lisp/eshell/em-rebind.el

   1 ;;; em-rebind.el --- rebind keys when point is at current input  -*- lexical-binding:t -*-
   2
   3 ;; Copyright (C) 1999-2016 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 (require 'esh-mode)
  27 (eval-when-compile (require 'eshell))
  28
  29 ;;;###autoload
  30 (progn
  31 (defgroup eshell-rebind nil
  32   "This module allows for special keybindings that only take effect
  33 while the point is in a region of input text.  By default, it binds
  34 C-a to move to the beginning of the input text (rather than just the
  35 beginning of the line), and C-p and C-n to move through the input
  36 history, C-u kills the current input text, etc.  It also, if
  37 `eshell-confine-point-to-input' is non-nil, does not allow certain
  38 commands to cause the point to leave the input area, such as
  39 `backward-word', `previous-line', etc.  This module intends to mimic
  40 the behavior of normal shells while the user editing new input text."
  41   :tag "Rebind keys at input"
  42   :group 'eshell-module))
  43
  44 ;;; User Variables:
  45
  46 (defcustom eshell-rebind-load-hook nil
  47   "A list of functions to call when loading `eshell-rebind'."
  48   :version "24.1"                       ; removed eshell-rebind-initialize
  49   :type 'hook
  50   :group 'eshell-rebind)
  51
  52 (defcustom eshell-rebind-keys-alist
  53   '(([(control ?a)] . eshell-bol)
  54     ([home]         . eshell-bol)
  55     ([(control ?d)] . eshell-delchar-or-maybe-eof)
  56     ([backspace]    . eshell-delete-backward-char)
  57     ([delete]       . eshell-delete-backward-char)
  58     ([(control ?w)] . backward-kill-word)
  59     ([(control ?u)] . eshell-kill-input))
  60   "Bind some keys differently if point is in input text."
  61   :type '(repeat (cons (vector :tag "Keys to bind"
  62                                (repeat :inline t sexp))
  63                        (function :tag "Command")))
  64   :group 'eshell-rebind)
  65
  66 (defcustom eshell-confine-point-to-input t
  67   "If non-nil, do not allow the point to leave the current input.
  68 This is more difficult to do nicely in Emacs than one might think.
  69 Basically, the `point-left' attribute is added to the input text, and
  70 a function is placed on that hook to take the point back to
  71 `eshell-last-output-end' every time the user tries to move away.  But
  72 since there are many cases in which the point _ought_ to move away
  73 \(for programmatic reasons), the variable
  74 `eshell-cannot-leave-input-list' defines commands which are affected
  75 from this rule.  However, this list is by no means as complete as it
  76 probably should be, so basically all one can hope for is that other
  77 people will left the point alone in the Eshell buffer.  Sigh."
  78   :type 'boolean
  79   :group 'eshell-rebind)
  80
  81 (defcustom eshell-error-if-move-away t
  82   "If non-nil, consider it an error to try to move outside current input.
  83 This is default behavior of shells like bash."
  84   :type 'boolean
  85   :group 'eshell-rebind)
  86
  87 (defcustom eshell-remap-previous-input t
  88   "If non-nil, remap input keybindings on previous prompts as well."
  89   :type 'boolean
  90   :group 'eshell-rebind)
  91
  92 (defcustom eshell-cannot-leave-input-list
  93   '(beginning-of-line-text
  94     beginning-of-line
  95     move-to-column
  96     move-to-left-margin
  97     move-to-tab-stop
  98     forward-char
  99     backward-char
 100     delete-char
 101     delete-backward-char
 102     backward-delete-char
 103     backward-delete-char-untabify
 104     kill-paragraph
 105     backward-kill-paragraph
 106     kill-sentence
 107     backward-kill-sentence
 108     kill-sexp
 109     backward-kill-sexp
 110     kill-word
 111     backward-kill-word
 112     kill-region
 113     forward-list
 114     backward-list
 115     forward-page
 116     backward-page
 117     forward-point
 118     forward-paragraph
 119     backward-paragraph
 120     backward-prefix-chars
 121     forward-sentence
 122     backward-sentence
 123     forward-sexp
 124     backward-sexp
 125     forward-to-indentation
 126     backward-to-indentation
 127     backward-up-list
 128     forward-word
 129     backward-word
 130     forward-line
 131     previous-line
 132     next-line
 133     forward-visible-line
 134     forward-comment
 135     forward-thing)
 136   "A list of commands that cannot leave the input area."
