| 1 | ;;; delsel.el --- delete selection if you insert |
| 2 | |
| 3 | ;; Copyright (C) 1992, 1997-1998, 2001-2014 Free Software Foundation, |
| 4 | ;; Inc. |
| 5 | |
| 6 | ;; Author: Matthieu Devin <devin@lucid.com> |
| 7 | ;; Maintainer: emacs-devel@gnu.org |
| 8 | ;; Created: 14 Jul 92 |
| 9 | ;; Keywords: convenience emulations |
| 10 | |
| 11 | ;; This file is part of GNU Emacs. |
| 12 | |
| 13 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
| 14 | ;; it under the terms of the GNU General Public License as published by |
| 15 | ;; the Free Software Foundation, either version 3 of the License, or |
| 16 | ;; (at your option) any later version. |
| 17 | |
| 18 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 | ;; GNU General Public License for more details. |
| 22 | |
| 23 | ;; You should have received a copy of the GNU General Public License |
| 24 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
| 25 | |
| 26 | ;;; Commentary: |
| 27 | |
| 28 | ;; This file makes the active region be pending delete, meaning that |
| 29 | ;; text inserted while the region is active will replace the region contents. |
| 30 | ;; This is a popular behavior of personal computers text editors. |
| 31 | |
| 32 | ;; Interface: |
| 33 | |
| 34 | ;; Commands which will delete the selection need a 'delete-selection |
| 35 | ;; property on their symbols; commands which insert text but don't |
| 36 | ;; have this property won't delete the selection. It can be one of |
| 37 | ;; the values: |
| 38 | ;; 'yank |
| 39 | ;; For commands which do a yank; ensures the region about to be |
| 40 | ;; deleted isn't yanked. |
| 41 | ;; 'supersede |
| 42 | ;; Delete the active region and ignore the current command, |
| 43 | ;; i.e. the command will just delete the region. |
| 44 | ;; 'kill |
| 45 | ;; `kill-region' is used on the selection, rather than |
| 46 | ;; `delete-region'. (Text selected with the mouse will typically |
| 47 | ;; be yankable anyhow.) |
| 48 | ;; t |
| 49 | ;; The normal case: delete the active region prior to executing |
| 50 | ;; the command which will insert replacement text. |
| 51 | ;; <function> |
| 52 | ;; For commands which need to dynamically determine this behavior. |
| 53 | ;; The function should return one of the above values or nil. |
| 54 | |
| 55 | ;;; Code: |
| 56 | |
| 57 | ;;;###autoload |
| 58 | (defalias 'pending-delete-mode 'delete-selection-mode) |
| 59 | |
| 60 | ;;;###autoload |
| 61 | (define-minor-mode delete-selection-mode |
| 62 | "Toggle Delete Selection mode. |
| 63 | With a prefix argument ARG, enable Delete Selection mode if ARG |
| 64 | is positive, and disable it otherwise. If called from Lisp, |
| 65 | enable the mode if ARG is omitted or nil. |
| 66 | |
| 67 | When Delete Selection mode is enabled, typed text replaces the selection |
| 68 | if the selection is active. Otherwise, typed text is just inserted at |
| 69 | point regardless of any selection." |
| 70 | :global t :group 'editing-basics |
| 71 | (if (not delete-selection-mode) |
| 72 | (remove-hook 'pre-command-hook 'delete-selection-pre-hook) |
| 73 | (add-hook 'pre-command-hook 'delete-selection-pre-hook))) |
| 74 | |
| 75 | (defun delete-active-region (&optional killp) |
| 76 | "Delete the active region. |
| 77 | If KILLP in not-nil, the active region is killed instead of deleted." |
| 78 | (if killp |
| 79 | ;; Don't allow `kill-region' to change the value of `this-command'. |
| 80 | (let (this-command) |
| 81 | (kill-region (point) (mark) t)) |
| 82 | (funcall region-extract-function 'delete-only)) |
