mirror of
https://git.savannah.gnu.org/git/emacs.git
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cf9ac85785
* lisp/view.el (view-remove-frame-by-deleting): Remove variable
that hasn't been used since 2011 -- 357f93d245 reworked the
code and stopped using it (bug#58413).
935 lines
37 KiB
EmacsLisp
935 lines
37 KiB
EmacsLisp
;;; view.el --- peruse file or buffer without editing -*- lexical-binding: t -*-
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;; Copyright (C) 1985-2022 Free Software Foundation, Inc.
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;; Author: K. Shane Hartman
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;; Maintainer: emacs-devel@gnu.org
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;; Keywords: files
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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 3 of the License, or
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;; (at your option) 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. If not, see <https://www.gnu.org/licenses/>.
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;;; Commentary:
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;; This package provides the `view' minor mode documented in the Emacs
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;; user's manual.
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;;
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;; View mode entry and exit is done through the functions `view-mode-enter'
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;; and `view-mode-exit'. Use these functions to enter or exit `view-mode' from
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;; Emacs Lisp programs.
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;;
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;; We use both view- and View- as prefix for symbols. View- is used as
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;; prefix for commands that have a key binding. view- is used for commands
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;; without key binding. The purpose of this is to make it easier for a
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;; user to use command name completion.
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;;; Suggested key bindings:
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;;
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;; (keymap-set ctl-x-4-map "v" #'view-file-other-window) ; C-x 4 v
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;; (keymap-set ctl-x-5-map "v" #'view-file-other-frame) ; C-x 5 v
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;;
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;; You could also bind `view-file', `view-buffer', `view-buffer-other-window' and
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;; `view-buffer-other-frame' to keys.
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;;; Code:
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(defgroup view nil
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"Peruse file or buffer without editing."
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:link '(function-link view-mode)
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:link '(custom-manual "(emacs)Misc File Ops")
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:group 'text)
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(defcustom view-highlight-face 'highlight
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"The face used for highlighting the match found by View mode search."
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:type 'face)
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(defcustom view-scroll-auto-exit nil
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"Non-nil means scrolling past the end of buffer exits View mode.
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A value of nil means attempting to scroll past the end of the buffer,
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only rings the bell and gives a message on how to leave."
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:type 'boolean)
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(defcustom view-try-extend-at-buffer-end nil
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"Non-nil means try to load more of file when reaching end of buffer.
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This variable is mainly intended to be temporarily set to non-nil by
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the F command in `view-mode', but you can set it to t if you want the action
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for all scroll commands in view mode."
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:type 'boolean)
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(defcustom view-exits-all-viewing-windows nil
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"Non-nil means restore all windows used to view buffer.
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Commands that restore windows when finished viewing a buffer,
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apply to all windows that display the buffer and have restore
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information. If `view-exits-all-viewing-windows' is nil, only
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the selected window is considered for restoring."
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:type 'boolean)
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(defcustom view-inhibit-help-message nil
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"Non-nil inhibits the help message shown upon entering View mode.
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This setting takes effect only when View mode is entered via an
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interactive command; otherwise the help message is not shown."
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:type 'boolean
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:version "22.1")
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;;;###autoload
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(defvar-local view-mode nil
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"Non-nil if View mode is enabled.
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Don't change this variable directly, you must change it by one of the
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functions that enable or disable view mode.")
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(defcustom view-mode-hook nil
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"Normal hook run when starting to view a buffer or file."
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:type 'hook)
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(defvar-local view-old-buffer-read-only nil)
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(defvar-local view-page-size nil
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"Default number of lines to scroll by View page commands.
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If nil that means use the window size.")
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(defvar-local view-half-page-size nil
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"Default number of lines to scroll by View half page commands.
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If nil that means use half the window size.")
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(defvar-local view-last-regexp nil) ; Global is better???
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(defvar-local view-exit-action nil
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"If non-nil, a function called when finished viewing.
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The function should take one argument (a buffer).
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Commands like \\[view-file] and \\[view-file-other-window] may
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set this to bury or kill the viewed buffer.
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Observe that the buffer viewed might not appear in any window at
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the time this function is called.")
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(defvar view-no-disable-on-exit nil
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"If non-nil, View mode \"exit\" commands don't actually disable View mode.
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Instead, these commands just switch buffers or windows.
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This is set in certain buffers by specialized features such as help commands
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that use View mode automatically.")
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(defvar-local view-overlay nil
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"Overlay used to display where a search operation found its match.
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This is local in each buffer, once it is used.")
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;; Some redundant "less"-like key bindings below have been commented out.
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(defvar-keymap view-mode-map
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:doc "Keymap for `view-mode'."
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"C" #'View-kill-and-leave
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"c" #'View-leave
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"Q" #'View-quit-all
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"E" #'View-exit-and-edit
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;; "v" #'View-exit
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"e" #'View-exit
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"q" #'View-quit
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;; "N" #'View-search-last-regexp-backward
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"p" #'View-search-last-regexp-backward
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"n" #'View-search-last-regexp-forward
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;; "?" #'View-search-regexp-backward ; Less does this.
