lisp/eshell/em-rebind.el

   1 ;;; em-rebind.el --- rebind keys when point is at current input
   2
   3 ;; Copyright (C) 1999, 2000 Free Software Foundation
   4
   5 ;; Author: John Wiegley <johnw@gnu.org>
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  12 ;; any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22 ;; Boston, MA 02111-1307, USA.
  23
  24 (provide 'em-rebind)
  25
  26 (eval-when-compile (require 'esh-maint))
  27
  28 (defgroup eshell-rebind nil
  29   "This module allows for special keybindings that only take effect
  30 while the point is in a region of input text.  By default, it binds
  31 C-a to move to the beginning of the input text (rather than just the
  32 beginning of the line), and C-p and C-n to move through the input
  33 history, C-u kills the current input text, etc.  It also, if
  34 `eshell-confine-point-to-input' is non-nil, does not allow certain
  35 commands to cause the point to leave the input area, such as
  36 `backward-word', `previous-line', etc.  This module intends to mimic
  37 the behavior of normal shells while the user editing new input text."
  38   :tag "Rebind keys at input"
  39   :group 'eshell-module)
  40
  41 ;;; Commentary:
  42
  43 ;;; User Variables:
  44
  45 (defcustom eshell-rebind-load-hook '(eshell-rebind-initialize)
  46   "*A list of functions to call when loading `eshell-rebind'."
  47   :type 'hook
  48   :group 'eshell-rebind)
  49
  50 (defcustom eshell-rebind-keys-alist
  51   '(([(control ?a)] . eshell-bol)
  52     ([home]         . eshell-bol)
  53     ([(control ?d)] . eshell-delchar-or-maybe-eof)
  54     ([backspace]    . eshell-delete-backward-char)
  55     ([delete]       . eshell-delete-backward-char)
  56     ([(control ?w)] . backward-kill-word)
  57     ([(control ?u)] . eshell-kill-input))
  58   "*Bind some keys differently if point is in input text."
  59   :type '(repeat (cons (vector :tag "Keys to bind"
  60                                (repeat :inline t sexp))
  61                        (function :tag "Command")))
  62   :group 'eshell-rebind)
  63
  64 (defcustom eshell-confine-point-to-input t
  65   "*If non-nil, do not allow the point to leave the current input.
  66 This is more difficult to do nicely in Emacs than one might think.
  67 Basically, the `point-left' attribute is added to the input text, and
  68 a function is placed on that hook to take the point back to
  69 `eshell-last-output-end' every time the user tries to move away.  But
  70 since there are many cases in which the point _ought_ to move away
  71 \(for programmatic reasons), the variable
  72 `eshell-cannot-leave-input-list' defines commands which are affected
  73 from this rule.  However, this list is by no means as complete as it
  74 probably should be, so basically all one can hope for is that other
  75 people will left the point alone in the Eshell buffer.  Sigh."
  76   :type 'boolean
  77   :group 'eshell-rebind)
  78
  79 (defcustom eshell-error-if-move-away t
  80   "*If non-nil, consider it an error to try to move outside current input.
  81 This is default behavior of shells like bash."
  82   :type 'boolean
  83   :group 'eshell-rebind)
  84
  85 (defcustom eshell-remap-previous-input t
  86   "*If non-nil, remap input keybindings on previous prompts as well."
  87   :type 'boolean
  88   :group 'eshell-rebind)
  89
  90 (defcustom eshell-cannot-leave-input-list
  91   '(beginning-of-line-text
  92     beginning-of-line
  93     move-to-column
  94     move-to-column-force
  95     move-to-left-margin
  96     move-to-tab-stop
  97     forward-char
  98     backward-char
  99     delete-char
 100     delete-backward-char
 101     backward-delete-char
 102     backward-delete-char-untabify
 103     kill-paragraph
 104     backward-kill-paragraph
 105     kill-sentence
 106     backward-kill-sentence
 107     kill-sexp
 108     backward-kill-sexp
 109     kill-word
 110     backward-kill-word
 111     kill-region
 112     forward-list
 113     backward-list
 114     forward-page
 115     backward-page
 116     forward-point
 117     forward-paragraph
 118     backward-paragraph
 119     backward-prefix-chars
 120     forward-sentence
 121     backward-sentence
 122     forward-sexp
 123     backward-sexp
 124     forward-to-indentation
 125     backward-to-indentation
 126     backward-up-list
 127     forward-word
 128     backward-word
 129     forward-line
 130     previous-line
 131     next-line
 132     forward-visible-line
 133     forward-comment
 134     forward-thing)
 135   "*A list of commands that cannot leave the input area."