| 83 | t) |
| 84 | |
| 85 | (defun delete-selection-helper (type) |
| 86 | "Delete selection according to TYPE: |
| 87 | `yank' |
| 88 | For commands which do a yank; ensures the region about to be |
| 89 | deleted isn't yanked. |
| 90 | `supersede' |
| 91 | Delete the active region and ignore the current command, |
| 92 | i.e. the command will just delete the region. |
| 93 | `kill' |
| 94 | `kill-region' is used on the selection, rather than |
| 95 | `delete-region'. (Text selected with the mouse will typically |
| 96 | be yankable anyhow.) |
| 97 | t |
| 98 | The normal case: delete the active region prior to executing |
| 99 | the command which will insert replacement text. |
| 100 | FUNCTION |
| 101 | For commands which need to dynamically determine this behavior. |
| 102 | FUNCTION should take no argument and return one of the above values or nil." |
| 103 | (condition-case data |
| 104 | (cond ((eq type 'kill) |
| 105 | (delete-active-region t) |
| 106 | (if (and overwrite-mode |
| 107 | (eq this-command 'self-insert-command)) |
| 108 | (let ((overwrite-mode nil)) |
| 109 | (self-insert-command |
| 110 | (prefix-numeric-value current-prefix-arg)) |
| 111 | (setq this-command 'ignore)))) |
| 112 | ((eq type 'yank) |
| 113 | ;; Before a yank command, make sure we don't yank the |
| 114 | ;; head of the kill-ring that really comes from the |
| 115 | ;; currently active region we are going to delete. |
| 116 | ;; That would make yank a no-op. |
| 117 | (when (and (string= (buffer-substring-no-properties |
| 118 | (point) (mark)) |
| 119 | (car kill-ring)) |
| 120 | (fboundp 'mouse-region-match) |
| 121 | (mouse-region-match)) |
| 122 | (current-kill 1)) |
| 123 | (let ((pos (copy-marker (region-beginning)))) |
| 124 | (delete-active-region) |
| 125 | ;; If the region was, say, rectangular, make sure we yank |
| 126 | ;; from the top, to "replace". |
| 127 | (goto-char pos))) |
| 128 | ((eq type 'supersede) |
| 129 | (let ((empty-region (= (point) (mark)))) |
| 130 | (delete-active-region) |
| 131 | (unless empty-region |
| 132 | (setq this-command 'ignore)))) |
| 133 | ((functionp type) (delete-selection-helper (funcall type))) |
| 134 | (type |
| 135 | (delete-active-region) |
| 136 | (if (and overwrite-mode |
| 137 | (eq this-command 'self-insert-command)) |
| 138 | (let ((overwrite-mode nil)) |
| 139 | (self-insert-command |
| 140 | (prefix-numeric-value current-prefix-arg)) |
| 141 | (setq this-command 'ignore))))) |
| 142 | ;; If ask-user-about-supersession-threat signals an error, |
| 143 | ;; stop safe_run_hooks from clearing out pre-command-hook. |
| 144 | (file-supersession (message "%s" (cadr data)) (ding)) |
| 145 | (text-read-only |
| 146 | ;; This signal may come either from `delete-active-region' or |
| 147 | ;; `self-insert-command' (when `overwrite-mode' is non-nil). |
| 148 | ;; To avoid clearing out `pre-command-hook' we handle this case |
| 149 | ;; by issuing a simple message. Note, however, that we do not |
| 150 | ;; handle all related problems: When read-only text ends before |
| 151 | ;; the end of the region, the latter is not deleted but any |
| 152 | ;; subsequent insertion will succeed. We could avoid this case |
| 153 | ;; by doing a (setq this-command 'ignore) here. This would, |
| 154 | ;; however, still not handle the case where read-only text ends |
| 155 | ;; precisely where the region starts: In that case the deletion |
| 156 | ;; would succeed but the subsequent insertion would fail with a |
| 157 | ;; text-read-only error. To handle that case we would have to |
