;;; view.el --- peruse file or buffer without editing
;; Copyright (C) 1985, 1989, 1994, 1995, 1997, 2000, 2001, 2002,
-;; 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+;; 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
;; Author: K. Shane Hartman
;; Maintainer: Inge Frick <inge@nada.kth.se>
;; This file is part of GNU Emacs.
-;; GNU Emacs is free software; you can redistribute it and/or modify
+;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 3, or (at your option)
-;; any later version.
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-;; Boston, MA 02110-1301, USA.
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
\f
;;; Commands that enter or exit view mode.
+;; This is used when view mode is exited, to make sure we don't try to
+;; kill a buffer modified by the user. A buffer in view mode can
+;; become modified if the user types C-x C-q, edits the buffer, then
+;; types C-x C-q again to return to view mode.
+;;;###autoload
+(defun kill-buffer-if-not-modified (buf)
+ "Like `kill-buffer', but does nothing if the buffer is modified."
+ (let ((buf (get-buffer buf)))
+ (and buf (not (buffer-modified-p buf))
+ (kill-buffer buf))))
+
;;;###autoload
(defun view-file (file)
"View FILE in View mode, returning to previous buffer when done.
(progn
(switch-to-buffer buffer)
(message "Not using View mode because the major mode is special"))
- (view-buffer buffer (and (not had-a-buf) 'kill-buffer)))))
+ (view-buffer buffer (and (not had-a-buf) 'kill-buffer-if-not-modified)))))
;;;###autoload
(defun view-file-other-window (file)
"View FILE in View mode in another window.
-Return that window to its previous buffer when done. Emacs commands
-editing the buffer contents are not available; instead, a special set of
-commands (mostly letters and punctuation) are defined for moving around
-in the buffer.
+When done, return that window to its previous buffer, and kill the
+buffer visiting FILE if unmodified and if it wasn't visited before.
+
+Emacs commands editing the buffer contents are not available; instead,
+a special set of commands (mostly letters and punctuation)
+are defined for moving around in the buffer.
Space scrolls forward, Delete scrolls backward.
For a list of all View commands, type H or h while viewing.
This command runs the normal hook `view-mode-hook'."
(interactive "fIn other window view file: ")
(unless (file-exists-p file) (error "%s does not exist" file))
- (let ((had-a-buf (get-file-buffer file)))
- (view-buffer-other-window (find-file-noselect file) nil
- (and (not had-a-buf) 'kill-buffer))))
+ (let ((had-a-buf (get-file-buffer file))
+ (buf-to-view (find-file-noselect file)))
+ (view-buffer-other-window buf-to-view nil
+ (and (not had-a-buf)
+ 'kill-buffer-if-not-modified))))
;;;###autoload
(defun view-file-other-frame (file)
"View FILE in View mode in another frame.
-Maybe delete other frame and/or return to previous buffer when done.
-Emacs commands editing the buffer contents are not available; instead, a
-special set of commands (mostly letters and punctuation) are defined for
-moving around in the buffer.
+When done, kill the buffer visiting FILE if unmodified and if it wasn't
+visited before; also, maybe delete other frame and/or return to previous
+buffer.
+
+Emacs commands editing the buffer contents are not available; instead,
+a special set of commands (mostly letters and punctuation)
+are defined for moving around in the buffer.
Space scrolls forward, Delete scrolls backward.
For a list of all View commands, type H or h while viewing.
This command runs the normal hook `view-mode-hook'."
(interactive "fIn other frame view file: ")
(unless (file-exists-p file) (error "%s does not exist" file))
- (let ((had-a-buf (get-file-buffer file)))
- (view-buffer-other-frame (find-file-noselect file) nil
- (and (not had-a-buf) 'kill-buffer))))
+ (let ((had-a-buf (get-file-buffer file))
+ (buf-to-view (find-file-noselect file)))
+ (view-buffer-other-frame buf-to-view nil
+ (and (not had-a-buf)
+ 'kill-buffer-if-not-modified))))
;;;###autoload
Optional argument EXIT-ACTION is either nil or a function with buffer as
argument. This function is called when finished viewing buffer. Use
-this argument instead of explicitly setting `view-exit-action'."
+this argument instead of explicitly setting `view-exit-action'.
+
+Do not set EXIT-ACTION to `kill-buffer' when BUFFER visits a
+file: Users may suspend viewing in order to modify the buffer.
+Exiting View mode will then discard the user's edits. Setting
+EXIT-ACTION to `kill-buffer-if-not-modified' avoids this."
(interactive "bView buffer: ")
(let ((undo-window (list (window-buffer) (window-start) (window-point))))
(switch-to-buffer buffer)
(provide 'view)
-;;; arch-tag: 6d0ace36-1d12-4de3-8de3-1fa3231636d7
+;; arch-tag: 6d0ace36-1d12-4de3-8de3-1fa3231636d7
;;; view.el ends here
HCoop / bpt / emacs.git / blobdiff