1 ;;; which-func.el --- print current function in mode line
3 ;; Copyright (C) 1994, 1997-1998, 2001-2012 Free Software Foundation, Inc.
5 ;; Author: Alex Rezinsky <alexr@msil.sps.mot.com>
6 ;; (doesn't seem to be responsive any more)
7 ;; Keywords: mode-line, imenu, tools
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software: you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation, either version 3 of the License, or
14 ;; (at your option) any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
26 ;; This package prints name of function where your current point is
27 ;; located in mode line. It assumes that you work with imenu package
28 ;; and imenu--index-alist is up to date.
32 ;; Really this package shows not "function where the current point is
33 ;; located now", but "nearest function which defined above the current
34 ;; point". So if your current point is located after end of function
35 ;; FOO but before begin of function BAR, FOO will be displayed in mode
37 ;; - if two windows display the same buffer, both windows
38 ;; show the same `which-func' information.
42 ;; 1. Dependence on imenu package should be removed. Separate
43 ;; function determination mechanism should be used to determine the end
44 ;; of a function as well as the beginning of a function.
45 ;; 2. This package should be realized with the help of overlay
46 ;; properties instead of imenu--index-alist variable.
52 ;; Per Abrahamsen <abraham@iesd.auc.dk>
53 ;; Some ideas (inserting in mode-line, using of post-command hook
54 ;; and toggling this mode) have been borrowed from his package
56 ;; Peter Eisenhauer <pipe@fzi.de>
57 ;; Bug fixing in case nested indexes.
58 ;; Terry Tateyama <ttt@ursa0.cs.utah.edu>
59 ;; Suggestion to use find-file-hook for first imenu
64 ;; Variables for customization
65 ;; ---------------------------
67 (defvar which-func-unknown "???"
68 "String to display in the mode line when current function is unknown.")
70 (defgroup which-func nil
71 "Display the current function name in the mode line."
75 (defcustom which-func-modes t
76 ;; '(emacs-lisp-mode c-mode c++-mode objc-mode perl-mode cperl-mode python-mode
77 ;; makefile-mode sh-mode fortran-mode f90-mode ada-mode
79 "List of major modes for which Which Function mode should be used.
80 For other modes it is disabled. If this is equal to t,
81 then Which Function mode is enabled in any major mode that supports it."
83 :version "24.2" ; explicit list -> t
84 :type '(choice (const :tag "All modes" t)
85 (repeat (symbol :tag "Major mode"))))
87 (defcustom which-func-non-auto-modes nil
88 "List of major modes where Which Function mode is inactive till Imenu is used.
89 This means that Which Function mode won't really do anything
90 until you use Imenu, in these modes. Note that files
91 larger than `which-func-maxout' behave in this way too;
92 Which Function mode doesn't do anything until you use Imenu."
94 :type '(repeat (symbol :tag "Major mode")))
96 (defcustom which-func-maxout 500000
97 "Don't automatically compute the Imenu menu if buffer is this big or bigger.
98 Zero means compute the Imenu menu regardless of size."
102 (defvar which-func-keymap
103 (let ((map (make-sparse-keymap)))
104 (define-key map [mode-line mouse-1] 'beginning-of-defun)
105 (define-key map [mode-line mouse-2]
108 (if (eq (point-min) 1)
111 (define-key map [mode-line mouse-3] 'end-of-defun)
113 "Keymap to display on mode line which-func.")
116 ;; Whether `font-lock-function-name-face' is an appropriate face to
117 ;; inherit depends on the mode-line face; define several variants based
118 ;; on the default mode-line face.
119 '(;; The default mode-line face on a high-color display is a relatively
120 ;; light color ("grey75"), and only the light-background variant of
121 ;; `font-lock-function-name-face' is visible against it.
122 (((class color) (min-colors 88) (background light))
123 :inherit font-lock-function-name-face)
124 ;; The default mode-line face on other display types is inverse-video;
125 ;; it seems that only in the dark-background case is
126 ;; `font-lock-function-name-face' visible against it.
