--- /dev/null
+;;; delight.el --- A dimmer switch for your lighter text.
+;;
+;; Copyright (C) 2013, 2014, 2016 Phil Sainty
+;; Author: Phil Sainty <psainty@orcon.net.nz>
+;; Maintainer: Phil Sainty <psainty@orcon.net.nz>
+;; URL: https://savannah.nongnu.org/projects/delight
+;; Keywords: convenience
+;; Created: 25 Jun 2013
+;; Version: 1.05
+
+;; 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 of the License, 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:
+;;
+;; Enables you to customise the mode names displayed in the mode line.
+;;
+;; For major modes, the buffer-local `mode-name' variable is modified.
+;; For minor modes, the associated value in `minor-mode-alist' is set.
+;;
+;; Example usage:
+;;
+;; (require 'delight)
+;;
+;; (delight 'abbrev-mode " Abv" "abbrev")
+;;
+;; (delight '((abbrev-mode " Abv" "abbrev")
+;; (smart-tab-mode " \\t" "smart-tab")
+;; (eldoc-mode nil "eldoc")
+;; (rainbow-mode)
+;; (overwrite-mode " Ov" t)
+;; (emacs-lisp-mode "Elisp" :major)))
+;;
+;; The first argument is the mode symbol.
+;;
+;; The second argument is the replacement name to use in the mode line
+;; (or nil to hide it).
+;;
+;; The third argument is either the keyword :major for major modes or,
+;; for minor modes, the library which defines the mode. This is passed
+;; to ‘eval-after-load’ and so should be either the name (as a string)
+;; of the library file which defines the mode, or the feature (symbol)
+;; provided by that library. If this argument is nil, the mode symbol
+;; will be passed as the feature. If this argument is either t or 'emacs
+;; then it is assumed that the mode is already loaded (you can use this
+;; with standard minor modes that are pre-loaded by default when Emacs
+;; starts).
+;;
+;; To determine which library defines a mode, use e.g.: C-h f
+;; eldoc-mode RET. The name of the library is displayed in the first
+;; paragraph, with an “.el” suffix (in this example it displays
+;; “eldoc.el”, and therefore we could use the value “eldoc” for the
+;; library).
+;;
+;; Important note:
+;;
+;; Although strings are common, any mode-line construct is permitted
+;; as the value (for both minor and major modes); so before you
+;; override a value you should check the existing one, as you may
+;; want to replicate any structural elements in your replacement
+;; if it turns out not to be a simple string.
+;;
+;; For major modes, M-: mode-name
+;; For minor modes, M-: (cadr (assq 'MODE minor-mode-alist))
+;; for the minor MODE in question.
+;;
+;; Conversely, you may incorporate additional mode-line constructs in
+;; your replacement values, if you so wish. e.g.:
+;;
+;; (delight 'emacs-lisp-mode
+;; '("Elisp" (lexical-binding ":Lex" ":Dyn"))
+;; :major)
+;;
+;; See `mode-line-format' for information about mode-line constructs,
+;; and M-: (info "(elisp) Mode Line Format") for further details.
+;;
+;; Also bear in mind that some modes may dynamically update these
+;; values themselves (for instance dired-mode updates mode-name if
+;; you change the sorting criteria) in which cases this library may
+;; prove inadequate.
+
+;;; Change Log:
+;;
+;; 1.05 (2016-03-01) Support FILE value t, meaning that the minor MODE
+;; in question is guaranteed to already be loaded.
+;; 1.04 (2016-02-28) Respect `inhibit-mode-name-delight' when already set.
+;; 1.03 (2014-05-30) Added support for `mode-line-mode-menu'.
+;; 1.02 (2014-05-04) Bug fix for missing 'cl requirement for
+;; destructuring-bind macro.
+;; 1.01 (2014-05-04) Allow the keyword :major as the FILE argument for
+;; major modes, to avoid also processing them as minor modes.
+;; 1.00 (2013-06-25) Initial release.
+
+;;; Code:
+
+(eval-when-compile
+ (require 'cl))
+
+(defvar delighted-modes ()
+ "List of specs for modifying the display of mode names in the mode line.
+
+See `delight'.")
+
+;;;###autoload
+(defun delight (spec &optional value file)
+ "Modify the lighter value displayed in the mode line for the given mode SPEC
+if and when the mode is loaded.
