SGI Freeware 1999 August/SGI Freeware 1999 August.iso/dist/fw_emacs.idb/usr/freeware/share/emacs/19.34/lisp/uniquify.el.z/uniquify.el

Text File | 1998-10-28 | 15.0 KB | 385 lines

;;; uniquify.el --- unique buffer names dependent on file name

;; Copyright (c) 1989, 1995 Free Software Foundation, Inc.

;; Author: Dick King <[e-mail]>
;; Maintainer: Michael Ernst <[e-mail]>
;; Created: 15 May 86

;; 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., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; Emacs's standard method for making buffer names unique adds <2>, <3>,
;; etc. to the end of (all but one of) the buffers.  This file replaces
;; that behavior, for buffers visiting files and dired buffers, with a
;; uniquification that adds parts of the file name until the buffer names
;; are unique.  For instance, buffers visiting /u/mernst/tmp/Makefile and
;; /usr/projects/zaphod/Makefile would be named Makefile|tmp and
;; Makefile|zaphod, respectively (instead of Makefile and Makefile<2>).
;; Other buffer name styles are also available.

;; To use this file, just load it.
;; To disable it after loading, set variable uniquify-buffer-name-style to nil.
;; For other options, see "User-visible variables", below.

;; A version of uniquify.el that works under Emacs 18, Emacs 19, XEmacs,
;; and InfoDock is available from the maintainer.

;;; Change Log:

;; Originally by Dick King <[e-mail]> 15 May 86
;; Converted for Emacs 18 by Stephen Gildea <[e-mail]>
;; Make uniquify-min-dir-content 0 truly non-invasive.  gildea 23 May 89
;; Some cleanup.  uniquify-min-dir-content default 0.  gildea 01 Jun 89
;; Don't rename to "".  Michael Ernst <[e-mail]> 15 Jun 94
;; Add kill-buffer-hook.  Kenneth Manheimer <[e-mail]> 09 May 95
;; Add advice for rename-buffer and create-file-buffer, handle dired buffers,
;;  kill-buffer-rationalize-buffer-names-p, documentation.  mernst 24 May 95
;; Remove free variables, fix typos.  mernst 5 Jun 95
;; Efficiently support Emacs 19.27 & earlier.  ken.manheimer, mernst 10 Jun 95
;; Rename user options to "uniquify-...", add uniquify-reverse-dir-content-p,
;;  add uniquify-ask-about-buffer-names-p.  king, mernst 13 Jun 95
;; Prefix functions by "uniquify-..."; rename mnemonic-buffer-names to
;;  uniquify-buffer-name-style; add 'forward and 'post-forward-angle-brackets
;;  styles; remove uniquify-reverse-dir-content-p; add
;;  uniquify-trailing-separator-p.  mernst 4 Aug 95

;; Valuable feedback was provided by
;; Paul Smith <[e-mail]>,
;; Alastair Burt <[e-mail]>,
;; Bob Weiner <[e-mail]>,
;; Albert L. Ting <[e-mail]>,
;; [e-mail].


;;; Code:

(provide 'uniquify)

;;; User-visible variables

(defvar uniquify-buffer-name-style 'post-forward
  "*If non-nil, buffer names are uniquified with parts of directory name.
The value determines the buffer name style and is one of `forward',
`reverse', `post-forward' (the default), or `post-forward-angle-brackets'.
For example, files `/foo/bar/mumble/name' and `/baz/quux/mumble/name'
would have the following buffer names in the various styles:
  forward        bar/mumble/name  quux/mumble/name
  reverse        name\\mumble\\bar  name\\mumble\\quux
  post-forward   name|bar/mumble  name|quux/mumble
  post-forward-angle-brackets   name<bar/mumble>  name<quux/mumble>
  nil            name  name<2>")

(defvar uniquify-after-kill-buffer-p nil
  "*If non-nil, rerationalize buffer names after a buffer has been killed.
This can be dangerous if Emacs Lisp code is keeping track of buffers by their
names (rather than keeping pointers to the buffers themselves).")

