;;; delsel.el --- delete selection if you insert
;; Copyright (C) 1992, 1997, 1998, 2001, 2002, 2003, 2004,
-;; 2005, 2006, 2007 Free Software Foundation, Inc.
+;; 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
;; Author: Matthieu Devin <devin@lucid.com>
;; Maintainer: FSF
;;;###autoload
(define-minor-mode delete-selection-mode
"Toggle Delete Selection mode.
-With prefix ARG, turn Delete Selection mode on if and only if ARG is
-positive.
+With prefix ARG, turn Delete Selection mode on if ARG is
+positive, off if ARG is not positive.
When Delete Selection mode is enabled, Transient Mark mode is also
enabled and typed text replaces the selection if the selection is
;; stop safe_run_hooks from clearing out pre-command-hook.
(and (eq inhibit-quit 'pre-command-hook)
(setq inhibit-quit 'delete-selection-dummy))
- (signal 'file-supersession (cdr data)))))))
+ (signal 'file-supersession (cdr data)))
+ (text-read-only
+ ;; This signal may come either from `delete-active-region' or
+ ;; `self-insert-command' (when `overwrite-mode' is non-nil).
+ ;; To avoid clearing out `pre-command-hook' we handle this case
+ ;; by issuing a simple message. Note, however, that we do not
+ ;; handle all related problems: When read-only text ends before
+ ;; the end of the region, the latter is not deleted but any
+ ;; subsequent insertion will succeed. We could avoid this case
+ ;; by doing a (setq this-command 'ignore) here. This would,
+ ;; however, still not handle the case where read-only text ends
+ ;; precisely where the region starts: In that case the deletion
+ ;; would succeed but the subsequent insertion would fail with a
+ ;; text-read-only error. To handle that case we would have to
+ ;; investigate text properties at both ends of the region and
+ ;; skip the deletion when inserting text is forbidden there.
+ (message "Text is read-only") (ding))))))
(put 'self-insert-command 'delete-selection t)
(put 'self-insert-iso 'delete-selection t)
(dolist (sym '(self-insert-command self-insert-iso yank clipboard-yank
insert-register delete-backward-char backward-delete-char-untabify
delete-char newline-and-indent newline open-line))
- (remprop sym 'delete-selection))
+ (put sym 'delete-selection nil))
;; continue standard unloading
nil)