1;;; msb.el --- customizable buffer-selection with multiple menus
2
3;; Copyright (C) 1993, 1994, 1995, 1997, 1998, 1999, 2000, 2001, 2002,
4;;   2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Author: Lars Lindberg <lars.lindberg@home.se>
7;; Maintainer: FSF
8;; Created: 8 Oct 1993
9;; Lindberg's last update version: 3.34
10;; Keywords: mouse buffer menu
11
12;; This file is part of GNU Emacs.
13
14;; GNU Emacs is free software; you can redistribute it and/or modify
15;; it under the terms of the GNU General Public License as published by
16;; the Free Software Foundation; either version 2, or (at your option)
17;; any later version.
18
19;; GNU Emacs is distributed in the hope that it will be useful,
20;; but WITHOUT ANY WARRANTY; without even the implied warranty of
21;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22;; GNU General Public License for more details.
23
24;; You should have received a copy of the GNU General Public License
25;; along with GNU Emacs; see the file COPYING.  If not, write to the
26;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
27;; Boston, MA 02110-1301, USA.
28
29;;; Commentary:
30
31;; Purpose of this package:
32;;   1. Offer a function for letting the user choose buffer,
33;;      not necessarily for switching to it.
34;;   2. Make a better mouse-buffer-menu.  This is done as a global
35;;      minor mode, msb-mode.
36;;
37;; Customization:
38;;   Look at the variable `msb-menu-cond' for deciding what menus you
39;;   want.  It's not that hard to customize, despite my not-so-good
40;;   doc-string.  Feel free to send me a better doc-string.
41;;   There are some constants for you to try here:
42;;   msb--few-menus
43;;   msb--very-many-menus (default)
44;;
45;;   Look at the variable `msb-item-handling-function' for customization
46;;   of the appearance of every menu item.  Try for instance setting
47;;   it to `msb-alon-item-handler'.
48;;
49;;   Look at the variable `msb-item-sort-function' for customization
50;;   of sorting the menus.  Set it to t for instance, which means no
51;;   sorting - you will get latest used buffer first.
52;;
53;;   Also check out the variable `msb-display-invisible-buffers-p'.
54
55;; Known bugs:
56;; - Files-by-directory
57;;   + No possibility to show client/changed buffers separately.
58;;   + All file buffers only appear in a file sub-menu, they will
59;;     for instance not appear in the Mail sub-menu.
60
61;; Future enhancements:
62
63;;; Thanks goes to
64;;  Mark Brader <msb@sq.com>
65;;  Jim Berry <m1jhb00@FRB.GOV>
66;;  Hans Chalupsky <hans@cs.Buffalo.EDU>
67;;  Larry Rosenberg <ljr@ictv.com>
68;;  Will Henney <will@astroscu.unam.mx>
69;;  Jari Aalto <jaalto@tre.tele.nokia.fi>
70;;  Michael Kifer <kifer@sbkifer.cs.sunysb.edu>
71;;  Gael Marziou <gael@gnlab030.grenoble.hp.com>
72;;  Dave Gillespie <daveg@thymus.synaptics.com>
73;;  Alon Albert <alon@milcse.rtsg.mot.com>
74;;  Kevin Broadey, <KevinB@bartley.demon.co.uk>
75;;  Ake Stenhof <ake@cadpoint.se>
76;;  Richard Stallman <rms@gnu.org>
77;;  Steve Fisk <fisk@medved.bowdoin.edu>
78
79;; This version turned into a global minor mode and subsequently
80;; hacked on by Dave Love.
81;;; Code:
82
83(eval-when-compile (require 'cl))
84
85;;;
86;;; Some example constants to be used for `msb-menu-cond'.  See that
87;;; variable for more information.  Please note that if the condition
88;;; returns `multi', then the buffer can appear in several menus.
89;;;
90(defconst msb--few-menus
91  '(((and (boundp 'server-buffer-clients)
92	  server-buffer-clients
93	  'multi)
94     3030
95     "Clients (%d)")
96    ((and msb-display-invisible-buffers-p
97	  (msb-invisible-buffer-p)
98	  'multi)
99     3090
100     "Invisible buffers (%d)")
101    ((eq major-mode 'dired-mode)
102     2010
103     "Dired (%d)"
104     msb-dired-item-handler
105     msb-sort-by-directory)
106    ((eq major-mode 'Man-mode)
107     4090
108     "Manuals (%d)")
109    ((eq major-mode 'w3-mode)
110     4020
111     "WWW (%d)")
112    ((or (memq major-mode
113	       '(rmail-mode rmail-edit-mode vm-summary-mode vm-mode mail-mode))
114	 (memq major-mode '(mh-letter-mode mh-show-mode mh-folder-mode))
115	 (memq major-mode
116	       '(gnus-summary-mode message-mode gnus-group-mode
117	         gnus-article-mode score-mode gnus-browse-killed-mode)))
118     4010
119     "Mail (%d)")
120    ((not buffer-file-name)
121     4099
122     "Buffers (%d)")
123    ('no-multi
124     1099
125     "Files (%d)")))
126
127(defconst msb--very-many-menus
128  '(((and (boundp 'server-buffer-clients)
129	  server-buffer-clients
130	  'multi)
131     1010
132     "Clients (%d)")
133    ((and (boundp 'vc-mode) vc-mode 'multi)
134     1020
135     "Version Control (%d)")
136    ((and buffer-file-name
137	  (buffer-modified-p)
138	  'multi)
139     1030
140     "Changed files (%d)")
141    ((and (get-buffer-process (current-buffer))
142	  'multi)
143     1040
144     "Processes (%d)")
145    ((and msb-display-invisible-buffers-p
146	  (msb-invisible-buffer-p)
147	  'multi)
148     1090
149     "Invisible buffers (%d)")
150    ((eq major-mode 'dired-mode)
151     2010
152     "Dired (%d)"
153     ;; Note this different menu-handler
154     msb-dired-item-handler
155     ;; Also note this item-sorter
156     msb-sort-by-directory)
157    ((eq major-mode 'Man-mode)
158     5030
159     "Manuals (%d)")