+
+SPEC can be either a mode symbol, or a list containing multiple elements of
+the form (MODE VALUE FILE). In the latter case the two optional arguments are
+omitted, as they are instead specified for each element of the list.
+
+For minor modes, VALUE is the replacement lighter value (or nil to disable)
+to set in the `minor-mode-alist' variable. For major modes VALUE is the
+replacement buffer-local `mode-name' value to use when a buffer changes to
+that mode.
+
+In both cases VALUE is commonly a string, but may in fact contain any valid
+mode-line construct. For details see the `mode-line-format' variable, and
+Info node `(elisp) Mode Line Format'.
+
+The FILE argument is passed through to `eval-after-load'. If FILE is nil then
+the mode symbol is passed as the required feature. If FILE is t then it is
+assumed that the mode is already loaded. (Note that you can also use 'emacs
+for this purpose). These FILE options are relevant to minor modes only.
+
+For major modes you should specify the keyword :major as the value of FILE,
+to prevent the mode being treated as a minor mode."
+ (add-hook 'after-change-major-mode-hook 'delight-major-mode)
+ (let ((glum (if (consp spec) spec (list (list spec value file)))))
+ (while glum
+ (destructuring-bind (mode &optional value file) (pop glum)
+ (assq-delete-all mode delighted-modes)
+ (add-to-list 'delighted-modes (list mode value file))
+ (unless (eq file :major)
+ (eval-after-load (if (eq file t) 'emacs (or file mode))
+ `(let ((minor-delight (assq ',mode minor-mode-alist)))
+ (when minor-delight
+ (setcar (cdr minor-delight) ',value)
+ (delight-mode-line-mode-menu ',mode ',value)))))))))
+
+(defun delight-mode-line-mode-menu (mode value)
+ "Delight `mode-line-mode-menu' (the \"Toggle minor modes\" menu)
+so that the Lighter text displayed in the menu matches that displayed in
+the mode line (when such menu items exist).
+
+The expected naming scheme for the menu items is: \"Friendly name (Lighter)\"
+e.g.: \"Highlight changes (Chg)\".
+
+We replace the \"Lighter\" portion of that with our delighted VALUE, for the
+specified MODE, unless VALUE is empty/nil, in which case we remove the text
+and parentheses altogether.
+
+If the delighted VALUE is not a string and not nil, we do nothing."
+ (when (string-or-null-p value)
+ (let* ((menu-keymap mode-line-mode-menu)
+ (menu-item (assq mode (cdr menu-keymap))))
+ (when menu-item
+ ;; Lighter text is typically prefixed with a space to separate
+ ;; it from the preceding lighter. We need to trim that space.
+ (let* ((trimmed-value (if (and value (string-match "\\`\\s-+" value))
+ (replace-match "" t t value)
+ value))
+ (wrapped-value (if (> (length trimmed-value) 0)
+ (concat " (" trimmed-value ")")
+ ""))
+ (menu-def (cdr menu-item))
+ (label (cadr menu-def))
+ (new-label (and (stringp label)
+ (or (string-match "\\s-+(.+?)\\s-*\\'" label)
+ (string-match "\\s-*\\'" label))
+ (replace-match wrapped-value t t label))))
+ (when new-label
+ ;; Pure storage is used for the default menu items, so we
+ ;; cannot modify those objects directly.
+ (setq menu-def (copy-sequence menu-def))
+ (setf (cadr menu-def) new-label)
+ (define-key menu-keymap (vector mode) menu-def)))))))
+
+(defun delight-major-mode ()
+ "Delight the 'pretty name' of the current buffer's major mode
+when displayed in the mode-line.
+
+When `mode-name' is displayed in other contexts (such as in the
+`describe-mode' help buffer), its original value will be used."
+ (let ((major-delight (assq major-mode delighted-modes)))
+ (when major-delight
+ (setq mode-name `(inhibit-mode-name-delight
+ ,mode-name ;; glum
+ ,(cadr major-delight)))))) ;; delighted
+
+(defvar inhibit-mode-name-delight)
+
+(defadvice format-mode-line (around delighted-modes-are-glum activate)
+ "Delighted modes should exhibit their original `mode-name' when
+`format-mode-line' is called. See `delight-major-mode'."
+ (let ((inhibit-mode-name-delight (if (boundp 'inhibit-mode-name-delight)
+ inhibit-mode-name-delight
+ t)))
+ ad-do-it))
+
+(provide 'delight)
+;;; delight.el ends here