;;; recentf.el --- setup a menu of recently opened files

;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2005
;;   Free Software Foundation, Inc.

;; Author: David Ponce <david@dponce.com>
;; Created: July 19 1999
;; Maintainer: FSF
;; Keywords: files

;; 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:

;; This package maintains a menu for visiting files that were operated
;; on recently.  When enabled a new "Open Recent" submenu is displayed
;; in the "Files" menu.  The recent files list is automatically saved
;; across Emacs sessions.  You can customize the number of recent
;; files displayed, the location of the menu and others options (see
;; the source code for details).

;;; History:
;;

;;; Code:
(require 'easymenu)
(require 'wid-edit)
(require 'timer)

;;; Internal data
;;
(defvar recentf-list nil
  "List of recently opened files.")

(defvar recentf-data-cache nil
  "Cache of data used to build the recentf menu.
The menu is rebuilt when this data has changed.")

;;; Customization
;;
(defgroup recentf nil
  "Maintain a menu of recently opened files."
  :version "21.1"
  :group 'files)

(defgroup recentf-filters nil
  "Group to customize recentf menu filters.
You should define the options of your own filters in this group."
  :group 'recentf)

(defcustom recentf-max-saved-items 20
  "*Maximum number of items of the recent list that will be saved.
nil means to save the whole list.
See the command `recentf-save-list'."
  :group 'recentf
  :type 'integer)

(defcustom recentf-save-file "~/.recentf"
  "*File to save the recent list into."
  :group 'recentf
  :type 'file)

(defcustom recentf-exclude nil
"*List of regexps and predicates for filenames excluded from the recent list.
When a filename matches any of the regexps or satisfies any of the
predicates it is excluded from the recent list.
A predicate is a function that is passed a filename to check and that
must return non-nil to exclude it."
  :group 'recentf
  :type '(repeat (choice regexp function)))

(defcustom recentf-keep
  '(file-readable-p)
  "*List of regexps and predicates for filenames kept in the recent list.
Regexps and predicates are tried in the specified order.
When nil all filenames are kept in the recent list.
When a filename matches any of the regexps or satisfies any of the
predicates it is kept in the recent list.
The default is to keep readable files.
A predicate is a function that is passed a filename to check and that
must return non-nil to keep it.  For example, you can add the
`file-remote-p' predicate in front of this list to keep remote file
names in the recent list without checking their readability through a
remote access."
  :group 'recentf
  :type '(repeat (choice regexp function)))

(defun recentf-menu-customization-changed (variable value)
  "Function called when the recentf menu customization has changed.
Set VARIABLE with VALUE, and force a rebuild of the recentf menu."
  (when (featurep 'recentf)
    ;; Unavailable until recentf has been loaded.
    (recentf-clear-data))
  (set-default variable value))

(defcustom recentf-menu-title "Open Recent"
  "*Name of the recentf menu."
  :group 'recentf
  :type 'string
  :set 'recentf-menu-customization-changed)

(defcustom recentf-menu-path '("File")
  "*Path where to add the recentf menu.
If nil add it at top level (see also `easy-menu-add-item')."
  :group 'recentf
  :type '(choice (const :tag "Top Level" nil)
                 (sexp :tag "Menu Path"))
  :set 'recentf-menu-customization-changed)

(defcustom recentf-menu-before "Open File..."
  "*Name of the menu before which the recentf menu will be added.
If nil add it at end of menu (see also `easy-menu-add-item')."
  :group 'recentf
  :type '(choice (string :tag "Name")
                 (const :tag "Last" nil))
  :set 'recentf-menu-customization-changed)

(defcustom recentf-menu-action 'find-file
  "*Function to invoke with a filename item of the recentf menu.
The default is to call `find-file' to edit the selected file."
  :group 'recentf
  :type 'function
  :set 'recentf-menu-customization-changed)

(defcustom recentf-max-menu-items 10
  "*Maximum number of items in the recentf menu."
  :group 'recentf
  :type 'integer
  :set 'recentf-menu-customization-changed)

(defcustom recentf-menu-filter nil
  "*Function used to filter files displayed in the recentf menu.
nil means no filter.  The following functions are predefined:

- `recentf-sort-ascending'
    Sort menu items in ascending order.
- `recentf-sort-descending'
    Sort menu items in descending order.
- `recentf-sort-basenames-ascending'
    Sort menu items by filenames sans directory in ascending order.
- `recentf-sort-basenames-descending'
    Sort menu items by filenames sans directory in descending order.
- `recentf-sort-directories-ascending'
    Sort menu items by directories in ascending order.
- `recentf-sort-directories-descending'
    Sort menu items by directories in descending order.
- `recentf-show-basenames'
    Show filenames sans directory in menu items.
- `recentf-show-basenames-ascending'
    Show filenames sans directory in ascending order.
- `recentf-show-basenames-descending'
    Show filenames sans directory in descending order.
- `recentf-relative-filter'
    Show filenames relative to `default-directory'.
- `recentf-arrange-by-rule'
    Show sub-menus following user defined rules.
- `recentf-arrange-by-mode'
    Show a sub-menu for each major mode.
- `recentf-arrange-by-dir'
    Show a sub-menu for each directory.
- `recentf-filter-changer'
    Manage a ring of filters.