160    ((eq major-mode 'w3-mode)
161     5020
162     "WWW (%d)")
163    ((or (memq major-mode
164	       '(rmail-mode rmail-edit-mode vm-summary-mode vm-mode mail-mode))
165	 (memq major-mode '(mh-letter-mode mh-show-mode mh-folder-mode))
166	 (memq major-mode '(gnus-summary-mode message-mode gnus-group-mode
167			    gnus-article-mode score-mode
168			    gnus-browse-killed-mode)))
169     5010
170     "Mail (%d)")
171    ;; Catchup for all non-file buffers
172    ((and (not buffer-file-name)
173	  'no-multi)
174     5099
175     "Other non-file buffers (%d)")
176    ((and (string-match "/\\.[^/]*$" buffer-file-name)
177	  'multi)
178     3090
179     "Hidden Files (%d)")
180    ((memq major-mode '(c-mode c++-mode))
181     3010
182     "C/C++ Files (%d)")
183    ((eq major-mode 'emacs-lisp-mode)
184     3020
185     "Elisp Files (%d)")
186    ((eq major-mode 'latex-mode)
187     3030
188     "LaTeX Files (%d)")
189    ('no-multi
190     3099
191     "Other files (%d)")))
192
193;; msb--many-menus is obsolete
194(defvar msb--many-menus msb--very-many-menus)
195
196;;;
197;;; Customizable variables
198;;;
199
200(defgroup msb nil
201  "Customizable buffer-selection with multiple menus."
202  :prefix "msb-"
203  :group 'mouse)
204
205(defun msb-custom-set (symbol value)
206  "Set the value of custom variables for msb."
207  (set symbol value)
208  (if (and (featurep 'msb) msb-mode)
209      ;; wait until package has been loaded before bothering to update
210      ;; the buffer lists.
211      (msb-menu-bar-update-buffers t)))
212
213(defcustom msb-menu-cond msb--very-many-menus
214  "*List of criteria for splitting the mouse buffer menu.
215The elements in the list should be of this type:
216 (CONDITION MENU-SORT-KEY MENU-TITLE ITEM-HANDLING-FN ITEM-SORT-FN).
217
218When making the split, the buffers are tested one by one against the
219CONDITION, just like a Lisp cond: When hitting a true condition, the
220other criteria are *not* tested and the buffer name will appear in the
221menu with the menu-title corresponding to the true condition.
222
223If the condition returns the symbol `multi', then the buffer will be
224added to this menu *and* tested for other menus too.  If it returns
225`no-multi', then the buffer will only be added if it hasn't been added
226to any other menu.
227
228During this test, the buffer in question is the current buffer, and
229the test is surrounded by calls to `save-excursion' and
230`save-match-data'.
231
232The categories are sorted by MENU-SORT-KEY.  Smaller keys are on top.
233A value of nil means don't display this menu.
234
235MENU-TITLE is really a format.  If you add %d in it, the %d is
236replaced with the number of items in that menu.
237
238ITEM-HANDLING-FN, is optional.  If it is supplied and is a function,
239than it is used for displaying the items in that particular buffer
240menu, otherwise the function pointed out by
241`msb-item-handling-function' is used.
242
243ITEM-SORT-FN, is also optional.
244If it is not supplied, the function pointed out by
245`msb-item-sort-function' is used.
246If it is nil, then no sort takes place and the buffers are presented
247in least-recently-used order.
248If it is t, then no sort takes place and the buffers are presented in
249most-recently-used order.
250If it is supplied and non-nil and not t than it is used for sorting
251the items in that particular buffer menu.
252
253Note1: There should always be a `catch-all' as last element, in this
254list.  That is an element like (t TITLE ITEM-HANDLING-FUNCTION).
255Note2: A buffer menu appears only if it has at least one buffer in it.
256Note3: If you have a CONDITION that can't be evaluated you will get an
257error every time you do \\[msb]."
258  :type `(choice (const :tag "long" :value ,msb--very-many-menus)
259		 (const :tag "short" :value ,msb--few-menus)
260		 (sexp :tag "user"))
261  :set 'msb-custom-set
262  :group 'msb)
263
264(defcustom msb-modes-key 4000
265  "The sort key for files sorted by mode."
266  :type 'integer
267  :set 'msb-custom-set
268  :group 'msb
269  :version "20.3")
270
271(defcustom msb-separator-diff 100
272  "*Non-nil means use separators.
273The separators will appear between all menus that have a sorting key
274that differs by this value or more."
275  :type '(choice integer (const nil))
276  :set 'msb-custom-set
277  :group 'msb)
278
279(defvar msb-files-by-directory-sort-key 0
280  "*The sort key for files sorted by directory.")
281
282(defcustom msb-max-menu-items 15
283  "*The maximum number of items in a menu.
284If this variable is set to 15 for instance, then the submenu will be
285split up in minor parts, 15 items each.  nil means no limit."
286  :type '(choice integer (const nil))
287  :set 'msb-custom-set
288  :group 'msb)
289
290(defcustom msb-max-file-menu-items 10
291  "*The maximum number of items from different directories.
292
293When the menu is of type `file by directory', this is the maximum
294number of buffers that are clumped together from different
295directories.
296
297Set this to 1 if you want one menu per directory instead of clumping
298them together.
299
300If the value is not a number, then the value 10 is used."
301  :type 'integer
302  :set 'msb-custom-set
303  :group 'msb)
304
305(defcustom msb-most-recently-used-sort-key -1010
306  "*Where should the menu with the most recently used buffers be placed?"
