-;;; delsel.el --- delete selection if you insert
+;;; delsel.el --- delete selection if you insert -*- lexical-binding:t -*-
-;; Copyright (C) 1992, 1997-1998, 2001-2012 Free Software Foundation, Inc.
+;; Copyright (C) 1992, 1997-1998, 2001-2016 Free Software Foundation,
+;; Inc.
;; Author: Matthieu Devin <devin@lucid.com>
-;; Maintainer: FSF
+;; Maintainer: emacs-devel@gnu.org
;; Created: 14 Jul 92
;; Keywords: convenience emulations
;; property on their symbols; commands which insert text but don't
;; have this property won't delete the selection. It can be one of
;; the values:
-;; 'yank
+;; `yank'
;; For commands which do a yank; ensures the region about to be
-;; deleted isn't yanked.
-;; 'supersede
+;; deleted isn't immediately yanked back, which would make the
+;; command a no-op.
+;; `supersede'
;; Delete the active region and ignore the current command,
-;; i.e. the command will just delete the region.
-;; 'kill
+;; i.e. the command will just delete the region. This is for
+;; commands that normally delete small amounts of text, like
+;; a single character -- they will instead delete the whole
+;; active region.
+;; `kill'
;; `kill-region' is used on the selection, rather than
;; `delete-region'. (Text selected with the mouse will typically
;; be yankable anyhow.)
-;; non-nil
+;; t
;; The normal case: delete the active region prior to executing
;; the command which will insert replacement text.
+;; FUNCTION
+;; For commands which need to dynamically determine this behavior.
+;; FUNCTION should take no argument and return one of the above
+;; values, or nil. In the latter case, FUNCTION should itself
+;; do with the active region whatever is appropriate."
;;; Code:
+(defvar delete-selection-save-to-register nil
+ "If non-nil, deleted region text is stored in this register.
+Value must be the register (key) to use.")
+
;;;###autoload
(defalias 'pending-delete-mode 'delete-selection-mode)
is positive, and disable it otherwise. If called from Lisp,
enable the mode if ARG is omitted or nil.
-When Delete Selection mode is enabled, Transient Mark mode is also
-enabled and typed text replaces the selection if the selection is
-active. Otherwise, typed text is just inserted at point regardless of
-any selection."
+When Delete Selection mode is enabled, typed text replaces the selection
+if the selection is active. Otherwise, typed text is just inserted at
+point regardless of any selection. Also, commands that normally delete
+just one character will delete the entire selection instead.
+
+See `delete-selection-helper' and `delete-selection-pre-hook' for
+information on adapting behavior of commands in Delete Selection mode."
:global t :group 'editing-basics
(if (not delete-selection-mode)
(remove-hook 'pre-command-hook 'delete-selection-pre-hook)
- (add-hook 'pre-command-hook 'delete-selection-pre-hook)
- (transient-mark-mode t)))
+ (add-hook 'pre-command-hook 'delete-selection-pre-hook)))
+
+(defvar delsel--replace-text-or-position nil)
(defun delete-active-region (&optional killp)
- (if killp
- (kill-region (point) (mark))
- (delete-region (point) (mark)))
- t)
+ "Delete the active region.
+If KILLP in not-nil, the active region is killed instead of deleted."
+ (cond
+ (killp
+ ;; Don't allow `kill-region' to change the value of `this-command'.
+ (let (this-command)
+ (kill-region (point) (mark) t)))
+ (delete-selection-save-to-register
+ (set-register delete-selection-save-to-register
+ (funcall region-extract-function t))
+ (setq delsel--replace-text-or-position
+ (cons (current-buffer)
+ (and (consp buffer-undo-list) (car buffer-undo-list)))))
+ (t
+ (funcall region-extract-function 'delete-only))))
+
+(defun delete-selection-repeat-replace-region (arg)
+ "Repeat replacing text of highlighted region with typed text.
+Search for the next stretch of text identical to the region last replaced
+by typing text over it and replaces it with the same stretch of text.
+With ARG, repeat that many times. `C-u' means until end of buffer."
