code.delx.au - gnu-emacs/blob - lisp/delsel.el

   1 ;;; pending-del.el --- pending delete selection
   2
   3 ;;; Copyright (C) 1992 Free Software Foundation, Inc.
   4
   5 ;; Author: Matthieu Devin <devin@lucid.com>
   6 ;; Created: 14 Jul 92
   7 ;; Last change  18-Feb-93, devin.
   8
   9 ;;; This file is part of GNU Emacs.
  10
  11 ;;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;;; it under the terms of the GNU General Public License as published by
  13 ;;; the Free Software Foundation; either version 2, or (at your option)
  14 ;;; any later version.
  15
  16 ;;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;;; GNU General Public License for more details.
  20
  21 ;;; You should have received a copy of the GNU General Public License
  22 ;;; along with GNU Emacs; see the file COPYING.  If not, write to
  23 ;;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 ;;; Commentary:
  26
  27 ;;; This file makes the active region be pending delete, meaning that
  28 ;;; text inserted while the region is active will replace the region contents.
  29 ;;; This is a popular behavior of personal computers text editors.
  30
  31 ;;; Code:
  32
  33 (defvar pending-delete-mode t
  34   "*Non-nil means Pending Delete mode is enabled.
  35 In Pending Delete mode, when a region is highlighted,
  36 insertion commands first delete the region and then insert.")
  37
  38 (defun delete-active-region (&optional killp)
  39   (if killp
  40       (kill-region (point) (mark))
  41     (delete-region (point) (mark)))
  42   (setq mark-active nil)
  43   (run-hooks 'deactivate-mark-hook)
  44   t)
  45
  46 (defun pending-delete-pre-hook ()
  47   (if (and pending-delete-mode
  48            (not buffer-read-only)
  49            transient-mark-mode mark-active)
  50       (let ((type (and (symbolp this-command)
  51                        (get this-command 'pending-delete))))
  52         (cond ((eq type 'kill)
  53                (delete-active-region t))
  54               ((eq type 'supersede)
  55                (if (delete-active-region ())
  56                    (setq this-command '(lambda () (interactive)))))
  57               (type
  58                (delete-active-region ()))))))
  59
  60 (add-hook 'pre-command-hook 'pending-delete-pre-hook)
  61
  62 (put 'self-insert-command 'pending-delete t)
  63
  64 (put 'yank 'pending-delete t)
  65 (put 'x-yank-clipboard-selection 'pending-delete t)
  66
  67 (put 'delete-backward-char 'pending-delete 'supersede)
  68 (put 'backward-delete-char-untabify 'pending-delete 'supersede)
  69 (put 'delete-char 'pending-delete 'supersede)
  70
  71 (put 'newline-and-indent 'pending-delete 't)
  72 (put 'newline 'pending-delete t)
  73 (put 'open-line 'pending-delete t)
  74
  75 (defun pending-delete-mode (arg)
  76   "Toggle the state of pending-delete mode.
  77 When ON, typed text replaces the selection if the selection is active.
  78 When OFF, typed text is just inserted at point."
  79   (interactive "P")
  80   (setq pending-delete-mode
  81         (if (null arg) (not pending-delete-mode)
  82           (> (prefix-numeric-value arg) 0)))
  83   (set-buffer-modified-p (buffer-modified-p))) ;No-op, but updates mode line.
  84
  85 ;; This new definition of control-G makes the first control-G disown the
  86 ;; selection and the second one signal a QUIT.
  87 ;; This is very useful for cancelling a selection in the minibuffer without
  88 ;; aborting the minibuffer.
  89 ;; It has actually nothing to do with pending-delete but its more necessary
  90 ;; with pending delete because pending delete users use the selection more.
  91 (defun keyboard-quit ()
  92   "Signal a `quit' condition.
  93 During execution of Lisp code, this character causes a quit directly.
  94 At top-level, as an editor command, this simply beeps.
  95 In Transient Mark mode, if the mark is active, just deactivate it."
  96   (interactive)
  97   (if (and transient-mark-mode mark-active)
  98       (progn
  99         ;; Don't beep if just deactivating the region.
 100         (setq mark-active nil)
 101         (run-hooks 'deactivate-mark-hook))
 102     (signal 'quit nil)))
 103
 104 (defun minibuffer-keyboard-quit ()
 105   "Abort recursive edit.
 106 In Transient Mark mode, if the mark is active, just deactivate it."
 107   (interactive)
 108   (if (and transient-mark-mode mark-active)
 109       (progn
 110         ;; Don't beep if just deactivating the region.
 111         (setq mark-active nil)
 112         (run-hooks 'deactivate-mark-hook))
 113     (abort-recursive-edit)))
 114
 115 (define-key minibuffer-local-map "\C-g" 'minibuffer-keyboard-quit)
 116
 117 (provide 'pending-del)
 118
 119 ;;; pending-del.el ends here