307  :type 'integer
308  :set 'msb-custom-set
309  :group 'msb)
310
311(defcustom msb-display-most-recently-used 15
312  "*How many buffers should be in the most-recently-used menu.
313No buffers at all if less than 1 or nil (or any non-number)."
314  :type 'integer
315  :set 'msb-custom-set
316  :group 'msb)
317
318(defcustom msb-most-recently-used-title "Most recently used (%d)"
319  "*The title for the most-recently-used menu."
320  :type 'string
321  :set 'msb-custom-set
322  :group 'msb)
323
324(defvar msb-horizontal-shift-function '(lambda () 0)
325  "*Function that specifies how many pixels to shift the top menu leftwards.")
326
327(defcustom msb-display-invisible-buffers-p nil
328  "*Show invisible buffers or not.
329Non-nil means that the buffer menu should include buffers that have
330names that starts with a space character."
331  :type 'boolean
332  :set 'msb-custom-set
333  :group 'msb)
334
335(defvar msb-item-handling-function 'msb-item-handler
336  "*The appearance of a buffer menu.
337
338The default function to call for handling the appearance of a menu
339item.  It should take to arguments, BUFFER and MAX-BUFFER-NAME-LENGTH,
340where the latter is the max length of all buffer names.
341
342The function should return the string to use in the menu.
343
344When the function is called, BUFFER is the current buffer.  This
345function is called for items in the variable `msb-menu-cond' that have
346nil as ITEM-HANDLING-FUNCTION.  See `msb-menu-cond' for more
347information.")
348
349(defcustom msb-item-sort-function 'msb-sort-by-name
350  "*The order of items in a buffer menu.
351
352The default function to call for handling the order of items in a menu
353item.  This function is called like a sort function.  The items look
354like (ITEM-NAME . BUFFER).
355
356ITEM-NAME is the name of the item that will appear in the menu.
357BUFFER is the buffer, this is not necessarily the current buffer.
358
359Set this to nil or t if you don't want any sorting (faster)."
360  :type '(choice (const msb-sort-by-name)
361		 (const :tag "Newest first" t)
362		 (const :tag "Oldest first" nil))
363  :set 'msb-custom-set
364  :group 'msb)
365
366(defcustom msb-files-by-directory nil
367  "*Non-nil means that files should be sorted by directory.
368This is instead of the groups in `msb-menu-cond'."
369  :type 'boolean
370  :set 'msb-custom-set
371  :group 'msb)
372
373(defcustom msb-after-load-hook nil
374  "Hook run after the msb package has been loaded."
375  :type 'hook
376  :set 'msb-custom-set
377  :group 'msb)
378
379;;;
380;;; Internal variables
381;;;
382
383;; The last calculated menu.
384(defvar msb--last-buffer-menu nil)
385
386;; If this is non-nil, then it is a string that describes the error.
387(defvar msb--error nil)
388
389;;;
390;;; Some example function to be used for `msb-item-handling-function'.
391;;;
392(defun msb-item-handler (buffer &optional maxbuf)
393  "Create one string item, concerning BUFFER, for the buffer menu.
394The item looks like:
395*% <buffer-name>
396The `*' appears only if the buffer is marked as modified.
397The `%' appears only if the buffer is read-only.
398Optional second argument MAXBUF is completely ignored."
399  (let ((name (buffer-name))
400	(modified (if (buffer-modified-p) "*" " "))
401	(read-only (if buffer-read-only "%" " ")))
402    (format "%s%s %s" modified read-only name)))
403
404
405(eval-when-compile (require 'dired))
406
407;; `dired' can be called with a list of the form (directory file1 file2 ...)
408;; which causes `dired-directory' to be in the same form.
409(defun msb--dired-directory ()
410  (cond ((stringp dired-directory)
411	 (abbreviate-file-name (expand-file-name dired-directory)))
412	((consp dired-directory)
413	 (abbreviate-file-name (expand-file-name (car dired-directory))))
414	(t
415	 (error "Unknown type of `dired-directory' in buffer %s"
416		(buffer-name)))))
417
418(defun msb-dired-item-handler (buffer &optional maxbuf)
419  "Create one string item, concerning a dired BUFFER, for the buffer menu.
420The item looks like:
421*% <buffer-name>
422The `*' appears only if the buffer is marked as modified.
423The `%' appears only if the buffer is read-only.
424Optional second argument MAXBUF is completely ignored."
425  (let ((name (msb--dired-directory))
426	(modified (if (buffer-modified-p) "*" " "))
427	(read-only (if buffer-read-only "%" " ")))
428    (format "%s%s %s" modified read-only name)))
429
430(defun msb-alon-item-handler (buffer maxbuf)
431  "Create one string item for the buffer menu.
432The item looks like:
433<buffer-name> *%# <file-name>
434The `*' appears only if the buffer is marked as modified.
435The `%' appears only if the buffer is read-only.
436The `#' appears only version control file (SCCS/RCS)."
437  (format (format "%%%ds  %%s%%s%%s  %%s" maxbuf)
438          (buffer-name buffer)
439          (if (buffer-modified-p) "*" " ")
440          (if buffer-read-only "%" " ")
441          (if (and (boundp 'vc-mode) vc-mode) "#" " ")
442          (or buffer-file-name "")))
443
444;;;
445;;; Some example function to be used for `msb-item-sort-function'.
446;;;
447(defun msb-sort-by-name (item1 item2)
448  "Sort the items ITEM1 and ITEM2 by their `buffer-name'.
449An item looks like (NAME . BUFFER)."
450  (string-lessp (buffer-name (cdr item1))
451		(buffer-name (cdr item2))))
452
453
454(defun msb-sort-by-directory (item1 item2)
455  "Sort the items ITEM1 and ITEM2 by directory name.  Made for dired.