(defconst uniquify-ask-about-buffer-names-p nil
  "*If non-nil, permit user to choose names for buffers with same base file.
If the user chooses to name a buffer, uniquification is preempted and no
other buffer names are changed.")

(defvar uniquify-min-dir-content 0
  "*Minimum parts of directory name included in buffer name.")

(defvar uniquify-separator nil
  "*String separator for buffer name components.
When `uniquify-buffer-name-style' is `post-forward', separates
base file name from directory part in buffer names (default \"|\").
When `uniquify-buffer-name-style' is `reverse', separates all
file name components (default \"\\\").")

(defvar uniquify-trailing-separator-p nil
  "*If non-nil, add a file name separator to dired buffer names.
If `uniquify-buffer-name-style' is `forward', add the separator at the end;
if it is `reverse', add the separator at the beginning; otherwise, this
variable is ignored.")


;;; Utilities

(defmacro uniquify-push (item list)
  (` (setq (, list) (cons (, item) (, list)))))

(defmacro uniquify-fix-list-base (a)
  (` (car (, a))))

(defmacro uniquify-fix-list-filename (a)
  (` (car (cdr (, a)))))

(defmacro uniquify-fix-list-buffer (a)
  (` (car (cdr (cdr (, a))))))

(defmacro uniquify-cadddr (a)
  (` (car (cdr (cdr (cdr (, a)))))))

;; Internal variables used free
(defvar uniquify-non-file-buffer-names nil)
(defvar uniquify-possibly-resolvable nil)

;;; Main entry point.

(defun uniquify-rationalize-file-buffer-names (&optional newbuffile newbuf)
  "Makes file buffer names unique by adding segments from file name.
If `uniquify-min-dir-content' > 0, always pulls that many
file name elements.  Arguments cause only a subset of buffers to be renamed."
  (interactive)
  (let (fix-list
    uniquify-non-file-buffer-names
    (depth uniquify-min-dir-content))
    (let ((buffers (buffer-list)))
      (while buffers
    (let* ((buffer (car buffers))
           (bfn (if (eq buffer newbuf)
            (and newbuffile
                 (expand-file-name newbuffile))
              (uniquify-buffer-file-name buffer)))
           (rawname (and bfn (file-name-nondirectory bfn)))
           (deserving (and rawname
                   (or (not newbuffile)
                   (equal rawname
                      (file-name-nondirectory newbuffile))))))
      (if deserving
          (uniquify-push (list rawname bfn buffer nil) fix-list)
        (uniquify-push (list (buffer-name buffer))
               uniquify-non-file-buffer-names)))
    (setq buffers (cdr buffers))))
    ;; selects buffers whose names may need changing, and others that
    ;; may conflict.
    (setq fix-list
      (sort fix-list 'uniquify-fix-list-filename-lessp))
    ;; bringing conflicting names together
    (uniquify-rationalize-a-list fix-list depth)
    (mapcar 'uniquify-unrationalized-buffer fix-list)))

;; uniquify's version of buffer-file-name
(defun uniquify-buffer-file-name (buffer)
  "Return name of file BUFFER is visiting, or nil if none.
Works on dired buffers as well as ordinary file-visiting buffers."
  (or (buffer-file-name buffer)
      (save-excursion
    (set-buffer buffer)
    list-buffers-directory)))

(defun uniquify-fix-list-filename-lessp (fixlist1 fixlist2)
  (uniquify-filename-lessp
   (uniquify-fix-list-filename fixlist1) (uniquify-fix-list-filename fixlist2)))

;; This examines the filename components in reverse order.
(defun uniquify-filename-lessp (s1 s2)
  (let ((s1f (file-name-nondirectory s1))
    (s2f (file-name-nondirectory s2)))
    (and (not (equal s2f ""))
     (or (string-lessp s1f s2f)
         (and (equal s1f s2f)
          (let ((s1d (file-name-directory s1))
            (s2d (file-name-directory s2)))
            (and (not (<= (length s2d) 1))
             (or (<= (length s1d) 1)
                 (uniquify-filename-lessp
                  (substring s1d 0 -1)
                  (substring s2d 0 -1))))))))))

