (> num-windows 1)
  81         (progn (other-window 1)
  82                (while (< count num-windows)
  83                  (call-interactively 'fkey-scroll-up)
  84                  (other-window 1)
  85                  (setq count (1+ count)))))))
  86
  87 (defun scroll-all-page-up-all (arg)
  88   "Page up in all visible windows."
  89   (interactive "P")
  90   (let ((num-windows (count-windows))
  91         (count 1))
  92     (if (> num-windows 1)
  93         (progn (other-window 1)
  94                (while (< count num-windows)
  95                  (call-interactively 'fkey-scroll-down)
  96                  (other-window 1)
  97                  (setq count (1+ count)))))))
  98
  99
 100 (defun scroll-all-check-to-scroll ()
 101   "Check `last-command' to see if a scroll was done."
 102   (if (eq this-command 'next-line)
 103       (call-interactively 'scroll-all-scroll-down-all))
 104   (if (eq this-command 'previous-line)
 105       (call-interactively 'scroll-all-scroll-up-all))
 106   (if (eq this-command 'fkey-scroll-up)
 107       (call-interactively 'scroll-all-page-down-all))
 108   (if (eq this-command 'fkey-scroll-down)
 109       (call-interactively 'scroll-all-page-up-all)))
 110
 111
 112 (defun scroll-all-mode (arg)
 113   "Toggle Scroll-All minor mode."
 114   (interactive "P")
 115   (setq scroll-all-mode (not scroll-all-mode))
 116   (cond
 117    ((eq scroll-all-mode 't)
 118     (add-hook 'post-command-hook 'scroll-all-check-to-scroll))
 119    ((eq scroll-all-mode 'nil)
 120     (remove-hook 'post-command-hook 'scroll-all-check-to-scroll))))
 121
 122 (provide 'scroll-all)
 123
 124 ;; scroll-all.el ends here