456An item look like (NAME . BUFFER)."
457  (string-lessp (save-excursion (set-buffer (cdr item1))
458				(msb--dired-directory))
459		(save-excursion (set-buffer (cdr item2))
460				(msb--dired-directory))))
461
462;;;
463;;; msb
464;;;
465;;; This function can be used instead of (mouse-buffer-menu EVENT)
466;;; function in "mouse.el".
467;;;
468(defun msb (event)
469  "Pop up several menus of buffers for selection with the mouse.
470This command switches buffers in the window that you clicked on, and
471selects that window.
472
473See the function `mouse-select-buffer' and the variable
474`msb-menu-cond' for more information about how the menus are split."
475  (interactive "e")
476  (let ((old-window (selected-window))
477	(window (posn-window (event-start event)))
478	early-release)
479    (unless (framep window) (select-window window))
480    ;; This `sit-for' magically makes the menu stay up if the mouse
481    ;; button is released within 0.1 second.
482    (setq early-release (not (sit-for 0.1 t)))
483    (let ((buffer (mouse-select-buffer event)))
484      (if buffer
485	  (switch-to-buffer buffer)
486	(select-window old-window)))
487    ;; If the above `sit-for' was interrupted by a mouse-up, avoid
488    ;; generating a drag event.
489    (if (and early-release (memq 'down (event-modifiers last-input-event)))
490	(discard-input)))
491  nil)
492
493;;;
494;;; Some supportive functions
495;;;
496(defun msb-invisible-buffer-p (&optional buffer)
497  "Return t if optional BUFFER is an \"invisible\" buffer.
498If the argument is left out or nil, then the current buffer is considered."
499  (and (> (length (buffer-name buffer)) 0)
500       (eq ?\s (aref (buffer-name buffer) 0))))
501
502(defun msb--strip-dir (dir)
503  "Strip one hierarchy level from the end of DIR."
504  (file-name-directory (directory-file-name dir)))
505
506;; Create an alist with all buffers from LIST that lies under the same
507;; directory will be in the same item as the directory name.
508;; ((DIR1 . (BUFFER-1 BUFFER-2 ...)) (DIR2 . (BUFFER-K BUFFER-K+1...)) ...)
509(defun msb--init-file-alist (list)
510  (let ((buffer-alist
511	 ;; Make alist that looks like
512	 ;; ((DIR-1 BUFFER-1) (DIR-2 BUFFER-2) ...)
513	 ;; sorted on DIR-x
514	 (sort
515	  (apply #'nconc
516		 (mapcar
517		  (lambda (buffer)
518		    (let ((file-name (expand-file-name
519				      (buffer-file-name buffer))))
520		      (when file-name
521			(list (cons (msb--strip-dir file-name) buffer)))))
522		  list))
523	  (lambda (item1 item2)
524	    (string< (car item1) (car item2))))))
525    ;; Now clump buffers together that have the same directory name
526    ;; Make alist that looks like
527    ;; ((DIR1 . (BUFFER-1 BUFFER-2 ...)) (DIR2 . (BUFFER-K)) ...)
528    (let ((dir nil)
529	  (buffers nil))
530      (nconc
531       (apply
532	#'nconc
533	(mapcar (lambda (item)
534		  (cond
535		   ((equal dir (car item))
536		    ;; The same dir as earlier:
537		    ;; Add to current list of buffers.
538		    (push (cdr item) buffers)
539		    ;; This item should not be added to list
540		    nil)
541		   (t
542		    ;; New dir
543		    (let ((result (and dir (cons dir buffers))))
544		      (setq dir (car item))
545		      (setq buffers (list (cdr item)))
546		      ;; Add the last result the list.
547		      (and result (list result))))))
548		buffer-alist))
549       ;; Add the last result to the list
550       (list (cons dir buffers))))))
551
552(defun msb--format-title (top-found-p dir number-of-items)
553  "Format a suitable title for the menu item."
554  (format (if top-found-p "%s... (%d)" "%s (%d)")
555	  (abbreviate-file-name dir) number-of-items))
556
557;; Variables for debugging.
558(defvar msb--choose-file-menu-list)
559(defvar msb--choose-file-menu-arg-list)
560
561(defun msb--choose-file-menu (list)
562  "Choose file-menu with respect to directory for every buffer in LIST."
563  (setq msb--choose-file-menu-arg-list list)
564  (let ((buffer-alist (msb--init-file-alist list))
565	(final-list nil)
566	(max-clumped-together (if (numberp msb-max-file-menu-items)
567				  msb-max-file-menu-items
568				10))
569	(top-found-p nil)
570	(last-dir nil)
571	first rest dir buffers old-dir)
572    ;; Prepare for looping over all items in buffer-alist
573    (setq first (car buffer-alist)
574	  rest (cdr buffer-alist)
575	  dir (car first)
576	  buffers (cdr first))
577    (setq msb--choose-file-menu-list (copy-sequence rest))
578    ;; This big loop tries to clump buffers together that have a
579    ;; similar name. Remember that buffer-alist is sorted based on the
580    ;; directory name of the buffers' visited files.
581    (while rest
582      (let ((found-p nil)
583	    (tmp-rest rest)
584	    result
585	    new-dir item)
586	(setq item (car tmp-rest))
587	;; Clump together the "rest"-buffers that have a dir that is
588	;; a subdir of the current one.
589	(while (and tmp-rest
590		    (<= (length buffers) max-clumped-together)
591		    (>= (length (car item)) (length dir))
592		    ;; `completion-ignore-case' seems to default to t
593		    ;; on the systems with case-insensitive file names.
