* calendar/todos.el Add and revise further doc strings and

comments; major code rearrangement.
(todos-merged-files, todos-prompt-merged-files)
(todos-print-priorities, todos-tmp-buffer-name)
(todos-top-priorities-widgets, todos-update-merged-files)
(todos-merged-top-priorities, todos-merged-diary-items)
(todos-merged-regexp-items, todos-merged-custom-items)
(todos-raw-mode, todos-change-default-file)
(todos-toggle-diary-inclusion, todos-toggle-item-diary-nonmarking)
(todos-toggle-diary-nonmarking, todos-validate-category-name):
Remove.
(todos-category-string-matcher): Comment out.
(todos-categories): New defgroup.
(todos-initial-file, todos-filter-buffer)
(todos-top-priorities-buffer, todos-categories-category-label)
(todos-diary-items-buffer, todos-regexp-items-buffer)
(todos-custom-items-buffer, todos-filter-files)
(todos-highlight-item, todos-todo-mode-date-time-regexp):
New defcustoms.
(todos-diary-expired): New face.
(todos-print-buffer, todos-multiple-files)
(todos-multiple-files-widget, todos-key-bindings): New variables.
(todos-short-file-name, todos-reevaluate-default-file-defcustom)
(todos-special-buffer-name)
(todos-reevaluate-filter-files-defcustom)
(todos-reset-highlight-item, todos-reevaluate-defcustoms)
(todos-nondiary-marker-matcher, todos-diary-nonmarking-matcher)
(todos-diary-expired-matcher, todos-category-string-matcher-1)
(todos-category-string-matcher-2, todos-repair-categories-sexp)
(todos-validate-name, todos-multiple-files)
(todos-display-categories-1, todos-update-categories-display)
(todos-modes-set-3, todos-mode-external-set): New functions.
(todos-set-top-priorities-in-file)
(todos-set-top-priorities-in-category)
(todos-top-priorities-multifile, todos-diary-items-multifile)
(todos-regexp-items-multifile, todos-custom-items-multifile)
(todos-convert-legacy-files, todos-jump-to-item)
(todos-edit-multiline-item, todos-edit-item-date-from-calendar)
(todos-edit-item-diary-inclusion)
(todos-edit-category-diary-inclusion)
(todos-edit-item-diary-nonmarking)
(todos-edit-category-diary-nonmarking): New commands.
(todos, todos-faces): Update :version.
(todos-done-separator, todos-completion-ignore-case):
Change default value.
(todos-done-separator): Change :set function.
(todos-indent-to-here): Add :validate function to :type.
(todos-prefix-string, todos-mark, todos-button)
(todos-sorted-column, todos-archived-only, todos-search)
(todos-done, todos-done-sep): Provide full face definitions
instead of inheriting.
(todos-edit-buffer, todos-categories-buffer): Change from
defcustom to defvar.
(todos-category-beg, todos-category-done): Change from defvar to
defconst.
(todos-files): Check if todos-files-directory exists.
(todos-default-todos-file, todos-mode-line-control, todos-print):
Use todos-short-file-name.
(todos-font-lock-keywords): Use todos-nondiary-marker-matcher,
todos-diary-nonmarking-matcher, todos-category-string-matcher-1,
todos-category-string-matcher-2, todos-diary-expired-matcher.
(todos-category-select): Use todos-done-string-start, and
condition search on todos-show-with-done; don't make display
overlay for done items separator string if there already is one;
use todos-highlight-item, require hl-line and activate
hl-line-mode here in order to avoid a hang if done in todos-mode
or the mode hook.
(todos-update-categories-sexp): Use todos-categories-full if set,
otherwise todos-categories.
(todos-make-categories-list): Don't test for archive file when
processing a legacy todo-mode file.
(todos-check-format): Add check for todos-categories sexp.
(todos-diary-item-p): Use todos-nondiary-start instead of
todos-date-pattern.
(todos-marked-item-p): Rename from todos-item-marked-p.
(todos-read-file-name): Don't accept empty name; validate.
(todos-read-category): Validate new name before prompting whether
to add new category; force quit if user answers no.
(todos-filter-items): Improve implementation.
(todos-set-top-priorities): Rewrite as a noninteractive function
using minibuffer input instead of widgets.
(todos-insert-sort-button): Call todos-display-sorted with
argument nil to display categories in numerical order, instead of
calling todos-display-categories.
(powerset-recursive): Borrow and slightly reformulate the (GDFL'd)
Common Lisp powerset function at
http://rosettacode.org/wiki/Power_set#Common_Lisp.
(powerset-bitwise): Implement in Emacs Lisp the (GDFL'd) C
powerset function at http://rosettacode.org/wiki/Power_set#C.
(todos-powerset): Defalias to powerset-bitwise.
(todos-mode-map): Generate from todos-key-bindings instead of
listing each key definition.
(todos-categories-mode-map): Add two bindings.
(todos-filter-items-mode-map): Add some bindings, remove others.
(todos-mode): Derive from special-mode; use todos-modes-set-3; add
function setting todos-done-separator to
window-configuration-change-hook.
(todos-unload-hook): Remove function setting todos-done-separator
from window-configuration-change-hook.
(todos-archive-mode): Derive from todos-mode; use todos-modes-set-3.
(todos-edit-mode): Derive from text-mode; use todos-mode-external-set.
(todos-categories-mode): Derive from special-mode; use
todos-mode-external-set.
(todos-filter-items-mode): Derive from special-mode.
(todos-quit): Save archive file if it hasn't yet been saved.
(todos-display-categories): Delegate all functionality to
todos-display-categories-1 and todos-update-categories-display.
(todos-toggle-view-done-items): Improve implementation.
(todos-highlight-item): Require hl-line.
(todos-toggle-display-date-time): Remove argument and make it
apply only to whole file.
(todos-top-priorities, todos-diary-items, todos-regexp-items)
(todos-custom-items): Use todos-special-buffer-name.
(todos-add-file): Use todos-short-file-name and
todos-reevaluate-defcustoms; remove validation, since it's now
done in todos-read-file-name.
(todos-add-category): Also update todos-categories-full if non-nil.
(todos-delete-category): Delete file after confirmation if only
category is deleted.
(todos-move-category): Use todos-short-file-name and
todos-reevaluate-defcustoms.
(todos-insert-item): Fix getting date from the calendar and
insertion of time string.
(todos-set-date-from-calendar): Enter calendar buffer, suppressing
display of diary entries.
(todos-edit-multiline): Add optional argument to restrict editing
buffer to current item, otherwise make entire buffer (i.e. whole
file) editable.
(todos-edit-quit): When whole file is editable, check file format
validity before killing buffer, and if valid, recalculate
categories sexp to be safe.
(todos-edit-item-header): Allow choosing date from calendar.
(todos-item-done): Handle marked items.

2 files changed, 2912 insertions, 2037 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 9fe801d3f06..1933b7cea01 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,139 @@
+2012-09-20  Stephen Berman  <stephen.berman@gmx.net>
+
+        * calendar/todos.el Add and revise further doc strings and
+        comments; major code rearrangement.
+        (todos-merged-files, todos-prompt-merged-files)
+        (todos-print-priorities, todos-tmp-buffer-name)
+        (todos-top-priorities-widgets, todos-update-merged-files)
+        (todos-merged-top-priorities, todos-merged-diary-items)
+        (todos-merged-regexp-items, todos-merged-custom-items)
+        (todos-raw-mode, todos-change-default-file)
+        (todos-toggle-diary-inclusion, todos-toggle-item-diary-nonmarking)
+        (todos-toggle-diary-nonmarking, todos-validate-category-name):
+        Remove.
+        (todos-category-string-matcher): Comment out.
+        (todos-categories): New defgroup.
+        (todos-initial-file, todos-filter-buffer)
+        (todos-top-priorities-buffer, todos-categories-category-label)
+        (todos-diary-items-buffer, todos-regexp-items-buffer)
+        (todos-custom-items-buffer, todos-filter-files)
+        (todos-highlight-item, todos-todo-mode-date-time-regexp):
+        New defcustoms.
+        (todos-diary-expired): New face.
+        (todos-print-buffer, todos-multiple-files)
+        (todos-multiple-files-widget, todos-key-bindings): New variables.
+        (todos-short-file-name, todos-reevaluate-default-file-defcustom)
+        (todos-special-buffer-name)
+        (todos-reevaluate-filter-files-defcustom)
+        (todos-reset-highlight-item, todos-reevaluate-defcustoms)
+        (todos-nondiary-marker-matcher, todos-diary-nonmarking-matcher)
+        (todos-diary-expired-matcher, todos-category-string-matcher-1)
+        (todos-category-string-matcher-2, todos-repair-categories-sexp)
+        (todos-validate-name, todos-multiple-files)
+        (todos-display-categories-1, todos-update-categories-display)
+        (todos-modes-set-3, todos-mode-external-set): New functions.
+        (todos-set-top-priorities-in-file)
+        (todos-set-top-priorities-in-category)
+        (todos-top-priorities-multifile, todos-diary-items-multifile)
+        (todos-regexp-items-multifile, todos-custom-items-multifile)
+        (todos-convert-legacy-files, todos-jump-to-item)
+        (todos-edit-multiline-item, todos-edit-item-date-from-calendar)
+        (todos-edit-item-diary-inclusion)
+        (todos-edit-category-diary-inclusion)
+        (todos-edit-item-diary-nonmarking)
+        (todos-edit-category-diary-nonmarking): New commands.
+        (todos, todos-faces): Update :version.
+        (todos-done-separator, todos-completion-ignore-case):
+        Change default value.
+        (todos-done-separator): Change :set function.
+        (todos-indent-to-here): Add :validate function to :type.
+        (todos-prefix-string, todos-mark, todos-button)
+        (todos-sorted-column, todos-archived-only, todos-search)
+        (todos-done, todos-done-sep): Provide full face definitions
+        instead of inheriting.
+        (todos-edit-buffer, todos-categories-buffer): Change from
+        defcustom to defvar.
+        (todos-category-beg, todos-category-done): Change from defvar to
+        defconst.
+        (todos-files): Check if todos-files-directory exists.
+        (todos-default-todos-file, todos-mode-line-control, todos-print):
+        Use todos-short-file-name.
+        (todos-font-lock-keywords): Use todos-nondiary-marker-matcher,
+        todos-diary-nonmarking-matcher, todos-category-string-matcher-1,
+        todos-category-string-matcher-2, todos-diary-expired-matcher.
+        (todos-category-select): Use todos-done-string-start, and
+        condition search on todos-show-with-done; don't make display
+        overlay for done items separator string if there already is one;
+        use todos-highlight-item, require hl-line and activate
+        hl-line-mode here in order to avoid a hang if done in todos-mode
+        or the mode hook.
+        (todos-update-categories-sexp): Use todos-categories-full if set,
+        otherwise todos-categories.
+        (todos-make-categories-list): Don't test for archive file when
+        processing a legacy todo-mode file.
+        (todos-check-format): Add check for todos-categories sexp.
+        (todos-diary-item-p): Use todos-nondiary-start instead of
+        todos-date-pattern.
+        (todos-marked-item-p): Rename from todos-item-marked-p.
+        (todos-read-file-name): Don't accept empty name; validate.
+        (todos-read-category): Validate new name before prompting whether
+        to add new category; force quit if user answers no.
+        (todos-filter-items): Improve implementation.
+        (todos-set-top-priorities): Rewrite as a noninteractive function
+        using minibuffer input instead of widgets.
+        (todos-insert-sort-button): Call todos-display-sorted with
+        argument nil to display categories in numerical order, instead of
+        calling todos-display-categories.
+        (powerset-recursive): Borrow and slightly reformulate the (GDFL'd)
+        Common Lisp powerset function at
+        http://rosettacode.org/wiki/Power_set#Common_Lisp.
+        (powerset-bitwise): Implement in Emacs Lisp the (GDFL'd) C
+        powerset function at http://rosettacode.org/wiki/Power_set#C.
+        (todos-powerset): Defalias to powerset-bitwise.
+        (todos-mode-map): Generate from todos-key-bindings instead of
+        listing each key definition.
+        (todos-categories-mode-map): Add two bindings.
+        (todos-filter-items-mode-map): Add some bindings, remove others.
+        (todos-mode): Derive from special-mode; use todos-modes-set-3; add
+        function setting todos-done-separator to
+        window-configuration-change-hook.
+        (todos-unload-hook): Remove function setting todos-done-separator
+        from window-configuration-change-hook.
+        (todos-archive-mode): Derive from todos-mode; use todos-modes-set-3.
+        (todos-edit-mode): Derive from text-mode; use todos-mode-external-set.
+        (todos-categories-mode): Derive from special-mode; use
+        todos-mode-external-set.
+        (todos-filter-items-mode): Derive from special-mode.
+        (todos-quit): Save archive file if it hasn't yet been saved.
+        (todos-display-categories): Delegate all functionality to
+        todos-display-categories-1 and todos-update-categories-display.
+        (todos-toggle-view-done-items): Improve implementation.
+        (todos-highlight-item): Require hl-line.
+        (todos-toggle-display-date-time): Remove argument and make it
+        apply only to whole file.
+        (todos-top-priorities, todos-diary-items, todos-regexp-items)
+        (todos-custom-items): Use todos-special-buffer-name.
+        (todos-add-file): Use todos-short-file-name and
+        todos-reevaluate-defcustoms; remove validation, since it's now
+        done in todos-read-file-name.
+        (todos-add-category): Also update todos-categories-full if non-nil.
+        (todos-delete-category): Delete file after confirmation if only
+        category is deleted.
+        (todos-move-category): Use todos-short-file-name and
+        todos-reevaluate-defcustoms.
+        (todos-insert-item): Fix getting date from the calendar and
+        insertion of time string.
+        (todos-set-date-from-calendar): Enter calendar buffer, suppressing
+        display of diary entries.
+        (todos-edit-multiline): Add optional argument to restrict editing
+        buffer to current item, otherwise make entire buffer (i.e. whole
+        file) editable.
+        (todos-edit-quit): When whole file is editable, check file format
+        validity before killing buffer, and if valid, recalculate
+        categories sexp to be safe.
+        (todos-edit-item-header): Allow choosing date from calendar.
+        (todos-item-done): Handle marked items.
+
 2012-09-19  Stephen Berman  <stephen.berman@gmx.net>
 
         * calendar/todos.el (todos-item-start): Restore commented out code
diff --git a/lisp/calendar/todos.el b/lisp/calendar/todos.el
index 457e49c267e..b6b62808613 100644
--- a/lisp/calendar/todos.el
+++ b/lisp/calendar/todos.el
@@ -1,6 +1,6 @@
 ;;; Todos.el --- facilities for making and maintaining Todo lists
 
-;; Copyright (C) 1997, 1999, 2001-2011  Free Software Foundation, Inc.
+;; Copyright (C) 1997, 1999, 2001-2012  Free Software Foundation, Inc.
 
 ;; Author: Oliver Seidel <privat@os10000.net>
 ;;         Stephen Berman <stephen.berman@gmx.net>
@@ -8,7 +8,7 @@
 ;; Created: 2 Aug 1997
 ;; Keywords: calendar, todo
 
-;; This file is part of GNU Emacs.
+;; This file is [not yet] 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
@@ -25,30 +25,11 @@
 
 ;;; Commentary:
 
-;; UI
-;; - display
-;;   - show todos in cat
-;;   - show done in cat
-;;   - show catlist
-;;   - show top priorities in all cats
-;;   - show archived
-;; - navigation
-;;   -
-;; - editing
-;;
-;; Internals
-;; - cat props: name, number, todos, done, archived
-;; - item props: priority, date-time, status?
-;; - file format
-;;   - cat begin
-;;   - todo items 0...n
-;;   - empty line
-;;   - done-separator
-;;   - done item 0...n
-
 ;;; Code:
 
 (require 'diary-lib)
+;; For remove-duplicates in todos-insertion-commands-args.
+(eval-when-compile (require 'cl))
 
 ;; ---------------------------------------------------------------------------
 ;;; User options
@@ -56,9 +37,86 @@
 (defgroup todos nil
   "Create and maintain categorized lists of todo items."
   :link '(emacs-commentary-link "todos")
-  :version "24.1"
+  :version "24.2"
   :group 'calendar)
 
+(defcustom todos-files-directory (locate-user-emacs-file "todos/")
+  "Directory where user's Todos files are saved."
+  :type 'directory
+  :group 'todos)
+
+(defun todos-files (&optional archives)
+  "Default value of `todos-files-function'.
+This returns the case-insensitive alphabetically sorted list of
+file truenames in `todos-files-directory' with the extension
+\".todo\".  With non-nil ARCHIVES return the list of archive file
+truenames (those with the extension \".toda\")."
+  (let ((files (if (file-exists-p todos-files-directory)
+                   (mapcar 'file-truename
+                    (directory-files todos-files-directory t
+                                     (if archives "\.toda$" "\.todo$") t)))))
+    (sort files (lambda (s1 s2) (let ((cis1 (upcase s1))
+                                      (cis2 (upcase s2)))
+                                  (string< cis1 cis2))))))
+
+(defcustom todos-files-function 'todos-files
+  "Function returning the value of the variable `todos-files'.
+This function should take an optional argument that, if non-nil,
+makes it return the value of the variable `todos-archives'."
+  :type 'function
+  :group 'todos)
+
+(defun todos-short-file-name (file)
+  "Return short form of Todos FILE.
+This lacks the extension and directory components."
+  (file-name-sans-extension (file-name-nondirectory file)))
+
+(defcustom todos-default-todos-file (car (funcall todos-files-function))
+  "Todos file visited by first session invocation of `todos-show'."
+  :type `(radio ,@(mapcar (lambda (f) (list 'const f))
+                          (mapcar 'todos-short-file-name
+                                  (funcall todos-files-function))))
+  :group 'todos)
+
+;; FIXME: is there a better alternative to this?
+(defun todos-reevaluate-default-file-defcustom ()
+  "Reevaluate defcustom of `todos-default-todos-file'.
+Called after adding or deleting a Todos file."
+  (eval (defcustom todos-default-todos-file (car (funcall todos-files-function))
+          "Todos file visited by first session invocation of `todos-show'."
+          :type `(radio ,@(mapcar (lambda (f) (list 'const f))
+                                  (mapcar 'todos-short-file-name
+                                          (funcall todos-files-function))))
+          :group 'todos)))
+
+(defcustom todos-show-current-file t
+  "Non-nil to make `todos-show' visit the current Todos file.
+Otherwise, `todos-show' always visits `todos-default-todos-file'."
+  :type 'boolean
+  :initialize 'custom-initialize-default
+  :set 'todos-toggle-show-current-file
+  :group 'todos)
+
+(defun todos-toggle-show-current-file (symbol value)
+  "The :set function for user option `todos-show-current-file'."
+  (custom-set-default symbol value)
+  (if value
+      (add-hook 'pre-command-hook 'todos-show-current-file nil t)
+    (remove-hook 'pre-command-hook 'todos-show-current-file t)))
+
+(defcustom todos-visit-files-commands (list 'find-file 'dired-find-file)
+  "List of commands to visit files for `todos-after-find-file'.
+Invoking these commands to visit a Todos or Todos Archive file
+calls `todos-show' or `todos-show-archive', so that the file is
+displayed correctly."
+  :type '(repeat function)
+  :group 'todos)
+
+(defcustom todos-initial-file "Todo"
+  "Default file name offered on adding first Todos file."
+  :type 'string
+  :group 'todos)
+
 (defcustom todos-initial-category "Todo"
   "Default category name offered on initializing a new Todos file."
   :type 'string
@@ -84,17 +142,46 @@ These reflect the priorities of the items in each category."
   :set 'todos-reset-prefix
   :group 'todos)
 