The filter function is called with one argument, the list of menu
elements used to build the menu and must return a new list of menu
elements (see `recentf-make-menu-element' for menu element form)."
  :group 'recentf
  :type '(radio (const nil)
                (function-item recentf-sort-ascending)
                (function-item recentf-sort-descending)
                (function-item recentf-sort-basenames-ascending)
                (function-item recentf-sort-basenames-descending)
                (function-item recentf-sort-directories-ascending)
                (function-item recentf-sort-directories-descending)
                (function-item recentf-show-basenames)
                (function-item recentf-show-basenames-ascending)
                (function-item recentf-show-basenames-descending)
                (function-item recentf-relative-filter)
                (function-item recentf-arrange-by-rule)
                (function-item recentf-arrange-by-mode)
                (function-item recentf-arrange-by-dir)
                (function-item recentf-filter-changer)
                function)
  :set 'recentf-menu-customization-changed)

(defcustom recentf-menu-append-commands-flag t
  "*non-nil means to append command items to the menu."
  :group 'recentf
  :type 'boolean
  :set 'recentf-menu-customization-changed)

(defvaralias 'recentf-menu-append-commands-p
  'recentf-menu-append-commands-flag)
(make-obsolete-variable 'recentf-menu-append-commands-p
                        'recentf-menu-append-commands-flag
                        "22.1")

(defcustom recentf-auto-cleanup 'mode
  "*Define when to automatically cleanup the recent list.
The following values can be set:

- `mode'
    Cleanup when turning the mode on (default).
- `never'
    Never cleanup the list automatically.
- A number
    Cleanup each time Emacs has been idle that number of seconds.
- A time string
    Cleanup at specified time string, for example at \"11:00pm\".

Setting this variable directly does not take effect;
use \\[customize].

See also the command `recentf-cleanup', that can be used to manually
cleanup the list."
  :group 'recentf
  :type '(radio (const  :tag "When mode enabled"
                        :value mode)
                (const  :tag "Never"
                        :value never)
                (number :tag "When idle that seconds"
                        :value 300)
                (string :tag "At time"
                        :value "11:00pm"))
  :set (lambda (variable value)
         (set-default variable value)
         (when (featurep 'recentf)
           ;; Unavailable until recentf has been loaded.
           (recentf-auto-cleanup))))

(defcustom recentf-initialize-file-name-history t
  "*non-nil means to initialize `file-name-history' with the recent list.
If `file-name-history' is not empty, do nothing."
  :group 'recentf
  :type  'boolean)

(defcustom recentf-load-hook nil
   "*Normal hook run at end of loading the `recentf' package."
  :group 'recentf
  :type 'hook)

(defcustom recentf-filename-handler nil
  "Function to call to process filename handled by recentf.
It is passed a filename to give a chance to transform it.
If it returns nil, the filename is left unchanged."
  :group 'recentf
  :type 'function)

;;; Utilities
;;
(defconst recentf-case-fold-search
  (memq system-type '(vax-vms windows-nt cygwin))
  "Non-nil if recentf searches and matches should ignore case.")

(defsubst recentf-string-equal (s1 s2)
  "Return non-nil if strings S1 and S2 have identical contents.
Ignore case if `recentf-case-fold-search' is non-nil."
  (if recentf-case-fold-search
      (string-equal (downcase s1) (downcase s2))
    (string-equal s1 s2)))

(defsubst recentf-string-lessp (s1 s2)
  "Return non-nil if string S1 is less than S2 in lexicographic order.
Ignore case if `recentf-case-fold-search' is non-nil."
  (if recentf-case-fold-search
      (string-lessp (downcase s1) (downcase s2))
    (string-lessp s1 s2)))

(defun recentf-string-member (elt list)
  "Return non-nil if ELT is an element of LIST.
The value is actually the tail of LIST whose car is ELT.
ELT must be a string and LIST a list of strings.
Ignore case if `recentf-case-fold-search' is non-nil."
  (while (and list (not (recentf-string-equal elt (car list))))
    (setq list (cdr list)))
  list)

(defsubst recentf-trunc-list (l n)
  "Return from L the list of its first N elements."
  (let (nl)
    (while (and l (> n 0))
      (setq nl (cons (car l) nl)
            n  (1- n)
            l  (cdr l)))
    (nreverse nl)))

(defun recentf-dump-variable (variable &optional limit)
  "Insert a \"(setq VARIABLE value)\" in the current buffer.
When the value of VARIABLE is a list, optional argument LIMIT
specifies a maximum number of elements to insert.  By default insert
the full list."
  (let ((value (symbol-value variable)))
    (if (atom value)
        (insert (format "\n(setq %S %S)\n" variable value))
      (when (and (integerp limit) (> limit 0))
        (setq value (recentf-trunc-list value limit)))
      (insert (format "\n(setq %S\n      '(" variable))
      (dolist (e value)
        (insert (format "\n        %S" e)))
      (insert "\n        ))\n"))))

(defvar recentf-auto-cleanup-timer nil
  "Timer used to automatically cleanup the recent list.
See also the option `recentf-auto-cleanup'.")