594		    (eq t (compare-strings dir 0 nil
595					   (car item) 0 (length dir)
596					   completion-ignore-case)))
597	  (setq found-p t)
598	  (setq buffers (append buffers (cdr item))) ;nconc is faster than append
599	  (setq tmp-rest (cdr tmp-rest)
600		item (car tmp-rest)))
601	(cond
602	 ((> (length buffers) max-clumped-together)
603	  ;; Oh, we failed. Too many buffers clumped together.
604	  ;; Just use the original ones for the result.
605	  (setq last-dir (car first))
606	  (push (cons (msb--format-title top-found-p
607					 (car first)
608					 (length (cdr first)))
609		      (cdr first))
610		final-list)
611	  (setq top-found-p nil)
612	  (setq first (car rest)
613		rest (cdr rest)
614		dir (car first)
615		buffers (cdr first)))
616	 (t
617	  ;; The first pass of clumping together worked out, go ahead
618	  ;; with this result.
619	  (when found-p
620	    (setq top-found-p t)
621	    (setq first (cons dir buffers)
622		  rest tmp-rest))
623	  ;; Now see if we can clump more buffers together if we go up
624	  ;; one step in the file hierarchy.
625	  ;; If dir isn't changed by msb--strip-dir, we are looking
626	  ;; at the machine name component of an ange-ftp filename.
627	  (setq old-dir dir)
628	  (setq dir (msb--strip-dir dir)
629		buffers (cdr first))
630	  (if (equal old-dir dir)
631	      (setq last-dir dir))
632	  (when (and last-dir
633		     (or (and (>= (length dir) (length last-dir))
634			      (eq t (compare-strings
635				     last-dir 0 nil dir 0
636				     (length last-dir)
637				     completion-ignore-case)))
638			 (and (< (length dir) (length last-dir))
639			      (eq t (compare-strings
640				     dir 0 nil last-dir 0 (length dir)
641				     completion-ignore-case)))))
642	    ;; We have reached the same place in the file hierarchy as
643	    ;; the last result, so we should quit at this point and
644	    ;; take what we have as result.
645	    (push (cons (msb--format-title top-found-p
646					   (car first)
647					   (length (cdr first)))
648			(cdr first))
649		  final-list)
650	    (setq top-found-p nil)
651	    (setq first (car rest)
652		  rest (cdr rest)
653		  dir (car first)
654		  buffers (cdr first)))))))
655    ;; Now take care of the last item.
656    (when first
657      (push (cons (msb--format-title top-found-p
658				     (car first)
659				     (length (cdr first)))
660		  (cdr first))
661	    final-list))
662    (setq top-found-p nil)
663    (nreverse final-list)))
664
665(defun msb--create-function-info (menu-cond-elt)
666  "Create a vector from an element MENU-COND-ELT of `msb-menu-cond'.
667This takes the form:
668\]BUFFER-LIST-VARIABLE CONDITION MENU-SORT-KEY MENU-TITLE ITEM-HANDLER SORTER)
669See `msb-menu-cond' for a description of its elements."
670  (let* ((list-symbol (make-symbol "-msb-buffer-list"))
671	 (tmp-ih (and (> (length menu-cond-elt) 3)
672		      (nth 3 menu-cond-elt)))
673	 (item-handler (if (and tmp-ih (fboundp tmp-ih))
674			   tmp-ih
675			 msb-item-handling-function))
676	 (tmp-s (if (> (length menu-cond-elt) 4)
677		    (nth 4 menu-cond-elt)
678		  msb-item-sort-function))
679	 (sorter (if (or (fboundp tmp-s)
680			 (null tmp-s)
681			 (eq tmp-s t))
682		     tmp-s
683		   msb-item-sort-function)))
684    (when (< (length menu-cond-elt) 3)
685      (error "Wrong format of msb-menu-cond"))
686    (when (and (> (length menu-cond-elt) 3)
687	       (not (fboundp tmp-ih)))
688      (signal 'invalid-function (list tmp-ih)))
689    (when (and (> (length menu-cond-elt) 4)
690	       tmp-s
691	       (not (fboundp tmp-s))
692	       (not (eq tmp-s t)))
693      (signal 'invalid-function (list tmp-s)))
694    (set list-symbol ())
695    (vector list-symbol			;BUFFER-LIST-VARIABLE
696	    (nth 0 menu-cond-elt)	;CONDITION
697	    (nth 1 menu-cond-elt)	;SORT-KEY
698	    (nth 2 menu-cond-elt)	;MENU-TITLE
699	    item-handler		;ITEM-HANDLER
700	    sorter)			;SORTER
701    ))
702
703;; This defsubst is only used in `msb--choose-menu' below.  It was
704;; pulled out merely to make the code somewhat clearer.  The indentation
705;; level was too big.
706(defsubst msb--collect (function-info-vector)
707  (let ((result nil)
708	(multi-flag nil)
709	function-info-list)
710    (setq function-info-list
711	  (loop for fi
712		across function-info-vector
713		if (and (setq result
714			      (eval (aref fi 1))) ;Test CONDITION
715			(not (and (eq result 'no-multi)
716				  multi-flag))
717			(progn (when (eq result 'multi)
718				 (setq multi-flag t))
719			       t))
720		collect fi
721		until (and result
722			   (not (eq result 'multi)))))
723    (when (and (not function-info-list)
724	       (not result))
725      (error "No catch-all in msb-menu-cond!"))
726    function-info-list))
727
728(defun msb--add-to-menu (buffer function-info max-buffer-name-length)
729  "Add BUFFER to the menu depicted by FUNCTION-INFO.
730All side-effects.  Adds an element of form (BUFFER-TITLE . BUFFER)
731to the buffer-list variable in function-info."
732  (let ((list-symbol (aref function-info 0))) ;BUFFER-LIST-VARIABLE
733    ;; Here comes the hairy side-effect!
