1 ;;; page.el --- page motion commands for Emacs
3 ;; Copyright (C) 1985, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
6 ;; Keywords: wp convenience
8 ;; This file is part of GNU Emacs.
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)
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.
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., 51 Franklin Street, Fifth Floor,
23 ;; Boston, MA 02110-1301, USA.
27 ;; This code provides the page-oriented movement and selection commands
28 ;; documented in the Emacs manual.
32 (defun forward-page (&optional count)
33 "Move forward to page boundary. With arg, repeat, or go back if negative.
34 A page boundary is any line whose beginning matches the regexp
37 (or count (setq count 1))
38 (while (and (> count 0) (not (eobp)))
39 ;; In case the page-delimiter matches the null string,
40 ;; don't find a match without moving.
41 (if (bolp) (forward-char 1))
42 (if (re-search-forward page-delimiter nil t)
44 (goto-char (point-max)))
45 (setq count (1- count)))
46 (while (and (< count 0) (not (bobp)))
47 ;; In case the page-delimiter matches the null string,
48 ;; don't find a match without moving.
49 (and (save-excursion (re-search-backward page-delimiter nil t))
50 (= (match-end 0) (point))
51 (goto-char (match-beginning 0)))
53 (if (re-search-backward page-delimiter nil t)
54 ;; We found one--move to the end of it.
55 (goto-char (match-end 0))
56 ;; We found nothing--go to beg of buffer.
57 (goto-char (point-min)))
58 (setq count (1+ count))))
60 (defun backward-page (&optional count)
61 "Move backward to page boundary. With arg, repeat, or go fwd if negative.
62 A page boundary is any line whose beginning matches the regexp
65 (or count (setq count 1))
66 (forward-page (- count)))
68 (defun mark-page (&optional arg)
69 "Put mark at end of page, point at beginning.
70 A numeric arg specifies to move forward or backward by that many pages,
71 thus marking a page other than the one point was originally in."
73 (setq arg (if arg (prefix-numeric-value arg) 0))
77 (forward-page (1- arg))))
82 (defun narrow-to-page (&optional arg)
83 "Make text outside current page invisible.
84 A numeric arg specifies to move forward or backward by that many pages,
85 thus showing a page other than the one point was originally in."
87 (setq arg (if arg (prefix-numeric-value arg) 0))
95 ;; If we are not now at the beginning of a page,
96 ;; move back one extra time, to get to the start of this page.
99 (or (and (looking-at page-delimiter)
100 (eq (match-end 0) opoint))
102 (forward-page (- arg adjust)))))
103 ;; Find the end of the page.
106 ;; If we stopped due to end of buffer, stay there.
107 ;; If we stopped after a page delimiter, put end of restriction
108 ;; at the beginning of that line.
109 ;; Before checking the match that was found,
110 ;; verify that forward-page actually set the match data.
111 (if (and (match-beginning 0)
113 (goto-char (match-beginning 0)) ; was (beginning-of-line)
114 (looking-at page-delimiter)))
116 (narrow-to-region (point)
118 ;; Find the top of the page.
120 ;; If we found beginning of buffer, stay there.
121 ;; If extra text follows page delimiter on same line,
123 ;; Otherwise, show text starting with following line.
124 (if (and (eolp) (not (bobp)))
127 (put 'narrow-to-page 'disabled t)
129 (defun count-lines-page ()
130 "Report number of lines on current page, and how many are before or after point."
133 (let ((opoint (point)) beg end
137 (or (looking-at page-delimiter)
142 (setq total (count-lines beg end)
143 before (count-lines beg opoint)
144 after (count-lines opoint end))
145 (message "Page has %d lines (%d + %d)" total before after))))
148 "Print page and line number of point."
157 (while (re-search-forward page-delimiter opoint t)
158 (setq count (1+ count)))
159 (message "Page %d, line %d"
161 (1+ (count-lines (point) opoint)))))))
163 ;;; Place `provide' at end of file.
166 ;;; arch-tag: e8d7a0bd-8655-4b6e-b852-f2ee25316a1d
167 ;;; page.el ends here