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"\\" #'View-search-regexp-backward
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"/" #'View-search-regexp-forward
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"r" #'isearch-backward
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"s" #'isearch-forward
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"m" #'point-to-register
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"'" #'register-to-point
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"x" #'exchange-point-and-mark
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"@" #'View-back-to-mark
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"." #'set-mark-command
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"%" #'View-goto-percent
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;; "G" #'View-goto-line-last
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"g" #'View-goto-line
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"=" #'what-line
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"F" #'View-revert-buffer-scroll-page-forward
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;; "k" #'View-scroll-line-backward
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"y" #'View-scroll-line-backward
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;; "j" #'View-scroll-line-forward
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"C-j" #'View-scroll-line-forward
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"RET" #'View-scroll-line-forward
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"u" #'View-scroll-half-page-backward
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"d" #'View-scroll-half-page-forward
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"z" #'View-scroll-page-forward-set-page-size
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"w" #'View-scroll-page-backward-set-page-size
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;; "b" #'View-scroll-page-backward
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"DEL" #'View-scroll-page-backward
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;; "f" #'View-scroll-page-forward
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"SPC" #'View-scroll-page-forward
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"S-SPC" #'View-scroll-page-backward
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"o" #'View-scroll-to-buffer-end
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">" #'end-of-buffer
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"<" #'beginning-of-buffer
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"-" #'negative-argument
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"9" #'digit-argument
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"8" #'digit-argument
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"7" #'digit-argument
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"6" #'digit-argument
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"5" #'digit-argument
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"4" #'digit-argument
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"3" #'digit-argument
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"2" #'digit-argument
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"1" #'digit-argument
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"0" #'digit-argument
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"H" #'describe-mode
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"?" #'describe-mode ; Maybe do as less instead? See above.
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"h" #'describe-mode)
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;;; Commands that enter or exit view mode.
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;; This is used when view mode is exited, to make sure we don't try to
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;; kill a buffer modified by the user. A buffer in view mode can
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;; become modified if the user types C-x C-q, edits the buffer, then
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;; types C-x C-q again to return to view mode.
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;;;###autoload
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(defun kill-buffer-if-not-modified (buf)
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"Like `kill-buffer', but does nothing if buffer BUF is modified."
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(let ((buf (get-buffer buf)))
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(and buf (not (buffer-modified-p buf))
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(kill-buffer buf))))
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;;;###autoload
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(defun view-file (file)
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"View FILE in View mode, returning to previous buffer when done.
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Emacs commands editing the buffer contents are not available; instead, a
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special set of commands (mostly letters and punctuation) are defined for
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moving around in the buffer.
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Space scrolls forward, Delete scrolls backward.
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For a list of all View commands, type H or h while viewing.
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This command runs the normal hook `view-mode-hook'."
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(interactive "fView file: ")
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(unless (file-exists-p file) (error "%s does not exist" file))
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(let ((had-a-buf (get-file-buffer file))
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(buffer (find-file-noselect file)))
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(view-buffer buffer (and (not had-a-buf) 'kill-buffer-if-not-modified))))
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;;;###autoload
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(defun view-file-other-window (file)
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"View FILE in View mode in another window.
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When done, return that window to its previous buffer, and kill the
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buffer visiting FILE if unmodified and if it wasn't visited before.
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Emacs commands editing the buffer contents are not available; instead,
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a special set of commands (mostly letters and punctuation)
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are defined for moving around in the buffer.
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Space scrolls forward, Delete scrolls backward.
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For a list of all View commands, type H or h while viewing.
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This command runs the normal hook `view-mode-hook'."
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(interactive "fIn other window view file: ")
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(unless (file-exists-p file) (error "%s does not exist" file))
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(let ((had-a-buf (get-file-buffer file))
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(buf-to-view (find-file-noselect file)))
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(view-buffer-other-window buf-to-view nil
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(and (not had-a-buf)
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'kill-buffer-if-not-modified))))
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;;;###autoload
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(defun view-file-other-frame (file)
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"View FILE in View mode in another frame.
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When done, kill the buffer visiting FILE if unmodified and if it wasn't
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visited before; also, maybe delete other frame and/or return to previous
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buffer.
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Emacs commands editing the buffer contents are not available; instead,
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a special set of commands (mostly letters and punctuation)
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are defined for moving around in the buffer.
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Space scrolls forward, Delete scrolls backward.
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For a list of all View commands, type H or h while viewing.
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This command runs the normal hook `view-mode-hook'."
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(interactive "fIn other frame view file: ")
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(unless (file-exists-p file) (error "%s does not exist" file))
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(let ((had-a-buf (get-file-buffer file))
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(buf-to-view (find-file-noselect file)))
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(view-buffer-other-frame buf-to-view nil
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(and (not had-a-buf)
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'kill-buffer-if-not-modified))))
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;;;###autoload
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(defun view-buffer (buffer &optional exit-action)
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"View BUFFER in View mode, returning to previous buffer when done.
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Emacs commands editing the buffer contents are not available; instead, a
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special set of commands (mostly letters and punctuation) are defined for
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moving around in the buffer.
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Space scrolls forward, Delete scrolls backward.
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For a list of all View commands, type H or h while viewing.
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This command runs the normal hook `view-mode-hook'.
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Optional argument EXIT-ACTION is either nil or a function with buffer as
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argument. This function is called when finished viewing buffer. Use
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this argument instead of explicitly setting `view-exit-action'.
