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 (eval-when-compile
  36   (require 'cl))
  37
  38 ;;;###autoload
  39 (defalias 'pending-delete-mode 'delete-selection-mode)
  40
  41 ;;;###autoload
  42 (defun delete-selection-mode (&optional arg)
  43   "Toggle Delete Selection mode.
  44 With prefix ARG, turn Delete Selection mode on if and only if ARG is positive.
  45
  46 When Delete Selection mode is enabled, Transient Mark mode is also enabled and
  47 typed text replaces the selection if the selection is active.  Otherwise, typed
  48 text is just inserted at point regardless of any selection."
  49   (interactive "P")
  50   (setq delete-selection-mode (if arg
  51                                   (> (prefix-numeric-value arg) 0)
  52                                 (not delete-selection-mode)))
  53   (if (not delete-selection-mode)
  54       (remove-hook 'pre-command-hook 'delete-selection-pre-hook)
  55     (add-hook 'pre-command-hook 'delete-selection-pre-hook)
  56     (transient-mark-mode t)))
  57
  58 ;;;###autoload
  59 (defcustom delete-selection-mode nil
  60   "Toggle Delete Selection mode.
  61 When Delete Selection mode is enabled, Transient Mark mode is also enabled and
  62 typed text replaces the selection if the selection is active.
  63 You must modify via \\[customize] for this variable to have an effect."
  64   :set (lambda (symbol value)
  65          (delete-selection-mode (or value 0)))
  66   :initialize 'custom-initialize-default
  67   :type 'boolean
  68   :group 'editing-basics
  69   :require 'delsel)
  70 ;; Force loading of this file in order to customize delete-selection-mode.
  71 (put 'delete-selection-mode 'custom-loads '(delsel))
  72
  73 ;; This is the standard way mechanism to put the mode into effect
  74 ;; if delete-selection-mode has already been set to t
  75 ;; when this file is loaded.
  76 (when delete-selection-mode
  77   (delete-selection-mode t))
  78
  79 (defun delete-active-region (&optional killp)
  80   (if killp
  81       (kill-region (point) (mark))
  82     (delete-region (point) (mark)))
  83   (setq mark-active nil)
  84   (run-hooks 'deactivate-mark-hook)
  85   t)
  86
  87 (defun delete-selection-pre-hook ()
  88   (when (and delete-selection-mode transient-mark-mode mark-active
  89              (not buffer-read-only))
  90     (let ((type (and (symbolp this-command)
  91                      (get this-command 'delete-selection))))
  92       (cond ((eq type 'kill)
  93              (delete-active-region t))
  94             ((eq type 'yank)
  95              ;; Before a yank command,
  96              ;; make sure we don't yank the same region
  97              ;; that we are going to delete.
  98              ;; That would make yank a no-op.
  99              (when (string= (buffer-substring-no-properties (point) (mark))
 100                             (car kill-ring))
 101                (current-kill 1))
 102              (delete-active-region nil))
 103             ((eq type 'supersede)
 104              (when (delete-active-region nil)
 105                (setq this-command '(lambda () (interactive)))))
 106             (type
 107              (delete-active-region nil))))))
 108
 109 (put 'self-insert-command 'delete-selection t)
 110 (put 'self-insert-iso 'delete-selection t)
 111
 112 (put 'yank 'delete-selection 'yank)
 113 (put 'clipboard-yank 'delete-selection 'yank)
 114 (put 'insert-register 'delete-selection t)
 115
 116 (put 'delete-backward-char 'delete-selection 'supersede)
 117 (put 'backward-delete-char-untabify 'delete-selection 'supersede)
 118 (put 'delete-char 'delete-selection 'supersede)
 119
 120 (put 'newline-and-indent 'delete-selection 't)
 121 (put 'newline 'delete-selection t)
 122 (put 'open-line 'delete-selection t)
 123
 124 ;; This is very useful for cancelling a selection in the minibuffer without
 125 ;; aborting the minibuffer.
 126 (defun minibuffer-keyboard-quit ()
 127   "Abort recursive edit.
 128 In Delete Selection mode mode, if the mark is active, just deactivate it;
 129 then it takes a second C-g to abort the minibuffer."
 130   (interactive)
 131   (if (and delete-selection-mode transient-mark-mode mark-active)
 132       (setq deactivate-mark t)
 133     (abort-recursive-edit)))
 134
 135 (define-key minibuffer-local-map "\C-g" 'minibuffer-keyboard-quit)
 136 (define-key minibuffer-local-ns-map "\C-g" 'minibuffer-keyboard-quit)
 137 (define-key minibuffer-local-completion-map "\C-g" 'minibuffer-keyboard-quit)
 138 (define-key minibuffer-local-must-match-map "\C-g" 'minibuffer-keyboard-quit)
 139 (define-key minibuffer-local-isearch-map "\C-g" 'minibuffer-keyboard-quit)
 140
 141 (provide 'delsel)
 142
 143 ;;; delsel.el ends here