+(defun todos-reset-prefix (symbol value)
+  "The :set function for `todos-prefix' and `todos-number-prefix'."
+  (let ((oldvalue (symbol-value symbol))
+        (files (append todos-files todos-archives)))
+    (custom-set-default symbol value)
+    (when (not (equal value oldvalue))
+      (dolist (f files)
+        (with-current-buffer (find-file-noselect f)
+          (save-window-excursion
+            (todos-show)
+            (save-excursion
+              (widen)
+              (goto-char (point-min))
+              (while (not (eobp))
+                (remove-overlays (point) (point)); 'before-string prefix)
+                (forward-line)))
+            ;; Activate the new setting (save-restriction does not help).
+            (save-excursion (todos-category-select))))))))
+
 ;; FIXME: Update when window-width changes.  Add todos-reset-separator to
 ;; window-configuration-change-hook in todos-mode?  But this depends on the
 ;; value being window-width instead of a constant length.
-(defcustom todos-done-separator (make-string (window-width) ?-)
+(defcustom todos-done-separator (make-string (window-width) ?_)
   "String used to visual separate done from not done items.
 Displayed in a before-string overlay by `todos-toggle-view-done-items'."
   :type 'string
   :initialize 'custom-initialize-default
-  :set 'todos-reset-prefix
+  :set 'todos-reset-separator
   :group 'todos)
 
+;; (defun todos-reset-separator (symbol value)
+;;   "The :set function for `todos-done-separator'
+;; Also added to `window-configuration-change-hook' in Todos mode."
+;;   (let ((oldvalue (symbol-value symbol)))
+;;     (custom-set-default symbol value)
+;;     (when (not (equal value oldvalue))
+;;       (make-string (window-width) ?_)
+;;       ;; (save-excursion (todos-category-select))
+;;       )))
+
 (defcustom todos-done-string "DONE "
   "Identifying string appended to the front of done todos items."
   :type 'string
@@ -102,6 +189,29 @@ Displayed in a before-string overlay by `todos-toggle-view-done-items'."
   :set 'todos-reset-done-string
   :group 'todos)
 
+(defun todos-reset-done-string (symbol value)
+  "The :set function for user option `todos-done-string'."
+  (let ((oldvalue (symbol-value symbol))
+        (files (append todos-files todos-archives)))
+    (custom-set-default symbol value)
+    ;; Need to reset this to get font-locking right.
+    (setq todos-done-string-start
+          (concat "^\\[" (regexp-quote todos-done-string)))
+    (when (not (equal value oldvalue))
+      (dolist (f files)
+        (with-current-buffer (find-file-noselect f)
+          (let (buffer-read-only)
+            (widen)
+            (goto-char (point-min))
+            (while (not (eobp))
+              (if (re-search-forward
+                   (concat "^" (regexp-quote todos-nondiary-start)
+                           "\\(" (regexp-quote oldvalue) "\\)")
+                   nil t)
+                  (replace-match value t t nil 1)
+                (forward-line)))
+            (todos-category-select)))))))
+
 (defcustom todos-comment-string "COMMENT"
   "String inserted before optional comment appended to done item."
   :type 'string
@@ -109,6 +219,27 @@ Displayed in a before-string overlay by `todos-toggle-view-done-items'."
   :set 'todos-reset-comment-string
   :group 'todos)
 
+(defun todos-reset-comment-string (symbol value)
+  "The :set function for user option `todos-comment-string'."
+  (let ((oldvalue (symbol-value symbol))
+        (files (append todos-files todos-archives)))
+    (custom-set-default symbol value)
+    (when (not (equal value oldvalue))
+      (dolist (f files)
+        (with-current-buffer (find-file-noselect f)
+          (let (buffer-read-only)
+            (save-excursion
+              (widen)
+              (goto-char (point-min))
+              (while (not (eobp))
+                (if (re-search-forward
+                     (concat
+                             "\\[\\(" (regexp-quote oldvalue) "\\): [^]]*\\]")
+                     nil t)
+                    (replace-match value t t nil 1)
+                  (forward-line)))
+              (todos-category-select))))))))
+
 (defcustom todos-show-with-done nil
   "Non-nil to display done items in all categories."
   :type 'boolean
@@ -119,147 +250,98 @@ Displayed in a before-string overlay by `todos-toggle-view-done-items'."
 Argument CAT is the name of the current Todos category.
 This function is the value of the user variable
 `todos-mode-line-function'."
-  (let ((file (file-name-sans-extension
-               (file-name-nondirectory todos-current-todos-file))))
-  (format "%s category %d: %s" file todos-category-number cat)))
+  (let ((file (todos-short-file-name todos-current-todos-file)))
+    (format "%s category %d: %s" file todos-category-number cat)))
 
 (defcustom todos-mode-line-function 'todos-mode-line-control
   "Function that returns a mode line control for Todos buffers.
-The function is expected to take one argument that holds the name
-of the current Todos category.  The resulting control becomes the
-local value of `mode-line-buffer-identification' in each Todos
-buffer."
-  :type 'function
-  :group 'todos)
-
-(defcustom todos-files-directory (locate-user-emacs-file "todos/")
-  "Directory where user's Todos files are saved."
-  :type 'directory
-  :group 'todos)
-
-(defun todos-files (&optional archives)
-  "Default value of `todos-files-function'.
-This returns the case-insensitive alphabetically sorted list of
-file truenames in `todos-files-directory' with the extension
-\".todo\".  With non-nil ARCHIVES return the list of archive file
-truenames (those with the extension \".toda\")."
-  (let ((files (mapcar 'file-truename
-                       (directory-files todos-files-directory t
-                                        (if archives "\.toda$" "\.todo$") t))))
-    (sort files (lambda (s1 s2) (let ((cis1 (upcase s1))
-                                      (cis2 (upcase s2)))
-                                  (string< cis1 cis2))))))
-
-(defcustom todos-files-function 'todos-files
-  "Function returning the value of the variable `todos-files'.
-This function should take an optional argument that, if non-nil,
-makes it return the value of the variable `todos-archives'."
+The function expects one argument holding the name of the current
+Todos category.  The resulting control becomes the local value of
+`mode-line-buffer-identification' in each Todos buffer."
   :type 'function
   :group 'todos)
 
-(defcustom todos-filter-function nil
-  ""
-  :type 'function
-  :group 'todos)
-
-(defcustom todos-priorities-rules (list)
-  "List of rules for choosing top priorities of each Todos file.
-The rules should be set interactively by invoking
-`todos-set-top-priorities'.
-
-Each rule is a list whose first element is a member of
-`todos-files', whose second element is a number specifying the
-default number of top priority items for the categories in that
-file, and whose third element is an alist whose elements are
-conses of a category name in that file and the number of top
-priority items in that category that `todos-top-priorities' shows
-by default, which overrides the number for the file."
-  :type 'list
-  :group 'todos)
-
-(defcustom todos-merged-files nil
-  "List of files for `todos-merged-top-priorities'."
-  :type `(set ,@(mapcar (lambda (x) (list 'const x))
-                        (funcall todos-files-function)))
-  :group 'todos)
-
-(defcustom todos-prompt-merged-files nil
-  "Non-nil to prompt for merging files for `todos-filter-items'."
-  :type 'boolean
-  :group 'todos)
-
-(defcustom todos-show-current-file t
-  "Non-nil to make `todos-show' visit the current Todos file.
-Otherwise, `todos-show' always visits `todos-default-todos-file'."
-  :type 'boolean
-  :initialize 'custom-initialize-default
-  :set 'todos-toggle-show-current-file
-  :group 'todos)
-
-;; FIXME: omit second sentence from doc string?
-(defcustom todos-default-todos-file (car (funcall todos-files-function))
-  "Todos file visited by first session invocation of `todos-show'.
-Normally this should be set by invoking `todos-change-default-file'
-either directly or as a side effect of `todos-add-file'."
-  :type `(radio ,@(mapcar (lambda (x) (list 'const x))
-                          (funcall todos-files-function)))
-  :group 'todos)
-
-(defcustom todos-visit-files-commands (list 'find-file 'dired-find-file)
-  "List of commands to visit files for `todos-after-find-file'.
-Invoking these commands to visit a Todos or Todos Archive file
-calls `todos-show' or `todos-show-archive', so that the file is
-displayed correctly."
-  :type '(repeat function)
-  :group 'todos)
-
-(defcustom todos-categories-buffer "*Todos Categories*"
-  "Name of buffer displayed by `todos-display-categories'."
+(defun todos-special-buffer-name (buffer-type file-list)
+  "Rename Todos special buffer.
+The new name is concatenated from the string BUFFER-TYPE and the
+names of the files in FILE-LIST.  Used in the mode-list of
+buffers displaying top priorities, diary items, regexp items
+etc. for single and multiple files."
+  (let* ((flist (if (listp file-list) file-list (list file-list)))
+         (multi (> (length flist) 1))
+         (fnames (mapconcat (lambda (f) (todos-short-file-name f))
+                           flist ", ")))
+    (rename-buffer (format (concat "%s for file" (if multi "s" "")
+                                   " \"%s\"") buffer-type fnames))))
+
+(defcustom todos-filter-buffer "Todos filtered items"
+  "Initial name of buffer in Todos Filter mode."
   :type 'string
   :group 'todos)
 
-(defcustom todos-categories-category-label "Category"
-  "Category button label in `todos-categories-buffer'."
+(defcustom todos-top-priorities-buffer "Todos top priorities"
+  "Name of buffer displaying top priorities in Todos Filter mode."
   :type 'string
   :group 'todos)
 
-(defcustom todos-categories-todo-label "Todo"
-  "Todo button label in `todos-categories-buffer'."
+(defcustom todos-diary-items-buffer "Todos diary items"
+  "Name of buffer displaying diary items in Todos Filter mode."
   :type 'string
   :group 'todos)
 
-(defcustom todos-categories-diary-label "Diary"
-  "Diary button label in `todos-categories-buffer'."
+(defcustom todos-regexp-items-buffer "Todos regexp items"
+  "Name of buffer displaying regexp items in Todos Filter mode."
   :type 'string
   :group 'todos)
 
-(defcustom todos-categories-done-label "Done"
-  "Done button label in `todos-categories-buffer'."
+(defcustom todos-custom-items-buffer "Todos custom items"
+  "Name of buffer displaying custom items in Todos Filter mode."
   :type 'string
   :group 'todos)
 
-(defcustom todos-categories-archived-label "Archived"
-  "Archived button label in `todos-categories-buffer'."
-  :type 'string
+(defcustom todos-priorities-rules nil
+  "List of rules giving how many items `todos-top-priorities' shows.
+This variable should be set interactively by
+`\\[todos-set-top-priorities-in-file]' or
+`\\[todos-set-top-priorities-in-category]'.
+
+Each rule is a list of the form (FILE NUM ALIST), where FILE is a
+member of `todos-files', NUM is a number specifying the default
+number of top priority items for each category in that file, and
+ALIST, when non-nil, consists of conses of a category name in
+FILE and a number specifying the default number of top priority
+items in that category, which overrides NUM."
+  :type 'list
   :group 'todos)
 
-(defcustom todos-categories-totals-label "Totals"
-  "String to label total item counts in `todos-categories-buffer'."
-  :type 'string
+(defcustom todos-show-priorities 1
+  "Default number of top priorities shown by `todos-top-priorities'."
+  :type 'integer
   :group 'todos)
 
-(defcustom todos-categories-number-separator " | "
-  "String between number and category in `todos-categories-buffer'.
-This separates the number from the category name in the default
-categories display according to priority."
-  :type 'string
+(defcustom todos-filter-function nil
+  ""
+  :type 'function
   :group 'todos)
 
-(defcustom todos-categories-align 'center
-  "Alignment of category names in `todos-categories-buffer'."
-  :type '(radio (const left) (const center) (const right))
+(defcustom todos-filter-files nil
+  "List of default files for multifile item filtering."
+  :type `(set ,@(mapcar (lambda (f) (list 'const f))
+                        (mapcar 'todos-short-file-name
+                                (funcall todos-files-function))))
   :group 'todos)
 
+;; FIXME: is there a better alternative to this?
+(defun todos-reevaluate-filter-files-defcustom ()
+  "Reevaluate defcustom of `todos-filter-files'.
+Called after adding or deleting a Todos file."
+  (eval (defcustom todos-filter-files nil
+          "List of files for multifile item filtering."
+          :type `(set ,@(mapcar (lambda (f) (list 'const f))
+                                (mapcar 'todos-short-file-name
+                                        (funcall todos-files-function))))
+          :group 'todos)))
+
 (defcustom todos-ignore-archived-categories nil
   "Non-nil to ignore categories with only archived items.
 When non-nil such categories are omitted from `todos-categories'
@@ -273,21 +355,17 @@ archived categories."
   :set 'todos-reset-categories
   :group 'todos)
 
-;; FIXME
-(defcustom todos-edit-buffer "*Todos Edit*"
-  "Name of current buffer in Todos Edit mode."
-  :type 'string
-  :group 'todos)
-
-;; (defcustom todos-edit-buffer "*Todos Top Priorities*"
-;;   "TODO Edit buffer name."
-;;   :type 'string
-;;   :group 'todos)
-
-;; (defcustom todos-edit-buffer "*Todos Diary Entries*"
-;;   "TODO Edit buffer name."
-;;   :type 'string
-;;   :group 'todos)
+(defun todos-reset-categories (symbol value)
+  "The :set function for `todos-ignore-archived-categories'."
+  (custom-set-default symbol value)
+  (dolist (f (funcall todos-files-function))
+    (with-current-buffer (find-file-noselect f)
+      (if value
+          (setq todos-categories-full todos-categories
+                todos-categories (todos-truncate-categories-list))
+        (setq todos-categories todos-categories-full
+              todos-categories-full nil))
+      (todos-category-select))))
 
 (defcustom todos-use-only-highlighted-region t
   "Non-nil to enable inserting only highlighted region as new item."
@@ -317,29 +395,70 @@ the diary date."
   :initialize 'custom-initialize-default
   :set 'todos-reset-nondiary-marker)
 
+(defun todos-reset-nondiary-marker (symbol value)
+  "The :set function for user option `todos-nondiary-marker'."
+  (let ((oldvalue (symbol-value symbol))
+        (files (append todos-files todos-archives)))
+    (custom-set-default symbol value)
+    ;; Need to reset these to get font-locking right.
+    (setq todos-nondiary-start (nth 0 todos-nondiary-marker)
+          todos-nondiary-end (nth 1 todos-nondiary-marker)
+          todos-date-string-start
+          ;; See comment in defvar of `todos-date-string-start'.
+          (concat "^\\(" (regexp-quote todos-nondiary-start) "\\|"
+                  (regexp-quote diary-nonmarking-symbol) "\\)?"))
+    (when (not (equal value oldvalue))
+      (dolist (f files)
+        (with-current-buffer (find-file-noselect f)
+          (let (buffer-read-only)
+            (widen)
+            (goto-char (point-min))
+            (while (not (eobp))
+              (if (re-search-forward
+                   (concat "^\\(" todos-done-string-start "[^][]+] \\)?"
+                           "\\(?1:" (regexp-quote (car oldvalue))
+                           "\\)" todos-date-pattern "\\( "
+                           diary-time-regexp "\\)?\\(?2:"
+                           (regexp-quote (cadr oldvalue)) "\\)")
+                   nil t)
+                  (progn
+                    (replace-match (nth 0 value) t t nil 1)
+                    (replace-match (nth 1 value) t t nil 2))
+                (forward-line)))
+            (todos-category-select)))))))
+
 (defcustom todos-print-function 'ps-print-buffer-with-faces
   "Function called to print buffer content; see `todos-print'."
   :type 'symbol
   :group 'todos)
 
-;; FIXME: rename, change meaning of zero, refer to todos-priorities-rules
-(defcustom todos-show-priorities 1
-  "Default number of priorities to show by `todos-top-priorities'.
-0 means show all entries."
-  :type 'integer
-  :group 'todos)
-
-(defcustom todos-print-priorities 0
-  "Default number of priorities to print by `todos-print'.
-0 means print all entries."
-  :type 'integer
+(defcustom todos-completion-ignore-case nil
+  "Non-nil means case of user input in `todos-read-*' is ignored."
+  :type 'boolean
   :group 'todos)
 
-(defcustom todos-completion-ignore-case t ;; FIXME: nil for release?
-  "Non-nil means don't consider case significant in `todos-read-category'."
+(defcustom todos-highlight-item nil
+  "Non-nil means highlight items at point."
   :type 'boolean
+  :initialize 'custom-initialize-default
+  :set 'todos-reset-highlight-item
   :group 'todos)
 
+(defun todos-reset-highlight-item (symbol value)
+  "The :set function for `todos-highlight-item'."
+  (let ((oldvalue (symbol-value symbol))
+        (files (append todos-files todos-archives)))
+    (custom-set-default symbol value)
+    (when (not (equal value oldvalue))
+      (dolist (f files)
+        (let ((buf (get-file-buffer f)))
+          (when buf
+            (with-current-buffer buf
+              (require 'hl-line)
+              (if value
+                  (hl-line-mode 1)
+                (hl-line-mode -1)))))))))
+
 (defcustom todos-always-add-time-string nil
   "Non-nil adds current time to a new item's date header by default.
 When the Todos insertion commands have a non-nil \"maybe-notime\"
@@ -350,99 +469,341 @@ current time, if nil, they include it."
   :group 'todos)
 
 (defcustom todos-wrap-lines t
-  "Non-nil to wrap long lines by `todos-line-wrapping-function'." ;FIXME
+  "Non-nil to wrap long lines via `todos-line-wrapping-function'."
   :group 'todos
   :type 'boolean)
 