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Do not set EXIT-ACTION to `kill-buffer' when BUFFER visits a
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file: Users may suspend viewing in order to modify the buffer.
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Exiting View mode will then discard the user's edits. Setting
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EXIT-ACTION to `kill-buffer-if-not-modified' avoids this.
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This function does not enable View mode if the buffer's major mode
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has a `special' mode-class, because such modes usually have their
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own View-like bindings."
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(interactive "bView buffer: ")
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(switch-to-buffer buffer)
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(if (eq (get major-mode 'mode-class) 'special)
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(message "Not using View mode because the major mode is special")
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(view-mode-enter nil exit-action)))
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;;;###autoload
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(defun view-buffer-other-window (buffer &optional _not-return exit-action)
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"View BUFFER in View mode in another window.
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Emacs commands editing the buffer contents are not available;
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instead, a special set of commands (mostly letters and
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punctuation) are defined for moving around in the buffer.
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Space scrolls forward, Delete scrolls backward.
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For a list of all View commands, type H or h while viewing.
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This command runs the normal hook `view-mode-hook'.
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Optional argument NOT-RETURN is ignored.
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Optional argument EXIT-ACTION is either nil or a function with buffer as
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argument. This function is called when finished viewing buffer. Use
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this argument instead of explicitly setting `view-exit-action'.
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This function does not enable View mode if the buffer's major mode
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has a `special' mode-class, because such modes usually have their
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own View-like bindings."
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(interactive "bIn other window view buffer:\nP")
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(let ((pop-up-windows t))
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(pop-to-buffer buffer t))
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(if (eq (get major-mode 'mode-class) 'special)
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(message "Not using View mode because the major mode is special")
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(view-mode-enter nil exit-action)))
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;;;###autoload
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(defun view-buffer-other-frame (buffer &optional _not-return exit-action)
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"View BUFFER in View mode in another frame.
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Emacs commands editing the buffer contents are not available;
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instead, a special set of commands (mostly letters and
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punctuation) are defined for moving around in the buffer.
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Space scrolls forward, Delete scrolls backward.
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For a list of all View commands, type H or h while viewing.
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This command runs the normal hook `view-mode-hook'.
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Optional argument NOT-RETURN is ignored.
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Optional argument EXIT-ACTION is either nil or a function with buffer as
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argument. This function is called when finished viewing buffer. Use
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this argument instead of explicitly setting `view-exit-action'.
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This function does not enable View mode if the buffer's major mode
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has a `special' mode-class, because such modes usually have their
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own View-like bindings."
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(interactive "bView buffer in other frame: \nP")
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(let ((pop-up-frames t))
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(pop-to-buffer buffer t))
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(if (eq (get major-mode 'mode-class) 'special)
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(message "Not using View mode because the major mode is special")
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(view-mode-enter nil exit-action)))
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;;;###autoload
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(define-minor-mode view-mode
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;; In the following documentation string we have to use some explicit key
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;; bindings instead of using the \\[] construction. The reason for this
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;; is that most commands have more than one key binding.
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"Toggle View mode, a minor mode for viewing text but not editing it.
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When View mode is enabled, commands that do not change the buffer
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contents are available as usual. Kill commands save text but
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do not delete it from the buffer. Most other commands beep and
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tell the user that the buffer is read-only.
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\\<view-mode-map>
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The following additional commands are provided. Most commands
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take prefix arguments. Page commands default to \"page size\"
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lines which is almost a whole window, or number of lines set by
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\\[View-scroll-page-forward-set-page-size] or \\[View-scroll-page-backward-set-page-size].
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Half page commands default to and set \"half page size\" lines
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which initially is half a window full. Search commands default
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to a repeat count of one.
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H, h, ? This message.
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Digits provide prefix arguments.
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\\[negative-argument] negative prefix argument.
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\\[beginning-of-buffer] move to the beginning of buffer.
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> move to the end of buffer.
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\\[View-scroll-to-buffer-end] scroll so that buffer end is at last line of window.
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SPC scroll forward \"page size\" lines.
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With prefix scroll forward prefix lines.
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DEL, S-SPC scroll backward \"page size\" lines.
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With prefix scroll backward prefix lines.
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\\[View-scroll-page-forward-set-page-size] like \\[View-scroll-page-forward] but with prefix sets \"page size\" to prefix.
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\\[View-scroll-page-backward-set-page-size] like \\[View-scroll-page-backward] but with prefix sets \"page size\" to prefix.
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\\[View-scroll-half-page-forward] scroll forward \"half page size\" lines. With prefix, sets
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\"half page size\" to prefix lines and scrolls forward that much.
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\\[View-scroll-half-page-backward] scroll backward \"half page size\" lines. With prefix, sets
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\"half page size\" to prefix lines and scrolls backward that much.
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RET, LFD scroll forward one line. With prefix scroll forward prefix line(s).
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y scroll backward one line. With prefix scroll backward prefix line(s).
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\\[View-revert-buffer-scroll-page-forward] revert-buffer if necessary and scroll forward.
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Use this to view a changing file.
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\\[what-line] prints the current line number.
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\\[View-goto-percent] goes prefix argument (default 100) percent into buffer.