127 (((class grayscale mono) (background dark))
128 :inherit font-lock-function-name-face)
129 (((class color) (background light))
130 :inherit font-lock-function-name-face)
131 ;; If none of the above cases, use an explicit color chosen to contrast
132 ;; well with the default mode-line face.
133 (((class color) (min-colors 88) (background dark))
138 :foreground "LightSkyBlue"))
139 "Face used to highlight mode line function names."
142 (defcustom which-func-format
144 (:propertize which-func-current
145 local-map ,which-func-keymap
147 mouse-face mode-line-highlight
148 help-echo "mouse-1: go to beginning\n\
149 mouse-2: toggle rest visibility\n\
152 "Format for displaying the function in the mode line."
153 :version "24.2" ; added mouse-face
156 ;;;###autoload (put 'which-func-format 'risky-local-variable t)
158 (defvar which-func-imenu-joiner-function (lambda (x) (car (last x)))
159 "Function to join together multiple levels of imenu nomenclature.
160 Called with a single argument, a list of strings giving the names
161 of the menus we had to traverse to get to the item. Returns a
162 single string, the new name of the item.")
164 (defvar which-func-cleanup-function nil
165 "Function to transform a string before displaying it in the mode line.
166 The function is called with one argument, the string to display.
167 Its return value is displayed in the mode line.
168 If nil, no function is called. The default value is nil.
170 This feature can be useful if Imenu is set up to make more
171 detailed entries (e.g., containing the argument list of a function),
172 and you want to simplify them for the mode line
173 \(e.g., removing the parameter list to just have the function name.)")
175 ;;; Code, nothing to customize below here
176 ;;; -------------------------------------
180 (defvar which-func-table (make-hash-table :test 'eq :weakness 'key))
182 (defconst which-func-current
183 '(:eval (replace-regexp-in-string
185 (gethash (selected-window) which-func-table which-func-unknown))))
186 ;;;###autoload (put 'which-func-current 'risky-local-variable t)
188 (defvar which-func-mode nil
189 "Non-nil means display current function name in mode line.
190 This makes a difference only if `which-function-mode' is non-nil.")
191 (make-variable-buffer-local 'which-func-mode)
192 ;;(put 'which-func-mode 'permanent-local t)
194 (add-hook 'find-file-hook 'which-func-ff-hook t)
196 (defun which-func-ff-hook ()
197 "File find hook for Which Function mode.
198 It creates the Imenu index for the buffer, if necessary."
199 (setq which-func-mode
200 (and which-function-mode
201 (or (eq which-func-modes t)
202 (member major-mode which-func-modes))))
205 (if (and which-func-mode
206 (not (member major-mode which-func-non-auto-modes))
207 (or (null which-func-maxout)
208 (< buffer-saved-size which-func-maxout)
209 (= which-func-maxout 0)))
210 (setq imenu--index-alist
211 (save-excursion (funcall imenu-create-index-function))))
214 '(user-error "This buffer cannot use `imenu-default-create-index-function'"))
215 (message "which-func-ff-hook error: %S" err))
216 (setq which-func-mode nil))))
218 (defun which-func-update ()
219 ;; "Update the Which-Function mode display for all windows."
220 ;; (walk-windows 'which-func-update-1 nil 'visible))
221 (which-func-update-1 (selected-window)))
223 (defun which-func-update-1 (window)
224 "Update the Which Function mode display for window WINDOW."
225 (with-selected-window window
226 (when which-func-mode
228 (let ((current (which-function)))
229 (unless (equal current (gethash window which-func-table))
230 (puthash window current which-func-table)
231 (force-mode-line-update)))
233 (setq which-func-mode nil)
234 (error "Error in which-func-update: %S" info))))))
237 (defun which-func-mode (&optional arg)
238 (which-function-mode arg))
239 (make-obsolete 'which-func-mode 'which-function-mode "24.1")
241 (defvar which-func-update-timer nil)
243 ;; This is the name people would normally expect.