 (defcustom todos-line-wrapping-function 'todos-wrap-and-indent
-  "Function called when `todos-wrap-lines' is non-nil." ;FIXME
+  "Line wrapping function used with non-nil `todos-wrap-lines'."
   :group 'todos
   :type 'function)
 
+(defun todos-wrap-and-indent ()
+  "Use word wrapping on long lines and indent with a wrap prefix.
+The amount of indentation is given by user option
+`todos-indent-to-here'."
+  (set (make-local-variable 'word-wrap) t)
+  (set (make-local-variable 'wrap-prefix) (make-string todos-indent-to-here 32))
+  (unless (member '(continuation) fringe-indicator-alist)
+    (push '(continuation) fringe-indicator-alist)))
+
+;; FIXME: :set function (otherwise change takes effect only after revisiting)
 (defcustom todos-indent-to-here 6
-    "Number of spaces `todos-line-wrapping-function' indents to."
-  :type 'integer
+  "Number of spaces `todos-line-wrapping-function' indents to."
+  :type '(integer :validate
+                  (lambda (widget)
+                    (unless (> (widget-value widget) 0)
+                      (widget-put widget :error
+                                  "Invalid value: must be a positive integer")
+                      widget)))
   :group 'todos)
 
+(defun todos-indent ()
+  "Indent from point to `todos-indent-to-here'."
+  (indent-to todos-indent-to-here todos-indent-to-here))
+
+(defcustom todos-todo-mode-date-time-regexp
+  (concat "\\(?1:[0-9]\\{4\\}\\)-\\(?2:[0-9]\\{2\\}\\)-"
+          "\\(?3:[0-9]\\{2\\}\\) \\(?4:[0-9]\\{2\\}:[0-9]\\{2\\}\\)")
+  "Regexp matching legacy todo-mode.el item date-time strings.
+In order for `todos-convert-legacy-files' to correctly convert this
+string to the current Todos format, the regexp must contain four
+explicitly numbered groups (see `(elisp) Regexp Backslash'),
+where group 1 matches a string for the year, group 2 a string for
+the month, group 3 a string for the day and group 4 a string for
+the time.  The default value converts date-time strings built
+using the default value of `todo-time-string-format' from
+todo-mode.el."
+  :type 'regexp
+  :group 'todos)
+
+(defgroup todos-categories nil
+  "Faces for Todos Categories mode."
+  :version "24.2"
+  :group 'todos)
+
+(defcustom todos-categories-category-label "Category"
+  "Category button label in Todos Categories mode."
+  :type 'string
+  :group 'todos-categories)
+
+(defcustom todos-categories-todo-label "Todo"
+  "Todo button label in Todos Categories mode."
+  :type 'string
+  :group 'todos-categories)
+
+(defcustom todos-categories-diary-label "Diary"
+  "Diary button label in Todos Categories mode."
+  :type 'string
+  :group 'todos-categories)
+
+(defcustom todos-categories-done-label "Done"
+  "Done button label in Todos Categories mode."
+  :type 'string
+  :group 'todos-categories)
+
+(defcustom todos-categories-archived-label "Archived"
+  "Archived button label in Todos Categories mode."
+  :type 'string
+  :group 'todos-categories)
+
+(defcustom todos-categories-totals-label "Totals"
+  "String to label total item counts in Todos Categories mode."
+  :type 'string
+  :group 'todos-categories)
+
+(defcustom todos-categories-number-separator " | "
+  "String between number and category in Todos Categories mode.
+This separates the number from the category name in the default
+categories display according to priority."
+  :type 'string
+  :group 'todos-categories)
+
+(defcustom todos-categories-align 'center
+  "Alignment of category names in Todos Categories mode."
+  :type '(radio (const left) (const center) (const right))
+  :group 'todos-categories)
+
 ;; ---------------------------------------------------------------------------
 ;;; Faces
 
 (defgroup todos-faces nil
   "Faces for the Todos modes."
-  :version "24.1"
+  :version "24.2"
   :group 'todos)
 
 (defface todos-prefix-string
-  '((t :inherit font-lock-constant-face))
+  ;; '((t :inherit font-lock-constant-face))
+  '((((class grayscale) (background light))
+     (:foreground "LightGray" :weight bold :underline t))
+    (((class grayscale) (background dark))
+     (:foreground "Gray50" :weight bold :underline t))
+    (((class color) (min-colors 88) (background light)) (:foreground "dark cyan"))
+    (((class color) (min-colors 88) (background dark)) (:foreground "Aquamarine"))
+    (((class color) (min-colors 16) (background light)) (:foreground "CadetBlue"))
+    (((class color) (min-colors 16) (background dark)) (:foreground "Aquamarine"))
+    (((class color) (min-colors 8)) (:foreground "magenta"))
+    (t (:weight bold :underline t)))
   "Face for Todos prefix string."
   :group 'todos-faces)
 
 (defface todos-mark
-  '((t :inherit font-lock-warning-face))
+  ;; '((t :inherit font-lock-warning-face))
+  '((((class color)
+      (min-colors 88)
+      (background light))
+     (:weight bold :foreground "Red1"))
+    (((class color)
+      (min-colors 88)
+      (background dark))
+     (:weight bold :foreground "Pink"))
+    (((class color)
+      (min-colors 16)
+      (background light))
+     (:weight bold :foreground "Red1"))
+    (((class color)
+      (min-colors 16)
+      (background dark))
+     (:weight bold :foreground "Pink"))
+    (((class color)
+      (min-colors 8))
+     (:foreground "red"))
+    (t
+     (:weight bold :inverse-video t)))
   "Face for marks on Todos items."
   :group 'todos-faces)
 
 (defface todos-button
-  '((t :inherit widget-field))
+  ;; '((t :inherit widget-field))
+  '((((type tty))
+     (:foreground "black" :background "yellow3"))
+    (((class grayscale color)
+      (background light))
+     (:background "gray85"))
+    (((class grayscale color)
+      (background dark))
+     (:background "dim gray"))
+    (t
+     (:slant italic)))
   "Face for buttons in todos-display-categories."
   :group 'todos-faces)
 
 (defface todos-sorted-column
-  '((t :inherit fringe))
+  ;; '((t :inherit fringe))
+  '((((class color)
+      (background light))
+     (:foreground "grey95"))
+    (((class color)
+      (background dark))
+     (:foreground "grey10"))
+    (t
+     (:foreground "gray")))
   "Face for buttons in todos-display-categories."
   :group 'todos-faces)
 
 (defface todos-archived-only
-  '((t (:inherit (shadow))))
+  ;; '((t (:inherit (shadow))))
+  '((((class color)
+      (background light))
+     (:foreground "grey50"))
+    (((class color)
+      (background dark))
+     (:foreground "grey70"))
+    (t
+     (:foreground "gray")))
   "Face for archived-only categories in todos-display-categories."
   :group 'todos-faces)
 
 (defface todos-search
-  '((t :inherit match))
+  ;; '((t :inherit match))
+  '((((class color)
+      (min-colors 88)
+      (background light))
+     (:background "yellow1"))
+    (((class color)
+      (min-colors 88)
+      (background dark))
+     (:background "RoyalBlue3"))
+    (((class color)
+      (min-colors 8)
+      (background light))
+     (:foreground "black" :background "yellow"))
+    (((class color)
+      (min-colors 8)
+      (background dark))
+     (:foreground "white" :background "blue"))
+    (((type tty)
+      (class mono))
+     (:inverse-video t))
+    (t
+     (:background "gray")))
   "Face for matches found by todos-search."
   :group 'todos-faces)
 
+(defface todos-diary-expired
+  ;; '((t :inherit font-lock-warning-face))
+  '((((class color)
+      (min-colors 16))
+     (:weight bold :foreground "DarkOrange"))
+    (((class color))
+     (:weight bold :foreground "yellow"))
+    (t
+     (:weight bold)))
+  "Face for expired dates of diary items."
+  :group 'todos-faces)
+(defvar todos-diary-expired-face 'todos-diary-expired)
+
 (defface todos-date
   '((t :inherit diary))
-  "Face for Todos prefix string."
+  "Face for the date string of a Todos item."
   :group 'todos-faces)
 (defvar todos-date-face 'todos-date)
 
 (defface todos-time
   '((t :inherit diary-time))
-  "Face for Todos prefix string."
+  "Face for the time string of a Todos item."
   :group 'todos-faces)
 (defvar todos-time-face 'todos-time)
 
 (defface todos-done
-  '((t :inherit font-lock-comment-face))
+  ;; '((t :inherit font-lock-comment-face))
+  '((((class grayscale)
+      (background light))
+     (:slant italic :weight bold :foreground "DimGray"))
+    (((class grayscale)
+      (background dark))
+     (:slant italic :weight bold :foreground "LightGray"))
+    (((class color)
+      (min-colors 88)
+      (background light))
+     (:foreground "Firebrick"))
+    (((class color)
+      (min-colors 88)
+      (background dark))
+     (:foreground "chocolate1"))
+    (((class color)
+      (min-colors 16)
+      (background light))
+     (:foreground "red"))
+    (((class color)
+      (min-colors 16)
+      (background dark))
+     (:foreground "red1"))
+    (((class color)
+      (min-colors 8)
+      (background light))
+     (:foreground "red"))
+    (((class color)
+      (min-colors 8)
+      (background dark))
+     (:foreground "yellow"))
+    (t
+     (:slant italic :weight bold)))
   "Face for done Todos item header string."
   :group 'todos-faces)
 (defvar todos-done-face 'todos-done)
 
 (defface todos-comment
-  '((t :inherit font-lock-comment-face))
+  '((t :inherit todos-done))
   "Face for comments appended to done Todos items."
   :group 'todos-faces)
 (defvar todos-comment-face 'todos-comment)
 
 (defface todos-done-sep
-  '((t :inherit font-lock-type-face))
+  ;; '((t :inherit font-lock-type-face))
+  '((((class grayscale)
+      (background light))
+     (:weight bold :foreground "Gray90"))
+    (((class grayscale)
+      (background dark))
+     (:weight bold :foreground "DimGray"))
+    (((class color)
+      (min-colors 88)
+      (background light))
+     (:foreground "ForestGreen"))
+    (((class color)
+      (min-colors 88)
+      (background dark))
+     (:foreground "PaleGreen"))
+    (((class color)
+      (min-colors 16)
+      (background light))
+     (:foreground "ForestGreen"))
+    (((class color)
+      (min-colors 16)
+      (background dark))
+     (:foreground "PaleGreen"))
+    (((class color)
+      (min-colors 8))
+     (:foreground "green"))
+    (t
+     (:underline t :weight bold)))
   "Face for separator string bewteen done and not done Todos items."
   :group 'todos-faces)
 (defvar todos-done-sep-face 'todos-done-sep)
 
 (defvar todos-font-lock-keywords
   (list
+   ;; '(todos-nondiary-marker-matcher 1 todos-nondiary-face t)
+   ;; '(todos-nondiary-marker-matcher 2 todos-nondiary-face t)
+   '(todos-nondiary-marker-matcher 1 todos-done-sep-face t)
+   '(todos-nondiary-marker-matcher 2 todos-done-sep-face t)
+   ;; This is the face used by diary-lib.el.
+   '(todos-diary-nonmarking-matcher 1 font-lock-constant-face t)
    '(todos-date-string-matcher 1 todos-date-face t)
    '(todos-time-string-matcher 1 todos-time-face t)
    '(todos-done-string-matcher 0 todos-done-face t)
    '(todos-comment-string-matcher 1 todos-done-face t)
-   '(todos-category-string-matcher 1 todos-done-sep-face t))
-  "Font-locking for Todos mode.")
+   ;; '(todos-category-string-matcher 1 todos-done-sep-face t)
+   '(todos-category-string-matcher-1 1 todos-done-sep-face t t)
+   '(todos-category-string-matcher-2 1 todos-done-sep-face t t)
+   '(todos-diary-expired-matcher 1 todos-diary-expired-face t)
+   '(todos-diary-expired-matcher 2 todos-diary-expired-face t t)
+   )
+  "Font-locking for Todos modes.")
 
 ;; ---------------------------------------------------------------------------
-;;; Modes setup
+;;; Todos mode local variables and hook functions
 
 (defvar todos-files (funcall todos-files-function)
   "List of truenames of user's Todos files.")
@@ -450,34 +811,29 @@ current time, if nil, they include it."
 (defvar todos-archives (funcall todos-files-function t)
   "List of truenames of user's Todos archives.")
 
-(defvar todos-categories nil
-  "Alist of categories in the current Todos file.
-The elements are cons cells whose car is a category name and
-whose cdr is a vector of the category's item counts.  These are,
-in order, the numbers of todo items, todo items included in the
-Diary, done items and archived items.")
-
-(defvar todos-categories-full nil
-  "Variable holding non-truncated copy of `todos-categories'.
-Set when `todos-ignore-archived-categories' is set to non-nil, to
-restore full `todos-categories' list when
-`todos-ignore-archived-categories' is reset to nil.")
-
 (defvar todos-current-todos-file nil
   "Variable holding the name of the currently active Todos file.")
-;; Automatically set by `todos-switch-todos-file'.")
 
-;; FIXME: Add function to kill-buffer-hook that sets this to the latest
-;; existing Todos file or else todos-default-todos-file on killing the buffer
-;; of a Todos file
-(defvar todos-global-current-todos-file nil
-  "Variable holding name of current Todos file.
-Used by functions called from outside of Todos mode to visit the
-current Todos file rather than the default Todos file (i.e. when
-users option `todos-show-current-file' is non-nil).")
+(defun todos-show-current-file ()
+  "Visit current instead of default Todos file with `todos-show'.
+This function is added to `pre-command-hook' when user option
+`todos-show-current-file' is set to non-nil."
+  (setq todos-global-current-todos-file todos-current-todos-file))
+  ;; (and (eq major-mode 'todos-mode)
+       ;; (setq todos-global-current-todos-file (buffer-file-name))))
+
+(defun todos-after-find-file ()
+  "Show Todos files correctly when visited from outside of Todos mode."
+  (and (member this-command todos-visit-files-commands)
+       (= (- (point-max) (point-min)) (buffer-size))
+       (member major-mode '(todos-mode todos-archive-mode))
+       (todos-category-select)))
 
 (defun todos-reset-global-current-todos-file ()
-  ""
+  "Update the value of `todos-global-current-todos-file'.
+This becomes the latest existing Todos file or, if there is none,
+the value of `todos-default-todos-file'.
+This function is added to `kill-buffer-hook' in Todos mode."
   (let ((buflist (copy-sequence (buffer-list)))
         (cur todos-global-current-todos-file))
     (catch 'done
@@ -492,23 +848,77 @@ users option `todos-show-current-file' is non-nil).")
     (if (equal cur todos-global-current-todos-file)
         (setq todos-global-current-todos-file todos-default-todos-file))))    
 
+(defvar todos-categories nil
+  "Alist of categories in the current Todos file.
+The elements are cons cells whose car is a category name and
+whose cdr is a vector of the category's item counts.  These are,
+in order, the numbers of todo items, todo items included in the
+Diary, done items and archived items.")
+
+(defvar todos-categories-full nil
+  "Variable holding non-truncated copy of `todos-categories'.
+Set when `todos-ignore-archived-categories' is set to non-nil, to
+restore full `todos-categories' list when
+`todos-ignore-archived-categories' is reset to nil.")
+
+(defvar todos-categories-with-marks nil
+  "Alist of categories and number of marked items they contain.")
+
 (defvar todos-category-number 1
   "Variable holding the number of the current Todos category.
-This number is one more than the index of the category in
-`todos-categories'.")
+Todos categories are numbered starting from 1.")
 
 (defvar todos-first-visit t
   "Non-nil if first display of this file in the current session.
 See `todos-display-categories-first'.")
 
-;; FIXME: rename?
-(defvar todos-tmp-buffer-name " *todo tmp*")
+(defvar todos-show-done-only nil
+  "If non-nil display only done items in current category.
+Set by `todos-toggle-show-done-only' and used by
+`todos-category-select'.")
 
-(defvar todos-category-beg "--==-- "
-  "String marking beginning of category (inserted with its name).")
+;; ---------------------------------------------------------------------------
+;;; Global variables and helper functions
 
-(defvar todos-category-done "==--== DONE "
-  "String marking beginning of category's done items.")
+(defvar todos-global-current-todos-file nil
+  "Variable holding name of current Todos file.
+Used by functions called from outside of Todos mode to visit the
+current Todos file rather than the default Todos file (i.e. when
+users option `todos-show-current-file' is non-nil).")
+
+(defun todos-reevaluate-defcustoms ()
+  "Reevaluate defcustoms that show list of Todos files."
+  (custom-set-default 'todos-default-todos-file
+                      (symbol-value 'todos-default-todos-file))
+  (todos-reevaluate-default-file-defcustom)
+  (custom-set-default 'todos-filter-files (symbol-value 'todos-filter-files))
+  (todos-reevaluate-filter-files-defcustom))
+
+(defvar todos-edit-buffer "*Todos Edit*"
+  "Name of current buffer in Todos Edit mode.")
+
+(defvar todos-categories-buffer "*Todos Categories*"
+  "Name of buffer in Todos Categories mode.")
+
+(defvar todos-print-buffer "*Todos Print*"
+  "Name of buffer containing printable Todos text.")
+
+(defvar todos-date-pattern
+  (let ((dayname (diary-name-pattern calendar-day-name-array nil t)))
+    (concat "\\(?:" dayname "\\|"
+            (let ((dayname)
+                  ;; FIXME: how to choose between abbreviated and unabbreviated
+                  ;; month name?
+                  (monthname (format "\\(?:%s\\|\\*\\)"
+                                     (diary-name-pattern
+                                      calendar-month-name-array
+                                      calendar-month-abbrev-array t)))
+                  (month "\\(?:[0-9]+\\|\\*\\)")
+                  (day "\\(?:[0-9]+\\|\\*\\)")
+                  (year "-?\\(?:[0-9]+\\|\\*\\)"))
+              (mapconcat 'eval calendar-date-display-form ""))
+            "\\)"))
+  "Regular expression matching a Todos date header.")
 
 (defvar todos-nondiary-start (nth 0 todos-nondiary-marker)
   "String inserted before item date to block diary inclusion.")
@@ -516,20 +926,1171 @@ See `todos-display-categories-first'.")
 (defvar todos-nondiary-end (nth 1 todos-nondiary-marker)
   "String inserted after item date matching `todos-nondiary-start'.")
 