734    (set list-symbol
735	 (cons (cons (funcall (aref function-info 4) ;ITEM-HANDLER
736			      buffer
737			      max-buffer-name-length)
738		     buffer)
739	       (eval list-symbol)))))
740
741(defsubst msb--choose-menu (buffer function-info-vector max-buffer-name-length)
742  "Select the appropriate menu for BUFFER."
743  ;; This is all side-effects, folks!
744  ;; This should be optimized.
745  (unless (and (not msb-display-invisible-buffers-p)
746	       (msb-invisible-buffer-p buffer))
747    (condition-case nil
748	(save-excursion
749	  (set-buffer buffer)
750	  ;; Menu found.  Add to this menu
751	  (dolist (info (msb--collect function-info-vector))
752	    (msb--add-to-menu buffer info max-buffer-name-length)))
753      (error (unless msb--error
754	       (setq msb--error
755		     (format
756		      "In msb-menu-cond, error for buffer `%s'."
757		      (buffer-name buffer)))
758	       (error "%s" msb--error))))))
759
760(defun msb--create-sort-item (function-info)
761  "Return (SORT-KEY TITLE . BUFFER-LIST) or nil if the buffer-list is empty."
762  (let ((buffer-list (eval (aref function-info 0))))
763    (when buffer-list
764      (let ((sorter (aref function-info 5)) ;SORTER
765	    (sort-key (aref function-info 2))) ;MENU-SORT-KEY
766	(when sort-key
767	  (cons sort-key
768		(cons (format (aref function-info 3) ;MENU-TITLE
769			      (length buffer-list))
770		      (cond
771		       ((null sorter)
772			buffer-list)
773		       ((eq sorter t)
774			(nreverse buffer-list))
775		       (t
776			(sort buffer-list sorter))))))))))
777
778(defun msb--aggregate-alist (alist same-predicate sort-predicate)
779  "Return ALIST as a sorted, aggregated alist.
780
781In the result all items with the same car element (according to
782SAME-PREDICATE) are aggregated together.  The alist is first sorted by
783SORT-PREDICATE.
784
785Example:
786\(msb--aggregate-alist
787 '((a . a1) (a . a2) (b . b1) (c . c3) (a . a4) (a . a3) (b . b3) (b . b2))
788 (function string=)
789 (lambda (item1 item2)
790   (string< (symbol-name item1) (symbol-name item2))))
791results in
792\((a a1 a2 a4 a3) (b b1 b3 b2) (c c3))"
793  (when (not (null alist))
794    (let (result
795	  same
796	  tmp-old-car
797	  tmp-same
798	  (first-time-p t)
799	  old-car)
800      (nconc
801       (apply #'nconc
802	      (mapcar
803	       (lambda (item)
804		 (cond
805		  (first-time-p
806		   (push (cdr item) same)
807		   (setq first-time-p nil)
808		   (setq old-car (car item))
809		   nil)
810		  ((funcall same-predicate (car item) old-car)
811		   (push (cdr item) same)
812		   nil)
813		  (t
814		   (setq tmp-same same
815			 tmp-old-car old-car)
816		   (setq same (list (cdr item))
817			 old-car (car item))
818		   (list (cons tmp-old-car (nreverse tmp-same))))))
819	       (sort alist (lambda (item1 item2)
820			     (funcall sort-predicate (car item1) (car item2))))))
821       (list (cons old-car (nreverse same)))))))
822
823
824(defun msb--mode-menu-cond ()
825  (let ((key msb-modes-key))
826    (mapcar (lambda (item)
827	      (incf key)
828	      (list `( eq major-mode (quote ,(car item)))
829		    key
830		    (concat (cdr item) " (%d)")))
831	    (sort
832	     (let ((mode-list nil))
833	       (dolist (buffer (cdr (buffer-list)))
834		 (save-excursion
835		   (set-buffer buffer)
836		   (when (and (not (msb-invisible-buffer-p))
837			      (not (assq major-mode mode-list)))
838		     (push (cons major-mode mode-name)
839			   mode-list))))
840	       mode-list)
841	     (lambda (item1 item2)
842	       (string< (cdr item1) (cdr item2)))))))
843
844(defun msb--most-recently-used-menu (max-buffer-name-length)
845  "Return a list for the most recently used buffers.
846It takes the form ((TITLE . BUFFER-LIST)...)."
847  (when (and (numberp msb-display-most-recently-used)
848 	     (> msb-display-most-recently-used 0))
849    (let* ((buffers (cdr (buffer-list)))
850	   (most-recently-used
851	    (loop with n = 0
852		  for buffer in buffers
853		  if (save-excursion
854		       (set-buffer buffer)
855		       (and (not (msb-invisible-buffer-p))
856			    (not (eq major-mode 'dired-mode))))
857		  collect (save-excursion
858			    (set-buffer buffer)
859			    (cons (funcall msb-item-handling-function
860					   buffer
861					   max-buffer-name-length)
862				  buffer))
863		  and do (incf n)
864		  until (>= n msb-display-most-recently-used))))
865      (cons (if (stringp msb-most-recently-used-title)
866		(format msb-most-recently-used-title
867			(length most-recently-used))
868	      (signal 'wrong-type-argument (list msb-most-recently-used-title)))
869	    most-recently-used))))
870
871(defun msb--create-buffer-menu-2 ()
872  (let ((max-buffer-name-length 0)
873	file-buffers
874	function-info-vector)
875    ;; Calculate the longest buffer name.