245 (define-minor-mode which-function-mode
246 "Toggle mode line display of current function (Which Function mode).
247 With a prefix argument ARG, enable Which Function mode if ARG is
248 positive, and disable it otherwise. If called from Lisp, enable
249 the mode if ARG is omitted or nil.
251 Which Function mode is a global minor mode. When enabled, the
252 current function name is continuously displayed in the mode line,
253 in certain major modes."
254 :global t :group 'which-func
255 (when (timerp which-func-update-timer)
256 (cancel-timer which-func-update-timer))
257 (setq which-func-update-timer nil)
258 (if which-function-mode
261 (setq which-func-update-timer
262 (run-with-idle-timer idle-update-delay t 'which-func-update))
263 (dolist (buf (buffer-list))
264 (with-current-buffer buf
265 (setq which-func-mode
266 (or (eq which-func-modes t)
267 (member major-mode which-func-modes))))))
269 (dolist (buf (buffer-list))
270 (with-current-buffer buf (setq which-func-mode nil)))))
272 (defvar which-function-imenu-failed nil
273 "Locally t in a buffer if `imenu--make-index-alist' found nothing there.")
275 (defvar which-func-functions nil
276 "List of functions for `which-function' to call with no arguments.
277 It calls them sequentially, and if any returns non-nil,
278 `which-function' uses that name and stops looking for the name.")
280 (defun which-function ()
281 "Return current function name based on point.
282 Uses `which-func-functions', `imenu--index-alist'
283 or `add-log-current-defun'.
284 If no function name is found, return nil."
286 ;; Try the `which-func-functions' functions first.
287 (run-hook-with-args-until-success 'which-func-functions)))
289 ;; If Imenu is loaded, try to make an index alist with it.
290 (when (and (null name)
291 (boundp 'imenu--index-alist) (null imenu--index-alist)
292 (null which-function-imenu-failed))
293 (imenu--make-index-alist t)
294 (unless imenu--index-alist
295 (set (make-local-variable 'which-function-imenu-failed) t)))
296 ;; If we have an index alist, use it.
297 (when (and (null name)
298 (boundp 'imenu--index-alist) imenu--index-alist)
299 (let ((alist imenu--index-alist)
300 (minoffset (point-max))
301 offset pair mark imstack namestack)
302 ;; Elements of alist are either ("name" . marker), or
303 ;; ("submenu" ("name" . marker) ... ). The list can be
304 ;; arbitrarily nested.
305 (while (or alist imstack)
307 (setq alist (car imstack)
308 namestack (cdr namestack)
309 imstack (cdr imstack))
311 (setq pair (car-safe alist)
312 alist (cdr-safe alist))
315 ((atom pair)) ; Skip anything not a cons.
317 ((imenu--subalist-p pair)
318 (setq imstack (cons alist imstack)
319 namestack (cons (car pair) namestack)
322 ((number-or-marker-p (setq mark (cdr pair)))
323 (when (and (>= (setq offset (- (point) mark)) 0)
324 (< offset minoffset)) ; Find the closest item.
325 (setq minoffset offset
326 name (if (null which-func-imenu-joiner-function)
329 which-func-imenu-joiner-function
330 (reverse (cons (car pair) namestack))))))))))))
332 ;; Try using add-log support.
334 (setq name (add-log-current-defun)))
335 ;; Filter the name if requested.
337 (if which-func-cleanup-function
338 (funcall which-func-cleanup-function name)
342 ;;; Integration with other packages
344 (defun which-func-update-ediff-windows ()
345 "Update Which-Function mode display for Ediff windows.
346 This function is meant to be called from `ediff-select-hook'."
347 (when (eq major-mode 'ediff-mode)
349 (which-func-update-1 ediff-window-A))
351 (which-func-update-1 ediff-window-B))
353 (which-func-update-1 ediff-window-C))))
355 (add-hook 'ediff-select-hook 'which-func-update-ediff-windows)
357 (provide 'which-func)
359 ;;; which-func.el ends here