-(defvar todos-show-done-only nil
-  "If non-nil display only done items in current category.
-Set by `todos-toggle-show-done-only' and used by
-`todos-category-select'.")
+;; By itself this matches anything, because of the `?'; however, it's only
+;; used in the context of `todos-date-pattern' (but Emacs Lisp lacks
+;; lookahead).
+(defvar todos-date-string-start
+  (concat "^\\(" (regexp-quote todos-nondiary-start) "\\|"
+          (regexp-quote diary-nonmarking-symbol) "\\)?")
+  "Regular expression matching part of item header before the date.")
+
+(defvar todos-done-string-start
+  (concat "^\\[" (regexp-quote todos-done-string))
+  "Regular expression matching start of done item.")
+
+(defun todos-date-string-matcher (lim)
+  "Search for Todos date string within LIM for font-locking."
+  (re-search-forward
+   (concat todos-date-string-start "\\(?1:" todos-date-pattern "\\)") lim t))
+
+(defun todos-time-string-matcher (lim)
+  "Search for Todos time string within LIM for font-locking."
+  (re-search-forward (concat todos-date-string-start todos-date-pattern
+                             " \\(?1:" diary-time-regexp "\\)") lim t))
+
+(defun todos-nondiary-marker-matcher (lim)
+  "Search for Todos nondiary markers within LIM for font-locking."
+  (re-search-forward (concat "^\\(?1:" (regexp-quote todos-nondiary-start) "\\)"
+                             todos-date-pattern "\\(?: " diary-time-regexp
+                             "\\)?\\(?2:" (regexp-quote todos-nondiary-end) "\\)")
+                     lim t))
+
+(defun todos-diary-nonmarking-matcher (lim)
+  "Search for diary nonmarking symbol within LIM for font-locking."
+  (re-search-forward (concat "^\\(?1:" (regexp-quote diary-nonmarking-symbol)
+                             "\\)" todos-date-pattern) lim t))
+
+(defun todos-diary-expired-matcher (lim)
+  "Search for expired diary item date within LIM for font-locking."
+  (when (re-search-forward (concat "^\\(?:"
+                                   (regexp-quote diary-nonmarking-symbol)
+                                   "\\)?\\(?1:" todos-date-pattern "\\) \\(?2:"
+                                   diary-time-regexp "\\)?") lim t)
+    (let* ((date (match-string-no-properties 1))
+           (time (match-string-no-properties 2))
+           ;; days-between needs a non-empty time string.
+           (date-time (concat date " " (or time "00:00"))))
+      (or (and (not (string-match ".+day\\|\\*" date))
+               (< (days-between date-time (current-time-string)) 0))
+          (todos-diary-expired-matcher lim)))))
+
+(defun todos-done-string-matcher (lim)
+  "Search for Todos done header within LIM for font-locking."
+  (re-search-forward (concat todos-done-string-start
+                      "[^][]+]")
+                     lim t))
+
+(defun todos-comment-string-matcher (lim)
+  "Search for Todos done comment within LIM for font-locking."
+  (re-search-forward (concat "\\[\\(?1:" todos-comment-string "\\):")
+                     lim t))
 