| 158 | ;; investigate text properties at both ends of the region and |
| 159 | ;; skip the deletion when inserting text is forbidden there. |
| 160 | (message "Text is read-only") (ding)))) |
| 161 | |
| 162 | (defun delete-selection-pre-hook () |
| 163 | "Function run before commands that delete selections are executed. |
| 164 | Commands which will delete the selection need a `delete-selection' |
| 165 | property on their symbol; commands which insert text but don't |
| 166 | have this property won't delete the selection. |
| 167 | See `delete-selection-helper'." |
| 168 | (when (and delete-selection-mode (use-region-p) |
| 169 | (not buffer-read-only)) |
| 170 | (delete-selection-helper (and (symbolp this-command) |
| 171 | (get this-command 'delete-selection))))) |
| 172 | |
| 173 | (put 'self-insert-command 'delete-selection |
| 174 | (lambda () |
| 175 | (not (run-hook-with-args-until-success |
| 176 | 'self-insert-uses-region-functions)))) |
| 177 | |
| 178 | (put 'insert-char 'delete-selection t) |
| 179 | (put 'quoted-insert 'delete-selection t) |
| 180 | |
| 181 | (put 'yank 'delete-selection 'yank) |
| 182 | (put 'clipboard-yank 'delete-selection 'yank) |
| 183 | (put 'insert-register 'delete-selection t) |
| 184 | ;; delete-backward-char and delete-forward-char already delete the selection by |
| 185 | ;; default, but not delete-char. |
| 186 | (put 'delete-char 'delete-selection 'supersede) |
| 187 | |
| 188 | (put 'reindent-then-newline-and-indent 'delete-selection t) |
| 189 | (put 'newline-and-indent 'delete-selection t) |
| 190 | (put 'newline 'delete-selection t) |
| 191 | (put 'electric-newline-and-maybe-indent 'delete-selection t) |
| 192 | (put 'open-line 'delete-selection 'kill) |
| 193 | |
| 194 | ;; This is very useful for canceling a selection in the minibuffer without |
| 195 | ;; aborting the minibuffer. |
| 196 | (defun minibuffer-keyboard-quit () |
| 197 | "Abort recursive edit. |
| 198 | In Delete Selection mode, if the mark is active, just deactivate it; |
| 199 | then it takes a second \\[keyboard-quit] to abort the minibuffer." |
| 200 | (interactive) |
| 201 | (if (and delete-selection-mode (region-active-p)) |
| 202 | (setq deactivate-mark t) |
| 203 | (abort-recursive-edit))) |
| 204 | |
| 205 | (define-key minibuffer-local-map "\C-g" 'minibuffer-keyboard-quit) |
| 206 | (define-key minibuffer-local-ns-map "\C-g" 'minibuffer-keyboard-quit) |
| 207 | (define-key minibuffer-local-completion-map "\C-g" 'minibuffer-keyboard-quit) |
| 208 | (define-key minibuffer-local-must-match-map "\C-g" 'minibuffer-keyboard-quit) |
| 209 | (define-key minibuffer-local-isearch-map "\C-g" 'minibuffer-keyboard-quit) |
| 210 | |
| 211 | (defun delsel-unload-function () |
| 212 | "Unload the Delete Selection library." |
| 213 | (define-key minibuffer-local-map "\C-g" 'abort-recursive-edit) |
| 214 | (define-key minibuffer-local-ns-map "\C-g" 'abort-recursive-edit) |
| 215 | (define-key minibuffer-local-completion-map "\C-g" 'abort-recursive-edit) |
| 216 | (define-key minibuffer-local-must-match-map "\C-g" 'abort-recursive-edit) |
| 217 | (define-key minibuffer-local-isearch-map "\C-g" 'abort-recursive-edit) |
| 218 | (dolist (sym '(self-insert-command insert-char quoted-insert yank |
| 219 | clipboard-yank insert-register newline-and-indent |
| 220 | reindent-then-newline-and-indent newline open-line)) |
| 221 | (put sym 'delete-selection nil)) |
| 222 | ;; continue standard unloading |
| 223 | nil) |
| 224 | |
| 225 | (provide 'delsel) |
| 226 | |
| 227 | ;;; delsel.el ends here |