lisp/delsel.el

   1 ;;; delsel.el --- delete selection if you insert
   2
   3 ;; Copyright (C) 1992 Free Software Foundation, Inc.
   4
   5 ;; Author: Matthieu Devin <devin@lucid.com>
   6 ;; Maintainer: FSF
   7 ;; Created: 14 Jul 92
   8 ;; Last change  18-Feb-93, devin.
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; This file makes the active region be pending delete, meaning that
  30 ;; text inserted while the region is active will replace the region contents.
  31 ;; This is a popular behavior of personal computers text editors.
  32
  33 ;;; Code:
  34
  35 (defvar delete-selection-mode t
  36   "*Non-nil means Delete Selection mode is enabled.
  37 In Delete Selection mode, when a region is highlighted,
  38 insertion commands first delete the region and then insert.")
  39
  40 (defun delete-active-region (&optional killp)
  41   (if killp
  42       (kill-region (point) (mark))
  43     (delete-region (point) (mark)))
  44   (setq mark-active nil)
  45   (run-hooks 'deactivate-mark-hook)
  46   t)
  47
  48 (defun delete-selection-pre-hook ()
  49   (if (and delete-selection-mode
  50            (not buffer-read-only)
  51            transient-mark-mode mark-active)
  52       (let ((type (and (symbolp this-command)
  53                        (get this-command 'delete-selection))))
  54         (cond ((eq type 'kill)
  55                (delete-active-region t))
  56               ((eq type 'yank)
  57                ;; Before a yank command,
  58                ;; make sure we don't yank the same region
  59                ;; that we are going to delete.
  60                ;; That would make yank a no-op.
  61                (if (string= (buffer-substring (point) (mark))
  62                             (car kill-ring))
  63                    (current-kill 1))
  64                (delete-active-region nil))
  65               ((eq type 'supersede)
  66                (if (delete-active-region nil)
  67                    (setq this-command '(lambda () (interactive)))))
  68               (type
  69                (delete-active-region nil))))))
  70
  71 (add-hook 'pre-command-hook 'delete-selection-pre-hook)
  72
  73 (put 'self-insert-command 'delete-selection t)
  74 (put 'self-insert-iso 'delete-selection t)
  75
  76 (put 'yank 'delete-selection 'yank)
  77 (put 'clipboard-yank 'delete-selection 'yank)
  78 (put 'insert-register 'delete-selection t)
  79
  80 (put 'delete-backward-char 'delete-selection 'supersede)
  81 (put 'backward-delete-char-untabify 'delete-selection 'supersede)
  82 (put 'delete-char 'delete-selection 'supersede)
  83
  84 (put 'newline-and-indent 'delete-selection 't)
  85 (put 'newline 'delete-selection t)
  86 (put 'open-line 'delete-selection t)
  87
  88 ;;;###autoload
  89 (defalias 'pending-delete-mode 'delete-selection-mode)
  90 ;;;###autoload
  91 (defun delete-selection-mode (arg)
  92   "Toggle Delete Selection mode.
  93 When ON, typed text replaces the selection if the selection is active.
  94 When OFF, typed text is just inserted at point.
  95
  96 Delete Selection mode works only when Transient Mark mode is enabled.
  97 Use \\[transient-mark-mode] to enable or disable Transient Mark mode.
  98
  99 A positive argument turns the mode on, negative argument turns it off,
 100 and no argument (or nil) toggles the mode."
 101   (interactive "P")
 102   (setq delete-selection-mode
 103         (if (null arg) (not delete-selection-mode)
 104           (> (prefix-numeric-value arg) 0)))
 105   (force-mode-line-update))
 106
 107 ;; This is very useful for cancelling a selection in the minibuffer without
 108 ;; aborting the minibuffer.
 109 (defun minibuffer-keyboard-quit ()
 110   "Abort recursive edit.
 111 In Delete Selection mode mode, if the mark is active, just deactivate it;
 112 then it takes a second C-g to abort the minibuffer."
 113   (interactive)
 114   (if (and delete-selection-mode transient-mark-mode mark-active)
 115       (setq deactivate-mark t)
 116     (abort-recursive-edit)))
 117
 118 (define-key minibuffer-local-map "\C-g" 'minibuffer-keyboard-quit)
 119 (define-key minibuffer-local-ns-map "\C-g" 'minibuffer-keyboard-quit)
 120 (define-key minibuffer-local-completion-map "\C-g" 'minibuffer-keyboard-quit)
 121 (define-key minibuffer-local-must-match-map "\C-g" 'minibuffer-keyboard-quit)
 122 (define-key minibuffer-local-isearch-map "\C-g" 'minibuffer-keyboard-quit)
 123
 124 (provide 'delsel)
 125
 126 ;;; delsel.el ends here