1 ;;; page.el --- page motion commands for Emacs
3 ;; Copyright (C) 1985, 2001, 2002, 2003, 2004, 2005,
4 ;; 2006, 2007 Free Software Foundation, Inc.
7 ;; Keywords: wp convenience
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 3, or (at your option)
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 ;; Boston, MA 02110-1301, USA.
28 ;; This code provides the page-oriented movement and selection commands
29 ;; documented in the Emacs manual.
33 (defun forward-page (&optional count)
34 "Move forward to page boundary. With arg, repeat, or go back if negative.
35 A page boundary is any line whose beginning matches the regexp
38 (or count (setq count 1))
39 (while (and (> count 0) (not (eobp)))
40 ;; In case the page-delimiter matches the null string,
41 ;; don't find a match without moving.
42 (if (bolp) (forward-char 1))
43 (if (re-search-forward page-delimiter nil t)
45 (goto-char (point-max)))
46 (setq count (1- count)))
47 (while (and (< count 0) (not (bobp)))
48 ;; In case the page-delimiter matches the null string,
49 ;; don't find a match without moving.
50 (and (save-excursion (re-search-backward page-delimiter nil t))
51 (= (match-end 0) (point))
52 (goto-char (match-beginning 0)))
54 (if (re-search-backward page-delimiter nil t)
55 ;; We found one--move to the end of it.
56 (goto-char (match-end 0))
57 ;; We found nothing--go to beg of buffer.
58 (goto-char (point-min)))
59 (setq count (1+ count))))
61 (defun backward-page (&optional count)
62 "Move backward to page boundary. With arg, repeat, or go fwd if negative.
63 A page boundary is any line whose beginning matches the regexp
66 (or count (setq count 1))
67 (forward-page (- count)))
69 (defun mark-page (&optional arg)
70 "Put mark at end of page, point at beginning.
71 A numeric arg specifies to move forward or backward by that many pages,
72 thus marking a page other than the one point was originally in."
74 (setq arg (if arg (prefix-numeric-value arg) 0))
78 (forward-page (1- arg))))
83 (defun narrow-to-page (&optional arg)
84 "Make text outside current page invisible.
85 A numeric arg specifies to move forward or backward by that many pages,
86 thus showing a page other than the one point was originally in."
88 (setq arg (if arg (prefix-numeric-value arg) 0))
96 ;; If we are not now at the beginning of a page,
97 ;; move back one extra time, to get to the start of this page.
100 (or (and (looking-at page-delimiter)
101 (eq (match-end 0) opoint))
103 (forward-page (- arg adjust)))))
104 ;; Find the end of the page.
107 ;; If we stopped due to end of buffer, stay there.
108 ;; If we stopped after a page delimiter, put end of restriction
109 ;; at the beginning of that line.
110 ;; Before checking the match that was found,
111 ;; verify that forward-page actually set the match data.
112 (if (and (match-beginning 0)
114 (goto-char (match-beginning 0)) ; was (beginning-of-line)
115 (looking-at page-delimiter)))
116 (goto-char (match-beginning 0))) ; was (beginning-of-line)
117 (narrow-to-region (point)
119 ;; Find the top of the page.
121 ;; If we found beginning of buffer, stay there.
122 ;; If extra text follows page delimiter on same line,
124 ;; Otherwise, show text starting with following line.
125 (if (and (eolp) (not (bobp)))
128 (put 'narrow-to-page 'disabled t)
130 (defun count-lines-page ()
131 "Report number of lines on current page, and how many are before or after point."
134 (let ((opoint (point)) beg end
138 (or (looking-at page-delimiter)
143 (setq total (count-lines beg end)
144 before (count-lines beg opoint)
145 after (count-lines opoint end))
146 (message "Page has %d lines (%d + %d)" total before after))))
149 "Print page and line number of point."
158 (while (re-search-forward page-delimiter opoint t)
159 (setq count (1+ count)))
160 (message "Page %d, line %d"
162 (1+ (count-lines (point) opoint)))))))
164 ;;; Place `provide' at end of file.
167 ;;; arch-tag: e8d7a0bd-8655-4b6e-b852-f2ee25316a1d
168 ;;; page.el ends here