 136   :type '(repeat function)
 137   :group 'eshell-rebind)
 138
 139 ;; Internal Variables:
 140
 141 (defvar eshell-input-keymap)
 142 (defvar eshell-previous-point)
 143 (defvar eshell-lock-keymap)
 144
 145 ;;; Functions:
 146
 147 (defun eshell-rebind-initialize ()
 148   "Initialize the inputing code."
 149   (unless eshell-non-interactive-p
 150     (add-hook 'eshell-mode-hook 'eshell-setup-input-keymap nil t)
 151     (make-local-variable 'eshell-previous-point)
 152     (add-hook 'pre-command-hook 'eshell-save-previous-point nil t)
 153     (make-local-variable 'overriding-local-map)
 154     (add-hook 'post-command-hook 'eshell-rebind-input-map nil t)
 155     (set (make-local-variable 'eshell-lock-keymap) nil)
 156     (define-key eshell-command-map [(meta ?l)] 'eshell-lock-local-map)))
 157
 158 (defun eshell-lock-local-map (&optional arg)
 159   "Lock or unlock the current local keymap.
 160 Within a prefix arg, set the local keymap to its normal value, and
 161 lock it at that."
 162   (interactive "P")
 163   (if (or arg (not eshell-lock-keymap))
 164       (progn
 165         (use-local-map eshell-mode-map)
 166         (setq eshell-lock-keymap t)
 167         (message "Local keymap locked in normal mode"))
 168     (use-local-map eshell-input-keymap)
 169     (setq eshell-lock-keymap nil)
 170     (message "Local keymap unlocked: obey context")))
 171
 172 (defun eshell-save-previous-point ()
 173   "Save the location of point before the next command is run."
 174   (setq eshell-previous-point (point)))
 175
 176 (defsubst eshell-point-within-input-p (pos)
 177   "Test whether POS is within an input range."
 178   (let (begin)
 179     (or (and (>= pos eshell-last-output-end)
 180              eshell-last-output-end)
 181         (and eshell-remap-previous-input
 182              (setq begin
 183                    (save-excursion
 184                      (eshell-bol)
 185                      (and (not (bolp)) (point))))
 186              (>= pos begin)
 187              (<= pos (line-end-position))
 188              begin))))
 189
 190 (defun eshell-rebind-input-map ()
 191   "Rebind the input keymap based on the location of the cursor."
 192   (ignore-errors
 193     (unless eshell-lock-keymap
 194       (if (eshell-point-within-input-p (point))
 195           (use-local-map eshell-input-keymap)
 196         (let (begin)
 197           (if (and eshell-confine-point-to-input
 198                    (setq begin
 199                          (eshell-point-within-input-p eshell-previous-point))
 200                    (memq this-command eshell-cannot-leave-input-list))
 201               (progn
 202                 (use-local-map eshell-input-keymap)
 203                 (goto-char begin)
 204                 (if (and eshell-error-if-move-away
 205                          (not (eq this-command 'kill-region)))
 206                     (beep)))
 207             (use-local-map eshell-mode-map)))))))
 208
 209 (defun eshell-setup-input-keymap ()
 210   "Setup the input keymap to be used during input editing."
 211   (make-local-variable 'eshell-input-keymap)
 212   (setq eshell-input-keymap (make-sparse-keymap))
 213   (set-keymap-parent eshell-input-keymap eshell-mode-map)
 214   (let ((bindings eshell-rebind-keys-alist))
 215     (while bindings
 216       (define-key eshell-input-keymap (caar bindings)
 217         (cdar bindings))
 218       (setq bindings (cdr bindings)))))
 219
 220 (defun eshell-delete-backward-char (n &optional killflag)
 221   "Delete the last character, unless it's part of the output."
 222   (interactive "P")
 223   (let ((count (prefix-numeric-value n)))
 224     (if (eshell-point-within-input-p (- (point) count))
 225         (delete-backward-char count n)
 226       (beep))))
 227
 228 (defun eshell-delchar-or-maybe-eof (arg)
 229   "Delete ARG characters forward or send an EOF to subprocess.
 230 Sends an EOF only if point is at the end of the buffer and there is no
 231 input."
 232   (interactive "p")
 233   (let ((proc (eshell-interactive-process)))
 234     (if (eobp)
 235         (cond
 236          ((/= (point) eshell-last-output-end)
 237           (beep))
 238          (proc
 239           (process-send-eof))
 240          (t
 241           (eshell-life-is-too-much)))
 242       (eshell-delete-backward-char (- arg)))))
 243
 244 ;;; Code:
 245
 246 ;;; em-rebind.el ends here