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\\[View-goto-line] goes to line given by prefix argument (default first line).
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. set the mark.
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x exchanges point and mark.
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\\[View-back-to-mark] return to mark and pops mark ring.
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Mark ring is pushed at start of every successful search and when
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jump to line occurs. The mark is set on jump to buffer start or end.
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\\[point-to-register] save current position in character register.
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\\=' go to position saved in character register.
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s do forward incremental search.
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r do reverse incremental search.
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\\[View-search-regexp-forward] searches forward for regular expression, starting after current page.
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! and @ have a special meaning at the beginning of the regexp.
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! means search for a line with no match for regexp. @ means start
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search at beginning (end for backward search) of buffer.
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\\ searches backward for regular expression, starting before current page.
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\\[View-search-last-regexp-forward] searches forward for last regular expression.
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p searches backward for last regular expression.
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\\[View-quit] quit View mode, restoring this window and buffer to previous state.
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\\[View-quit] is the normal way to leave view mode.
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\\[View-exit] exit View mode but stay in current buffer. Use this if you started
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viewing a buffer (file) and find out you want to edit it.
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This command restores the previous read-only status of the buffer.
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\\[View-exit-and-edit] exit View mode, and make the current buffer editable
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even if it was not editable before entry to View mode.
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\\[View-quit-all] quit View mode, restoring all windows to previous state.
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\\[View-leave] quit View mode and maybe switch buffers, but don't kill this buffer.
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\\[View-kill-and-leave] quit View mode, kill current buffer and go back to other buffer.
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The effect of \\[View-leave], \\[View-quit] and \\[View-kill-and-leave] depends on how view-mode was entered. If it was
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entered by view-file, view-file-other-window, view-file-other-frame, or
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\\[dired-view-file] \(\\[view-file], \\[view-file-other-window],
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\\[view-file-other-frame], or the Dired mode v command),
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then \\[View-quit] will try to kill the current buffer.
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If view-mode was entered from another buffer, by \\[view-buffer],
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\\[view-buffer-other-window], \\[view-buffer-other frame], \\[view-file],
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\\[view-file-other-window], or \\[view-file-other-frame],
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then \\[View-leave], \\[View-quit] and \\[View-kill-and-leave] will return to that buffer.
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Entry to view-mode runs the normal hook `view-mode-hook'."
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:lighter " View" :keymap view-mode-map
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(if view-mode (view--enable) (view--disable)))
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(defun view--enable ()
|
||
;; Always leave view mode before changing major mode.
|
||
;; This is to guarantee that the buffer-read-only variable is restored.
|
||
(add-hook 'change-major-mode-hook 'view--disable nil t)
|
||
(setq view-page-size nil
|
||
view-half-page-size nil
|
||
view-old-buffer-read-only buffer-read-only
|
||
buffer-read-only t)
|
||
;; Make reverting the buffer preserve unreadableness.
|
||
(setq-local read-only-mode--state t))
|
||
|
||
|
||
(define-obsolete-function-alias 'view-mode-enable 'view-mode "24.4")
|
||
(defun view-mode-disable ()
|
||
"Turn off View mode."
|
||
(declare (obsolete view-mode "24.4"))
|
||
(view-mode -1))
|
||
|
||
(defun view--disable ()
|
||
(remove-hook 'change-major-mode-hook 'view--disable t)
|
||
(and view-overlay (delete-overlay view-overlay))
|
||
;; Calling read-only-mode while View mode is enabled
|
||
;; sets view-read-only to t as a buffer-local variable
|
||
;; after exiting View mode. That arranges that the next read-only-mode
|
||
;; will reenable View mode.
|
||
;; Canceling View mode in any other way should cancel that, too,
|
||
;; so that View mode stays off if read-only-mode is called.
|
||
(if (local-variable-p 'view-read-only)
|
||
(kill-local-variable 'view-read-only))
|
||
(if buffer-read-only
|
||
(setq buffer-read-only view-old-buffer-read-only)))
|
||
|
||
;;;###autoload
|
||
(defun view-mode-enter (&optional quit-restore exit-action)
|
||
"Enter View mode and set up exit from view mode depending on optional arguments.
|
||
Optional argument QUIT-RESTORE if non-nil must specify a valid
|
||
entry for quitting and restoring any window showing the current
|
||
buffer. This entry replaces any parameter installed by
|
||
`display-buffer' and is used by `view-mode-exit'.
|
||
|
||
Optional argument EXIT-ACTION, if non-nil, must specify a
|
||
function that takes a buffer as argument. This function will be
|
||
called by `view-mode-exit'.
|
||
|
||
For a list of all View commands, type H or h while viewing.
|
||
|
||
This function runs the normal hook `view-mode-hook'."
|
||
(when quit-restore
|
||
(dolist (window (get-buffer-window-list nil nil t))
|
||
(set-window-parameter window 'quit-restore quit-restore)))
|
||
|
||
(when exit-action
|
||
(setq view-exit-action exit-action))
|
||
|
||
(unless view-mode
|
||
(view-mode 1)
|
||
(when (and (not view-inhibit-help-message)
|
||
;; Avoid spamming the echo area if `view-mode' is entered
|
||
;; non-interactively, e.g., in a temporary buffer (bug#44629).