+;; (defun todos-category-string-matcher (lim)
+;;   "Search for Todos category name within LIM for font-locking.
+;; This is for fontifying category names appearing in Todos filter
+;; mode."
+;;   (if (eq major-mode 'todos-filter-items-mode)
+;;       (re-search-forward
+;;        (concat "^\\(?:" todos-date-string-start "\\)?" todos-date-pattern
+;;                     "\\(?: " diary-time-regexp "\\)?\\(?:"
+;;                     (regexp-quote todos-nondiary-end) "\\)? \\(?1:\\[.+\\]\\)")
+;;        lim t)))
+
+(defun todos-category-string-matcher-1 (lim)
+  "Search for Todos category name within LIM for font-locking.
+This is for fontifying category names appearing in Todos filter
+mode following done items."
+  (if (eq major-mode 'todos-filter-items-mode)
+      (re-search-forward (concat todos-done-string-start todos-date-pattern
+                                 "\\(?: " diary-time-regexp
+                                 ;; Use non-greedy operator to prevent
+                                 ;; capturing possible following non-diary
+                                 ;; date string.
+                                 "\\)?] \\(?1:\\[.+?\\]\\)")
+                         lim t)))
+
+(defun todos-category-string-matcher-2 (lim)
+  "Search for Todos category name within LIM for font-locking.
+This is for fontifying category names appearing in Todos filter
+mode following todo (not done) items."
+  (if (eq major-mode 'todos-filter-items-mode)
+      (re-search-forward (concat todos-date-string-start todos-date-pattern
+                                 "\\(?: " diary-time-regexp "\\)?\\(?:"
+                                 (regexp-quote todos-nondiary-end)
+                                 "\\)? \\(?1:\\[.+\\]\\)")
+                         lim t)))
+
+(defun todos-category-number (cat)
+  "Return the number of category CAT in this Todos file.
+The buffer-local variable `todos-category-number' holds this
+number as its value."
+  (let ((categories (mapcar 'car todos-categories)))
+    (setq todos-category-number
+          ;; Increment by one, so that the highest priority category in Todos
+          ;; Categories mode is numbered one rather than zero.
+          (1+ (- (length categories)
+                 (length (member cat categories)))))))
+
+(defun todos-current-category ()
+  "Return the name of the current category."
+  (car (nth (1- todos-category-number) todos-categories)))
+
+(defconst todos-category-beg "--==-- "
+  "String marking beginning of category (inserted with its name).")
+
+(defconst todos-category-done "==--== DONE "
+  "String marking beginning of category's done items.")
+
+(defun todos-category-select ()
+  "Display the current category correctly."
+  (let ((name (todos-current-category))
+        cat-begin cat-end done-start done-sep-start done-end)
+    (widen)
+    (goto-char (point-min))
+    (re-search-forward
+     (concat "^" (regexp-quote (concat todos-category-beg name)) "$") nil t)
+    (setq cat-begin (1+ (line-end-position)))
+    (setq cat-end (if (re-search-forward
+                       (concat "^" (regexp-quote todos-category-beg)) nil t)
+                      (match-beginning 0)
+                    (point-max)))
+    (setq mode-line-buffer-identification
+          (funcall todos-mode-line-function name))
+    (narrow-to-region cat-begin cat-end)
+    (todos-prefix-overlays)
+    (goto-char (point-min))
+    (if (re-search-forward (concat "\n\\(" (regexp-quote todos-category-done)
+                                   "\\)") nil t)
+        (progn
+          (setq done-start (match-beginning 0))
+          (setq done-sep-start (match-beginning 1))
+          (setq done-end (match-end 0)))
+      (error "Category %s is missing todos-category-done string" name))
+    (if todos-show-done-only
+        (narrow-to-region (1+ done-end) (point-max))
+      (when (and todos-show-with-done
+                 (re-search-forward todos-done-string-start nil t))
+        ;; Now we want to see the done items, so reset displayed end to end of
+        ;; done items.
+        (setq done-start cat-end)
+        ;; Make display overlay for done items separator string, unless there
+        ;; already is one.
+        (let* ((done-sep todos-done-separator)
+               (ovs (overlays-at done-sep-start))
+               ov-sep)
+          (unless (and ovs (string= (overlay-get (car ovs) 'display) done-sep))
+            (setq ov-sep (make-overlay done-sep-start done-end))
+            (overlay-put ov-sep 'display done-sep))))
+      (narrow-to-region (point-min) done-start)
+      ;; Loading this from todos-mode, or adding it to the mode hook, causes
+      ;; Emacs to hang in todos-item-start, at looking-at.
+      (when todos-highlight-item
+        (require 'hl-line)
+        (hl-line-mode 1)))))
+
+(defun todos-get-count (type &optional category)
+  "Return count of TYPE items in CATEGORY.
+If CATEGORY is nil, default to the current category."
+  (let* ((cat (or category (todos-current-category)))
+         (counts (cdr (assoc cat todos-categories)))
+         (idx (cond ((eq type 'todo) 0)
+                    ((eq type 'diary) 1)
+                    ((eq type 'done) 2)
+                    ((eq type 'archived) 3))))
+    (aref counts idx)))
+
+(defun todos-set-count (type increment &optional category)
+  "Increment count of TYPE items in CATEGORY by INCREMENT.
+If CATEGORY is nil, default to the current category."
+  (let* ((cat (or category (todos-current-category)))
+         (counts (cdr (assoc cat todos-categories)))
+         (idx (cond ((eq type 'todo) 0)
+                    ((eq type 'diary) 1)
+                    ((eq type 'done) 2)
+                    ((eq type 'archived) 3))))
+    (aset counts idx (+ increment (aref counts idx)))))
+
+(defun todos-set-categories ()
+  "Set `todos-categories' from the sexp at the top of the file."
+  ;; New archive files created by `todos-move-category' are empty, which would
+  ;; make the sexp test fail and raise an error, so in this case we skip it.
+  (unless (zerop (buffer-size))
+    (save-excursion
+      (save-restriction
+        (widen)
+        (goto-char (point-min))
+        ;; todos-truncate-categories-list needs non-nil todos-categories.
+        (setq todos-categories-full
+              (if (looking-at "\(\(\"")
+                  (read (buffer-substring-no-properties
+                         (line-beginning-position)
+                         (line-end-position)))
+                (error "Invalid or missing todos-categories sexp"))
+              todos-categories todos-categories-full)))
+    (if (and todos-ignore-archived-categories
+             (eq major-mode 'todos-mode))
+        (todos-truncate-categories-list)
+      todos-categories-full)))
+
+(defun todos-update-categories-sexp ()
+  "Update the `todos-categories' sexp at the top of the file."
+  (let (buffer-read-only)
+    (save-excursion
+      (save-restriction
+        (widen)
+        (goto-char (point-min))
+        (if (looking-at (concat "^" (regexp-quote todos-category-beg)))
+            (progn (newline) (goto-char (point-min)))
+          ;; With empty buffer (e.g. with new archive in
+          ;; `todos-move-category') `kill-line' signals end of buffer.
+          (kill-region (line-beginning-position) (line-end-position)))
+        ;; todos-categories-full is nil on adding first category.
+        (prin1 (or todos-categories-full todos-categories)
+               (current-buffer))))))
+
+(defun todos-make-categories-list (&optional force)
+  "Return an alist of Todos categories and their item counts.
+With non-nil argument FORCE parse the entire file to build the
+list; otherwise, get the value by reading the sexp at the top of
+the file."
+  (setq todos-categories nil)
+  (save-excursion
+    (save-restriction
+      (widen)
+      (goto-char (point-min))
+      (let (counts cat archive)
+        (when buffer-file-name   ; Don't check with `todos-convert-legacy-files'.
+          ;; FIXME: can todos-archives be too old here?
+          (unless (member buffer-file-name (funcall todos-files-function t))
+            (setq archive (concat (file-name-sans-extension
+                                   todos-current-todos-file) ".toda"))))
+        (while (not (eobp))
+          (cond ((looking-at (concat (regexp-quote todos-category-beg)
+                                     "\\(.*\\)\n"))
+                 (setq cat (match-string-no-properties 1))
+                 ;; Counts for each category: [todo diary done archive]
+                 (setq counts (make-vector 4 0))
+                 (setq todos-categories
+                       (append todos-categories (list (cons cat counts))))
+                 ;; todos-archives may be too old here (e.g. during
+                 ;; todos-move-category).
+                 (when (member archive (funcall todos-files-function t))
+                   (let ((archive-count 0))
+                     (with-current-buffer (find-file-noselect archive)
+                       (widen)
+                       (goto-char (point-min))
+                       (when (re-search-forward
+                              (concat (regexp-quote todos-category-beg) cat)
+                              (point-max) t)
+                         (forward-line)
+                         (while (not (or (looking-at
+                                          (concat
+                                           (regexp-quote todos-category-beg)
+                                           "\\(.*\\)\n"))
+                                         (eobp)))
+                           (when (looking-at todos-done-string-start)
+                             (setq archive-count (1+ archive-count)))
+                           (forward-line))))
+                     (todos-set-count 'archived archive-count cat))))
+                ((looking-at todos-done-string-start)
+                 (todos-set-count 'done 1 cat))
+                ((looking-at (concat "^\\("
+                                     (regexp-quote diary-nonmarking-symbol)
+                                     "\\)?" todos-date-pattern))
+                 (todos-set-count 'diary 1 cat)
+                 (todos-set-count 'todo 1 cat))
+                ((looking-at (concat todos-date-string-start todos-date-pattern))
+                 (todos-set-count 'todo 1 cat))
+                ;; If first line is todos-categories list, use it and end loop
+                ;; -- unless FORCEd to scan whole file.
+                ((bobp)
+                 (unless force
+                   (setq todos-categories (read (buffer-substring-no-properties
+                                                 (line-beginning-position)
+                                                 (line-end-position))))
+                   (goto-char (1- (point-max))))))
+          (forward-line)))))
+  todos-categories)
+
+(defun todos-truncate-categories-list ()
+  "Return a truncated alist of Todos categories plus item counts.
+Categories containing only archived items are omitted.  This list
+is used in Todos mode when `todos-ignore-archived-categories' is
+non-nil."
+  (let (cats)
+    (dolist (catcons todos-categories-full cats)
+      (let ((cat (car catcons)))
+        (setq cats
+              (append cats
+                      (unless (and (zerop (todos-get-count 'todo cat))
+                                   (zerop (todos-get-count 'done cat))
+                                   (not (zerop (todos-get-count 'archived cat))))
+                        (list catcons))))))))
+
+(defun todos-check-format ()
+  "Signal an error if the current Todos file is ill-formatted.
+Otherwise return t.  The error message gives the line number
+where the invalid formatting was found."
+  (save-excursion
+    (save-restriction
+      (widen)
+      (goto-char (point-min))
+      ;; Check for `todos-categories' sexp as the first line
+      (let ((cats (prin1-to-string (or todos-categories-full todos-categories))))
+        (unless (looking-at (regexp-quote cats))
+          (error "Invalid or missing todos-categories sexp")))
+      (forward-line)
+      (let ((legit (concat "\\(^" (regexp-quote todos-category-beg) "\\)"
+                           "\\|\\(" todos-date-string-start todos-date-pattern "\\)"
+                           "\\|\\(^[ \t]+[^ \t]*\\)"
+                           "\\|^$"
+                           "\\|\\(^" (regexp-quote todos-category-done) "\\)"
+                           "\\|\\(" todos-done-string-start "\\)")))
+        (while (not (eobp))
+          (unless (looking-at legit)
+            (error "Illegitimate Todos file format at line %d"
+                   (line-number-at-pos (point))))
+          (forward-line)))))
+  ;; (message "This Todos file is well-formatted.")
+  t)
+
+(defun todos-repair-categories-sexp ()
+  "Repair corrupt Todos categories sexp."
+  (interactive)
+  (let ((todos-categories-full (todos-make-categories-list t)))
+    (todos-update-categories-sexp)))
+
+(defvar todos-item-start (concat "\\(" todos-date-string-start "\\|"
+                                 todos-done-string-start "\\)"
+                                 todos-date-pattern)
+  "String identifying start of a Todos item.")
+
+(defun todos-item-start ()
+  "Move to start of current Todos item and return its position."
+  (unless (or
+           ;; Point is either on last item in this category or on the empty
+           ;; line between done and not done items.
+           (looking-at "^$")
+           ;; There are no done items in this category yet.
+           (looking-at (regexp-quote todos-category-beg)))
+    (goto-char (line-beginning-position))
+    (while (not (looking-at todos-item-start))
+      (forward-line -1))
+    (point)))
+
+(defun todos-item-end ()
+  "Move to end of current Todos item and return its position."
+  ;; Items cannot end with a blank line.
+  (unless (looking-at "^$")
+    (let ((done (todos-done-item-p)))
+      (todos-forward-item)
+      ;; Adjust if item is last unfinished one before displayed done items.
+      (when (and (not done) (todos-done-item-p))
+        (forward-line -1))
+      (backward-char))
+    (point)))
+
+(defun todos-item-string ()
+  "Return bare text of current item as a string."
+  (let ((opoint (point))
+        (start (todos-item-start))
+        (end (todos-item-end)))
+    (goto-char opoint)
+    (and start end (buffer-substring-no-properties start end))))
+
+(defun todos-remove-item ()
+  "Internal function called in editing, deleting or moving items."
+  (let* ((beg (todos-item-start))
+         (end (progn (todos-item-end) (1+ (point))))
+         (ovs (overlays-in beg beg)))
+    ;; There can be both prefix/number and mark overlays.
+    (while ovs (delete-overlay (car ovs)) (pop ovs))
+    (delete-region beg end)))
+
+(defun todos-diary-item-p ()
+  "Return non-nil if item at point is marked for diary inclusion."
+  (save-excursion
+    (todos-item-start)
+    ;; (looking-at todos-date-pattern)))
+    (not (looking-at (regexp-quote todos-nondiary-start)))))
+
+(defun todos-done-item-p ()
+  "Return non-nil if item at point is a done item."
+  (save-excursion
+    (todos-item-start)
+    (looking-at todos-done-string-start)))
+
+(defvar todos-item-mark (propertize (if (equal todos-prefix "*") "@" "*")
+                                    'face 'todos-mark)
+  "String used to mark items.")
+
+(defun todos-marked-item-p ()
+  "If this item is marked, return mark overlay."
+  (let ((ovs (overlays-in (line-beginning-position) (line-beginning-position)))
+        (mark todos-item-mark)
+        ov marked)
+    (catch 'stop
+      (while ovs
+        (setq ov (pop ovs))
+        (and (equal (overlay-get ov 'before-string) mark)
+             (throw 'stop (setq marked t)))))
+    (when marked ov)))
+
+(defun todos-insert-with-overlays (item)
+  "Insert ITEM at point and update prefix/priority number overlays."
+  (todos-item-start)
+  (insert item "\n")
+  (todos-backward-item)
+  (todos-prefix-overlays))
+
+(defun todos-prefix-overlays ()
+  "Put before-string overlay in front of this category's items.
+The overlay's value is the string `todos-prefix' or with non-nil
+`todos-number-prefix' an integer in the sequence from 1 to the
+number of todo or done items in the category indicating the
+item's priority.  Todo and done items are numbered independently
+of each other."
+  (when (or todos-number-prefix
+            (not (string-match "^[[:space:]]*$" todos-prefix)))
+    (let ((prefix (propertize (concat todos-prefix " ")
+                              'face 'todos-prefix-string))
+          (num 0))
+      (save-excursion
+        (goto-char (point-min))
+        (while (not (eobp))
+          (when (or (todos-date-string-matcher (line-end-position))
+                    (todos-done-string-matcher (line-end-position)))
+            (goto-char (match-beginning 0))
+            (when todos-number-prefix
+              (setq num (1+ num))
+              ;; Reset number to 1 for first done item.
+              (when (and (looking-at todos-done-string-start)
+                         (looking-back (concat "^"
+                                               (regexp-quote todos-category-done)
+                                               "\n")))
+                (setq num 1))
+              (setq prefix (propertize (concat (number-to-string num) " ")
+                                       'face 'todos-prefix-string)))
+            (let ((ovs (overlays-in (point) (point)))
+                  marked ov-pref)
+              (if ovs
+                  (dolist (ov ovs)
+                    (let ((val (overlay-get ov 'before-string)))
+                      (if (equal val "*")
+                          (setq marked t)
+                        (setq ov-pref val)))))
+              (unless (equal ov-pref prefix)
+                ;; Why doesn't this work?
+                ;; (remove-overlays (point) (point) 'before-string)
+                (remove-overlays (point) (point))
+                (overlay-put (make-overlay (point) (point))
+                             'before-string prefix)
+                (and marked (overlay-put (make-overlay (point) (point))
+                                         'before-string todos-item-mark)))))
+          (forward-line))))))
+
+(defun todos-read-file-name (prompt &optional archive mustmatch)
+  "Choose and return the name of a Todos file, prompting with PROMPT.
+
+Show completions with TAB or SPC; the names are shown in short
+form but the absolute truename is returned.  With non-nil ARCHIVE
+return the absolute truename of a Todos archive file.  With non-nil
+MUSTMATCH the name of an existing file must be chosen;
+otherwise, a new file name is allowed."
+  (unless (file-exists-p todos-files-directory)
+    (make-directory todos-files-directory))
+  (let ((completion-ignore-case todos-completion-ignore-case)
+        (files (mapcar 'file-name-sans-extension
+                       (directory-files todos-files-directory nil
+                                        (if archive "\.toda$" "\.todo$"))))
+        (file ""))
+    (while (string= "" file)
+      (setq file (completing-read prompt files nil mustmatch))
+      (setq prompt "Enter a non-empty name (TAB for list of current files): "))
+    (setq file (concat todos-files-directory file
+                       (if archive ".toda" ".todo")))
+    (unless mustmatch
+      (when (not (member file todos-files))
+        (todos-validate-name file 'file)))
+    (file-truename file)))
+
+(defun todos-read-category (prompt &optional mustmatch)
+  "Choose and return a category name, prompting with PROMPT.
+Show completions with TAB or SPC.  With non-nil MUSTMATCH the
+name must be that of an existing category; otherwise, a new
+category name is allowed, after checking its validity."
+  ;; Allow SPC to insert spaces, for adding new category names.
+  (let ((map minibuffer-local-completion-map))
+    (define-key map " " nil)
+    ;; Make a copy of todos-categories in case history-delete-duplicates is
+    ;; non-nil, which makes completing-read alter todos-categories.
+    (let* ((categories (copy-sequence todos-categories))
+           (history (cons 'todos-categories (1+ todos-category-number)))
+           (completion-ignore-case todos-completion-ignore-case)
+           (cat (completing-read prompt todos-categories nil
+                                 mustmatch nil history
+                                 ;; Default for existing categories is the
+                                 ;; current category.
+                                 (if todos-categories
+                                     (todos-current-category)
+                                   ;; Trigger prompt for initial category
+                                   ""))))
+      (unless mustmatch
+        (when (not (assoc cat categories))
+                (todos-validate-name cat 'category)       
+          (if (y-or-n-p (format (concat "There is no category \"%s\" in "
+                                        "this file; add it? ") cat))
+              (todos-add-category cat)
+            (keyboard-quit))))
+      ;; Restore the original value of todos-categories.
+      (setq todos-categories categories)
+      cat)))
+
+(defun todos-validate-name (name type)
+  "Prompt for new NAME for TYPE until it is valid, then return it.
+TYPE can be either a file or a category"
+  (let (prompt file cat shortname)
+    (while
+        (and (cond ((string= "" name)
+                    (setq prompt
+                          (cond ((eq type 'file)
+                                 ;; FIXME: just todos-files ?
+                                 (if (funcall (todos-files))
+                                     "Enter a non-empty file name: "
+                                   ;; Empty string passed by todos-show to
+                                   ;; prompt for initial Todos file.
+                                   (concat "Initial file name ["
+                                           todos-initial-file "]: ")))
+                                ((eq type 'category)
+                                 (if todos-categories
+                                     "Enter a non-empty category name: "
+                                   ;; Empty string passed by todos-show to
+                                   ;; prompt for initial category of a new
+                                   ;; Todos file.
+                                   (concat "Initial category name ["
+                                           todos-initial-category "]: "))))))
+                   ((string-match "\\`\\s-+\\'" name)
+                    (setq prompt
+                          "Enter a name that does not contain only white space: "))
+                   ((and (eq type 'file) (member name todos-files))
+                    (setq prompt "Enter a non-existing file name: "))
+                   ((and (eq type 'category) (assoc name todos-categories))
+                    (setq prompt "Enter a non-existing category name: ")))
+             (setq name (if (or (and (eq type 'file) todos-files)
+                               (and (eq type 'category) todos-categories))
+                           (read-from-minibuffer prompt)
+                          ;; Offer default initial name.
+                          (read-string prompt nil nil
+                                       (cond ((eq type 'file)
+                                              todos-initial-file)
+                                             ((eq type 'category)
+                                              todos-initial-category))))))))
+  name)
+
+;; Adapted from calendar-read-date and calendar-date-string.
+(defun todos-read-date ()
+  "Prompt for Gregorian date and return it in the current format.
+Also accepts `*' as an unspecified month, day, or year."
+  (let* ((year (calendar-read
+                ;; FIXME: maybe better like monthname with RET for current month
+                "Year (>0 or * for any year): "
+                (lambda (x) (or (eq x '*) (> x 0)))
+                (number-to-string (calendar-extract-year
+                                   (calendar-current-date)))))
+         (month-array (vconcat calendar-month-name-array (vector "*")))
+         (abbrevs (vconcat calendar-month-abbrev-array (vector "*")))
+         (completion-ignore-case todos-completion-ignore-case)
+         (monthname (completing-read
+                     "Month name (RET for current month, * for any month): "
+                     (mapcar 'list (append month-array nil))
+                     nil t nil nil
+                     (calendar-month-name (calendar-extract-month
+                                           (calendar-current-date)) t)))
+         (month (cdr (assoc-string
+                      monthname (calendar-make-alist month-array nil nil
+                                                     abbrevs))))
+         (last (if (= month 13)
+                   31                   ; FIXME: what about shorter months?
+                 (let ((yr (if (eq year '*)
+                               1999     ; FIXME: no Feb. 29
+                             year)))
+                   (calendar-last-day-of-month month yr))))
+         day dayname)
+    (while (if (numberp day) (or (< day 0) (< last day)) (not (eq day '*)))
+      (setq day (read-from-minibuffer
+                 (format "Day (1-%d or RET for today or * for any day): " last)
+                 nil nil t nil
+                 (number-to-string
+                  (calendar-extract-day (calendar-current-date))))))
+    (setq year (if (eq year '*) (symbol-name '*) (number-to-string year)))
+    (setq day (if (eq day '*) (symbol-name '*) (number-to-string day)))
+    ;; FIXME: make abbreviation customizable
+    (setq monthname
+          (or (and (= month 13) "*")
+              (calendar-month-name (calendar-extract-month (list month day year))
+                                   t)))
+    (mapconcat 'eval calendar-date-display-form "")))
+
+(defun todos-read-dayname ()
+  "Choose name of a day of the week with completion and return it."
+  (let ((completion-ignore-case todos-completion-ignore-case))
+    (completing-read "Enter a day name: "
+                     (append calendar-day-name-array nil)
+                     nil t)))
+  
+(defun todos-read-time ()
+  "Prompt for and return a valid clock time as a string.
+
+Valid time strings are those matching `diary-time-regexp'.
+Typing `<return>' at the prompt returns the current time, if the
+user option `todos-always-add-time-string' is non-nil, otherwise
+the empty string (i.e., no time string)."
+  (let (valid answer)
+    (while (not valid)
+      (setq answer (read-string "Enter a clock time: " nil nil
+                                (when todos-always-add-time-string
+                                  (substring (current-time-string) 11 16))))
+      (when (or (string= "" answer)
+                (string-match diary-time-regexp answer))
+        (setq valid t)))
+    answer))
+
+(defun todos-convert-legacy-date-time ()
+  "Return converted date-time string.
+Helper function for `todos-convert-legacy-files'."
+  (let* ((year (match-string 1))
+         (month (match-string 2))
+         (monthname (calendar-month-name (string-to-number month) t))
+         (day (match-string 3))
+         (time (match-string 4))
+         dayname)
+    (replace-match "")
+    (insert (mapconcat 'eval calendar-date-display-form "")
+            (when time (concat " " time)))))
+
+;; ---------------------------------------------------------------------------
+;;; Item filtering
+
+(defvar todos-multiple-files nil
+  "List of files returned by `todos-multiple-files' widget.")
+
+(defvar todos-multiple-files-widget nil
+  "Variable holding widget created by `todos-multiple-files'.")
+
+(defun todos-multiple-files ()
+  "Pop to a buffer with a widget for choosing multiple filter files."
+  (require 'widget)
+  (eval-when-compile
+    (require 'wid-edit))
+    (with-current-buffer (get-buffer-create "*Todos Filter Files*")
+      (pop-to-buffer (current-buffer))
+      (erase-buffer)
+      (kill-all-local-variables)
+      (widget-insert "Select files for generating the top priorities list.\n\n")
+      (setq todos-multiple-files-widget
+            (widget-create
+             `(set ,@(mapcar (lambda (x) (list 'const x))
+                             (mapcar 'todos-short-file-name
+                                     (funcall todos-files-function))))))
+      (widget-insert "\n")
+      (widget-create 'push-button
+                     :notify (lambda (widget &rest ignore)
+                               (setq todos-multiple-files 'quit)
+                               (quit-window t)
+                               (exit-recursive-edit))
+                     "Cancel")
+      (widget-insert "   ")
+      (widget-create 'push-button
+                     :notify (lambda (&rest ignore)
+                               (setq todos-multiple-files
+                                     (mapcar (lambda (f)
+                                               (concat todos-files-directory
+                                                       f ".todo"))
+                                             (widget-value
+                                              todos-multiple-files-widget)))
+                               (quit-window t)
+                               (exit-recursive-edit))
+                     "Apply")
+      (use-local-map widget-keymap)
+      (widget-setup))
+  (message "Click \"Apply\" after selecting files.")
+  (recursive-edit))
+
+;; FIXME: should done and archived items be included?  Maybe just for regexp
+;; and custom filters?
+(defun todos-filter-items (filter &optional multifile)
+  "Build and display a list of items from different categories.
+
+The items are selected according to the value of FILTER, which
+can be `top' for top priority items, `diary' for diary items,
+`regexp' for items matching a regular expresion entered by the
+user, or `custom' for items chosen by user-defined function
+`todos-filter-function'.
+
+With non-nil argument MULTIFILE list top priorities of multiple
+Todos files, by default those in `todos-filter-files'."
+  (let ((num (if (consp filter) (cdr filter) todos-show-priorities))
+        (buf (get-buffer-create todos-filter-buffer))
+        (files (list todos-current-todos-file))
+        regexp fname bufstr cat beg end done)
+    (when multifile
+      (setq files (if (or (consp filter) (null todos-filter-files))
+                      (progn (todos-multiple-files) todos-multiple-files)
+                    todos-filter-files)
+            todos-multiple-files nil))
+    (if (eq files 'quit) (keyboard-quit))
+    (if (null files)
+        (error "No files have been chosen for filtering")
+      (with-current-buffer buf
+        (erase-buffer)
+        (kill-all-local-variables)
+        (todos-filter-items-mode))
+      (when (eq filter 'regexp)
+        (setq regexp (read-string "Enter a regular expression: ")))
+      (save-current-buffer
+        (dolist (f files)
+          ;; Before inserting file contents into temp buffer, save a modified
+          ;; buffer visiting it.
+          (let ((bf (find-buffer-visiting f)))
+            (when (buffer-modified-p bf)
+              (with-current-buffer bf (save-buffer))))
+          (setq fname (todos-short-file-name f))
+          (with-temp-buffer
+            (insert-file-contents f)
+            (goto-char (point-min))
+            (let (fnum)
+              ;; Unless the number of items to show was supplied by prefix
+              ;; argument of caller, override `todos-show-priorities' with the
+              ;; file-wide value from `todos-priorities-rules'.
+              (unless (consp filter)
+                (setq fnum (nth 1 (assoc f todos-priorities-rules))))
+              (unless (looking-at (concat "^" (regexp-quote todos-category-beg)))
+                (kill-line 1))
+              (while (re-search-forward
+                      (concat "^" (regexp-quote todos-category-beg) "\\(.+\\)\n")
+                      nil t)
+                (setq cat (match-string 1))
+                (let (cnum)
+                  ;; Unless the number of items to show was supplied by prefix
+                  ;; argument of caller, override the file-wide value from
+                  ;; `todos-priorities-rules' if set, else
+                  ;; `todos-show-priorities' with non-nil category-wide value
+                  ;; from `todos-priorities-rules'.
+                  (unless (consp filter)
+                    (let ((cats (nth 2 (assoc f todos-priorities-rules))))
+                      (setq cnum (or (cdr (assoc cat cats))
+                                     fnum
+                                     ;; FIXME: need this?
+                                     todos-show-priorities))))
+                  (delete-region (match-beginning 0) (match-end 0))
+                  (setq beg (point)) ; Start of first item.
+                  (setq end (if (re-search-forward
+                                 (concat "^" (regexp-quote todos-category-beg))
+                                 nil t)
+                                (match-beginning 0)
+                              (point-max)))
+                  (goto-char beg)
+                  (setq done
+                        (if (re-search-forward
+                             (concat "\n" (regexp-quote todos-category-done))
+                             end t)
+                            (match-beginning 0)
+                          end))
+                  ;; Leave done items only with regexp filter.
+                  ;; FIXME: and custom filter?
+                  (unless (eq filter 'regexp)
+                    (delete-region done end)
+                    (setq end done))
+                  (narrow-to-region beg end)    ; Process current category.
+                  (goto-char (point-min))
+                  ;; Apply the filter.
+                  (cond ((eq filter 'diary)
+                         (while (not (eobp))
+                           (if (looking-at (regexp-quote todos-nondiary-start))
+                               (todos-remove-item)
+                             (todos-forward-item))))
+                        ((eq filter 'regexp)
+                         (while (not (eobp))
+                           (if (looking-at todos-item-start)
+                               (if (string-match regexp (todos-item-string))
+                                   (todos-forward-item)
+                                 (todos-remove-item))
+                             ;; Kill lines that aren't part of a todo or done
+                             ;; item (empty or todos-category-done).
+                             (delete-region (line-beginning-position)
+                                            (1+ (line-end-position))))
+                           ;; If last todo item in file matches regexp and
+                           ;; there are no following done items,
+                           ;; todos-category-done string is left dangling,
+                           ;; because todos-forward-item jumps over it.
+                           (if (and (eobp) (looking-back
+                                            (concat (regexp-quote todos-done-string)
+                                                    "\n")))
+                               (delete-region (point) (progn
+                                                        (forward-line -2)
+                                                        (point))))))
+                        ((eq filter 'custom)
+                         (if todos-filter-function
+                             (funcall todos-filter-function)
+                           (error "No custom filter function has been defined")))
+                        (t ; Filter top priority items.
+                         (setq num (or cnum fnum num))
+                         (unless (zerop num)
+                           (todos-forward-item num))))
+                  (setq beg (point))
+                  (unless (member filter '(diary regexp custom))
+                    (delete-region beg end))
+                  (goto-char (point-min))
+                  ;; Add file (if using multiple files) and category tags to
+                  ;; item.
+                  (while (not (eobp))
+                    (when (re-search-forward
+                           (concat "\\(" todos-done-string-start
+                                   todos-date-pattern "\\( " diary-time-regexp
+                                   "\\)?]\\)\\|\\("
+                                   ;; todos-date-string-start doesn't work
+                                   ;; here because of `^'
+                                   "\\(" (regexp-quote todos-nondiary-start)
+                                   "\\|" (regexp-quote diary-nonmarking-symbol)
+                                   "\\)?" todos-date-pattern "\\( "
+                                   diary-time-regexp "\\)?"
+                                   (regexp-quote todos-nondiary-end) "?\\)")
+                           nil t)
+                      (insert (concat " [" (if multifile (concat fname ":"))
+                                      cat "]")))
+                    (forward-line))
+                  (widen)))
+                (setq bufstr (buffer-string))
+                (with-current-buffer buf
+                  (let (buffer-read-only)
+                    (insert bufstr)))))))
+      ;; FIXME: let-bind todos-mode-line-control according to FILTER?
+      (set-window-buffer (selected-window) (set-buffer buf))
+      (todos-prefix-overlays)
+      (goto-char (point-min))
+      ;; FIXME: this is necessary -- why?
+      (font-lock-fontify-buffer))))
+
+(defun todos-set-top-priorities (&optional arg)
+  "Set number of top priorities shown by `todos-top-priorities'.
+With non-nil ARG, set the number only for the current Todos
+category; otherwise, set the number for all categories in the
+current Todos file.
+
+Calling this function via either of the commands
+`todos-set-top-priorities-in-file' or
+`todos-set-top-priorities-in-category' is the recommended way to
+set the user customizable option `todos-priorities-rules'."
+  (let* ((cat (todos-current-category))
+         (file todos-current-todos-file)
+         (rules todos-priorities-rules)
+         (frule (assoc-string file rules))
+         (crule (assoc-string cat (nth 2 frule)))
+         (cur (or (if arg (cdr crule) (nth 1 frule))
+                  todos-show-priorities))
+         (prompt (concat "Current number of top priorities in this "
+                         (if arg "category" "file") ": %d; "
+                         "enter new number: "))
+         (new "-1")
+         nrule)
+    (while (or (not (string-match "[0-9]+" new)) ; Don't accept "" or "bla".
+               (< (string-to-number new) 0))
+      (let ((cur0 cur))
+        (setq new (read-string (format prompt cur0) nil nil cur0)
+              prompt "Enter a non-negative number: "
+              cur0 nil)))
+    (setq new (string-to-number new))
+    (setq nrule (if arg
+                    (append (nth 2 (delete crule frule)) (list (cons cat new)))
+                  (append (list file new) (list (nth 2 frule)))))
+    (setq rules (cons (if arg
+                          (list file cur nrule)
+                        nrule)
+                      (delete frule rules)))
+    (customize-save-variable 'todos-priorities-rules rules)))
+
+
+;; ---------------------------------------------------------------------------
+;;; Sorting and display routines for Todos Categories mode.
+
+(defun todos-longest-category-name-length (categories)
+  "Return the length of the longest name in list CATEGORIES."
+  (let ((longest 0))
+    (dolist (c categories longest)
+      (setq longest (max longest (length c))))))
+
+(defun todos-padded-string (str)
+  "Return string STR padded with spaces.
+The placement of the padding is determined by the value of user
+option `todos-categories-align'."
+  (let* ((categories (mapcar 'car todos-categories))
+         (len (max (todos-longest-category-name-length categories)
+                   (length todos-categories-category-label)))
+         (strlen (length str))
+         (strlen-odd (eq (logand strlen 1) 1)) ; oddp from cl.el
+         (padding (max 0 (/ (- len strlen) 2)))
+         (padding-left (cond ((eq todos-categories-align 'left) 0)
+                             ((eq todos-categories-align 'center) padding)
+                             ((eq todos-categories-align 'right)
+                              (if strlen-odd (1+ (* padding 2)) (* padding 2)))))
+         (padding-right (cond ((eq todos-categories-align 'left)
+                               (if strlen-odd (1+ (* padding 2)) (* padding 2)))
+                              ((eq todos-categories-align 'center)
+                               (if strlen-odd (1+ padding) padding))
+                              ((eq todos-categories-align 'right) 0))))
+    (concat (make-string padding-left 32) str (make-string padding-right 32))))
+
+(defvar todos-descending-counts nil
+  "List of keys for category counts sorted in descending order.")
+
+(defun todos-sort (list &optional key)
+  "Return a copy of LIST, possibly sorted according to KEY."
+  (let* ((l (copy-sequence list))
+         (fn (if (eq key 'alpha)
+                   (lambda (x) (upcase x)) ; Alphabetize case insensitively.
+                 (lambda (x) (todos-get-count key x))))
+         (descending (member key todos-descending-counts))
+         (cmp (if (eq key 'alpha)
+                  'string<
+                (if descending '< '>)))
+         (pred (lambda (s1 s2) (let ((t1 (funcall fn (car s1)))
+                                     (t2 (funcall fn (car s2))))
+                                 (funcall cmp t1 t2)))))
+    (when key
+      (setq l (sort l pred))
+      (if descending
+          (setq todos-descending-counts
+                (delete key todos-descending-counts))
+        (push key todos-descending-counts)))
+    l))
+
+(defun todos-display-sorted (type)
+  "Keep point on the TYPE count sorting button just clicked."
+  (let ((opoint (point)))
+    (todos-update-categories-display type)
+    (goto-char opoint)))
+
+(defun todos-label-to-key (label)
+  "Return symbol for sort key associated with LABEL."
+  (let (key)
+    (cond ((string= label todos-categories-category-label)
+           (setq key 'alpha))
+          ((string= label todos-categories-todo-label)
+           (setq key 'todo))
+          ((string= label todos-categories-diary-label)
+           (setq key 'diary))
+          ((string= label todos-categories-done-label)
+           (setq key 'done))
+          ((string= label todos-categories-archived-label)
+           (setq key 'archived)))
+    key))
+
+(defun todos-insert-sort-button (label)
+  "Insert button for displaying categories sorted by item counts.
+LABEL determines which type of count is sorted."
+  (setq str (if (string= label todos-categories-category-label)
+                (todos-padded-string label)
+              label))
+  (setq beg (point))
+  (setq end (+ beg (length str)))
+  (insert-button str 'face nil
+                 'action
+                 `(lambda (button)
+                    (let ((key (todos-label-to-key ,label)))
+                      (if (and (member key todos-descending-counts)
+                               (eq key 'alpha))
+                          (progn
+                            ;; If display is alphabetical, switch back to
+                            ;; category order.
+                            (todos-display-sorted nil)
+                            (setq todos-descending-counts
+                                  (delete key todos-descending-counts)))
+                        (todos-display-sorted key)))))
+  (setq ovl (make-overlay beg end))
+  (overlay-put ovl 'face 'todos-button))
+
+(defun todos-total-item-counts ()
+  "Return a list of total item counts for the current file."
+  (mapcar (lambda (i) (apply '+ (mapcar (lambda (l) (aref l i))
+                                        (mapcar 'cdr todos-categories))))
+          (list 0 1 2 3)))
+
+(defun todos-insert-category-line (cat &optional nonum)
+  "Insert button displaying category CAT's name and item counts.
+With non-nil argument NONUM show only these; otherwise, insert a
+number in front of the button indicating the category's priority.
+The number and the category name are separated by the string
+which is the value of the user option
+`todos-categories-number-separator'."
+  (let* ((archive (member todos-current-todos-file todos-archives))
+        (str (todos-padded-string cat))
+        (opoint (point)))
+    ;; num is declared in caller.
+    (setq num (1+ num))
+    (insert-button
+     (concat (if nonum
+                 (make-string (+ 4 (length todos-categories-number-separator))
+                              32)
+               (format " %3d%s" num todos-categories-number-separator))
+             str
+             (mapconcat (lambda (elt)
+                          (concat
+                           (make-string (1+ (/ (length (car elt)) 2)) 32) ; label
+                           (format "%3d" (todos-get-count (cdr elt) cat)) ; count
+                           ;; Add an extra space if label length is odd
+                           ;; (using def of oddp from cl.el).
+                           (if (eq (logand (length (car elt)) 1) 1) " ")))
+                        (if archive
+                            (list (cons todos-categories-done-label 'done))
+                          (list (cons todos-categories-todo-label 'todo)
+                                (cons todos-categories-diary-label 'diary)
+                                (cons todos-categories-done-label 'done)
+                                (cons todos-categories-archived-label
+                                      'archived)))
+                          ""))
+     'face (if (and todos-ignore-archived-categories
+                    (zerop (todos-get-count 'todo cat))
+                    (zerop (todos-get-count 'done cat))
+                    (not (zerop (todos-get-count 'archived cat))))
+               'todos-archived-only
+             nil)
+     'action `(lambda (button) (let ((buf (current-buffer)))
+                                 (todos-jump-to-category ,cat)
+                                 (kill-buffer buf))))
+    ;; Highlight the sorted count column.
+    (let* ((beg (+ opoint 6 (length str)))
+           end ovl)
+      (cond ((eq nonum 'todo)
+             (setq beg (+ beg 1 (/ (length todos-categories-todo-label) 2))))
+            ((eq nonum 'diary)
+             (setq beg (+ beg 1 (length todos-categories-todo-label)
+                           2 (/ (length todos-categories-diary-label) 2))))
+            ((eq nonum 'done)
+             (setq beg (+ beg 1 (length todos-categories-todo-label)
+                           2 (length todos-categories-diary-label)
+                           2 (/ (length todos-categories-done-label) 2))))
+            ((eq nonum 'archived)
+             (setq beg (+ beg 1 (length todos-categories-todo-label)
+                           2 (length todos-categories-diary-label)
+                           2 (length todos-categories-done-label)
+                           2 (/ (length todos-categories-archived-label) 2)))))
+      (unless (= beg (+ opoint 6 (length str)))
+        (setq end (+ beg 4))
+        (setq ovl (make-overlay beg end))
+        (overlay-put ovl 'face 'todos-sorted-column)))
+    (newline)))
+
+(defun todos-display-categories-1 ()
+  "Prepare buffer for displaying table of categories and item counts."
+  (unless (eq major-mode 'todos-categories-mode)
+    (setq todos-global-current-todos-file (or todos-current-todos-file
+                                              todos-default-todos-file))
+    (set-window-buffer (selected-window)
+                       (set-buffer (get-buffer-create todos-categories-buffer)))
+    (kill-all-local-variables)
+    (todos-categories-mode)
+    (let (buffer-read-only) 
+      (erase-buffer)
+      ;; FIXME: add usage tips?
+      (insert (format "Category counts for Todos file \"%s\"."
+                      (todos-short-file-name todos-current-todos-file)))
+      (newline 2)
+      ;; Make space for the column of category numbers.
+      (insert (make-string (+ 4 (length todos-categories-number-separator)) 32))
+      ;; Add the category and item count buttons (if this is the list of
+      ;; categories in an archive, show only done item counts).
+      (todos-insert-sort-button todos-categories-category-label)
+      (if (member todos-current-todos-file todos-archives)
+          (insert (concat (make-string 6 32)
+                          (format "%s" todos-categories-archived-label)))
+        (insert (make-string 3 32))
+        (todos-insert-sort-button todos-categories-todo-label)
+        (insert (make-string 2 32))
+        (todos-insert-sort-button todos-categories-diary-label)
+        (insert (make-string 2 32))
+        (todos-insert-sort-button todos-categories-done-label)
+        (insert (make-string 2 32))
+        (todos-insert-sort-button todos-categories-archived-label))
+      (newline 2))))
+
+(defun todos-update-categories-display (sortkey)
+  ""
+  (let* ((cats0 (if (and todos-ignore-archived-categories
+                           (not (eq major-mode 'todos-categories-mode)))
+                      todos-categories-full
+                    todos-categories))
+           (cats (todos-sort cats0 sortkey))
+           (archive (member todos-current-todos-file todos-archives))
+           ;; `num' is used by todos-insert-category-line.
+           (num 0)
+           ;; Find start of Category button if we just entered Todos Categories
+           ;; mode.
+           (pt (if (eq (point) (point-max))
+                   (save-excursion
+                     (forward-line -2)
+                     (goto-char (next-single-char-property-change
+                                 (point) 'face nil (line-end-position))))))
+           (buffer-read-only))
+      (forward-line 2)
+      (delete-region (point) (point-max))
+      ;; Fill in the table with buttonized lines, each showing a category and
+      ;; its item counts.
+      (mapc (lambda (cat) (todos-insert-category-line cat sortkey))
+            (mapcar 'car cats))
+      (newline)
+      ;; Add a line showing item count totals.
+      (insert (make-string (+ 4 (length todos-categories-number-separator)) 32)
+              (todos-padded-string todos-categories-totals-label)
+              (mapconcat
+               (lambda (elt)
+                 (concat
+                  (make-string (1+ (/ (length (car elt)) 2)) 32)
+                  (format "%3d" (nth (cdr elt) (todos-total-item-counts)))
+                  ;; Add an extra space if label length is odd (using
+                  ;; definition of oddp from cl.el).
+                  (if (eq (logand (length (car elt)) 1) 1) " ")))
+               (if archive
+                   (list (cons todos-categories-done-label 2))
+                 (list (cons todos-categories-todo-label 0)
+                       (cons todos-categories-diary-label 1)
+                       (cons todos-categories-done-label 2)
+                       (cons todos-categories-archived-label 3)))
+               ""))
+      ;; Put cursor on Category button initially.
+      (if pt (goto-char pt))
+      (setq buffer-read-only t)))
+
+;; ---------------------------------------------------------------------------
 ;;; Todos insertion commands, key bindings and keymap
 
