;;; smart-tab.el --- Intelligent tab completion and indentation.
;; This file is NOT part of GNU Emacs.
;; Copyright (C) 2009-2019 John SJ Anderson,
;; Sebastien Rocca Serra,
;; Daniel Hackney
;; Author: John SJ Anderson <genehack@genehack.org>,
;; Sebastien Rocca Serra <sroccaserra@gmail.com>,
;; Daniel Hackney <dan@haxney.org>
;; Maintainer: John SJ Anderson <genehack@genehack.org>
;; Keywords: extensions
;; Created: 2009-05-24
;; URL: http://github.com/genehack/smart-tab/tree/master
;; Version: 0.5
;;
;; This program 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 3, or (at your option) any later version.
;;
;; This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; INSTALL
;;
;; To install, put this file along your Emacs-Lisp `load-path' and add
;; the following into your ~/.emacs startup file or set
;; `global-smart-tab-mode' to non-nil with customize:
;;
;; (require 'smart-tab)
;; (global-smart-tab-mode 1)
;;
;; DESCRIPTION
;;
;; Try to 'do the smart thing' when tab is pressed. `smart-tab'
;; attempts to expand the text before the point or indent the current
;; line or selection.
;;
;; See <http://www.emacswiki.org/cgi-bin/wiki/TabCompletion#toc2>.
;; There are a number of available customizations on that page.
;;
;; Features that might be required by this library:
;;
;; `easy-mmmode'
;;; Change Log:
;;; Code:
(require 'easy-mmode)
(defgroup smart-tab nil
"Options for `smart-tab-mode'."
:group 'tools)
(defvar smart-tab-debug nil
"Turn on for logging about which `smart-tab' function ends up being called.")
(defcustom smart-tab-using-hippie-expand nil
"Use `hippie-expand' to expand text.
Use either `hippie-expand' or `dabbrev-expand' for expanding text
when we don't have to indent."
:type '(choice
(const :tag "hippie-expand" t)
(const :tag "dabbrev-expand" nil))
:group 'smart-tab)
(defcustom smart-tab-completion-functions-alist
'((emacs-lisp-mode . lisp-complete-symbol)
(text-mode . dabbrev-completion))
"A-list of major modes in which to use a mode specific completion function.
If current major mode is not found in this alist, fall back to
`hippie-expand' or `dabbrev-expand', depending on the value of
`smart-tab-using-hippie-expand'"
:type '(alist :key-type (symbol :tag "Major mode")
:value-type (function :tag "Completion function to use in this mode"))
:group 'smart-tab)
(defcustom smart-tab-disabled-major-modes '(org-mode term-mode eshell-mode w3m-mode magit-mode)
"List of major modes that should not use `smart-tab'."
:type 'sexp
:group 'smart-tab)
(defcustom smart-tab-user-provided-completion-function nil
"Use a function provided by a completion framework to attempt expansion.
By default, we check for the presence of `auto-complete-mode' and
use it as the completion framework. Set this variable if you want to use a
different completion framework.
Eg: For `company-mode', you can set this var to `company-complete'."
:type '(function)
:group 'smart-tab)
(defun smart-tab-call-completion-function ()
"Completion is attempted as follows:
1. Check if a mode-specific completion function is defined in
`smart-tab-completion-functions-alist'. If yes, then use it.
2. Check if the user has plugged in a custom completion function
in `smart-tab-user-provided-completion-function'. If yes, then
use it.
3. Check if `auto-complete-mode' is installed. If yes, then use
it.
4. Check if user prefers `hippie-expand' instead of
`dabbrev-expand' by referring to `smart-tab-using-hippie-expand'.
Use one of these default methods to attempt completion."
(if smart-tab-debug
(message "complete"))
(let ((smart-tab-mode-specific-completion-function
(cdr (assq major-mode smart-tab-completion-functions-alist))))
(cond
((fboundp smart-tab-mode-specific-completion-function)
(funcall smart-tab-mode-specific-completion-function))
((and (not (minibufferp))
(fboundp smart-tab-user-provided-completion-function))
(funcall smart-tab-user-provided-completion-function))
((and (not (minibufferp))
(memq 'auto-complete-mode minor-mode-list)
(boundp 'auto-complete-mode)
auto-complete-mode
(fboundp 'ac-start))
(ac-start :force-init t nil))
(smart-tab-using-hippie-expand
(hippie-expand nil))
(t (dabbrev-expand nil)))))
(defcustom smart-tab-expand-eolp nil
"Controls whether `smart-tab' should offer completion when point is at EOL.
The default behaviour is to do nothing. Set this to t to
enable (for example) method completions."
:type '(boolean)
:group 'smart-tab)
(defun smart-tab-must-expand (&optional prefix)
"If PREFIX is \\[universal-argument] or the mark is active, do not expand.
Otherwise, uses the user's preferred expansion function to expand
the text at point."
(unless (or (consp prefix)
(use-region-p))
(looking-at "\\_>")))
(defun smart-tab-default ()
"Indent region if mark is active, or current line otherwise."
(interactive)
(if smart-tab-debug
(message "default"))
(let* ((smart-tab-mode nil)
(global-smart-tab-mode nil)
(ev last-command-event)
(triggering-key (cl-case (type-of ev)
(integer (char-to-string ev))
(symbol (vector ev))))
(original-func (or (key-binding triggering-key)
(key-binding (lookup-key local-function-key-map
triggering-key))
'indent-for-tab-command)))
(call-interactively original-func)))
;;;###autoload
(defun smart-tab (&optional prefix)
"Try to 'do the smart thing' when tab is pressed.
`smart-tab' attempts to expand the text before the point or
indent the current line or selection.
In a regular buffer, `smart-tab' will attempt to expand with
either `hippie-expand' or `dabbrev-expand', depending on the
value of `smart-tab-using-hippie-expand'. Alternatively, if a
`smart-tab-user-provided-completion-function' is defined, it will
be used to attempt expansion. If the mark is active, or PREFIX is
\\[universal-argument], then `smart-tab' will indent the region
or the current line (if the mark is not active)."
(interactive "P")
(cond
(buffer-read-only
(smart-tab-default))
((use-region-p)
(indent-region (region-beginning)
(region-end)))
((smart-tab-must-expand prefix)
(smart-tab-call-completion-function))
((and smart-tab-expand-eolp (eolp))
(smart-tab-call-completion-function))
(t
(smart-tab-default))))
;;;###autoload
(defun smart-tab-mode-on ()
"Turn on `smart-tab-mode'."
(smart-tab-mode 1))
(defun smart-tab-mode-off ()
"Turn off `smart-tab-mode'."
(smart-tab-mode -1))
;;;###autoload
(define-minor-mode smart-tab-mode
"Enable `smart-tab' to be used in place of tab.
With no argument, this command toggles the mode.
Non-null prefix argument turns on the mode.
Null prefix argument turns off the mode."
:lighter " Smrt"
:group 'smart-tab
:require 'smart-tab
:keymap '(("\t" . smart-tab)
([(tab)] . smart-tab))
(if smart-tab-mode
(progn
;; Don't start `smart-tab-mode' when in the minibuffer or a read-only
;; buffer.
(when (or (minibufferp)
buffer-read-only
(member major-mode smart-tab-disabled-major-modes))
(smart-tab-mode-off)))))
;;;###autoload
(define-globalized-minor-mode global-smart-tab-mode
smart-tab-mode
smart-tab-mode-on
:group 'smart-tab)
(provide 'smart-tab)
;;; smart-tab.el ends here