|
||
this-command)
|
||
(message "%s"
|
||
(substitute-command-keys "\
|
||
View mode: type \\[help-command] for help, \\[describe-mode] for commands, \\[View-quit] to quit.")))))
|
||
|
||
;; This is awful because it assumes that the selected window shows the
|
||
;; current buffer when this is called.
|
||
(defun view-mode-exit (&optional exit-only exit-action all-windows)
|
||
"Exit View mode in various ways.
|
||
If all arguments are nil, remove the current buffer from the
|
||
selected window using the `quit-restore' information associated
|
||
with the selected window. If optional argument ALL-WINDOWS or
|
||
`view-exits-all-viewing-windows' are non-nil, remove the current
|
||
buffer from all windows showing it.
|
||
|
||
Optional argument EXIT-ONLY non-nil means just exit `view-mode'
|
||
\(unless `view-no-disable-on-exit' is non-nil) but do not change
|
||
the associations of any windows with the current buffer.
|
||
|
||
EXIT-ACTION, if non-nil, must specify a function that is called
|
||
with the current buffer as argument and is called after disabling
|
||
`view-mode' and removing any associations of windows with the
|
||
current buffer."
|
||
(when view-mode
|
||
(let ((buffer (window-buffer)))
|
||
(unless view-no-disable-on-exit
|
||
(view-mode -1))
|
||
|
||
(unless exit-only
|
||
(cond
|
||
((or all-windows view-exits-all-viewing-windows)
|
||
(dolist (window (get-buffer-window-list))
|
||
(quit-window nil window)))
|
||
((eq (window-buffer) (current-buffer))
|
||
(quit-window)))
|
||
|
||
(when exit-action
|
||
(funcall exit-action buffer))))))
|
||
|
||
(defun View-exit ()
|
||
"Exit View mode but stay in current buffer."
|
||
(interactive)
|
||
(view-mode-exit t))
|
||
|
||
;;;###autoload
|
||
(defun View-exit-and-edit ()
|
||
"Exit View mode and make the current buffer editable."
|
||
(interactive)
|
||
(let ((view-old-buffer-read-only nil)
|
||
(view-no-disable-on-exit nil))
|
||
(view-mode-exit t)))
|
||
|
||
(defun View-leave ()
|
||
"Quit View mode and maybe switch buffers, but don't kill this buffer."
|
||
(interactive)
|
||
(view-mode-exit))
|
||
|
||
(defun View-quit ()
|
||
"Quit View mode, trying to restore window and buffer to previous state.
|
||
Maybe kill this buffer. Try to restore selected window to previous state
|
||
and go to previous buffer or window."
|
||
(interactive)
|
||
(view-mode-exit nil view-exit-action))
|
||
|
||
(defun View-quit-all ()
|
||
"Quit View mode, trying to restore windows and buffers to previous state.
|
||
Maybe kill current buffer. Try to restore all windows viewing buffer to
|
||
previous state and go to previous buffer or window."
|
||
(interactive)
|
||
(view-mode-exit nil view-exit-action t))
|
||
|
||
(defun View-kill-and-leave ()
|
||
"Quit View mode, kill current buffer and return to previous buffer."
|
||
(interactive)
|
||
(view-mode-exit nil (or view-exit-action 'kill-buffer) t))
|
||
|
||
|
||
;;; Some help routines.
|
||
|
||
(defun view-window-size ()
|
||
;; Return the height of the current window, excluding the mode line.
|
||
;; Using `window-line-height' accounts for variable-height fonts.
|
||
(let ((h (window-line-height -1)))
|
||
(if h
|
||
(1+ (nth 1 h))
|
||
;; This should not happen, but if `window-line-height' returns
|
||
;; nil, fall back on `window-height'.
|
||
(1- (window-height)))))
|
||
|
||
;; (defun view-last-command (&optional who what)
|
||
;; (setq view-last-command-entry this-command)
|
||
;; (setq view-last-command who)
|
||
;; (setq view-last-command-argument what))
|
||
|
||
;; (defun View-repeat-last-command ()
|
||
;; "Repeat last command issued in View mode."
|
||
;; (interactive)
|
||
;; (if (and view-last-command
|
||
;; (eq view-last-command-entry last-command))
|
||
;; (funcall view-last-command view-last-command-argument))
|
||
;; (setq this-command view-last-command-entry))
|
||
|
||
(defun view-recenter ()
|
||
;; Recenter point in window and redisplay normally.
|
||
(recenter '(1)))
|
||
|
||
(defun view-page-size-default (lines)
|
||
"If LINES is nil, 0, or larger than `view-window-size', return nil.
|
||
Otherwise, return LINES."
|
||
(and lines
|
||
(not (zerop (setq lines (prefix-numeric-value lines))))
|
||
(<= (abs lines)
|
||
(abs (- (view-window-size) next-screen-context-lines)))
|
||
(abs lines)))
|
||
|
||
(defun view-set-half-page-size-default (lines)
|
||
"Get and maybe set half page size."
|
||
(if (not lines) (or view-half-page-size
|
||
(/ (view-window-size) 2))
|
||
(setq view-half-page-size
|
||
(if (zerop (setq lines (prefix-numeric-value lines)))
|
||
(/ (view-window-size) 2)
|
||
(view-page-size-default lines)))))
|
||
|
||
|
||
;;; Commands for moving around in the buffer.
