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166 lines
5.3 KiB
EmacsLisp
166 lines
5.3 KiB
EmacsLisp
;;; page.el --- page motion commands for Emacs
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;; Copyright (C) 1985 Free Software Foundation, Inc.
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;; Maintainer: FSF
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software; you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation; either version 2, or (at your option)
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;; any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs; see the file COPYING. If not, write to the
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;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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;; Boston, MA 02111-1307, USA.
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;;; Commentary:
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;; This code provides the page-oriented movement and selection commands
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;; documented in the Emacs manual.
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;;; Code:
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(defun forward-page (&optional count)
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"Move forward to page boundary. With arg, repeat, or go back if negative.
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A page boundary is any line whose beginning matches the regexp
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`page-delimiter'."
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(interactive "p")
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(or count (setq count 1))
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(while (and (> count 0) (not (eobp)))
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;; In case the page-delimiter matches the null string,
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;; don't find a match without moving.
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(if (bolp) (forward-char 1))
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(if (re-search-forward page-delimiter nil t)
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nil
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(goto-char (point-max)))
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(setq count (1- count)))
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(while (and (< count 0) (not (bobp)))
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;; In case the page-delimiter matches the null string,
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;; don't find a match without moving.
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(and (save-excursion (re-search-backward page-delimiter nil t))
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(= (match-end 0) (point))
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(goto-char (match-beginning 0)))
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(forward-char -1)
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(if (re-search-backward page-delimiter nil t)
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;; We found one--move to the end of it.
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(goto-char (match-end 0))
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;; We found nothing--go to beg of buffer.
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(goto-char (point-min)))
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(setq count (1+ count))))
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(defun backward-page (&optional count)
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"Move backward to page boundary. With arg, repeat, or go fwd if negative.
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A page boundary is any line whose beginning matches the regexp
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`page-delimiter'."
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(interactive "p")
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(or count (setq count 1))
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(forward-page (- count)))
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(defun mark-page (&optional arg)
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"Put mark at end of page, point at beginning.
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A numeric arg specifies to move forward or backward by that many pages,
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thus marking a page other than the one point was originally in."
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(interactive "P")
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(setq arg (if arg (prefix-numeric-value arg) 0))
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(if (> arg 0)
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(forward-page arg)
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(if (< arg 0)
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(forward-page (1- arg))))
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(forward-page)
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(push-mark nil t t)
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(forward-page -1))
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(defun narrow-to-page (&optional arg)
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"Make text outside current page invisible.
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A numeric arg specifies to move forward or backward by that many pages,
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thus showing a page other than the one point was originally in."
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(interactive "P")
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(setq arg (if arg (prefix-numeric-value arg) 0))
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(save-excursion
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(widen)
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(if (> arg 0)
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(forward-page arg)
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(if (< arg 0)
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(let ((adjust 0)
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(opoint (point)))
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;; If we are not now at the beginning of a page,
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;; move back one extra time, to get to the start of this page.
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(save-excursion
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(beginning-of-line)
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(or (and (looking-at page-delimiter)
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(eq (match-end 0) opoint))
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(setq adjust 1)))
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(forward-page (- arg adjust)))))
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;; Find the end of the page.
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(set-match-data nil)
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(forward-page)
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;; If we stopped due to end of buffer, stay there.
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;; If we stopped after a page delimiter, put end of restriction
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;; at the beginning of that line.
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;; Before checking the match that was found,
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;; verify that forward-page actually set the match data.
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(if (and (match-beginning 0)
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(save-excursion
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(goto-char (match-beginning 0)) ; was (beginning-of-line)
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(looking-at page-delimiter)))
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(beginning-of-line))
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(narrow-to-region (point)
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(progn
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;; Find the top of the page.
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(forward-page -1)
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;; If we found beginning of buffer, stay there.
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;; If extra text follows page delimiter on same line,
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;; include it.
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;; Otherwise, show text starting with following line.
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(if (and (eolp) (not (bobp)))
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(forward-line 1))
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(point)))))
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(put 'narrow-to-page 'disabled t)
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(defun count-lines-page ()
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"Report number of lines on current page, and how many are before or after point."
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(interactive)
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(save-excursion
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(let ((opoint (point)) beg end
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total before after)
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(forward-page)
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(beginning-of-line)
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(or (looking-at page-delimiter)
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(end-of-line))
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(setq end (point))
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(backward-page)
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(setq beg (point))
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(setq total (count-lines beg end)
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before (count-lines beg opoint)
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after (count-lines opoint end))
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(message "Page has %d lines (%d + %d)" total before after))))
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(defun what-page ()
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"Print page and line number of point."
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(interactive)
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(save-restriction
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(widen)
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(save-excursion
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(beginning-of-line)
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(let ((count 1)
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(opoint (point)))
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(goto-char 1)
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(while (re-search-forward page-delimiter opoint t)
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(setq count (1+ count)))
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(message "Page %d, line %d"
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count
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(1+ (count-lines (point) opoint)))))))
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;;; Place `provide' at end of file.
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(provide 'page)
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;;; page.el ends here
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