876    (dolist (buffer (buffer-list))
877      (when (or msb-display-invisible-buffers-p
878		(not (msb-invisible-buffer-p)))
879	(setq max-buffer-name-length
880	      (max max-buffer-name-length (length (buffer-name buffer))))))
881    ;; Make a list with elements of type
882    ;; (BUFFER-LIST-VARIABLE
883    ;;  CONDITION
884    ;;  MENU-SORT-KEY
885    ;;  MENU-TITLE
886    ;;  ITEM-HANDLER
887    ;;  SORTER)
888    ;; Uses "function-global" variables:
889    ;; function-info-vector
890    (setq function-info-vector
891	  (apply (function vector)
892		 (mapcar (function msb--create-function-info)
893			 (append msb-menu-cond (msb--mode-menu-cond)))))
894    ;; Split the buffer-list into several lists; one list for each
895    ;; criteria.  This is the most critical part with respect to time.
896    (dolist (buffer (buffer-list))
897      (cond ((and msb-files-by-directory
898		  (buffer-file-name buffer)
899		  ;; exclude ange-ftp buffers
900		  ;;(not (string-match "\\/[^/:]+:"
901		  ;;		   (buffer-file-name buffer)))
902		  )
903	     (push buffer file-buffers))
904	    (t
905	     (msb--choose-menu buffer
906			       function-info-vector
907			       max-buffer-name-length))))
908    (when file-buffers
909      (setq file-buffers
910	    (mapcar (lambda (buffer-list)
911		      (cons msb-files-by-directory-sort-key
912			    (cons (car buffer-list)
913				  (sort
914				   (mapcar (function
915					    (lambda (buffer)
916					      (cons (save-excursion
917						      (set-buffer buffer)
918						      (funcall msb-item-handling-function
919							       buffer
920							       max-buffer-name-length))
921						    buffer)))
922					   (cdr buffer-list))
923				   (function
924				    (lambda (item1 item2)
925				      (string< (car item1) (car item2))))))))
926		     (msb--choose-file-menu file-buffers))))
927    ;; Now make the menu - a list of (TITLE . BUFFER-LIST)
928    (let* (menu
929	   (most-recently-used
930	    (msb--most-recently-used-menu max-buffer-name-length))
931	   (others (nconc file-buffers
932			   (loop for elt
933				 across function-info-vector
934				 for value = (msb--create-sort-item elt)
935				 if value collect value))))
936      (setq menu
937	    (mapcar 'cdr		;Remove the SORT-KEY
938		    ;; Sort the menus - not the items.
939		    (msb--add-separators
940		    (sort
941		     ;; Get a list of (SORT-KEY TITLE . BUFFER-LIST)
942		     ;; Also sorts the items within the menus.
943		     (if (cdr most-recently-used)
944			 (cons
945			  ;; Add most recent used buffers
946			  (cons msb-most-recently-used-sort-key
947				most-recently-used)
948			  others)
949		       others)
950		     (lambda (elt1 elt2)
951		       (< (car elt1) (car elt2)))))))
952      ;; Now make it a keymap menu
953      (append
954       '(keymap "Select Buffer")
955       (msb--make-keymap-menu menu)
956       (when msb-separator-diff
957	 (list (list 'separator "--")))
958       (list (cons 'toggle
959		   (cons
960		   (if msb-files-by-directory
961			       "*Files by type*"
962			     "*Files by directory*")
963			   'msb--toggle-menu-type)))))))
964
965(defun msb--create-buffer-menu  ()
966  (save-match-data
967    (save-excursion
968      (msb--create-buffer-menu-2))))
969
970(defun msb--toggle-menu-type ()
971  "Multi purpose function for selecting a buffer with the mouse."
972  (interactive)
973  (setq msb-files-by-directory (not msb-files-by-directory))
974  ;; This gets a warning, but it is correct,
975  ;; because this file redefines menu-bar-update-buffers.
976  (msb-menu-bar-update-buffers t))
977
978(defun mouse-select-buffer (event)
979  "Pop up several menus of buffers, for selection with the mouse.
980Returns the selected buffer or nil if no buffer is selected.
981
982The way the buffers are split is conveniently handled with the
983variable `msb-menu-cond'."
984  ;; Popup the menu and return the selected buffer.
985  (when (or msb--error
986	    (not msb--last-buffer-menu)
987	    (not (fboundp 'frame-or-buffer-changed-p))
988	    (frame-or-buffer-changed-p))
989    (setq msb--error nil)
990    (setq msb--last-buffer-menu (msb--create-buffer-menu)))
991  (let ((position event)
992	choice)
993    (when (and (fboundp 'posn-x-y)
994	       (fboundp 'posn-window))
995      (let ((posX (car (posn-x-y (event-start event))))
996	    (posY (cdr (posn-x-y (event-start event))))
997	    (posWind (posn-window (event-start event))))
998	;; adjust position
999	(setq posX (- posX (funcall msb-horizontal-shift-function))
1000	      position (list (list posX posY) posWind))))
1001    ;; Popup the menu
1002    (setq choice (x-popup-menu position msb--last-buffer-menu))
1003    (cond
1004     ((eq (car choice) 'toggle)
1005      ;; Bring up the menu again with type toggled.
1006      (msb--toggle-menu-type)
1007      (mouse-select-buffer event))
1008     ((and (numberp (car choice))
1009	   (null (cdr choice)))
1010      (let ((msb--last-buffer-menu (nthcdr 2 (assq (car choice)
1011						   msb--last-buffer-menu))))
1012	(mouse-select-buffer event)))
1013     ((while (numberp (car choice))
1014	(setq choice (cdr choice))))
1015     ((and (stringp (car choice))
1016	   (null (cdr choice)))
1017      (car choice))
1018     ((null choice)
1019      choice)
1020     (t
1021      (error "Unknown form for buffer: %s" choice)))))
1022
1023;; Add separators
1024(defun msb--add-separators (sorted-list)
1025  (if (or (not msb-separator-diff)
1026	  (not (numberp msb-separator-diff)))
1027      sorted-list
1028    (let ((last-key nil))
1029      (apply #'nconc
1030	     (mapcar
1031	      (lambda (item)
1032		(cond
1033		 ((and msb-separator-diff
1034		       last-key
1035		       (> (- (car item) last-key)
1036			  msb-separator-diff))
1037		  (setq last-key (car item))
1038		  (list (cons last-key 'separator)
1039			item))
1040		 (t
1041		  (setq last-key (car item))
1042		  (list item))))
1043	      sorted-list)))))
1044
1045(defun msb--split-menus-2 (list mcount result)
1046  (cond
1047   ((> (length list) msb-max-menu-items)
1048    (let ((count 0)
1049	  sub-name
1050	  (tmp-list nil))
1051      (while (< count msb-max-menu-items)
1052	(push (pop list) tmp-list)
1053	(incf count))
1054      (setq tmp-list (nreverse tmp-list))
1055      (setq sub-name (concat (car (car tmp-list)) "..."))