|
||
|
||
(defun View-goto-percent (&optional percent)
|
||
"Move to end (or prefix PERCENT) of buffer in View mode.
|
||
Display is centered at point.
|
||
Also set the mark at the position where point was."
|
||
(interactive "P")
|
||
(push-mark)
|
||
(goto-char
|
||
(if percent
|
||
(+ (point-min)
|
||
(floor (* (- (point-max) (point-min)) 0.01
|
||
(max 0 (min 100 (prefix-numeric-value percent))))))
|
||
(point-max)))
|
||
(view-recenter))
|
||
|
||
;; (defun View-goto-line-last (&optional line)
|
||
;; "Move to last (or prefix LINE) line in View mode.
|
||
;; Display is centered at LINE.
|
||
;; Sets mark at starting position and pushes mark ring."
|
||
;; (interactive "P")
|
||
;; (push-mark)
|
||
;; (if line (goto-line (prefix-numeric-value line))
|
||
;; (goto-char (point-max))
|
||
;; (beginning-of-line))
|
||
;; (view-recenter))
|
||
|
||
(defun View-goto-line (&optional line)
|
||
"Move to first (or prefix LINE) line in View mode.
|
||
Display is centered at LINE.
|
||
Also set the mark at the position where point was."
|
||
(interactive "p")
|
||
(push-mark)
|
||
(goto-char (point-min))
|
||
(forward-line (1- line))
|
||
(view-recenter))
|
||
|
||
(defun View-back-to-mark (&optional _ignore)
|
||
"Return to last mark set in View mode, else beginning of file.
|
||
Display that line at the center of the window.
|
||
This command pops the mark ring, so that successive
|
||
invocations return to earlier marks."
|
||
(interactive)
|
||
(goto-char (or (mark t) (point-min)))
|
||
(pop-mark)
|
||
(view-recenter))
|
||
|
||
(defun view-scroll-lines (lines backward default maxdefault)
|
||
;; This function does the job for all the scrolling commands.
|
||
;; Scroll forward LINES lines. If BACKWARD is non-nil, scroll backwards.
|
||
;; If LINES is negative scroll in the other direction.
|
||
;; If LINES is 0 or nil, scroll DEFAULT lines (if DEFAULT is nil, scroll
|
||
;; by one page). If MAXDEFAULT is non-nil, scroll no more than a window.
|
||
(if (or (null lines) (zerop (setq lines (prefix-numeric-value lines))))
|
||
(setq lines default))
|
||
(when (and lines (< lines 0))
|
||
(setq backward (not backward) lines (- lines)))
|
||
(when (and maxdefault lines (> lines (view-window-size)))
|
||
(setq lines nil))
|
||
(cond (backward (scroll-down-command lines))
|
||
((view-really-at-end)
|
||
(if view-scroll-auto-exit
|
||
(View-quit)
|
||
(ding)
|
||
(view-end-message)))
|
||
(t (scroll-up-command lines)
|
||
(if (view-really-at-end) (view-end-message)))))
|
||
|
||
(defun view-really-at-end ()
|
||
"Return non-nil if buffer end visible. Maybe revert buffer and test."
|
||
(and (or (null scroll-error-top-bottom) (eobp))
|
||
(pos-visible-in-window-p (point-max))
|
||
(let ((buf (current-buffer))
|
||
(bufname (buffer-name))
|
||
(file (buffer-file-name)))
|
||
(or (not view-try-extend-at-buffer-end)
|
||
(null file)
|
||
(verify-visited-file-modtime buf)
|
||
(not (file-exists-p file))
|
||
(when (buffer-modified-p buf)
|
||
(setq file (file-name-nondirectory file))
|
||
(not (yes-or-no-p
|
||
(format
|
||
"File %s changed on disk. Discard your edits%s? "
|
||
file
|
||
(if (string= bufname file) ""
|
||
(concat " in " bufname))))))
|
||
(progn
|
||
(revert-buffer t t t)
|
||
(pos-visible-in-window-p (point-max)))))))
|
||
|
||
(defun view-end-message ()
|
||
"Tell that we are at end of buffer."
|
||
(goto-char (point-max))
|
||
(if (window-parameter nil 'quit-restore)
|
||
(message "End of buffer. Type %s to quit viewing."
|
||
(substitute-command-keys
|
||
(if view-scroll-auto-exit "\\[View-scroll-page-forward]"
|
||
"\\[View-quit]")))
|
||
(message "End of buffer")))
|
||
|
||
(defun View-scroll-to-buffer-end ()
|
||
"Scroll backward or forward so that buffer end is at last line of window."
|
||
(interactive)
|
||
(let ((p (if (pos-visible-in-window-p (point-max)) (point))))
|
||
(goto-char (point-max))
|
||
(recenter -1)
|
||
(and p (goto-char p))))
|
||
|
||
(defun View-scroll-page-forward (&optional lines)
|
||
"Scroll \"page size\" or prefix LINES lines forward in View mode.
|
||
Exit if end of text is visible and `view-scroll-auto-exit' is non-nil.