+ (interactive "P")
+ (let ((old-text (and delete-selection-save-to-register
+ (get-register delete-selection-save-to-register)))
+ (count (if (consp arg) (point-max)
+ (prefix-numeric-value current-prefix-arg))))
+ (if (not (and old-text
+ (> (length old-text) 0)
+ (or (stringp delsel--replace-text-or-position)
+ (buffer-live-p (car delsel--replace-text-or-position)))))
+ (message "No known previous replacement")
+ ;; If this is the first use after overwriting regions,
+ ;; find the replacement text by looking at the undo list.
+ (when (consp delsel--replace-text-or-position)
+ (let ((buffer (car delsel--replace-text-or-position))
+ (elt (cdr delsel--replace-text-or-position)))
+ (setq delsel--replace-text-or-position nil)
+ (with-current-buffer buffer
+ (save-restriction
+ (widen)
+ ;; Find the text that replaced the region via the undo list.
+ (let ((ul buffer-undo-list) u s e)
+ (when elt
+ (while (consp ul)
+ (setq u (car ul) ul (cdr ul))
+ (cond
+ ((eq u elt) ;; got it
+ (setq ul nil))
+ ((and (consp u) (integerp (car u)) (integerp (cdr u)))
+ (if (and s (= (cdr u) s))
+ (setq s (car u))
+ (setq s (car u) e (cdr u)))))))
+ (cond ((and s e (<= s e) (= s (mark t)))
+ (setq delsel--replace-text-or-position
+ (filter-buffer-substring s e))
+ (set-text-properties
+ 0 (length delsel--replace-text-or-position)
+ nil delsel--replace-text-or-position))
+ ((and (null s) (eq u elt)) ;; Nothing inserted.
+ (setq delsel--replace-text-or-position ""))
+ (t
+ (message "Cannot locate replacement text"))))))))
+ (while (and (> count 0)
+ delsel--replace-text-or-position
+ (search-forward old-text nil t))
+ (replace-match delsel--replace-text-or-position nil t)
+ (setq count (1- count))))))
+
+(defun delete-selection-helper (type)
+ "Delete selection according to TYPE:
+ `yank'
+ For commands which do a yank; ensures the region about to be
+ deleted isn't immediately yanked back, which would make the
+ command a no-op.
+ `supersede'
+ Delete the active region and ignore the current command,
+ i.e. the command will just delete the region. This is for
+ commands that normally delete small amounts of text, like
+ a single character -- they will instead delete the whole
+ active region.
+ `kill'
+ `kill-region' is used on the selection, rather than
+ `delete-region'. (Text selected with the mouse will
+ typically be yankable anyhow.)
+ FUNCTION
+ For commands which need to dynamically determine this
+ behavior. FUNCTION should take no argument and return a
+ value acceptable as TYPE, or nil. In the latter case,
+ FUNCTION should itself do with the active region whatever is
+ appropriate.
+ Other non-nil values
+ The normal case: delete the active region prior to executing
+ the command which will insert replacement text."
+ (condition-case data
+ (cond ((eq type 'kill) ;Deprecated, backward compatibility.
+ (delete-active-region t)
+ (if (and overwrite-mode
+ (eq this-command 'self-insert-command))
+ (let ((overwrite-mode nil))
+ (self-insert-command
+ (prefix-numeric-value current-prefix-arg))
+ (setq this-command 'ignore))))
+ ((eq type 'yank)
+ ;; Before a yank command, make sure we don't yank the
+ ;; head of the kill-ring that really comes from the
+ ;; currently active region we are going to delete.
+ ;; That would make yank a no-op.
+ (when (and (string= (buffer-substring-no-properties
+ (point) (mark))
+ (car kill-ring))
+ (fboundp 'mouse-region-match)
+ (mouse-region-match))
+ (current-kill 1))
+ (let ((pos (copy-marker (region-beginning))))
+ (delete-active-region)
+ ;; If the region was, say, rectangular, make sure we yank
+ ;; from the top, to "replace".
+ (goto-char pos)))
+ ((eq type 'supersede)
+ (let ((empty-region (= (point) (mark))))
+ (delete-active-region)
+ (unless empty-region
+ (setq this-command 'ignore))))
+ ((functionp type) (delete-selection-helper (funcall type)))
+ (type
+ (delete-active-region)
+ (if (and overwrite-mode
+ (eq this-command 'self-insert-command))
+ (let ((overwrite-mode nil))
+ (self-insert-command
+ (prefix-numeric-value current-prefix-arg))
+ (setq this-command 'ignore)))))
+ ;; If ask-user-about-supersession-threat signals an error,
+ ;; stop safe_run_hooks from clearing out pre-command-hook.