(defun recentf-auto-cleanup ()
  "Automatic cleanup of the recent list."
  (when (timerp recentf-auto-cleanup-timer)
    (cancel-timer recentf-auto-cleanup-timer))
  (when recentf-mode
    (setq recentf-auto-cleanup-timer
          (cond
           ((eq 'mode recentf-auto-cleanup)
            (recentf-cleanup)
            nil)
           ((numberp recentf-auto-cleanup)
            (run-with-idle-timer
             recentf-auto-cleanup t 'recentf-cleanup))
           ((stringp recentf-auto-cleanup)
            (run-at-time
             recentf-auto-cleanup nil 'recentf-cleanup))))))

;;; File functions
;;
(defsubst recentf-push (filename)
  "Push FILENAME into the recent list, if it isn't there yet.
If it is there yet, move it at the beginning of the list.
If `recentf-case-fold-search' is non-nil, ignore case when comparing
filenames."
  (let ((m (recentf-string-member filename recentf-list)))
    (and m (setq recentf-list (delq (car m) recentf-list)))
    (push filename recentf-list)))

(defsubst recentf-expand-file-name (name)
  "Convert filename NAME to absolute, and canonicalize it.
See also the function `expand-file-name'.
If defined, call the function `recentf-filename-handler' to post
process the canonical name."
  (let* ((filename (expand-file-name name)))
    (or (and recentf-filename-handler
             (funcall recentf-filename-handler filename))
        filename)))

(defun recentf-include-p (filename)
  "Return non-nil if FILENAME should be included in the recent list.
That is, if it doesn't match any of the `recentf-exclude' checks."
  (let ((case-fold-search recentf-case-fold-search)
        (checks recentf-exclude)
        (keepit t))
    (while (and checks keepit)
      (setq keepit (condition-case nil
                       (not (if (stringp (car checks))
                                ;; A regexp
                                (string-match (car checks) filename)
                              ;; A predicate
                              (funcall (car checks) filename)))
                     (error nil))
            checks (cdr checks)))
    keepit))

(defun recentf-keep-p (filename)
  "Return non-nil if FILENAME should be kept in the recent list.
That is, if it matches any of the `recentf-keep' checks."
  (let* ((case-fold-search recentf-case-fold-search)
         (checks recentf-keep)
         (keepit (null checks)))
    (while (and checks (not keepit))
      (setq keepit (condition-case nil
                       (if (stringp (car checks))
                           ;; A regexp
                           (string-match (car checks) filename)
                         ;; A predicate
                         (funcall (car checks) filename))
                     (error nil))
            checks (cdr checks)))
    keepit))

(defsubst recentf-add-file (filename)
  "Add or move FILENAME at the beginning of the recent list.
Does nothing if the name satisfies any of the `recentf-exclude'
regexps or predicates."
  (setq filename (recentf-expand-file-name filename))
  (when (recentf-include-p filename)
    (recentf-push filename)))

(defsubst recentf-remove-if-non-kept (filename)
  "Remove FILENAME from the recent list, if file is not kept.
Return non-nil if FILENAME has been removed."
  (unless (recentf-keep-p filename)
    (let ((m (recentf-string-member
              (recentf-expand-file-name filename) recentf-list)))
      (and m (setq recentf-list (delq (car m) recentf-list))))))

(defsubst recentf-directory-compare (f1 f2)
  "Compare absolute filenames F1 and F2.
First compare directories, then filenames sans directory.
Return non-nil if F1 is less than F2."
  (let ((d1 (file-name-directory f1))
        (d2 (file-name-directory f2)))
    (if (recentf-string-equal d1 d2)
        (recentf-string-lessp (file-name-nondirectory f1)
                              (file-name-nondirectory f2))
      (recentf-string-lessp d1 d2))))

;;; Menu building
;;
(defvar recentf-menu-items-for-commands
  (list ["Cleanup list"
         recentf-cleanup
         :help "Remove all excluded and non-kept files from the recent list"
         :active t]
        ["Edit list..."
         recentf-edit-list
         :help "Edit the files that are kept in the recent list"
         :active t]
        ["Save list now"
         recentf-save-list
         :help "Save the list of recently opened files now"
         :active t]
        ["Options..."
         (customize-group "recentf")
         :help "Customize recently opened files menu and options"
         :active t]
        )
  "List of menu items for recentf commands.")

(defvar recentf-menu-filter-commands nil
  "This variable can be used by menu filters to setup their own command menu.
If non-nil it must contain a list of valid menu-items to be appended
to the recent file list part of the menu.  Before calling a menu
filter function this variable is reset to nil.")

(defsubst recentf-elements (n)
  "Return a list of the first N elements of the recent list."
  (recentf-trunc-list recentf-list n))

(defsubst recentf-make-menu-element (menu-item menu-value)
  "Create a new menu-element.
A menu element is a pair (MENU-ITEM . MENU-VALUE), where MENU-ITEM is
the menu item string displayed.  MENU-VALUE is the file to be open
when the corresponding MENU-ITEM is selected.  Or it is a
pair (SUB-MENU-TITLE . MENU-ELEMENTS) where SUB-MENU-TITLE is a
sub-menu title and MENU-ELEMENTS is the list of menu elements in the
sub-menu."
  (cons menu-item menu-value))

(defsubst recentf-menu-element-item (e)
  "Return the item part of the menu-element E."
  (car e))

(defsubst recentf-menu-element-value (e)
  "Return the value part of the menu-element E."
  (cdr e))

(defsubst recentf-set-menu-element-item (e item)
  "Change the item part of menu-element E to ITEM."
  (setcar e item))

(defsubst recentf-set-menu-element-value (e value)
  "Change the value part of menu-element E to VALUE."
  (setcdr e value))

(defsubst recentf-sub-menu-element-p (e)
  "Return non-nil if menu-element E defines a sub-menu."
  (consp (recentf-menu-element-value e)))

(defsubst recentf-make-default-menu-element (file)
  "Make a new default menu element with FILE.
This a menu element (FILE . FILE)."
  (recentf-make-menu-element file file))

(defsubst recentf-menu-elements (n)
  "Return a list of the first N default menu elements from the recent list.
See also `recentf-make-default-menu-element'."
  (mapcar 'recentf-make-default-menu-element
          (recentf-elements n)))