|
||
\"page size\" is whole window full, or number of lines set by
|
||
\\[View-scroll-page-forward-set-page-size] or
|
||
\\[View-scroll-page-backward-set-page-size].
|
||
If LINES is more than a window-full, only the last window-full is shown."
|
||
(interactive "P")
|
||
(view-scroll-lines lines nil (view-page-size-default view-page-size) nil))
|
||
|
||
(defun View-scroll-page-backward (&optional lines)
|
||
"Scroll \"page size\" or prefix LINES lines backward in View mode.
|
||
See also `View-scroll-page-forward'."
|
||
(interactive "P")
|
||
(view-scroll-lines lines t (view-page-size-default view-page-size) nil))
|
||
|
||
(defun View-scroll-page-forward-set-page-size (&optional lines)
|
||
"Scroll forward LINES lines in View mode, setting the \"page size\".
|
||
This is the number of lines which \\[View-scroll-page-forward] and
|
||
\\[View-scroll-page-backward] scroll by default.
|
||
If LINES is omitted or = 0, sets \"page size\" to window height and
|
||
scrolls forward that much, otherwise scrolls forward LINES lines and sets
|
||
\"page size\" to the minimum of window height and the absolute value of LINES.
|
||
See also `View-scroll-page-forward'."
|
||
(interactive "P")
|
||
(view-scroll-lines lines nil
|
||
(setq view-page-size (view-page-size-default lines))
|
||
nil))
|
||
|
||
(defun View-scroll-page-backward-set-page-size (&optional lines)
|
||
"Scroll backward prefix LINES lines in View mode, setting the \"page size\".
|
||
See also `View-scroll-page-forward-set-page-size'."
|
||
(interactive "P")
|
||
(view-scroll-lines lines t
|
||
(setq view-page-size (view-page-size-default lines))
|
||
nil))
|
||
|
||
(defun View-scroll-line-forward (&optional lines)
|
||
"Scroll forward one line (or prefix LINES lines) in View mode.
|
||
See also `View-scroll-page-forward', but note that scrolling is limited
|
||
to minimum of LINES and one window-full."
|
||
(interactive "P")
|
||
(view-scroll-lines lines nil 1 t))
|
||
|
||
(defun View-scroll-line-backward (&optional lines)
|
||
"Scroll backward one line (or prefix LINES lines) in View mode.
|
||
See also `View-scroll-line-forward'."
|
||
(interactive "P")
|
||
(view-scroll-lines lines t 1 t))
|
||
|
||
(defun View-scroll-half-page-forward (&optional lines)
|
||
"Scroll forward a \"half page\" (or prefix LINES) lines in View mode.
|
||
If LINES is not omitted, the \"half page size\" is set to the minimum of
|
||
window height and the absolute value of LINES.
|
||
LINES=0 resets \"half page size\" to half window height."
|
||
(interactive "P")
|
||
(view-scroll-lines lines nil (view-set-half-page-size-default lines) t))
|
||
|
||
(defun View-scroll-half-page-backward (&optional lines)
|
||
"Scroll backward a \"half page\" (or prefix LINES) lines in View mode.
|
||
See also `View-scroll-half-page-forward'."
|
||
(interactive "P")
|
||
(view-scroll-lines lines t (view-set-half-page-size-default lines) t))
|
||
|
||
(defun View-revert-buffer-scroll-page-forward (&optional lines)
|
||
"Scroll forward, reverting buffer if needed, in View mode.
|
||
If buffer has not been changed and the corresponding file is newer, first
|
||
revert the buffer, then scroll.
|
||
This command is useful if you are viewing a changing file.
|
||
|
||
The prefix argument LINES says how many lines to scroll.
|
||
If you don't specify a prefix argument, it uses the number of lines set by
|
||
\\[View-scroll-page-forward-set-page-size] or
|
||
\\[View-scroll-page-backward-set-page-size].
|
||
If LINES is more than a window-full, only the last window-full is shown."
|
||
(interactive "P")
|
||
(let ((view-scroll-auto-exit nil)
|
||
(view-try-extend-at-buffer-end t))
|
||
(view-scroll-lines lines nil (view-page-size-default view-page-size) nil)))
|
||
|
||
(defun View-search-regexp-forward (n regexp)
|
||
"Search forward for first (or prefix Nth) occurrence of REGEXP in View mode.
|
||
|
||
Displays line found at center of window. Sets mark at starting position and
|
||
pushes mark ring.
|
||
|
||
Characters @ and ! are special at the beginning of REGEXP. They modify
|
||
the search rather than become part of the pattern searched for.
|
||
@ means search all the buffer i.e. start search at the beginning of buffer.
|
||
! means search for a line that contains no match for the pattern.
|
||
If REGEXP is empty or only consist of these control characters, then
|
||
an earlier remembered REGEXP is used, otherwise REGEXP is remembered
|
||
for use by later search commands.
|
||
|
||
The variable `view-highlight-face' controls the face that is used
|
||
for highlighting the match that is found."
|
||
(interactive "p\nsSearch forward (regexp): ")
|
||
(view-search n regexp))
|
||
|
||
(defun View-search-regexp-backward (n regexp)
|
||
"Search backward for first (or prefix Nth) occurrence of REGEXP in View mode.
|
||
|
||
Displays line found at center of window. Sets mark at starting position and
|
||
pushes mark ring.
