lisp/eshell/em-rebind.el

   1 ;;; em-rebind.el --- rebind keys when point is at current input
   2
   3 ;; Copyright (C) 1999-2011  Free Software Foundation, Inc.
   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 3 of the License, or
  12 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Commentary:
  23
  24 ;;; Code:
  25
  26 (eval-when-compile (require 'eshell))
  27
  28 ;;;###autoload
  29 (eshell-defgroup eshell-rebind nil
  30   "This module allows for special keybindings that only take effect
  31 while the point is in a region of input text.  By default, it binds
  32 C-a to move to the beginning of the input text (rather than just the
  33 beginning of the line), and C-p and C-n to move through the input
  34 history, C-u kills the current input text, etc.  It also, if
  35 `eshell-confine-point-to-input' is non-nil, does not allow certain
  36 commands to cause the point to leave the input area, such as
  37 `backward-word', `previous-line', etc.  This module intends to mimic
  38 the behavior of normal shells while the user editing new input text."
  39   :tag "Rebind keys at input"
  40   :group 'eshell-module)
  41
  42 ;;; User Variables:
  43
  44 (defcustom eshell-rebind-load-hook nil
  45   "A list of functions to call when loading `eshell-rebind'."
  46   :version "24.1"                       ; removed eshell-rebind-initialize
  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-left-margin
  95     move-to-tab-stop
  96     forward-char
  97     backward-char
  98     delete-char
  99     delete-backward-char
 100     backward-delete-char
 101     backward-delete-char-untabify
 102     kill-paragraph
 103     backward-kill-paragraph
 104     kill-sentence
 105     backward-kill-sentence
 106     kill-sexp
 107     backward-kill-sexp
 108     kill-word
 109     backward-kill-word
 110     kill-region
 111     forward-list
 112     backward-list
 113     forward-page
 114     backward-page
 115     forward-point
 116     forward-paragraph
 117     backward-paragraph
 118     backward-prefix-chars
 119     forward-sentence
 120     backward-sentence
 121     forward-sexp
 122     backward-sexp
 123     forward-to-indentation
 124     backward-to-indentation
 125     backward-up-list
 126     forward-word
 127     backward-word
 128     forward-line
 129     previous-line
 130     next-line
 131     forward-visible-line
 132     forward-comment
 133     forward-thing)
 134   "A list of commands that cannot leave the input area."
 135   :type '(repeat function)
 136   :group 'eshell-rebind)
 137
 138 ;; Internal Variables:
 139
 140 (defvar eshell-input-keymap)
 141 (defvar eshell-previous-point)
 142 (defvar eshell-lock-keymap)
 143
 144 ;;; Functions:
 145
 146 (defun eshell-rebind-initialize ()
 147   "Initialize the inputting code."
 148   (unless eshell-non-interactive-p
 149     (add-hook 'eshell-mode-hook 'eshell-setup-input-keymap nil t)
 150     (make-local-variable 'eshell-previous-point)
 151     (add-hook 'pre-command-hook 'eshell-save-previous-point nil t)
 152     (make-local-variable 'overriding-local-map)
 153     (add-hook 'post-command-hook 'eshell-rebind-input-map nil t)
 154     (set (make-local-variable 'eshell-lock-keymap) nil)
 155     (define-key eshell-command-map [(meta ?l)] 'eshell-lock-local-map)))
 156
 157 (defun eshell-lock-local-map (&optional arg)
 158   "Lock or unlock the current local keymap.
 159 Within a prefix arg, set the local keymap to its normal value, and
 160 lock it at that."
 161   (interactive "P")
 162   (if (or arg (not eshell-lock-keymap))
 163       (progn
 164         (use-local-map eshell-mode-map)
 165         (setq eshell-lock-keymap t)
 166         (message "Local keymap locked in normal mode"))
 167     (use-local-map eshell-input-keymap)
 168     (setq eshell-lock-keymap nil)
 169     (message "Local keymap unlocked: obey context")))
 170
 171 (defun eshell-save-previous-point ()
 172   "Save the location of point before the next command is run."
 173   (setq eshell-previous-point (point)))
 174
 175 (defsubst eshell-point-within-input-p (pos)
 176   "Test whether POS is within an input range."
 177   (let (begin)
 178     (or (and (>= pos eshell-last-output-end)
 179              eshell-last-output-end)
 180         (and eshell-remap-previous-input
 181              (setq begin
 182                    (save-excursion
 183                      (eshell-bol)
 184                      (and (not (bolp)) (point))))
 185              (>= pos begin)
 186              (<= pos (line-end-position))
 187              begin))))
 188
 189 (defun eshell-rebind-input-map ()
 190   "Rebind the input keymap based on the location of the cursor."
 191   (ignore-errors
 192     (unless eshell-lock-keymap
 193       (if (eshell-point-within-input-p (point))
 194           (use-local-map eshell-input-keymap)
 195         (let (begin)
 196           (if (and eshell-confine-point-to-input
 197                    (setq begin
 198                          (eshell-point-within-input-p eshell-previous-point))
 199                    (memq this-command eshell-cannot-leave-input-list))
 200               (progn
 201                 (use-local-map eshell-input-keymap)
 202                 (goto-char begin)
 203                 (if (and eshell-error-if-move-away
 204                          (not (eq this-command 'kill-region)))
 205                     (beep)))
 206             (use-local-map eshell-mode-map)))))))
 207
 208 (defun eshell-setup-input-keymap ()
 209   "Setup the input keymap to be used during input editing."
 210   (make-local-variable 'eshell-input-keymap)
 211   (setq eshell-input-keymap (make-sparse-keymap))
 212   (set-keymap-parent eshell-input-keymap eshell-mode-map)
 213   (let ((bindings eshell-rebind-keys-alist))
 214     (while bindings
 215       (define-key eshell-input-keymap (caar bindings)
 216         (cdar bindings))
 217       (setq bindings (cdr bindings)))))
 218
 219 (defun eshell-delete-backward-char (n &optional killflag)
 220   "Delete the last character, unless it's part of the output."
 221   (interactive "P")
 222   (let ((count (prefix-numeric-value n)))
 223     (if (eshell-point-within-input-p (- (point) count))
 224         (delete-backward-char count n)
 225       (beep))))
 226
 227 (defun eshell-delchar-or-maybe-eof (arg)
 228   "Delete ARG characters forward or send an EOF to subprocess.
 229 Sends an EOF only if point is at the end of the buffer and there is no
 230 input."
 231   (interactive "p")
 232   (let ((proc (eshell-interactive-process)))
 233     (if (eobp)
 234         (cond
 235          ((/= (point) eshell-last-output-end)
 236           (beep))
 237          (proc
 238           (process-send-eof))
 239          (t
 240           (eshell-life-is-too-much)))
 241       (eshell-delete-backward-char (- arg)))))
 242
 243 (provide 'em-rebind)
 244
 245 ;; Local Variables:
 246 ;; generated-autoload-file: "esh-groups.el"
 247 ;; End:
 248
 249 ;;; em-rebind.el ends here