(defun recentf-apply-menu-filter (filter l)
  "Apply function FILTER to the list of menu-elements L.
It takes care of sub-menu elements in L and recursively apply FILTER
to them.  It is guaranteed that FILTER receives only a list of single
menu-elements (no sub-menu)."
  (if (and l (functionp filter))
      (let ((case-fold-search recentf-case-fold-search)
            elts others)
        ;; split L into two sub-listes, one of sub-menus elements and
        ;; another of single menu elements.
        (dolist (elt l)
          (if (recentf-sub-menu-element-p elt)
              (push elt elts)
            (push elt others)))
        ;; Apply FILTER to single elements.
        (when others
          (setq others (funcall filter (nreverse others))))
        ;; Apply FILTER to sub-menu elements.
        (setq l nil)
        (dolist (elt elts)
          (recentf-set-menu-element-value
           elt (recentf-apply-menu-filter
                filter (recentf-menu-element-value elt)))
          (push elt l))
        ;; Return the new filtered menu element list.
        (nconc l others))
    l))

(defun recentf-make-menu-items ()
  "Make menu items from the recent list."
  (setq recentf-menu-filter-commands nil)
  (let ((file-items
         (mapcar 'recentf-make-menu-item
                 (recentf-apply-menu-filter
                  recentf-menu-filter
                  (recentf-menu-elements recentf-max-menu-items)))))
    (append (or file-items (list ["No files" t
                                  :help "No recent file to open"
                                  :active nil]))
            (and (< recentf-max-menu-items (length recentf-list))
                 (list ["More..." recentf-open-more-files
                        :help "Open files that are not in the menu"
                        :active t]))
            (and recentf-menu-filter-commands
                 (cons "---"
                       recentf-menu-filter-commands))
            (and recentf-menu-append-commands-flag
                 (cons "---"
                       recentf-menu-items-for-commands)))))

(defsubst recentf-make-menu-item (elt)
  "Make a menu item from menu element ELT."
  (let ((item  (recentf-menu-element-item  elt))
        (value (recentf-menu-element-value elt)))
    (if (recentf-sub-menu-element-p elt)
        (cons item (mapcar 'recentf-make-menu-item value))
      (vector item (list recentf-menu-action value)
              :help (concat "Open " value)
              :active t))))

(defsubst recentf-menu-bar ()
  "Return the keymap of the global menu bar."
  (lookup-key global-map [menu-bar]))

(defun recentf-clear-data ()
  "Clear data used to build the recentf menu.
This force a rebuild of the menu."
  (easy-menu-remove-item (recentf-menu-bar)
                         recentf-menu-path recentf-menu-title)
  (setq recentf-data-cache nil))

;;; Predefined menu filters
;;
(defsubst recentf-sort-ascending (l)
  "Sort the list of menu elements L in ascending order.
The MENU-ITEM part of each menu element is compared."
  (sort (copy-sequence l)
        #'(lambda (e1 e2)
            (recentf-string-lessp
             (recentf-menu-element-item e1)
             (recentf-menu-element-item e2)))))

(defsubst recentf-sort-descending (l)
  "Sort the list of menu elements L in descending order.
The MENU-ITEM part of each menu element is compared."
  (sort (copy-sequence l)
        #'(lambda (e1 e2)
            (recentf-string-lessp
             (recentf-menu-element-item e2)
             (recentf-menu-element-item e1)))))

(defsubst recentf-sort-basenames-ascending (l)
  "Sort the list of menu elements L in ascending order.
Only filenames sans directory are compared."
  (sort (copy-sequence l)
        #'(lambda (e1 e2)
            (recentf-string-lessp
             (file-name-nondirectory (recentf-menu-element-value e1))
             (file-name-nondirectory (recentf-menu-element-value e2))))))

(defsubst recentf-sort-basenames-descending (l)
  "Sort the list of menu elements L in descending order.
Only filenames sans directory are compared."
  (sort (copy-sequence l)
        #'(lambda (e1 e2)
            (recentf-string-lessp
             (file-name-nondirectory (recentf-menu-element-value e2))
             (file-name-nondirectory (recentf-menu-element-value e1))))))

(defsubst recentf-sort-directories-ascending (l)
  "Sort the list of menu elements L in ascending order.
Compares directories then filenames to order the list."
  (sort (copy-sequence l)
        #'(lambda (e1 e2)
            (recentf-directory-compare
             (recentf-menu-element-value e1)
             (recentf-menu-element-value e2)))))

(defsubst recentf-sort-directories-descending (l)
  "Sort the list of menu elements L in descending order.
Compares directories then filenames to order the list."
  (sort (copy-sequence l)
        #'(lambda (e1 e2)
            (recentf-directory-compare
             (recentf-menu-element-value e2)
             (recentf-menu-element-value e1)))))

(defun recentf-show-basenames (l &optional no-dir)
  "Filter the list of menu elements L to show filenames sans directory.
When a filename is duplicated, it is appended a sequence number if
optional argument NO-DIR is non-nil, or its directory otherwise."
  (let (filtered-names filtered-list full name counters sufx)
    (dolist (elt l (nreverse filtered-list))
      (setq full (recentf-menu-element-value elt)
            name (file-name-nondirectory full))
      (if (not (member name filtered-names))
          (push name filtered-names)
        (if no-dir
            (if (setq sufx (assoc name counters))
                (setcdr sufx (1+ (cdr sufx)))
              (setq sufx 1)
              (push (cons name sufx) counters))
          (setq sufx (file-name-directory full)))
        (setq name (format "%s(%s)" name sufx)))
      (push (recentf-make-menu-element name full) filtered-list))))

