lisp/delsel.el

   1 ;;; Pending delete selection
   2 ;;; Copyright (C) 1992 Free Software Foundation, Inc.
   3 ;;; Created: 14 Jul 92, Matthieu Devin <devin@lucid.com>
   4 ;;; Last change  18-Feb-93, devin.
   5
   6 ;;; This file is part of GNU Emacs.
   7
   8 ;;; GNU Emacs is free software; you can redistribute it and/or modify
   9 ;;; it under the terms of the GNU General Public License as published by
  10 ;;; the Free Software Foundation; either version 2, or (at your option)
  11 ;;; any later version.
  12
  13 ;;; GNU Emacs is distributed in the hope that it will be useful,
  14 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ;;; GNU General Public License for more details.
  17
  18 ;;; You should have received a copy of the GNU General Public License
  19 ;;; along with GNU Emacs; see the file COPYING.  If not, write to
  20 ;;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22
  23 ;;; This files makes the active region be pending delete, meaning that
  24 ;;; text inserted while the region is active will replace the region contents.
  25 ;;; This is a popular behavior of personal computers text editors.
  26
  27 (defvar pending-delete-mode t
  28   "*Non-nil means Pending Delete mode is enabled.
  29 In Pending Delete mode, when a region is highlighted,
  30 insertion commands first delete the region and then insert.")
  31
  32 (defun delete-active-region (&optional killp)
  33   (if killp
  34       (kill-region (point) (mark))
  35     (delete-region (point) (mark)))
  36   (setq mark-active nil)
  37   (run-hooks 'deactivate-mark-hook)
  38   t)
  39
  40 (defun pending-delete-pre-hook ()
  41   (if (and pending-delete-mode
  42            (not buffer-read-only)
  43            transient-mark-mode mark-active)
  44       (let ((type (and (symbolp this-command)
  45                        (get this-command 'pending-delete))))
  46         (cond ((eq type 'kill)
  47                (delete-active-region t))
  48               ((eq type 'supersede)
  49                (if (delete-active-region ())
  50                    (setq this-command '(lambda () (interactive)))))
  51               (type
  52                (delete-active-region ()))))))
  53
  54 (add-hook 'pre-command-hook 'pending-delete-pre-hook)
  55
  56 (put 'self-insert-command 'pending-delete t)
  57
  58 (put 'yank 'pending-delete t)
  59 (put 'x-yank-clipboard-selection 'pending-delete t)
  60
  61 (put 'delete-backward-char 'pending-delete 'supersede)
  62 (put 'backward-delete-char-untabify 'pending-delete 'supersede)
  63 (put 'delete-char 'pending-delete 'supersede)
  64
  65 (put 'newline-and-indent 'pending-delete 't)
  66 (put 'newline 'pending-delete t)
  67 (put 'open-line 'pending-delete t)
  68
  69 (defun pending-delete-mode (arg)
  70   "Toggle the state of pending-delete mode.
  71 When ON, typed text replaces the selection if the selection is active.
  72 When OFF, typed text is just inserted at point."
  73   (interactive "P")
  74   (setq pending-delete-mode
  75         (if (null arg) (not pending-delete-mode)
  76           (> (prefix-numeric-value arg) 0)))
  77   (set-buffer-modified-p (buffer-modified-p))) ;No-op, but updates mode line.
  78
  79 ;; This new definition of control-G makes the first control-G disown the
  80 ;; selection and the second one signal a QUIT.
  81 ;; This is very useful for cancelling a selection in the minibuffer without
  82 ;; aborting the minibuffer.
  83 ;; It has actually nothing to do with pending-delete but its more necessary
  84 ;; with pending delete because pending delete users use the selection more.
  85 (defun keyboard-quit ()
  86   "Signal a `quit' condition.
  87 During execution of Lisp code, this character causes a quit directly.
  88 At top-level, as an editor command, this simply beeps.
  89 In Transient Mark mode, if the mark is active, just deactivate it."
  90   (interactive)
  91   (if (and transient-mark-mode mark-active)
  92       (progn
  93         ;; Don't beep if just deactivating the region.
  94         (setq mark-active nil)
  95         (run-hooks 'deactivate-mark-hook))
  96     (signal 'quit nil)))
  97
  98 (defun minibuffer-keyboard-quit ()
  99   "Abort recursive edit.
 100 In Transient Mark mode, if the mark is active, just deactivate it."
 101   (interactive)
 102   (if (and transient-mark-mode mark-active)
 103       (progn
 104         ;; Don't beep if just deactivating the region.
 105         (setq mark-active nil)
 106         (run-hooks 'deactivate-mark-hook))
 107     (abort-recursive-edit)))
 108
 109 (define-key minibuffer-local-map "\C-g" 'minibuffer-keyboard-quit)
 110
 111 (provide 'pending-del)
 112
 113 ;; End of pending-del.el.