;; Was named do-the-buffers-you-couldnt-rationalize
(defun uniquify-unrationalized-buffer (item)
  (or (uniquify-cadddr item) nil))    ;maybe better in the future

(defun uniquify-rationalize-a-list (fix-list depth)
  (let (conflicting-sublist
    (old-name "")
    proposed-name uniquify-possibly-resolvable)
    (while fix-list
      (let ((item (car fix-list)))
    (setq proposed-name (uniquify-get-proposed-name item depth))
    (if (not (equal proposed-name old-name))
        (progn
          (uniquify-rationalize-conflicting-sublist
           conflicting-sublist old-name depth)
          (setq conflicting-sublist nil)))
    (uniquify-push item conflicting-sublist)
    (setq old-name proposed-name))
      (setq fix-list (cdr fix-list)))
    (uniquify-rationalize-conflicting-sublist
     conflicting-sublist old-name depth)))

(defun uniquify-get-proposed-name (item depth)
  (let (index
    (extra-string "")
    (n depth)
    (base (uniquify-fix-list-base item))
    (fn (uniquify-fix-list-filename item)))
    (while (and (> n 0)
        (setq index (string-match
                 (concat "\\(^\\|/[^/]*\\)/"
                     (regexp-quote extra-string)
                     (regexp-quote base)
                     "\\'")
                 fn)))
      (setq extra-string (substring fn
                    (if (zerop index) 0 (1+ index))
                    ;; (- (length base)) fails for base = "".
                    ;; Equivalently, we could have used
                    ;; (apply 'substring ...
                    ;;        (and (not (string= "" base))
                    ;;             (list (- (length base)))))
                    (- (length fn) (length base)))
        n (1- n)))
    (if (zerop n) (setq uniquify-possibly-resolvable t))


    ;; Distinguish directories by adding extra separator.
    (if (and uniquify-trailing-separator-p
         (file-directory-p fn)
         (not (string-equal base "")))
    (cond ((eq uniquify-buffer-name-style 'forward)
           (setq base (concat base "/")))
          ((eq uniquify-buffer-name-style 'reverse)
           (setq base (concat (or uniquify-separator "\\") base)))))

    ;; Trim trailing separator on directory part
    (if (and (not (string-equal extra-string ""))
         (or (eq uniquify-buffer-name-style 'post-forward)
         (eq uniquify-buffer-name-style 'post-forward-angle-brackets)))
    (setq extra-string (substring extra-string 0
                      (- (length extra-string) 1))))

    (cond ((string-equal extra-string "")
       base)
      ((string-equal base "")
       extra-string)
      ((eq uniquify-buffer-name-style 'forward)
       (concat extra-string base))
      ((eq uniquify-buffer-name-style 'reverse)
       (concat base (uniquify-reverse-components extra-string)))
      ((eq uniquify-buffer-name-style 'post-forward)
       (concat base (or uniquify-separator "|") extra-string))
      ((eq uniquify-buffer-name-style 'post-forward-angle-brackets)
       (concat base "<" extra-string ">"))
      (t (error "Bad value for uniquify-buffer-name-style: %s"
            uniquify-buffer-name-style)))))


;; Deal with conflicting-sublist, which is set by uniquify-rationalize-a-list.
;; This is only called by uniquify-rationalize-a-list.
(defun uniquify-rationalize-conflicting-sublist (conflicting-sublist old-name depth)
  (or (null conflicting-sublist)
      (and (null (cdr conflicting-sublist))
       (not (assoc old-name uniquify-non-file-buffer-names))
       (or (and (not (string= old-name ""))
            (uniquify-rename-buffer (car conflicting-sublist) old-name))
           t))
      (if uniquify-possibly-resolvable
      (uniquify-rationalize-a-list conflicting-sublist (1+ depth)))))