(defsubst recentf-show-basenames-ascending (l)
  "Filter the list of menu elements L to show filenames sans directory.
Filenames are sorted in ascending order.
This filter combines the `recentf-sort-basenames-ascending' and
`recentf-show-basenames' filters."
  (recentf-show-basenames (recentf-sort-basenames-ascending l)))

(defsubst recentf-show-basenames-descending (l)
  "Filter the list of menu elements L to show filenames sans directory.
Filenames are sorted in descending order.
This filter combines the `recentf-sort-basenames-descending' and
`recentf-show-basenames' filters."
  (recentf-show-basenames (recentf-sort-basenames-descending l)))

(defun recentf-relative-filter (l)
  "Filter the list of menu-elements L to show relative filenames.
Filenames are relative to the `default-directory'."
  (mapcar #'(lambda (menu-element)
              (let* ((ful (recentf-menu-element-value menu-element))
                     (rel (file-relative-name ful default-directory)))
                (if (string-match "^\\.\\." rel)
                    menu-element
                  (recentf-make-menu-element rel ful))))
          l))

;;; Rule based menu filters
;;
(defcustom recentf-arrange-rules
  '(
    ("Elisp files (%d)" ".\\.el$")
    ("Java files (%d)"  ".\\.java$")
    ("C/C++ files (%d)" "c\\(pp\\)?$")
    )
  "*List of rules used by `recentf-arrange-by-rule' to build sub-menus.
A rule is a pair (SUB-MENU-TITLE . MATCHER).  SUB-MENU-TITLE is the
displayed title of the sub-menu where a '%d' `format' pattern is
replaced by the number of items in the sub-menu.  MATCHER is a regexp
or a list of regexps.  Items matching one of the regular expressions in
MATCHER are added to the corresponding sub-menu."
  :group 'recentf-filters
  :type '(repeat (cons string (repeat regexp)))
  :set 'recentf-menu-customization-changed)

(defcustom recentf-arrange-by-rule-others "Other files (%d)"
  "*Title of the `recentf-arrange-by-rule' sub-menu.
This is for the menu where items that don't match any
`recentf-arrange-rules' are displayed.  If nil these items are
displayed in the main recent files menu.  A '%d' `format' pattern in
the title is replaced by the number of items in the sub-menu."
  :group 'recentf-filters
  :type '(choice (const  :tag "Main menu" nil)
                 (string :tag "Title"))
  :set 'recentf-menu-customization-changed)

(defcustom recentf-arrange-by-rules-min-items 0
  "*Minimum number of items in a `recentf-arrange-by-rule' sub-menu.
If the number of items in a sub-menu is less than this value the
corresponding sub-menu items are displayed in the main recent files
menu or in the `recentf-arrange-by-rule-others' sub-menu if
defined."
  :group 'recentf-filters
  :type 'number
  :set 'recentf-menu-customization-changed)

(defcustom recentf-arrange-by-rule-subfilter nil
  "*Function called by a rule based filter to filter sub-menu elements.
nil means no filter.  See also `recentf-menu-filter'.
You can't use another rule based filter here."
  :group 'recentf-filters
  :type '(choice (const nil) function)
  :set (lambda (variable value)
         (when (memq value '(recentf-arrange-by-rule
                             recentf-arrange-by-mode
                             recentf-arrange-by-dir))
           (error "Recursive use of a rule based filter"))
         (recentf-menu-customization-changed variable value)))

(defun recentf-match-rule-p (matcher filename)
  "Return non-nil if the rule specified by MATCHER match FILENAME.
See `recentf-arrange-rules' for details on MATCHER."
  (if (stringp matcher)
      (string-match matcher filename)
    (while (and (consp matcher)
                (not (string-match (car matcher) filename)))
      (setq matcher (cdr matcher)))
    matcher))

(defun recentf-arrange-by-rule (l)
  "Filter the list of menu-elements L.
Arrange them in sub-menus following rules in `recentf-arrange-rules'."
  (if (not recentf-arrange-rules)
      l
    (let ((menus (mapcar #'(lambda (r) (list (car r)))
                         recentf-arrange-rules))
          menu others min file rules elts count)
      (dolist (elt l)
        (setq file  (recentf-menu-element-value elt)
              rules recentf-arrange-rules
              elts  menus
              menu  nil)
        (while (and (not menu) rules)
          (when (recentf-match-rule-p (cdar rules) file)
            (setq menu (car elts))
            (recentf-set-menu-element-value
             menu (cons elt (recentf-menu-element-value menu))))
          (setq rules (cdr rules)
                elts  (cdr elts)))
        (unless menu
          (push elt others)))

      (setq l nil
            min (if (natnump recentf-arrange-by-rules-min-items)
                    recentf-arrange-by-rules-min-items 0))
      (dolist (menu menus)
        (when (setq elts (recentf-menu-element-value menu))
          (setq count (length elts))
          (if (< count min)
              (setq others (nconc elts others))
            (recentf-set-menu-element-item
             menu (format (recentf-menu-element-item menu) count))
            (recentf-set-menu-element-value
             menu (recentf-apply-menu-filter
                   recentf-arrange-by-rule-subfilter (nreverse elts)))
            (push menu l))))

      (if (and (stringp recentf-arrange-by-rule-others) others)
          (nreverse
           (cons
            (recentf-make-menu-element
             (format recentf-arrange-by-rule-others (length others))
             (recentf-apply-menu-filter
              recentf-arrange-by-rule-subfilter (nreverse others)))
            l))
        (nconc
         (nreverse l)
         (recentf-apply-menu-filter
          recentf-arrange-by-rule-subfilter (nreverse others)))))
    ))