+ (file-supersession (message "%s" (cadr data)) (ding))
+ (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))))
(defun delete-selection-pre-hook ()
- (when (and delete-selection-mode transient-mark-mode mark-active
+ "Function run before commands that delete selections are executed.
+Commands which will delete the selection need a `delete-selection'
+property on their symbol; commands which insert text but don't
+have this property won't delete the selection.
+See `delete-selection-helper'."
+ (when (and delete-selection-mode (use-region-p)
(not buffer-read-only))
- (let ((type (and (symbolp this-command)
- (get this-command 'delete-selection))))
- (condition-case data
- (cond ((eq type 'kill)
- (delete-active-region t))
- ((eq type 'yank)
- ;; Before a yank command, make sure we don't yank the
- ;; head of the kill-ring that really comes from the
- ;; currently active region we are going to delete.
- ;; That would make yank a no-op.
- (when (and (string= (buffer-substring-no-properties
- (point) (mark))
- (car kill-ring))
- (fboundp 'mouse-region-match)
- (mouse-region-match))
- (current-kill 1))
- (delete-active-region))
- ((eq type 'supersede)
- (let ((empty-region (= (point) (mark))))
- (delete-active-region)
- (unless empty-region
- (setq this-command 'ignore))))
- (type
- (delete-active-region)
- (if (and overwrite-mode
- (eq this-command 'self-insert-command))
- (let ((overwrite-mode nil))
- (self-insert-command
- (prefix-numeric-value current-prefix-arg))
- (setq this-command 'ignore)))))
- ;; If ask-user-about-supersession-threat signals an error,
- ;; stop safe_run_hooks from clearing out pre-command-hook.
- (file-supersession (message "%s" (cadr data)) (ding))
- (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)
+ (delete-selection-helper (and (symbolp this-command)
+ (get this-command 'delete-selection)))))
+
+(defun delete-selection-uses-region-p ()
+ "Return t when the current command will be using the region
+rather than having `delete-selection' delete it, nil otherwise.
+
+This function is intended for use as the value of the
+`delete-selection' property of a command, and shouldn't be used
+for anything else."
+ (not (run-hook-with-args-until-success
+ 'self-insert-uses-region-functions)))
+
+(put 'self-insert-command 'delete-selection 'delete-selection-uses-region-p)
+
+(put 'insert-char 'delete-selection t)
+(put 'quoted-insert 'delete-selection t)
(put 'yank 'delete-selection 'yank)
(put 'clipboard-yank 'delete-selection 'yank)
(put 'insert-register 'delete-selection t)
-
-(put 'delete-backward-char 'delete-selection 'supersede)
-(put 'backward-delete-char-untabify 'delete-selection 'supersede)
+;; delete-backward-char and delete-forward-char already delete the selection by
+;; default, but not delete-char.
(put 'delete-char 'delete-selection 'supersede)
+(put 'reindent-then-newline-and-indent 'delete-selection t)
(put 'newline-and-indent 'delete-selection t)
(put 'newline 'delete-selection t)
-(put 'open-line 'delete-selection 'kill)
+(put 'electric-newline-and-maybe-indent 'delete-selection t)
+(put 'open-line 'delete-selection t)
;; This is very useful for canceling a selection in the minibuffer without
;; aborting the minibuffer.
In Delete Selection mode, if the mark is active, just deactivate it;
then it takes a second \\[keyboard-quit] to abort the minibuffer."
(interactive)
- (if (and delete-selection-mode transient-mark-mode mark-active)
+ (if (and delete-selection-mode (region-active-p))
(setq deactivate-mark t)
(abort-recursive-edit)))
(define-key minibuffer-local-completion-map "\C-g" 'abort-recursive-edit)
(define-key minibuffer-local-must-match-map "\C-g" 'abort-recursive-edit)
(define-key minibuffer-local-isearch-map "\C-g" 'abort-recursive-edit)
- (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))
+ (dolist (sym '(self-insert-command insert-char quoted-insert yank
+ clipboard-yank insert-register newline-and-indent
+ reindent-then-newline-and-indent newline open-line))
(put sym 'delete-selection nil))
;; continue standard unloading
nil)