-;; http://rosettacode.org/wiki/Power_set#Common_Lisp (GFDL)
-(defun powerset (l)
-  (if (null l)
-      (list nil)
-    (let ((prev (powerset (cdr l))))
-      (append (mapcar #'(lambda (elt) (cons (car l) elt)) prev)
-              prev))))
+;; Can either of these be included in Emacs?  The originals are GFDL'd.
+;; Slightly reformulated from
+;; http://rosettacode.org/wiki/Power_set#Common_Lisp.
+(defun powerset-recursive (l)
+  (cond ((null l)
+         (list nil))
+        (t
+         (let ((prev (todos-powerset (cdr l))))
+           (append (mapcar (lambda (elt) (cons (car l) elt)) prev)
+                   prev)))))
+;; Elisp implementation of http://rosettacode.org/wiki/Power_set#C
+(defun powerset-bitwise (l)
+  (let ((binnum (lsh 1 (length l)))
+         pset elt)
+    (dotimes (i binnum)
+      (let ((bits i)
+            (ll l))
+        (while (not (zerop bits))
+          (let ((arg (pop ll)))
+            (unless (zerop (logand bits 1))
+              (setq elt (append elt (list arg))))
+            (setq bits (lsh bits -1))))
+        (setq pset (append pset (list elt)))
+        (setq elt nil)))
+    pset))
+
+;; (defalias 'todos-powerset 'powerset-recursive)
+(defalias 'todos-powerset 'powerset-bitwise)
 
 ;; Return list of lists of non-nil atoms produced from ARGLIST.  The elements
 ;; of ARGLIST may be atoms or lists.
@@ -554,13 +2115,11 @@ Set by `todos-toggle-show-done-only' and used by
   '(diary nonmarking (calendar date dayname) time (here region))
   "Generator list for argument lists of Todos insertion commands.")
 
-(eval-when-compile (require 'cl))       ; remove-duplicates
-
 (defvar todos-insertion-commands-args
   (let ((argslist (todos-gen-arglists todos-insertion-commands-args-genlist))
         res new)
     (setq res (remove-duplicates
-               (apply 'append (mapcar 'powerset argslist)) :test 'equal))
+               (apply 'append (mapcar 'todos-powerset argslist)) :test 'equal))
     (dolist (l res)
       (unless (= 5 (length l))
         (let ((v (make-vector 5 nil)) elt)
@@ -613,8 +2172,8 @@ Set by `todos-toggle-show-done-only' and used by
 
 (defvar todos-insertion-commands
   (mapcar (lambda (c)
-          (eval `(todos-define-insertion-command ,@c)))
-        todos-insertion-commands-args)
+            (eval `(todos-define-insertion-command ,@c)))
+          todos-insertion-commands-args)
   "List of Todos insertion commands.")
 
 (defvar todos-insertion-commands-arg-key-list
@@ -633,20 +2192,6 @@ Set by `todos-toggle-show-done-only' and used by
   (dolist (c todos-insertion-commands)
     (let* ((key "")
            (cname (symbol-name c)))
-      ;; (if (string-match "diary\\_>" cname) (setq key (concat key "yy")))
-      ;; (if (string-match "diary.+" cname) (setq key (concat key "y")))
-      ;; (if (string-match "nonmarking\\_>" cname) (setq key (concat key "kk")))
-      ;; (if (string-match "nonmarking.+" cname) (setq key (concat key "k")))
-      ;; (if (string-match "calendar\\_>" cname) (setq key (concat key "cc")))
-      ;; (if (string-match "calendar.+" cname) (setq key (concat key "c")))
-      ;; (if (string-match "date\\_>" cname) (setq key (concat key "dd")))
-      ;; (if (string-match "date.+" cname) (setq key (concat key "d")))
-      ;; (if (string-match "dayname\\_>" cname) (setq key (concat key "nn")))
-      ;; (if (string-match "dayname.+" cname) (setq key (concat key "n")))
-      ;; (if (string-match "time\\_>" cname) (setq key (concat key "tt")))
-      ;; (if (string-match "time.+" cname) (setq key (concat key "t")))
-      ;; (if (string-match "here" cname) (setq key (concat key "h")))
-      ;; (if (string-match "region" cname) (setq key (concat key "r")))
       (mapc (lambda (l)
               (let ((arg (nth 0 l))
                     (key1 (nth 1 l))
@@ -666,90 +2211,104 @@ Set by `todos-toggle-show-done-only' and used by
     map)
   "Keymap for Todos mode insertion commands.")
 