;;; Predefined rule based menu filters
;;
(defun recentf-build-mode-rules ()
  "Convert `auto-mode-alist' to menu filter rules.
Rules obey `recentf-arrange-rules' format."
  (let ((case-fold-search recentf-case-fold-search)
        regexp rule-name rule rules)
    (dolist (mode auto-mode-alist)
      (setq regexp (car mode)
            mode   (cdr mode))
      (when (symbolp mode)
        (setq rule-name (symbol-name mode))
        (if (string-match "\\(.*\\)-mode$" rule-name)
            (setq rule-name (match-string 1 rule-name)))
        (setq rule-name (concat rule-name " (%d)")
              rule (assoc rule-name rules))
        (if rule
            (setcdr rule (cons regexp (cdr rule)))
          (push (list rule-name regexp) rules))))
    ;; It is important to preserve auto-mode-alist order
    ;; to ensure the right file <-> mode association
    (nreverse rules)))

(defun recentf-arrange-by-mode (l)
  "Split the list of menu-elements L into sub-menus by major mode."
  (let ((recentf-arrange-rules (recentf-build-mode-rules))
        (recentf-arrange-by-rule-others "others (%d)"))
    (recentf-arrange-by-rule l)))

(defun recentf-build-dir-rules (l)
  "Convert directories in menu-elements L to menu filter rules.
Rules obey `recentf-arrange-rules' format."
  (let (dirs)
    (mapcar #'(lambda (e)
                (let ((dir (file-name-directory
                            (recentf-menu-element-value e))))
                  (or (recentf-string-member dir dirs)
                      (push dir dirs))))
            l)
    (mapcar #'(lambda (d)
                (cons (concat d " (%d)")
                      (concat "\\`" d)))
            (nreverse (sort dirs 'recentf-string-lessp)))))

(defun recentf-file-name-nondir (l)
  "Filter the list of menu-elements L to show filenames sans directory.
This simplified version of `recentf-show-basenames' does not handle
duplicates.  It is used by `recentf-arrange-by-dir' as its
`recentf-arrange-by-rule-subfilter'."
  (mapcar #'(lambda (e)
              (recentf-make-menu-element
               (file-name-nondirectory (recentf-menu-element-value e))
               (recentf-menu-element-value e)))
          l))

(defun recentf-arrange-by-dir (l)
  "Split the list of menu-elements L into sub-menus by directory."
  (let ((recentf-arrange-rules (recentf-build-dir-rules l))
        (recentf-arrange-by-rule-subfilter 'recentf-file-name-nondir)
        recentf-arrange-by-rule-others)
    (nreverse (recentf-arrange-by-rule l))))

;;; Ring of menu filters
;;
(defvar recentf-filter-changer-state nil
  "Used by `recentf-filter-changer' to hold its state.")

(defcustom recentf-filter-changer-alist
  '(
    (recentf-arrange-by-mode . "*Files by Mode*")
    (recentf-arrange-by-dir  . "*Files by Directory*")
    (recentf-arrange-by-rule . "*Files by User Rule*")
    )
  "*List of filters managed by `recentf-filter-changer'.
Each filter is defined by a pair (FUNCTION . LABEL), where FUNCTION is
the filter function, and LABEL is the menu item displayed to select
that filter."
  :group 'recentf-filters
  :type '(repeat (cons function string))
  :set (lambda (variable value)
         (setq recentf-filter-changer-state nil)
         (recentf-menu-customization-changed variable value)))

(defun recentf-filter-changer-goto-next ()
  "Go to the next filter available.
See `recentf-filter-changer'."
  (setq recentf-filter-changer-state (cdr recentf-filter-changer-state))
  (recentf-clear-data))

(defsubst recentf-filter-changer-get-current ()
  "Get the current filter available.
See `recentf-filter-changer'."
  (unless recentf-filter-changer-state
    (setq recentf-filter-changer-state recentf-filter-changer-alist))
  (car recentf-filter-changer-state))

(defsubst recentf-filter-changer-get-next ()
  "Get the next filter available.
See `recentf-filter-changer'."
  ;; At this point the current filter is the first element of
  ;; `recentf-filter-changer-state'.
  (car (or (cdr recentf-filter-changer-state)
           ;; There is no next element in
           ;; `recentf-filter-changer-state', so loop back to the
           ;; first element of `recentf-filter-changer-alist'.
           recentf-filter-changer-alist)))

(defun recentf-filter-changer (l)
  "Manage a ring of menu filters.
`recentf-filter-changer-alist' defines the filters in the ring.
Filtering of L is delegated to the current filter in the ring.  A
filter menu item is displayed allowing to dynamically activate the
next filter in the ring.  If the filter ring is empty, L is left
unchanged."
  (let ((filter (recentf-filter-changer-get-current)))
    (when filter
      (setq l (recentf-apply-menu-filter (car filter) l)
            filter (recentf-filter-changer-get-next))
      (when filter
        (setq recentf-menu-filter-commands
              (list (vector (cdr filter)
                            '(recentf-filter-changer-goto-next)
                            t)))))
    l))

;;; Common dialog stuff
;;
(defun recentf-cancel-dialog (&rest ignore)
  "Cancel the current dialog.
Used internally by recentf dialogs.
IGNORE arguments."
  (interactive)
  (kill-buffer (current-buffer))
  (message "Dialog canceled"))

(defvar recentf-dialog-mode-map
  (let ((km (make-sparse-keymap)))
    (define-key km "q" 'recentf-cancel-dialog)
    (define-key km [down-mouse-1] 'widget-button-click)
    (set-keymap-parent km widget-keymap)
    km)
  "Keymap used in recentf dialogs.")