|
||
|
||
Characters @ and ! are special at the beginning of REGEXP. They modify
|
||
the search rather than become part of the pattern searched for.
|
||
@ means search all the buffer i.e. start search at the end of buffer.
|
||
! means search for a line that contains no match for the pattern.
|
||
If REGEXP is empty or only consist of these control characters, then
|
||
an earlier remembered REGEXP is used, otherwise REGEXP is remembered
|
||
for use by later search commands.
|
||
|
||
The variable `view-highlight-face' controls the face that is used
|
||
for highlighting the match that is found."
|
||
(interactive "p\nsSearch backward (regexp): ")
|
||
(view-search (- n) regexp))
|
||
|
||
(defun View-search-last-regexp-forward (n) "\
|
||
Search forward for first (or prefix Nth) instance of last regexp in View mode.
|
||
Displays line found at center of window. Sets mark at starting position and
|
||
pushes mark ring.
|
||
|
||
The variable `view-highlight-face' controls the face that is used
|
||
for highlighting the match that is found."
|
||
(interactive "p")
|
||
(view-search n nil))
|
||
|
||
(defun View-search-last-regexp-backward (n) "\
|
||
Search backward for first (or prefix Nth) instance of last regexp in View mode.
|
||
Displays line found at center of window. Sets mark at starting position and
|
||
pushes mark ring.
|
||
|
||
The variable `view-highlight-face' controls the face that is used
|
||
for highlighting the match that is found."
|
||
(interactive "p")
|
||
(view-search (- n) nil))
|
||
|
||
(defun view-search (times regexp)
|
||
;; This function does the job for all the View-search- commands.
|
||
;; Search for the TIMESth match for REGEXP. If TIMES is negative
|
||
;; search backwards. If REGEXP is nil use `view-last-regexp'.
|
||
;; Characters "!" and "@" have a special meaning at the beginning of
|
||
;; REGEXP and are removed from REGEXP before the search "!" means
|
||
;; search for lines with no match for REGEXP. "@" means search in
|
||
;; the whole buffer, don't start searching from the present point.
|
||
(let (where no end ln)
|
||
(cond
|
||
((and regexp (> (length regexp) 0)
|
||
(or (not (memq (string-to-char regexp) '(?! ?@)))
|
||
(progn
|
||
(if (member (substring regexp 0 2) '("!@" "@!"))
|
||
(setq end t no t ln 2)
|
||
(setq no (not (setq end (eq ?@ (string-to-char regexp))))
|
||
ln 1))
|
||
(> (length (setq regexp (substring regexp ln))) 0))))
|
||
(setq view-last-regexp (if no (list regexp) regexp)))
|
||
((consp view-last-regexp)
|
||
(setq regexp (car view-last-regexp))
|
||
(unless (setq no (not no)) (setq view-last-regexp regexp)))
|
||
(view-last-regexp (setq regexp view-last-regexp)
|
||
(if no (setq view-last-regexp (list regexp))))
|
||
(t (error "No previous View-mode search")))
|
||
(save-excursion
|
||
(if end (goto-char (if (< times 0) (point-max) (point-min)))
|
||
(forward-line (if (< times 0) -1 1)))
|
||
(if (if no (view-search-no-match-lines times regexp)
|
||
(re-search-forward regexp nil t times))
|
||
(setq where (point))))
|
||
(if where
|
||
(progn
|
||
(push-mark)
|
||
(goto-char where)
|
||
(if view-overlay
|
||
(move-overlay view-overlay (match-beginning 0) (match-end 0))
|
||
(setq view-overlay
|
||
(make-overlay (match-beginning 0) (match-end 0))))
|
||
(overlay-put view-overlay 'face view-highlight-face)
|
||
(beginning-of-line)
|
||
(view-recenter))
|
||
(message "Can't find occurrence %d of %s%s"
|
||
times (if no "no " "") regexp)
|
||
(sit-for 4))))
|
||
|
||
;; This is the dumb approach, looking at each line. The original
|
||
;; version of this function looked like it might have been trying to
|
||
;; do something clever, but not succeeding:
|
||
;; https://lists.gnu.org/r/bug-gnu-emacs/2007-09/msg00073.html
|
||
(defun view-search-no-match-lines (times regexp)
|
||
"Search for the TIMESth occurrence of a line with no match for REGEXP.
|
||
If such a line is found, return non-nil and set the match data to that line.
|
||
If TIMES is negative, search backwards."
|
||
(let ((step (if (>= times 0) 1
|
||
(setq times (- times))
|
||
-1)))
|
||
;; Note that we do not check the current line.
|
||
(while (and (> times 0)
|
||
(zerop (forward-line step)))
|
||
;; (forward-line 1) returns 0 on moving within the last line.
|
||
(if (eobp)
|
||
(setq times -1)
|
||
(or (re-search-forward regexp (line-end-position) t)
|
||
(setq times (1- times))))))
|
||
(and (zerop times)
|
||
(looking-at ".*")))
|
||
|
||
(defvar-local view-old-Helper-return-blurb nil)
|
||
(make-obsolete 'view-old-Helper-return-blurb nil "29.1")
|
||
|
||
(provide 'view)
|
||
|
||
;;; view.el ends here
|