1056      (push (nconc (list mcount sub-name
1057			 'keymap sub-name)
1058		   tmp-list)
1059	    result))
1060    (msb--split-menus-2 list (1+ mcount) result))
1061   ((null result)
1062    list)
1063   (t
1064    (let (sub-name)
1065      (setq sub-name (concat (car (car list)) "..."))
1066      (push (nconc (list mcount sub-name 'keymap sub-name)
1067		   list)
1068	    result))
1069    (nreverse result))))
1070
1071(defun msb--split-menus (list)
1072  (if (and (integerp msb-max-menu-items)
1073	   (> msb-max-menu-items 0))
1074      (msb--split-menus-2 list 0 nil)
1075    list))
1076
1077(defun msb--make-keymap-menu (raw-menu)
1078  (let ((end (cons '(nil) 'menu-bar-select-buffer))
1079	(mcount 0))
1080    (mapcar
1081     (lambda (sub-menu)
1082       (cond
1083	((eq 'separator sub-menu)
1084	 (list 'separator "--"))
1085	(t
1086	 (let ((buffers (mapcar (lambda (item)
1087				  (cons (buffer-name (cdr item))
1088					(cons (car item) end)))
1089				(cdr sub-menu))))
1090	   (nconc (list (incf mcount) (car sub-menu)
1091			'keymap (car sub-menu))
1092		  (msb--split-menus buffers))))))
1093     raw-menu)))
1094
1095(defun msb-menu-bar-update-buffers (&optional arg)
1096  "A re-written version of `menu-bar-update-buffers'."
1097  ;; If user discards the Buffers item, play along.
1098  (when (and (lookup-key (current-global-map) [menu-bar buffer])
1099	     (or (not (fboundp 'frame-or-buffer-changed-p))
1100		 (frame-or-buffer-changed-p)
1101		 arg))
1102    (let ((frames (frame-list))
1103	  buffers-menu frames-menu)
1104      ;; Make the menu of buffers proper.
1105      (setq msb--last-buffer-menu (msb--create-buffer-menu))
1106      (setq buffers-menu msb--last-buffer-menu)
1107      ;; Make a Frames menu if we have more than one frame.
1108      (when (cdr frames)
1109	(let* ((frame-length (length frames))
1110	       (f-title  (format "Frames (%d)" frame-length)))
1111	  ;; List only the N most recently selected frames
1112	  (when (and (integerp msb-max-menu-items)
1113		     (>  msb-max-menu-items 1)
1114		     (> frame-length msb-max-menu-items))
1115	    (setcdr (nthcdr msb-max-menu-items frames) nil))
1116	  (setq frames-menu
1117		(nconc
1118		 (list 'frame f-title '(nil) 'keymap f-title)
1119		 (mapcar
1120		  (lambda (frame)
1121		    (nconc
1122		     (list (frame-parameter frame 'name)
1123			   (frame-parameter frame 'name)
1124			   (cons nil nil))
1125		     'menu-bar-select-frame))
1126		  frames)))))
1127      (define-key (current-global-map) [menu-bar buffer]
1128	(cons "Buffers"
1129	      (if (and buffers-menu frames-menu)
1130		  ;; Combine Frame and Buffers menus with separator between
1131		  (nconc (list 'keymap "Buffers and Frames" frames-menu
1132			       (and msb-separator-diff '(separator "--")))
1133			 (cddr buffers-menu))
1134		(or buffers-menu 'undefined)))))))
1135
1136;; Snarf current bindings of `mouse-buffer-menu' (normally
1137;; C-down-mouse-1).
1138(defvar msb-mode-map
1139  (let ((map (make-sparse-keymap "Msb")))
1140    (define-key map [remap mouse-buffer-menu] 'msb)
1141    map))
1142
1143;;;###autoload
1144(define-minor-mode msb-mode
1145  "Toggle Msb mode.
1146With arg, turn Msb mode on if and only if arg is positive.
1147This mode overrides the binding(s) of `mouse-buffer-menu' to provide a
1148different buffer menu using the function `msb'."
1149  :global t :group 'msb
1150  (if msb-mode
1151      (progn
1152	(add-hook 'menu-bar-update-hook 'msb-menu-bar-update-buffers)
1153	(remove-hook 'menu-bar-update-hook 'menu-bar-update-buffers)
1154	(msb-menu-bar-update-buffers t))
1155    (remove-hook 'menu-bar-update-hook 'msb-menu-bar-update-buffers)
1156    (add-hook 'menu-bar-update-hook 'menu-bar-update-buffers)
1157    (menu-bar-update-buffers t)))
1158
1159(defun msb-unload-hook ()
1160  (msb-mode 0))
1161(add-hook 'msb-unload-hook 'msb-unload-hook)
1162
1163(provide 'msb)
1164(eval-after-load "msb" '(run-hooks 'msb-after-load-hook 'msb-after-load-hooks))
1165
1166;;; arch-tag: 403f9e82-b92e-4e7a-a797-5d6d9b76da36
1167;;; msb.el ends here
1168