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 ;;; Code:
  41
  42 (defvar running-xemacs (string-match "XEmacs\\|Lucid" emacs-version))
  43
  44 ;;;###autoload
  45 (defcustom scroll-all-mode nil
  46   "Control/track scroll locking.
  47
  48 Setting this variable directly does not take effect;
  49 use either \\[customize] or the function `scroll-all-mode'."
  50   :set (lambda (symbol value) (scroll-all-mode (if value 1 0)))
  51   :initialize 'custom-initialize-default
  52   :require 'scroll-all
  53   :type 'boolean
  54   :group 'windows)
  55
  56 (if running-xemacs
  57     (add-minor-mode 'scroll-all-mode " *SL*")
  58   (or (assq 'scroll-all-mode minor-mode-alist)
  59       (setq minor-mode-alist
  60             (cons '(scroll-all-mode " *SL*") minor-mode-alist))))
  61
  62 (defun scroll-all-function-all (func arg)
  63   "Apply function FUNC with argument ARG to all visible windows."
  64   (let ((num-windows (count-windows))
  65         (count 1))
  66     (when (> num-windows 1)
  67       (other-window 1)
  68       (while (< count num-windows)
  69         (condition-case nil
  70             (funcall func arg)
  71           ;; Ignore beginning- or end-of-buffer error in other windows.
  72           (error nil)
  73           )
  74         (other-window 1)
  75         (setq count (1+ count))))))
  76
  77 (defun scroll-all-scroll-down-all (arg)
  78   "Scroll down in all visible windows."
  79   (interactive "p")
  80   (scroll-all-function-all 'next-line arg))
  81
  82 (defun scroll-all-scroll-up-all (arg)
  83   "Scroll up in all visible windows."
  84   (interactive "p")
  85   (scroll-all-function-all 'previous-line arg))
  86
  87 (defun scroll-all-page-down-all (arg)
  88   "Page down in all visible windows."
  89   (interactive "P")
  90   (scroll-all-function-all 'scroll-up arg))
  91
  92 (defun scroll-all-page-up-all (arg)
  93   "Page up in all visible windows."
  94   (interactive "P")
  95   (scroll-all-function-all 'scroll-down arg))
  96
  97 (defun scroll-all-beginning-of-buffer-all (arg)
  98   "Go to the beginning of the buffer in all visible windows."
  99   (interactive "P")
 100   (scroll-all-function-all 'beginning-of-buffer arg))
 101
 102 (defun scroll-all-end-of-buffer-all (arg)
 103   "Go to the end of the buffer in all visible windows."
 104   (interactive "P")
 105   (scroll-all-function-all 'end-of-buffer arg))
 106
 107
 108 (defun scroll-all-check-to-scroll ()
 109   "Check `this-command' to see if a scroll is to be done."
 110   (cond ((eq this-command 'next-line)
 111          (call-interactively 'scroll-all-scroll-down-all))
 112         ((eq this-command 'previous-line)
 113          (call-interactively 'scroll-all-scroll-up-all))
 114         ((eq this-command 'scroll-up)
 115          (call-interactively 'scroll-all-page-down-all))
 116         ((eq this-command 'scroll-down)
 117          (call-interactively 'scroll-all-page-up-all))
 118         ((eq this-command 'beginning-of-buffer)
 119          (call-interactively 'scroll-all-beginning-of-buffer-all))
 120         ((eq this-command 'end-of-buffer)
 121          (call-interactively 'scroll-all-end-of-buffer-all))))
 122
 123
 124 ;;;###autoload
 125 (defun scroll-all-mode (arg)
 126   "Toggle Scroll-All minor mode."
 127   (interactive "P")
 128   (setq scroll-all-mode (not scroll-all-mode))
 129   (cond
 130    ((eq scroll-all-mode 't)
 131     (add-hook 'post-command-hook 'scroll-all-check-to-scroll))
 132    ((eq scroll-all-mode 'nil)
 133     (remove-hook 'post-command-hook 'scroll-all-check-to-scroll))))
 134
 135 (provide 'scroll-all)
 136
 137 ;;; scroll-all.el ends here