1;;; page.el --- page motion commands for Emacs 2 3;; Copyright (C) 1985, 2001, 2002, 2003, 2004, 2005, 4;; 2006, 2007 Free Software Foundation, Inc. 5 6;; Maintainer: FSF 7;; Keywords: wp convenience 8 9;; This file is part of GNU Emacs. 10 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 2, or (at your option) 14;; any later version. 15 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. 20 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. 25 26;;; Commentary: 27 28;; This code provides the page-oriented movement and selection commands 29;; documented in the Emacs manual. 30 31;;; Code: 32 33(defun forward-page (&optional count) 34 "Move forward to page boundary. With arg, repeat, or go back if negative. 35A page boundary is any line whose beginning matches the regexp 36`page-delimiter'." 37 (interactive "p") 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) 44 nil 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))) 53 (forward-char -1) 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)))) 60 61(defun backward-page (&optional count) 62 "Move backward to page boundary. With arg, repeat, or go fwd if negative. 63A page boundary is any line whose beginning matches the regexp 64`page-delimiter'." 65 (interactive "p") 66 (or count (setq count 1)) 67 (forward-page (- count))) 68 69(defun mark-page (&optional arg) 70 "Put mark at end of page, point at beginning. 71A numeric arg specifies to move forward or backward by that many pages, 72thus marking a page other than the one point was originally in." 73 (interactive "P") 74 (setq arg (if arg (prefix-numeric-value arg) 0)) 75 (if (> arg 0) 76 (forward-page arg) 77 (if (< arg 0) 78 (forward-page (1- arg)))) 79 (forward-page) 80 (push-mark nil t t) 81 (forward-page -1)) 82 83(defun narrow-to-page (&optional arg) 84 "Make text outside current page invisible. 85A numeric arg specifies to move forward or backward by that many pages, 86thus showing a page other than the one point was originally in." 87 (interactive "P") 88 (setq arg (if arg (prefix-numeric-value arg) 0)) 89 (save-excursion 90 (widen) 91 (if (> arg 0) 92 (forward-page arg) 93 (if (< arg 0) 94 (let ((adjust 0) 95 (opoint (point))) 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. 98 (save-excursion 99 (beginning-of-line) 100 (or (and (looking-at page-delimiter) 101 (eq (match-end 0) opoint)) 102 (setq adjust 1))) 103 (forward-page (- arg adjust))))) 104 ;; Find the end of the page. 105 (set-match-data nil) 106 (forward-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) 113 (save-excursion 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) 118 (progn 119 ;; Find the top of the page. 120 (forward-page -1) 121 ;; If we found beginning of buffer, stay there. 122 ;; If extra text follows page delimiter on same line, 123 ;; include it. 124 ;; Otherwise, show text starting with following line. 125 (if (and (eolp) (not (bobp))) 126 (forward-line 1)) 127 (point))))) 128(put 'narrow-to-page 'disabled t) 129 130(defun count-lines-page () 131 "Report number of lines on current page, and how many are before or after point." 132 (interactive) 133 (save-excursion 134 (let ((opoint (point)) beg end 135 total before after) 136 (forward-page) 137 (beginning-of-line) 138 (or (looking-at page-delimiter) 139 (end-of-line)) 140 (setq end (point)) 141 (backward-page) 142 (setq beg (point)) 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)))) 147 148(defun what-page () 149 "Print page and line number of point." 150 (interactive) 151 (save-restriction 152 (widen) 153 (save-excursion 154 (beginning-of-line) 155 (let ((count 1) 156 (opoint (point))) 157 (goto-char 1) 158 (while (re-search-forward page-delimiter opoint t) 159 (setq count (1+ count))) 160 (message "Page %d, line %d" 161 count 162 (1+ (count-lines (point) opoint))))))) 163 164;;; Place `provide' at end of file. 165(provide 'page) 166 167;;; arch-tag: e8d7a0bd-8655-4b6e-b852-f2ee25316a1d 168;;; page.el ends here 169