(defun recentf-dialog-mode ()
  "Major mode of recentf dialogs.

\\{recentf-dialog-mode-map}"
  (interactive)
  (setq major-mode 'recentf-dialog-mode)
  (setq mode-name "recentf-dialog")
  (use-local-map recentf-dialog-mode-map))

;;; Hooks
;;
(defun recentf-track-opened-file ()
  "Insert the name of the file just opened or written into the recent list."
  (and buffer-file-name
       (recentf-add-file buffer-file-name))
  ;; Must return nil because it is run from `write-file-functions'.
  nil)

(defun recentf-track-closed-file ()
  "Update the recent list when a buffer is killed.
That is, remove a non kept file from the recent list."
  (and buffer-file-name
       (recentf-remove-if-non-kept buffer-file-name)))

(defun recentf-update-menu ()
  "Update the recentf menu from the current recent list."
  (let ((cache (cons default-directory recentf-list)))
    ;; Does nothing, if nothing has changed.
    (unless (equal recentf-data-cache cache)
      (setq recentf-data-cache cache)
      (condition-case err
          (easy-menu-add-item
           (recentf-menu-bar) recentf-menu-path
           (easy-menu-create-menu recentf-menu-title
                                  (recentf-make-menu-items))
           recentf-menu-before)
        (error
         (message "recentf update menu failed: %s"
                  (error-message-string err)))))))

(defconst recentf-used-hooks
  '(
    (find-file-hook       recentf-track-opened-file)
    (write-file-functions recentf-track-opened-file)
    (kill-buffer-hook     recentf-track-closed-file)
    (menu-bar-update-hook recentf-update-menu)
    (kill-emacs-hook      recentf-save-list)
    )
  "Hooks used by recentf.")

(defsubst recentf-enabled-p ()
  "Return non-nil if recentf mode is currently enabled."
  (memq 'recentf-update-menu menu-bar-update-hook))

;;; Commands
;;
(defvar recentf-edit-selected-items nil
  "List of files to be deleted from the recent list.
Used internally by `recentf-edit-list'.")

(defun recentf-edit-list-action (widget &rest ignore)
  "Checkbox WIDGET action that toogles a file selection.
Used internally by `recentf-edit-list'.
IGNORE other arguments."
  (let ((value (widget-get widget ':tag)))
    ;; if value is already in the selected items
    (if (memq value recentf-edit-selected-items)
        ;; then remove it
        (progn
          (setq recentf-edit-selected-items
                (delq value recentf-edit-selected-items))
          (message "%s removed from selection" value))
      ;; else add it
      (push value recentf-edit-selected-items)
      (message "%s added to selection" value))))

(defun recentf-edit-list ()
  "Show a dialog buffer to edit the recent list.
That is to select files to be deleted from the recent list."
  (interactive)
  (with-current-buffer
      (get-buffer-create (format "*%s - Edit list*" recentf-menu-title))
    (switch-to-buffer (current-buffer))
    ;; Cleanup buffer
    (kill-all-local-variables)
    (let ((inhibit-read-only t)
          (ol (overlay-lists)))
      (erase-buffer)
      ;; Delete all the overlays.
      (mapc 'delete-overlay (car ol))
      (mapc 'delete-overlay (cdr ol)))
    (setq recentf-edit-selected-items nil)
    ;; Insert the dialog header
    (widget-insert
     "\
Select the files to be deleted from the recent list.\n\n\
Click on Ok to update the list. \
Click on Cancel or type \"q\" to quit.\n")
    ;; Insert the list of files as checkboxes
    (dolist (item recentf-list)
      (widget-create
       'checkbox
       :value nil                       ; unselected checkbox
       :format "\n %[%v%]  %t"
       :tag item
       :notify 'recentf-edit-list-action))
    (widget-insert "\n\n")
    ;; Insert the Ok button
    (widget-create
     'push-button
     :notify (lambda (&rest ignore)
               (if recentf-edit-selected-items
                   (let ((i 0))
                     (kill-buffer (current-buffer))
                     (dolist (e recentf-edit-selected-items)
                       (setq recentf-list (delq e recentf-list)
                             i (1+ i)))
                     (message "%S file(s) removed from the list" i)
                     (recentf-clear-data))
                 (message "No file selected")))
     "Ok")
    (widget-insert " ")
    ;; Insert the Cancel button
    (widget-create
     'push-button
     :notify 'recentf-cancel-dialog
     "Cancel")
    (recentf-dialog-mode)
    (widget-setup)
    (goto-char (point-min))))

(defun recentf-open-files-action (widget &rest ignore)
  "Button WIDGET action that open a file.
Used internally by `recentf-open-files'.
IGNORE other arguments."
  (kill-buffer (current-buffer))
  (funcall recentf-menu-action (widget-value widget)))

(defvar recentf-open-files-item-shift ""
  "Amount of space to shift right sub-menu items.
Used internally by `recentf-open-files'.")