+;; ??FIXME: use easy-mmode-define-keymap and easy-mmode-defmap
+(defvar todos-key-bindings
+  `(
+    ;;               display
+    ("Cd"            . todos-display-categories) ;FIXME: Cs todos-show-categories?
+    ;(""             . todos-display-categories-alphabetically)
+    ("H"             . todos-highlight-item)
+    ("N"             . todos-toggle-item-numbering)
+    ("D"             . todos-toggle-display-date-time)
+    ("*"             . todos-toggle-mark-item)
+    ("C*"            . todos-mark-category)
+    ("Cu"            . todos-unmark-category)
+    ("PP"            . todos-print)
+    ("PF"            . todos-print-to-file)
+    ("v"             . todos-toggle-view-done-items)
+    ("V"             . todos-toggle-show-done-only)
+    ("Av"            . todos-view-archived-items)
+    ("As"            . todos-show-archive)
+    ("Ac"            . todos-choose-archive)
+    ("Y"             . todos-diary-items)
+    ;;(""            . todos-update-filter-files)
+    ("Fe"            . todos-edit-multiline)
+    ("Fh"            . todos-highlight-item)
+    ("Fn"            . todos-toggle-item-numbering)
+    ("Fd"            . todos-toggle-display-date-time)
+    ("Ftt"           . todos-top-priorities)
+    ("Ftm"           . todos-top-priorities-multifile)
+    ("Fts"           . todos-set-top-priorities-in-file)
+    ("Cts"           . todos-set-top-priorities-in-category)
+    ("Fyy"           . todos-diary-items)
+    ("Fym"           . todos-diary-items-multifile)
+    ("Fxx"           . todos-regexp-items)
+    ("Fxm"           . todos-regexp-items-multifile)
+    ("Fcc"           . todos-custom-items)
+    ("Fcm"           . todos-custom-items-multifile)
+    ;;(""            . todos-save-top-priorities)
+    ;;               navigation                 
+    ("f"             . todos-forward-category)
+    ("b"             . todos-backward-category)
+    ("j"             . todos-jump-to-category)
+    ("J"             . todos-jump-to-category-other-file)
+    ("n"             . todos-forward-item)
+    ("p"             . todos-backward-item)
+    ("S"             . todos-search)
+    ("X"             . todos-clear-matches)
+    ;;               editing                            
+    ("Fa"            . todos-add-file)
+    ("Ca"            . todos-add-category)
+    ("Cr"            . todos-rename-category)
+    ("Cg"            . todos-merge-category)
+    ;;(""            . todos-merge-categories)
+    ("Cm"            . todos-move-category)
+    ("Ck"            . todos-delete-category)
+    ("d"             . todos-item-done)
+    ("ee"            . todos-edit-item)
+    ("em"            . todos-edit-multiline-item)
+    ("eh"            . todos-edit-item-header)
+    ("edd"           . todos-edit-item-date)
+    ("edc"           . todos-edit-item-date-from-calendar)
+    ("edt"           . todos-edit-item-date-is-today)
+    ("et"            . todos-edit-item-time)
+    ("eyy"           . todos-edit-item-diary-inclusion)
+    ;; (""           . todos-edit-category-diary-inclusion)
+    ("eyn"           . todos-edit-item-diary-nonmarking)
+    ;;(""            . todos-edit-category-diary-nonmarking)
+    ("ec"            . todos-comment-done-item) ;FIXME: or just "c"?
+    ("i"             . ,todos-insertion-map)
+    ("k"             . todos-delete-item)
+    ("m"             . todos-move-item)
+    ("M"             . todos-move-item-to-file)
+    ;; FIXME: This binding prevents `-' from being used in a numerical prefix
+    ;; argument without typing C-u
+    ;; ("-"          . todos-raise-item-priority)
+    ("r"             . todos-raise-item-priority)
+    ;; ("+"          . todos-lower-item-priority)
+    ("l"             . todos-lower-item-priority)
+    ("#"             . todos-set-item-priority)
+    ("u"             . todos-item-undo)
+    ("Ad"            . todos-archive-done-item-or-items)  ;FIXME
+    ("AD"            . todos-archive-category-done-items) ;FIXME
+    ("Au"            . todos-unarchive-items)
+    ("AU"            . todos-unarchive-category)
+    ("s"             . todos-save)
+    ("q"             . todos-quit)
+    ([remap newline] . newline-and-indent)
+   )
+  "Alist pairing keys defined in Todos modes and their bindings.")
+
 (defvar todos-mode-map
   (let ((map (make-keymap)))
     ;; Don't suppress digit keys, so they can supply prefix arguments.
     (suppress-keymap map)
-    ;; display commands
-    (define-key map "Cd" 'todos-display-categories) ;FIXME: Cs todos-show-categories?
-    ;; (define-key map "" 'todos-display-categories-alphabetically)
-    (define-key map "H" 'todos-highlight-item)
-    (define-key map "N" 'todos-toggle-item-numbering)
-    (define-key map "D" 'todos-toggle-display-date-time)
-    (define-key map "*" 'todos-toggle-mark-item)
-    (define-key map "C*" 'todos-mark-category)
-    (define-key map "Cu" 'todos-unmark-category)
-    (define-key map "P" 'todos-print)
-    ;; (define-key map "" 'todos-print-to-file)
-    (define-key map "v" 'todos-toggle-view-done-items)
-    (define-key map "V" 'todos-toggle-show-done-only)
-    (define-key map "Av" 'todos-view-archived-items)
-    (define-key map "As" 'todos-show-archive)
-    (define-key map "Ac" 'todos-choose-archive)
-    (define-key map "Y" 'todos-diary-items)
-    ;; (define-key map "" 'todos-update-merged-files)
-    ;; (define-key map "" 'todos-set-top-priorities)
-    (define-key map "Ftt" 'todos-top-priorities)
-    (define-key map "Ftm" 'todos-merged-top-priorities)
-    (define-key map "Fdd" 'todos-diary-items)
-    (define-key map "Fdm" 'todos-merged-diary-items)
-    (define-key map "Frr" 'todos-regexp-items)
-    (define-key map "Frm" 'todos-merged-regexp-items)
-    (define-key map "Fcc" 'todos-custom-items)
-    (define-key map "Fcm" 'todos-merged-custom-items)
-    ;; (define-key map "" 'todos-save-top-priorities)
-    ;; navigation commands
-    (define-key map "f" 'todos-forward-category)
-    (define-key map "b" 'todos-backward-category)
-    (define-key map "j" 'todos-jump-to-category)
-    (define-key map "J" 'todos-jump-to-category-other-file)
-    (define-key map "n" 'todos-forward-item)
-    (define-key map "p" 'todos-backward-item)
-    (define-key map "S" 'todos-search)
-    (define-key map "X" 'todos-clear-matches)
-    ;; editing commands
-    (define-key map "Fa" 'todos-add-file)
-    ;; (define-key map "" 'todos-change-default-file)
-    (define-key map "Ca" 'todos-add-category)
-    (define-key map "Cr" 'todos-rename-category)
-    (define-key map "Cg" 'todos-merge-category)
-    ;; (define-key map "" 'todos-merge-categories)
-    (define-key map "Cm" 'todos-move-category)
-    (define-key map "Ck" 'todos-delete-category)
-    (define-key map "d" 'todos-item-done)
-    (define-key map "ee" 'todos-edit-item)
-    (define-key map "em" 'todos-edit-multiline)
-    (define-key map "eh" 'todos-edit-item-header)
-    (define-key map "ed" 'todos-edit-item-date)
-    (define-key map "ey" 'todos-edit-item-date-is-today)
-    (define-key map "et" 'todos-edit-item-time)
-    (define-key map "ec" 'todos-comment-done-item) ;FIXME: or just "c"?
-    (define-key map "i" todos-insertion-map)
-    (define-key map "k" 'todos-delete-item)
-    (define-key map "m" 'todos-move-item)
-    (define-key map "M" 'todos-move-item-to-file)
-    ;; FIXME: This prevents `-' from being used in a numerical prefix argument
-    ;; without typing C-u
-    (define-key map "-" 'todos-raise-item-priority)
-    (define-key map "r" 'todos-raise-item-priority)
-    (define-key map "+" 'todos-lower-item-priority)
-    (define-key map "l" 'todos-lower-item-priority)
-    (define-key map "#" 'todos-set-item-priority)
-    (define-key map "u" 'todos-item-undo)
-    (define-key map "Ad" 'todos-archive-done-item-or-items)  ;FIXME
-    (define-key map "AD" 'todos-archive-category-done-items) ;FIXME
-    ;; (define-key map "" 'todos-unarchive-items)
-    ;; (define-key map "" 'todos-unarchive-category)
-    (define-key map "y" 'todos-toggle-diary-inclusion)
-    ;; (define-key map "" 'todos-toggle-diary-inclusion)
-    ;; (define-key map "" 'todos-toggle-item-diary-nonmarking)
-    ;; (define-key map "" 'todos-toggle-diary-nonmarking)
-    (define-key map "s" 'todos-save)
-    (define-key map "q" 'todos-quit)
-    (define-key map [remap newline] 'newline-and-indent)
+    (dolist (ck todos-key-bindings)
+      (define-key map (car ck) (cdr ck)))
     map)
   "Todos mode keymap.")
 
+;; FIXME
 (easy-menu-define
   todos-menu todos-mode-map "Todos Menu"
   '("Todos"
@@ -774,10 +2333,10 @@ Set by `todos-toggle-show-done-only' and used by
      "---"
      ["View Diary Items" todos-diary-items t]
      ["View Top Priority Items" todos-top-priorities t]
-     ["View Merged Top Priority Items" todos-merged-top-priorities t]
+     ["View Multifile Top Priority Items" todos-top-priorities-multifile t]
      "---"
      ["View Archive" todos-view-archive t]
-     ["Print Category"     todos-print t]) ;FIXME
+     ["Print Category"     todos-print t])
     ("Editing"
      ["Insert New Item"      todos-insert-item t]
      ["Insert Item Here"     todos-insert-item-here t]
@@ -795,9 +2354,9 @@ Set by `todos-toggle-show-done-only' and used by
      ["Delete Item"          todos-delete-item t]
      ["Undo Done Item" todos-item-undo t]
      ["Mark/Unmark Item for Diary" todos-toggle-item-diary-inclusion t]
-     ["Mark/Unmark Items for Diary" todos-toggle-diary-inclusion t]
+     ["Mark/Unmark Items for Diary" todos-edit-item-diary-inclusion t]
      ["Mark & Hide Done Item" todos-item-done t]
-     ["Archive Done Items" todos-archive-category-done-items t] ;FIXME
+     ["Archive Done Items" todos-archive-category-done-items t]
      "---"
      ["Add New Todos File" todos-add-file t]
      ["Add New Category" todos-add-category t]
@@ -829,7 +2388,7 @@ Set by `todos-toggle-show-done-only' and used by
     (define-key map "s" 'todos-save)
     (define-key map "S" 'todos-search)
     (define-key map "t" 'todos-show)    ;FIXME: should show same category
-    ;; (define-key map "u" 'todos-unarchive-item)
+    (define-key map "u" 'todos-unarchive-item)
     (define-key map "U" 'todos-unarchive-category)
     map)
   "Todos Archive mode keymap.")
@@ -846,7 +2405,9 @@ Set by `todos-toggle-show-done-only' and used by
     (suppress-keymap map t)
     ;; (define-key map "a" 'todos-display-categories-alphabetically)
     (define-key map "c" 'todos-display-categories)
+    (define-key map "l" 'todos-lower-category)
     (define-key map "+" 'todos-lower-category)
+    (define-key map "r" 'todos-raise-category)
     (define-key map "-" 'todos-raise-category)
     (define-key map "n" 'forward-button)
     (define-key map "p" 'backward-button)
@@ -863,22 +2424,16 @@ Set by `todos-toggle-show-done-only' and used by
   (let ((map (make-keymap)))
     (suppress-keymap map t)
     ;; navigation commands
-    (define-key map "j" 'todos-jump-to-category)
+    (define-key map "j" 'todos-jump-to-item)
+    (define-key map [remap newline] 'todos-jump-to-item)
     (define-key map "n" 'todos-forward-item)
     (define-key map "p" 'todos-backward-item)
-    ;; (define-key map "S" 'todos-search)
-    ;; display commands
-    (define-key map "C" 'todos-display-categories)
-    ;; (define-key map "" 'todos-display-categories-alphabetically)
     (define-key map "H" 'todos-highlight-item)
     (define-key map "N" 'todos-toggle-item-numbering)
-    ;; (define-key map "" 'todos-toggle-display-date-time)
+    (define-key map "D" 'todos-toggle-display-date-time)
     (define-key map "P" 'todos-print)
     (define-key map "q" 'todos-quit)
     (define-key map "s" 'todos-save)
-    (define-key map "V" 'todos-view-archive)
-    (define-key map "v" 'todos-toggle-view-done-items)
-    (define-key map "Y" 'todos-diary-items)
     ;; (define-key map "S" 'todos-save-top-priorities)
     ;; editing commands
     (define-key map "l" 'todos-lower-item-priority)
@@ -895,8 +2450,7 @@ Set by `todos-toggle-show-done-only' and used by
   ""
   (set (make-local-variable 'font-lock-defaults) '(todos-font-lock-keywords t))
   (set (make-local-variable 'indent-line-function) 'todos-indent)
-  (when todos-wrap-lines (funcall todos-line-wrapping-function))
-)
+  (when todos-wrap-lines (funcall todos-line-wrapping-function)))
 
 (defun todos-modes-set-2 ()
   ""
@@ -904,75 +2458,72 @@ Set by `todos-toggle-show-done-only' and used by
   (setq buffer-read-only t)
   (set (make-local-variable 'hl-line-range-function)
        (lambda() (when (todos-item-end)
-                   (cons (todos-item-start) (todos-item-end)))))
-)
+                   (cons (todos-item-start) (todos-item-end))))))
+
+(defun todos-modes-set-3 ()
+  (set (make-local-variable 'todos-categories-full) nil)
+  ;; todos-set-categories sets todos-categories-full.
+  (set (make-local-variable 'todos-categories) (todos-set-categories))
+  (set (make-local-variable 'todos-category-number) 1)
+  (set (make-local-variable 'todos-first-visit) t)
+  (add-hook 'post-command-hook 'todos-after-find-file nil t))
+
+(put 'todos-mode 'mode-class 'special)
 
 ;; Autoloading isn't needed if files are identified by auto-mode-alist
 ;; ;; As calendar reads included Todos file before todos-mode is loaded.
 ;; ;;;###autoload
-(define-derived-mode todos-mode nil "Todos" () ;FIXME: derive from special-mode?
+(define-derived-mode todos-mode special-mode "Todos" ()
   "Major mode for displaying, navigating and editing Todo lists.
 
 \\{todos-mode-map}"
   (easy-menu-add todos-menu)
   (todos-modes-set-1)
   (todos-modes-set-2)
+  (todos-modes-set-3)
+  ;; Initialize todos-current-todos-file.
   (when (member (file-truename (buffer-file-name))
                 (funcall todos-files-function))
     (set (make-local-variable 'todos-current-todos-file)
          (file-truename (buffer-file-name))))
-  (set (make-local-variable 'todos-categories-full) nil)
-  ;; todos-set-categories sets todos-categories-full.
-  (set (make-local-variable 'todos-categories) (todos-set-categories))
   (set (make-local-variable 'todos-first-visit) t)
-  (set (make-local-variable 'todos-category-number) 1) ;0)
   (set (make-local-variable 'todos-show-done-only) nil)
-  (set (make-local-variable 'todos-categories-with-marks) nil)
+  (set (make-local-variable 'todos-categoreis-with-marks) nil)
   (when todos-show-current-file
     (add-hook 'pre-command-hook 'todos-show-current-file nil t))
-  (add-hook 'post-command-hook 'todos-after-find-file nil t)
+  ;; FIXME: works more or less, but should be tied to the defcustom
+  (add-hook 'window-configuration-change-hook
+            (lambda ()
+              (setq todos-done-separator (make-string (window-width) ?_)))
+            nil t)
   (add-hook 'kill-buffer-hook 'todos-reset-global-current-todos-file nil t))
 
-;; FIXME:
+;; FIXME: need this?
 (defun todos-unload-hook ()
   ""
   (remove-hook 'pre-command-hook 'todos-show-current-file t)
   (remove-hook 'post-command-hook 'todos-after-find-file t)
+  (remove-hook 'window-configuration-change-hook
+               (lambda ()
+                 (setq todos-done-separator
+                       (make-string (window-width) ?_))) t)
   (remove-hook 'kill-buffer-hook 'todos-reset-global-current-todos-file t))
 
-(define-derived-mode todos-archive-mode nil "Todos-Arch" ()
+(put 'todos-archive-mode 'mode-class 'special)
+
+(define-derived-mode todos-archive-mode todos-mode "Todos-Arch" ()
   "Major mode for archived Todos categories.
 
 \\{todos-archive-mode-map}"
   (todos-modes-set-1)
   (todos-modes-set-2)
-  (set (make-local-variable 'todos-show-done-only) t)
+  (todos-modes-set-3)
   (set (make-local-variable 'todos-current-todos-file)
        (file-truename (buffer-file-name)))
-  (set (make-local-variable 'todos-categories) (todos-set-categories))
-  (set (make-local-variable 'todos-category-number) 1) ; 0)
-  (add-hook 'post-command-hook 'todos-after-find-file nil t))
-
-;; FIXME: return to Todos or Archive mode
-(define-derived-mode todos-raw-mode nil "Todos Raw" ()
-  "Emergency repair mode for Todos files."
-  (when (member major-mode '(todos-mode todos-archive-mode))
-    (setq buffer-read-only nil)
-    (set (make-local-variable 'font-lock-defaults) '(todos-font-lock-keywords t))
-    (widen)
-    ;; FIXME: doesn't DTRT here
-    (todos-prefix-overlays)))
+  (set (make-local-variable 'todos-show-done-only) t))
 
-(define-derived-mode todos-edit-mode nil "Todos-Ed" ()
-  "Major mode for editing multiline Todo items.
-
-\\{todos-edit-mode-map}"
-  (todos-modes-set-1))
-
-(define-derived-mode todos-categories-mode nil "Todos-Cats" ()
-  "Major mode for displaying and editing Todos categories.
-
-\\{todos-categories-mode-map}"
+(defun todos-mode-external-set ()
+  ""
   (set (make-local-variable 'todos-current-todos-file)
        todos-global-current-todos-file)
   (let ((cats (with-current-buffer (get-file-buffer todos-current-todos-file)
@@ -981,7 +2532,24 @@ Set by `todos-toggle-show-done-only' and used by
                   (todos-set-categories)))))
     (set (make-local-variable 'todos-categories) cats)))
 
-(define-derived-mode todos-filter-items-mode nil "Todos-Top" ()
+(define-derived-mode todos-edit-mode text-mode "Todos-Ed" ()
+  "Major mode for editing multiline Todo items.
+
+\\{todos-edit-mode-map}"{
+  (todos-modes-set-1)
+  (todos-mode-external-set))
+
+(put 'todos-categories-mode 'mode-class 'special)
+
+(define-derived-mode todos-categories-mode special-mode "Todos-Cats" ()
+  "Major mode for displaying and editing Todos categories.
+
+\\{todos-categories-mode-map}"
+  (todos-mode-external-set))
+
+(put 'todos-filter-mode 'mode-class 'special)
+
+(define-derived-mode todos-filter-items-mode special-mode "Todos-Fltr" ()
   "Mode for displaying and reprioritizing top priority Todos.
 