 137   :type '(repeat function)
 138   :group 'eshell-rebind)
 139
 140 ;; Internal Variables:
 141
 142 (defvar eshell-input-keymap)
 143 (defvar eshell-previous-point)
 144 (defvar eshell-lock-keymap)
 145
 146 ;;; Functions:
 147
 148 (defun eshell-rebind-initialize ()
 149   "Initialize the inputting code."
 150   (unless eshell-non-interactive-p
 151     (add-hook 'eshell-mode-hook 'eshell-setup-input-keymap nil t)
 152     (make-local-variable 'eshell-previous-point)
 153     (add-hook 'pre-command-hook 'eshell-save-previous-point nil t)
 154     (make-local-variable 'overriding-local-map)
 155     (add-hook 'post-command-hook 'eshell-rebind-input-map nil t)
 156     (set (make-local-variable 'eshell-lock-keymap) nil)
 157     (define-key eshell-command-map [(meta ?l)] 'eshell-lock-local-map)))
 158
 159 (defun eshell-lock-local-map (&optional arg)
 160   "Lock or unlock the current local keymap.
 161 Within a prefix arg, set the local keymap to its normal value, and
 162 lock it at that."
 163   (interactive "P")
 164   (if (or arg (not eshell-lock-keymap))
 165       (progn
 166         (use-local-map eshell-mode-map)
 167         (setq eshell-lock-keymap t)
 168         (message "Local keymap locked in normal mode"))
 169     (use-local-map eshell-input-keymap)
 170     (setq eshell-lock-keymap nil)
 171     (message "Local keymap unlocked: obey context")))
 172
 173 (defun eshell-save-previous-point ()
 174   "Save the location of point before the next command is run."
 175   (setq eshell-previous-point (point)))
 176
 177 (defsubst eshell-point-within-input-p (pos)
 178   "Test whether POS is within an input range."
 179   (let (begin)
 180     (or (and (>= pos eshell-last-output-end)
 181              eshell-last-output-end)
 182         (and eshell-remap-previous-input
 183              (setq begin
 184                    (save-excursion
 185                      (eshell-bol)
 186                      (and (not (bolp)) (point))))
 187              (>= pos begin)
 188              (<= pos (line-end-position))
 189              begin))))
 190
 191 (defun eshell-rebind-input-map ()
 192   "Rebind the input keymap based on the location of the cursor."
 193   (ignore-errors
 194     (unless eshell-lock-keymap
 195       (if (eshell-point-within-input-p (point))
 196           (use-local-map eshell-input-keymap)
 197         (let (begin)
 198           (if (and eshell-confine-point-to-input
 199                    (setq begin
 200                          (eshell-point-within-input-p eshell-previous-point))
 201                    (memq this-command eshell-cannot-leave-input-list))
 202               (progn
 203                 (use-local-map eshell-input-keymap)
 204                 (goto-char begin)
 205                 (if (and eshell-error-if-move-away
 206                          (not (eq this-command 'kill-region)))
 207                     (beep)))
 208             (use-local-map eshell-mode-map)))))))
 209
 210 (defun eshell-setup-input-keymap ()
 211   "Setup the input keymap to be used during input editing."
 212   (make-local-variable 'eshell-input-keymap)
 213   (setq eshell-input-keymap (make-sparse-keymap))
 214   (set-keymap-parent eshell-input-keymap eshell-mode-map)
 215   (let ((bindings eshell-rebind-keys-alist))
 216     (while bindings
 217       (define-key eshell-input-keymap (caar bindings)
 218         (cdar bindings))
 219       (setq bindings (cdr bindings)))))
 220
 221 (defun eshell-delete-backward-char (n)
 222   "Delete the last character, unless it's part of the output."
 223   (interactive "P")
 224   (let ((count (prefix-numeric-value n)))
 225     (if (eshell-point-within-input-p (- (point) count))
 226         (delete-backward-char count n)
 227       (beep))))
 228
 229 (defun eshell-delchar-or-maybe-eof (arg)
 230   "Delete ARG characters forward or send an EOF to subprocess.
 231 Sends an EOF only if point is at the end of the buffer and there is no
 232 input."
 233   (interactive "p")
 234   (let ((proc (eshell-interactive-process)))
 235     (if (eobp)
 236         (cond
 237          ((/= (point) eshell-last-output-end)
 238           (beep))
 239          (proc
 240           (process-send-eof))
 241          (t
 242           (eshell-life-is-too-much)))
 243       (eshell-delete-backward-char (- arg)))))
 244
 245 (provide 'em-rebind)
 246
 247 ;; Local Variables:
 248 ;; generated-autoload-file: "esh-groups.el"
 249 ;; End:
 250
 251 ;;; em-rebind.el ends here