(defun uniquify-rename-buffer (item newname)
  (let ((buffer (uniquify-fix-list-buffer item)))
    (if (not (equal newname (buffer-name buffer)))
    (let ((unset (current-buffer))
          ;; avoid hooks on rename-buffer
          (uniquify-buffer-name-style nil))
      (set-buffer buffer)
      (rename-buffer newname)
      (set-buffer unset))))
  (rplaca (nthcdr 3 item) t))

(defun uniquify-reverse-components (instring)
  (let ((sofar '())
    (cursor 0)
    (len (length instring))
    (sep (or uniquify-separator "\\")))
    (while (< cursor len)
      (if (= (aref instring cursor) ?/)
          (setq sofar (cons sep sofar)
                cursor (1+ cursor))
        (let ((first-slash (or (string-match "/" instring cursor) len)))
          (setq sofar (cons (substring instring cursor first-slash) sofar)
                cursor first-slash))))
    (apply (function concat) sofar)))


;;; Hooks from the rest of Emacs

;; Emacs 19 (Emacs or XEmacs)

;; The logical place to put all this code is in generate-new-buffer-name.
;; It's written in C, so we would add a generate-new-buffer-name-function
;; which, if non-nil, would be called instead of the C.  One problem with
;; that is that generate-new-buffer-name takes a potential buffer name as
;; its argument -- not other information, such as what file the buffer will
;; visit.

;; The below solution works because generate-new-buffer-name is called
;; only by rename-buffer (which, as of 19.29, is never called from C) and
;; generate-new-buffer, which is called only by Lisp functions
;; create-file-buffer and rename-uniquely.  Rename-uniquely generally
;; isn't used for buffers visiting files, so it's sufficient to hook
;; rename-buffer and create-file-buffer.  (Setting find-file-hooks isn't
;; sufficient.)

(defadvice rename-buffer (after rename-buffer-uniquify activate)
  "Uniquify buffer names with parts of directory name."
  (if (and uniquify-buffer-name-style
       ;; UNIQUE argument
       (ad-get-arg 1))
      (progn
    (if uniquify-after-kill-buffer-p
        ;; call with no argument; rationalize vs. old name as well as new
        (uniquify-rationalize-file-buffer-names)
      ;; call with argument: rationalize vs. new name only
      (uniquify-rationalize-file-buffer-names
       (uniquify-buffer-file-name (current-buffer)) (current-buffer)))
    (setq ad-return-value (buffer-name (current-buffer))))))

(defadvice create-file-buffer (after create-file-buffer-uniquify activate)
  "Uniquify buffer names with parts of directory name."
  (if uniquify-buffer-name-style
      (uniquify-rationalize-file-buffer-names (ad-get-arg 0) ad-return-value)))

;; Buffer deletion
;; Rerationalize after a buffer is killed, to reduce coinciding buffer names.
;; This mechanism uses `kill-buffer-hook', which runs *before* deletion.
;; That means that the kill-buffer-hook function cannot just delete the
;; buffer -- it has to set something to do the rationalization *later*.
;; It actually puts another function on `post-command-hook'.  This other
;; function runs the rationalization and then removes itself from the hook.
;; Is there a better way to accomplish this?
;; (This ought to set some global variables so the work is done only for
;; buffers with names similar to the deleted buffer.  -MDE)

(defun delay-uniquify-rationalize-file-buffer-names ()
  "Add `delayed-uniquify-rationalize-file-buffer-names' to `post-command-hook'.
For use on, eg, `kill-buffer-hook', to rationalize *after* buffer deletion."
  (if (and uniquify-buffer-name-style
       uniquify-after-kill-buffer-p)
      (add-hook 'post-command-hook
        'delayed-uniquify-rationalize-file-buffer-names)))

(defun delayed-uniquify-rationalize-file-buffer-names ()
  "Rerationalize buffer names and remove self from `post-command-hook'.
See also `delay-rationalize-file-buffer-names' for hook setter."
  (uniquify-rationalize-file-buffer-names)
  (remove-hook 'post-command-hook
           'delayed-uniquify-rationalize-file-buffer-names))

(add-hook 'kill-buffer-hook 'delay-uniquify-rationalize-file-buffer-names)

;;; uniquify.el ends here