;;; em-rebind.el --- rebind keys when point is at current input
;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004,
;; 2005, 2006, 2007 Free Software Foundation, Inc.
;; Author: John Wiegley <email@example.com>
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.
(eval-when-compile (require 'esh-maint))
(defgroup eshell-rebind nil
"This module allows for special keybindings that only take effect
while the point is in a region of input text. By default, it binds
C-a to move to the beginning of the input text (rather than just the
beginning of the line), and C-p and C-n to move through the input
history, C-u kills the current input text, etc. It also, if
`eshell-confine-point-to-input' is non-nil, does not allow certain
commands to cause the point to leave the input area, such as
`backward-word', `previous-line', etc. This module intends to mimic
the behavior of normal shells while the user editing new input text."
:tag "Rebind keys at input"
;;; User Variables:
(defcustom eshell-rebind-load-hook '(eshell-rebind-initialize)
"*A list of functions to call when loading `eshell-rebind'."
'(([(control ?a)] . eshell-bol)
([home] . eshell-bol)
([(control ?d)] . eshell-delchar-or-maybe-eof)
([backspace] . eshell-delete-backward-char)
([delete] . eshell-delete-backward-char)
([(control ?w)] . backward-kill-word)
([(control ?u)] . eshell-kill-input))
"*Bind some keys differently if point is in input text."
:type '(repeat (cons (vector :tag "Keys to bind"
(repeat :inline t sexp))
(function :tag "Command")))
(defcustom eshell-confine-point-to-input t
"*If non-nil, do not allow the point to leave the current input.
This is more difficult to do nicely in Emacs than one might think.
Basically, the `point-left' attribute is added to the input text, and
a function is placed on that hook to take the point back to
`eshell-last-output-end' every time the user tries to move away. But
since there are many cases in which the point _ought_ to move away
\(for programmatic reasons), the variable
`eshell-cannot-leave-input-list' defines commands which are affected
from this rule. However, this list is by no means as complete as it
probably should be, so basically all one can hope for is that other
people will left the point alone in the Eshell buffer. Sigh."
(defcustom eshell-error-if-move-away t
"*If non-nil, consider it an error to try to move outside current input.
This is default behavior of shells like bash."
(defcustom eshell-remap-previous-input t
"*If non-nil, remap input keybindings on previous prompts as well."
"*A list of commands that cannot leave the input area."
:type '(repeat function)
;; Internal Variables:
(defun eshell-rebind-initialize ()
"Initialize the inputing code."
(add-hook 'eshell-mode-hook 'eshell-setup-input-keymap nil t)
(add-hook 'pre-command-hook 'eshell-save-previous-point nil t)
(add-hook 'post-command-hook 'eshell-rebind-input-map nil t)
(set (make-local-variable 'eshell-lock-keymap) nil)
(define-key eshell-command-map [(meta ?l)] 'eshell-lock-local-map)))
(defun eshell-lock-local-map (&optional arg)
"Lock or unlock the current local keymap.
Within a prefix arg, set the local keymap to its normal value, and
lock it at that."
(if (or arg (not eshell-lock-keymap))
(setq eshell-lock-keymap t)
(message "Local keymap locked in normal mode"))
(setq eshell-lock-keymap nil)
(message "Local keymap unlocked: obey context")))
(defun eshell-save-previous-point ()
"Save the location of point before the next command is run."
(setq eshell-previous-point (point)))
(defsubst eshell-point-within-input-p (pos)
"Test whether POS is within an input range."
(or (and (>= pos eshell-last-output-end)
(and (not (bolp)) (point))))
(>= pos begin)
(<= pos (line-end-position))
(defun eshell-rebind-input-map ()
"Rebind the input keymap based on the location of the cursor."
(if (eshell-point-within-input-p (point))
(if (and eshell-confine-point-to-input
(memq this-command eshell-cannot-leave-input-list))
(if (and eshell-error-if-move-away
(not (eq this-command 'kill-region)))
(defun eshell-setup-input-keymap ()
"Setup the input keymap to be used during input editing."
(setq eshell-input-keymap (make-sparse-keymap))
(set-keymap-parent eshell-input-keymap eshell-mode-map)
(let ((bindings eshell-rebind-keys-alist))
(define-key eshell-input-keymap (caar bindings)
(setq bindings (cdr bindings)))))
(defun eshell-delete-backward-char (n &optional killflag)
"Delete the last character, unless it's part of the output."
(let ((count (prefix-numeric-value n)))
(if (eshell-point-within-input-p (- (point) count))
(delete-backward-char count n)
(defun eshell-delchar-or-maybe-eof (arg)
"Delete ARG characters forward or send an EOF to subprocess.
Sends an EOF only if point is at the end of the buffer and there is no
(let ((proc (eshell-interactive-process)))
((/= (point) eshell-last-output-end)
(eshell-delete-backward-char (- arg)))))
;;; em-rebind.el ends here