(defun recentf-open-files-item (menu-element)
  "Insert an item widget for MENU-ELEMENT in the current dialog buffer.
Used internally by `recentf-open-files'."
  (let ((item (car menu-element))
        (file (cdr menu-element)))
    (if (consp file)               ; This is a sub-menu
        (let* ((shift recentf-open-files-item-shift)
               (recentf-open-files-item-shift (concat shift "  ")))
          (widget-create
           'item
           :tag item
           :sample-face 'bold
           :format (concat shift "%{%t%}:\n"))
          (mapc 'recentf-open-files-item file)
          (widget-insert "\n"))
      (widget-create
       'push-button
       :button-face 'default
       :tag item
       :help-echo (concat "Open " file)
       :format (concat recentf-open-files-item-shift "%[%t%]")
       :notify 'recentf-open-files-action
       file)
      (widget-insert "\n"))))

(defun recentf-open-files (&optional files buffer-name)
  "Show a dialog buffer to open a recent file.
If optional argument FILES is non-nil, it specifies the list of
recently-opened files to choose from.  It is the whole recent list
otherwise.
If optional argument BUFFER-NAME is non-nil, it specifies which buffer
name to use for the interaction.  It is \"*`recentf-menu-title'*\" by
default."
  (interactive)
  (unless files
    (setq files recentf-list))
  (unless buffer-name
    (setq buffer-name (format "*%s*" recentf-menu-title)))
  (with-current-buffer (get-buffer-create buffer-name)
    (switch-to-buffer (current-buffer))
    ;; Cleanup buffer
    (kill-all-local-variables)
    (let ((inhibit-read-only t)
          (ol (overlay-lists)))
      (erase-buffer)
      ;; Delete all the overlays.
      (mapc 'delete-overlay (car ol))
      (mapc 'delete-overlay (cdr ol)))
    ;; Insert the dialog header
    (widget-insert "Click on a file to open it. ")
    (widget-insert "Click on Cancel or type \"q\" to quit.\n\n" )
    ;; Insert the list of files as buttons
    (let ((recentf-open-files-item-shift ""))
      (mapc 'recentf-open-files-item
            (recentf-apply-menu-filter
             recentf-menu-filter
             (mapcar 'recentf-make-default-menu-element files))))
    (widget-insert "\n")
    ;; Insert the Cancel button
    (widget-create
     'push-button
     :notify 'recentf-cancel-dialog
     "Cancel")
    (recentf-dialog-mode)
    (widget-setup)
    (goto-char (point-min))))

(defun recentf-open-more-files ()
  "Show a dialog buffer to open a recent file that is not in the menu."
  (interactive)
  (recentf-open-files (nthcdr recentf-max-menu-items recentf-list)
                      (format "*%s - More*" recentf-menu-title)))

(defconst recentf-save-file-header
  ";;; Automatically generated by `recentf' on %s.\n"
  "Header to be written into the `recentf-save-file'.")

(defconst recentf-save-file-coding-system
  (if (coding-system-p 'utf-8-emacs)
      'utf-8-emacs
    'emacs-mule)
  "Coding system of the file `recentf-save-file'.")

(defun recentf-save-list ()
  "Save the recent list.
Write data into the file specified by `recentf-save-file'."
  (interactive)
  (condition-case error
      (with-temp-buffer
	(erase-buffer)
	(set-buffer-file-coding-system recentf-save-file-coding-system)
	(insert (format recentf-save-file-header (current-time-string)))
	(recentf-dump-variable 'recentf-list recentf-max-saved-items)
	(recentf-dump-variable 'recentf-filter-changer-state)
	(insert "\n\n;;; Local Variables:\n"
		(format ";;; coding: %s\n" recentf-save-file-coding-system)
		";;; End:\n")
	(write-file (expand-file-name recentf-save-file))
	nil)
    (error
     (warn "recentf mode: %s" (error-message-string error)))))

(defun recentf-load-list ()
  "Load a previously saved recent list.
Read data from the file specified by `recentf-save-file'.
When `recentf-initialize-file-name-history' is non-nil, initialize an
empty `file-name-history' with the recent list."
  (interactive)
  (let ((file (expand-file-name recentf-save-file)))
    (when (file-readable-p file)
      (load-file file)
      (and recentf-initialize-file-name-history
           (not file-name-history)
           (setq file-name-history (mapcar 'abbreviate-file-name
                                           recentf-list))))))

(defun recentf-cleanup ()
  "Remove all non-kept and excluded files from the recent list."
  (interactive)
  (message "Cleaning up the recentf list...")
  (let ((n 0) newlist)
    (dolist (f recentf-list)
      (if (and (recentf-include-p f)
               (recentf-keep-p f))
          (push f newlist)
        (setq n (1+ n))
        (message "File %s removed from the recentf list" f)))
    (message "Cleaning up the recentf list...done (%d removed)" n)
    (setq recentf-list (nreverse newlist))))

;;;###autoload
(define-minor-mode recentf-mode
  "Toggle recentf mode.
With prefix argument ARG, turn on if positive, otherwise off.
Returns non-nil if the new state is enabled.

When recentf mode is enabled, it maintains a menu for visiting files
that were operated on recently."
  :global t
  :group 'recentf
  (unless (and recentf-mode (recentf-enabled-p))
    (if recentf-mode
        (recentf-load-list)
      (recentf-save-list))
    (recentf-auto-cleanup)
    (recentf-clear-data)
    (let ((hook-setup (if recentf-mode 'add-hook 'remove-hook)))
      (dolist (hook recentf-used-hooks)
        (apply hook-setup hook)))
    (run-hooks 'recentf-mode-hook)
    (when (interactive-p)
      (message "Recentf mode %sabled" (if recentf-mode "en" "dis"))))
  recentf-mode)

(provide 'recentf)

(run-hooks 'recentf-load-hook)

;;; arch-tag: 78f1eec9-0d16-4d19-a4eb-2e4529edb62a
;;; recentf.el ends here