 \\{todos-filter-items-mode-map}"
@@ -992,15 +2560,14 @@ Set by `todos-toggle-show-done-only' and used by
 (defun todos-save ()
   "Save the current Todos file."
   (interactive)
-  ;; (todos-update-categories-sexp)
   (save-buffer)
   ;; (if todos-save-top-priorities-too (todos-save-top-priorities))
   )
 
 (defun todos-quit ()
   "Exit the current Todos-related buffer.
-Depending on the specific mode, this either kills and the buffer
-or buries it."
+Depending on the specific mode, this either kills the buffer or
+buries it and restores state as needed."
   (interactive)
   (cond ((eq major-mode 'todos-categories-mode)
          (kill-buffer)
@@ -1010,13 +2577,14 @@ or buries it."
          (kill-buffer)
          (todos-show))
         ((member major-mode (list 'todos-mode 'todos-archive-mode))
-         (todos-save)
+         ;; Have to write previously nonexistant archives to file.
+         (unless (file-exists-p (buffer-file-name)) (todos-save))
+         ;; FIXME: or should it save unconditionally?
+         ;; (todos-save)
          (bury-buffer))))
 
 ;; ---------------------------------------------------------------------------
-;;; Commands
-
-;;; Display
+;;; Display Commands
 
 ;;;###autoload
 (defun todos-show (&optional solicit-file)
@@ -1034,11 +2602,17 @@ of `todos-categories' for the current Todos file, on subsequent
 invocations whichever category was displayed last.  If
 `todos-display-categories-first' is non-nil, then the first
 invocation of `todos-show' displays a clickable listing of the
-categories in the current Todos file."
+categories in the current Todos file.
+
+In Todos mode just the category's unfinished todo items are shown
+by default.  The done items are hidden, but typing
+`\\[todos-toggle-view-done-items]' displays them below the todo
+items.  With non-nil user option `todos-show-with-done' both todo
+and done items are always shown on visiting a category."
   (interactive "P")
   (let ((file (cond (solicit-file
                      (if (funcall todos-files-function)
-                         (todos-read-file-name "Select a Todos file to visit: "
+                         (todos-read-file-name "Choose a Todos file to visit: "
                                                nil t)
                        (error "There are no Todos files")))
                     ((eq major-mode 'todos-archive-mode)
@@ -1062,6 +2636,61 @@ categories in the current Todos file."
       (save-excursion (todos-category-select)))
     (setq todos-first-visit nil)))
 
+(defun todos-display-categories ()
+  "Display a table of the current file's categories and item counts.
+
+In the initial display the categories are numbered, indicating
+their current order for navigating by \\[todos-forward-category]
+and \\[todos-backward-category].  You can persistantly change the
+order of the category at point by typing \\[todos-raise-category]
+or \\[todos-lower-category].
+
+The labels above the category names and item counts are buttons,
+and clicking these changes the display: sorted by category name
+or by the respective item counts (alternately descending or
+ascending).  In these displays the categories are not numbered
+and \\[todos-raise-category] and \\[todos-lower-category] are
+disabled.  (Programmatically, the sorting is triggered by passing
+a non-nil SORTKEY argument.)
+
+In addition, the lines with the category names and item counts
+are buttonized, and pressing one of these button jumps to the
+category in Todos mode (or Todos Archive mode, for categories
+containing only archived items, provided user option
+`todos-ignore-archived-categories' is non-nil.  These categories
+are shown in `todos-archived-only' face."
+  (interactive)
+  (todos-display-categories-1)
+  (let (sortkey)
+    (todos-update-categories-display sortkey)))
+
+;; ;; FIXME: make this toggle with todos-display-categories
+;; (defun todos-display-categories-alphabetically ()
+;;   ""
+;;   (interactive)
+;;   (todos-display-sorted 'alpha))
+
+;; ;; FIXME: provide key bindings for these or delete them
+;; (defun todos-display-categories-sorted-by-todo ()
+;;   ""
+;;   (interactive)
+;;   (todos-display-sorted 'todo))
+
+;; (defun todos-display-categories-sorted-by-diary ()
+;;   ""
+;;   (interactive)
+;;   (todos-display-sorted 'diary))
+
+;; (defun todos-display-categories-sorted-by-done ()
+;;   ""
+;;   (interactive)
+;;   (todos-display-sorted 'done))
+
+;; (defun todos-display-categories-sorted-by-archived ()
+;;   ""
+;;   (interactive)
+;;   (todos-display-sorted 'archived))
+
 (defun todos-toggle-item-numbering ()
   ""
   (interactive)
@@ -1070,20 +2699,16 @@ categories in the current Todos file."
 (defun todos-toggle-view-done-items ()
   "Show hidden or hide visible done items in current category."
   (interactive)
-  (save-excursion
-    (goto-char (point-min))
-    (let ((todos-show-with-done
-           (if (re-search-forward todos-done-string-start nil t)
-               nil
-             t))
-          (cat (todos-current-category)))
-      (todos-category-select)
-      (when (zerop (todos-get-count 'done cat))
-        (message "There are no done items in this category.")))))
+  (if (zerop (todos-get-count 'done (todos-current-category)))
+      (message "There are no done items in this category.")
+    (save-excursion
+      (goto-char (point-min))
+      (let ((todos-show-with-done (not (re-search-forward
+                                        todos-done-string-start nil t))))
+        (todos-category-select)))))
 
-;; FIXME: should there be `todos-toggle-view-todo-items'?
 (defun todos-toggle-show-done-only ()
-  "Make category display done or back to todo items." ;FIXME
+  "Switch between displaying only done or only todo items."
   (interactive)
   (setq todos-show-done-only (not todos-show-done-only))
   (todos-category-select))
@@ -1126,15 +2751,16 @@ last category displayed."
   (todos-show-archive t))
 
 (defun todos-highlight-item ()
-  "Highlight the todo item the cursor is on."
+  "Toggle highlighting the todo item the cursor is on."
   (interactive)
-  (if hl-line-mode ; todos-highlight-item
-      (hl-line-mode 0)
+  (require 'hl-line)
+  (if hl-line-mode
+      (hl-line-mode -1)
     (hl-line-mode 1)))
 
-(defun todos-toggle-display-date-time (&optional all)
-  "Hide or show date/time of todo items in current category.
-With non-nil prefix argument ALL do this in the whole file."
+(defun todos-toggle-display-date-time () ;(&optional all)
+  "Hide or show date-time header of todo items.";; in current category.
+;; With non-nil prefix argument ALL do this in the whole file."
   (interactive "P")
   (save-excursion
     (save-restriction
@@ -1145,7 +2771,9 @@ With non-nil prefix argument ALL do this in the whole file."
           (setq ov (pop ovs))
           (if (equal (overlay-get ov 'display) "")
               (setq ovs nil hidden t)))
-        (when all (widen) (goto-char (point-min)))
+        ;; (when all
+        (widen)
+        (goto-char (point-min));)
         (if hidden
             (remove-overlays (point-min) (point-max) 'display "")
           (while (not (eobp))
@@ -1177,7 +2805,7 @@ is \"*\", then the mark is \"@\"."
     (while (or (and all (not (eobp)))
                (< i n))
       (let* ((cat (todos-current-category))
-             (ov (todos-item-marked-p))
+             (ov (todos-marked-item-p))
              (marked (assoc cat todos-categories-with-marks)))
         (if (and ov (not all))
             (progn
@@ -1187,7 +2815,7 @@ is \"*\", then the mark is \"@\"."
                         (assq-delete-all cat todos-categories-with-marks))
                 (setcdr marked (1- (cdr marked)))))
           (when (todos-item-start)
-            (unless (and all (todos-item-marked-p))
+            (unless (and all (todos-marked-item-p))
               (setq ov (make-overlay (point) (point)))
               (overlay-put ov 'before-string todos-item-mark)
               (if marked
@@ -1211,274 +2839,323 @@ is \"*\", then the mark is \"@\"."
         (delq (assoc (todos-current-category) todos-categories-with-marks)
               todos-categories-with-marks)))
 
-(defun todos-update-merged-files ()
-  "Interactively add files to or remove from `todos-merged-files'.
-You can also customize `todos-merged-files' directly."
-  (interactive)                         ;FIXME
-  (let ((files (funcall todos-files-function)))
-    (dolist (f files)
-      (if (member f todos-merged-files)
-          (and (y-or-n-p
-                (format "Remove \"%s\" from list of merged Todos files? "
-                        (file-name-sans-extension (file-name-nondirectory f))))
-               (setq todos-merged-files (delete f todos-merged-files)))
-        (and (y-or-n-p
-              (format "Add \"%s\" to list of merged Todos files? "
-                      (file-name-sans-extension (file-name-nondirectory f))))
-             (setq todos-merged-files
-                   (append todos-merged-files (list f)))))))
-  (customize-save-variable 'todos-merged-files todos-merged-files))
-
-(defvar todos-top-priorities-widgets nil
-  "Widget placeholder used by `todos-set-top-priorities'.
-This variable temporarily holds user changed values which are
-saved to `todos-priorities-rules'.")
-
-(defun todos-set-top-priorities ()
-  ""
+(defun todos-set-top-priorities-in-file ()
+  "Set number of top priorities for this file.
+See `todos-set-top-priorities' for more details."
   (interactive)
-  (let ((buf (get-buffer-create "*Todos Top Priorities*"))
-        (files (funcall todos-files-function))
-        file frules cats fwidget cwidgets rules)
-    (with-current-buffer buf
-      (let ((inhibit-read-only t))
-        (erase-buffer))
-      (remove-overlays)
-      (kill-all-local-variables)
-      (setq todos-top-priorities-widgets nil)
-      (dolist (f files)
-        (with-temp-buffer
-          (insert-file-contents f)
-          (setq file (file-name-sans-extension (file-name-nondirectory f))
-                frules (assoc file todos-priorities-rules)
-                cats (mapcar 'car (todos-set-categories))))
-        (setq fwidget
-              (widget-create 'editable-field
-                             :size 2
-                             :value (or (and frules (cadr frules))
-                                        "")
-                             :tag file
-                             :format " %v : %t\n"))
-        (dolist (c cats)
-          (let ((tp-num (cdr (assoc c cats)))
-                cwidget)
-            (widget-insert "  ")
-            (setq cwidget (widget-create 'editable-field
-                                         :size 2
-                                         :value (or tp-num "")
-                                         :tag c
-                                         :format " %v : %t\n"))
-            (push cwidget cwidgets)))
-        (push (cons fwidget cwidgets) todos-top-priorities-widgets))
-      (widget-insert "\n\n")
-      (widget-create 'push-button
-                     :notify (lambda (widget &rest ignore)
-                               (kill-buffer))
-                     "Cancel")
-      (widget-insert " ")
-      (widget-create 'push-button
-                     :notify (lambda (&rest ignore)
-                               (let ((widgets todos-top-priorities-widgets)
-                                     (rules todos-priorities-rules)
-                                     tp-cats)
-                                 (setq rules nil)
-                                 (dolist (w widgets)
-                                   (let* ((fwid (car w))
-                                          (cwids (cdr w))
-                                          (fname (widget-get fwid :tag))
-                                          (fval (widget-value fwid)))
-                                     (dolist (c cwids)
-                                       (let ((cat (widget-get c :tag))
-                                             (cval (widget-value c)))
-                                         (push (cons cat cval) tp-cats)))
-                                     (push (list fname fval tp-cats) rules)))
-                                 (setq todos-priorities-rules rules)
-                                 (customize-save-variable 'todos-priorities-rules
-                                                          todos-priorities-rules)))
-                     "Apply")
-      (use-local-map widget-keymap)
-      (widget-setup))
-    (set-window-buffer (selected-window) (set-buffer buf))))
-
-(defun todos-filter-items (&optional filter merge)
-  "Display a filtered list of items from different categories.
+  (todos-set-top-priorities))
 
-The special items are either the first NUM items (the top priority items) or the items marked as diary entries in each category of the current Todos file.
-
-Number of entries for each category is given by NUM, which
-defaults to `todos-show-priorities'.  With non-nil argument
-MERGE list top priorities of all Todos files in
-`todos-merged-files'.  If `todos-prompt-merged-files' is non-nil,
-prompt to update the list of merged files."
-  (let ((num (if (consp filter) (cdr filter) todos-show-priorities))
-        (buf (get-buffer-create todos-tmp-buffer-name))
-        (files (list todos-current-todos-file))
-        regexp fname bufstr cat beg end done)
-    (when merge
-      ;; FIXME: same or different treatment for top priorities and other
-      ;; filters?  And what about todos-prompt-merged-files?
-      (setq files (if (member filter '(diary regexp custom))
-                      (or (and todos-prompt-merged-files
-                               (todos-update-merged-files))
-                          todos-merged-files
-                          (todos-update-merged-files))
-                    ;; Set merged files for top priorities.
-                    (or (mapcar (lambda (f)
-                              (let ((file (car f))
-                                    (val (nth 1 f)))
-                                (and val (not (zerop val))
-                                     (push file files))))
-                            todos-priorities-rules)
-                        (if (y-or-n-p "Choose files for merging top priorities? ")
-                            (progn (todos-set-top-priorities) (error ""))
-                          (error "No files are set for merging top priorities"))))))
-    (with-current-buffer buf
-      (erase-buffer)
-      (kill-all-local-variables)
-      (todos-filter-items-mode))
-    (when (eq filter 'regexp)
-      (setq regexp (read-string "Enter a regular expression: ")))
-    (save-current-buffer
-      (dolist (f files)
-        (setq fname (file-name-sans-extension (file-name-nondirectory f)))
-        (with-temp-buffer
-          (insert-file-contents f)
-          (goto-char (point-min))
-          ;; Unless the number of items to show was supplied by prefix
-          ;; argument of caller, override `todos-show-priorities' with the
-          ;; nonzero file-wide value from `todos-priorities-rules'.
-          (unless (consp filter)
-            (let ((tp-val (nth 1 (assoc fname todos-priorities-rules))))
-              (unless (zerop (length tp-val))
-                (setq num (string-to-number tp-val)))))
-          (unless (looking-at (concat "^" (regexp-quote todos-category-beg)))
-            (kill-line 1))
-          (while (re-search-forward
-                  (concat "^" (regexp-quote todos-category-beg) "\\(.+\\)\n")
-                  nil t)
-            (setq cat (match-string 1))
-            ;; Unless the number of items to show was supplied by prefix
-            ;; argument of caller, override `todos-show-priorities' with the
-            ;; nonzero category-wide value from `todos-priorities-rules'.
-            (unless (consp filter)
-              (let* ((cats (nth 2 (assoc fname todos-priorities-rules)))
-                     (tp-val (cdr (assoc cat cats))))
-                (unless (zerop (length tp-val))
-                  (setq num (string-to-number tp-val)))))
-            (delete-region (match-beginning 0) (match-end 0))
-            (setq beg (point)) ; Start of first entry.
-            (setq end (if (re-search-forward
-                           (concat "^" (regexp-quote todos-category-beg)) nil t)
-                          (match-beginning 0)
-                        (point-max)))
-            (goto-char beg)
-            (setq done
-                  (if (re-search-forward
-                       (concat "\n" (regexp-quote todos-category-done)) end t)
-                      (match-beginning 0)
-                    end))
-            (delete-region done end)
-            (setq end done)
-            (narrow-to-region beg end)  ; Process current category.
-            (goto-char (point-min))
-            ;; Apply the filter.
-            (cond ((eq filter 'diary)
-                   (while (not (eobp))
-                     (if (looking-at (regexp-quote todos-nondiary-start))
-                         (todos-remove-item)
-                       (todos-forward-item))))
-                  ((eq filter 'regexp)
-                   (while (not (eobp))
-                     (if (string-match regexp (todos-item-string))
-                         (todos-forward-item)
-                       (todos-remove-item))))
-                  ((eq filter 'custom)
-                   (if todos-filter-function
-                       (funcall todos-filter-function)
-                     (error "No custom filter function has been defined")))
-                  (t ; Filter top priority items.
-                   (todos-forward-item num)))
-              (setq beg (point))
-              (unless (member filter '(diary regexp custom))
-                (delete-region beg end))
-              (goto-char (point-min))
-              ;; Add file (if using merged files) and category tags to item.
-              (while (not (eobp))
-                (when (re-search-forward
-                       (concat todos-date-string-start todos-date-pattern
-                               "\\( " diary-time-regexp "\\)?"
-                               (regexp-quote todos-nondiary-end) "?")
-                       nil t)
-                  (insert (concat " [" (if merge (concat fname ":")) cat "]")))
-                (forward-line))
-              (widen))
-          (setq bufstr (buffer-string))
-          (with-current-buffer buf
-            (let (buffer-read-only)
-              (insert bufstr))))))
-    (set-window-buffer (selected-window) (set-buffer buf))
-    (todos-prefix-overlays)
-    (goto-char (point-min))
-    ;; FIXME: this is necessary -- why?
-    (font-lock-fontify-buffer)))
+(defun todos-set-top-priorities-in-category ()
+  "Set number of top priorities for this category.
+See `todos-set-top-priorities' for more details."
+  (interactive)
+  (todos-set-top-priorities t))
 
 (defun todos-top-priorities (&optional num)
-  "List top priorities of each category in `todos-merged-files'.
+  "List top priorities of each category in `todos-filter-files'.
 Number of entries for each category is given by NUM, which
 defaults to `todos-show-priorities'."
-  (interactive "p")
-  (let ((arg (if num (cons 'top num) 'top)))
-    (todos-filter-items arg)))
-
-(defun todos-merged-top-priorities (&optional num)
-  "List top priorities of each category in `todos-merged-files'.
-Number of entries for each category is given by NUM, which
-defaults to `todos-show-priorities'."
-  (interactive "p")
-  (let ((arg (if num (cons 'top num) 'top)))
-    (todos-filter-items arg t)))
+  (interactive "P")
+  (let ((arg (if num (cons 'top num) 'top))
+        (buf todos-top-priorities-buffer)
+        (file todos-current-todos-file))
+    (todos-filter-items arg)
+    (todos-special-buffer-name buf file)))
+
+(defun todos-top-priorities-multifile (&optional arg)
+  "List top priorities of each category in `todos-filter-files'.
+
+If the prefix argument ARG is a number, this is the maximum
+number of top priorities to list in each category.  If the prefix
+argument is `C-u', prompt for which files to filter and use
+`todos-show-priorities' as the number of top priorities to list
+in each category.  If the prefix argument is `C-uC-u', prompt
+both for which files to filter and for how many top priorities to
+list in each category."
+  (interactive "P")
+  (let* ((buf todos-top-priorities-buffer)
+         files
+         (pref (if (numberp arg)
+                   (cons 'top arg)
+                 (setq files (if (or (consp arg)
+                                     (null todos-filter-files))
+                                 (todos-multiple-files)
+                               todos-filter-files))
+                 (if (equal arg '(16))
+                     (cons 'top (read-number
+                                 "Enter number of top priorities to show: "
+                                 todos-show-priorities))
+                   'top))))
+    (todos-filter-items pref t)
+    (todos-special-buffer-name buf files)))
 
 (defun todos-diary-items ()
   "Display todo items for diary inclusion in this Todos file."
   (interactive)
-  (todos-filter-items 'diary))
+  (let ((buf todos-diary-items-buffer)
+        (file todos-current-todos-file))
+    (todos-filter-items 'diary)
+    (todos-special-buffer-name buf file)))
 
-(defun todos-merged-diary-items ()
+(defun todos-diary-items-multifile (&optional arg)
   "Display todo items for diary inclusion in one or more Todos file.
-The files are those listed in `todos-merged-files'."
-  (interactive)
-  (todos-filter-items 'diary t))
+The files are those listed in `todos-filter-files'."
+  (interactive "P")
+  (let ((buf todos-diary-items-buffer)
+        (files (if (or arg (null todos-filter-files))
+                   (todos-multiple-files)
+                 todos-filter-files)))
+    (todos-filter-items 'diary t)
+    (todos-special-buffer-name buf files)))
 
 (defun todos-regexp-items ()
   "Display todo items matching a user-entered regular expression.
 The items are those in the current Todos file."
   (interactive)
-  (todos-filter-items 'regexp))
+  (let ((buf todos-regexp-items-buffer)
+        (file todos-current-todos-file))
+    (todos-filter-items 'regexp)
+    (todos-special-buffer-name buf file)))
 
-(defun todos-merged-regexp-items ()
+(defun todos-regexp-items-multifile (&optional arg)
   "Display todo items matching a user-entered regular expression.
-The items are those in the files listed in `todos-merged-files'."
-  (interactive)
-  (todos-filter-items 'regexp t))
+The items are those in the files listed in `todos-filter-files'."
+  (interactive "P")
+  (let ((buf todos-regexp-items-buffer)
+        (files (if (or arg (null todos-filter-files))
+                   (todos-multiple-files)
+                 todos-filter-files)))
+    (todos-filter-items 'regexp t)
+    (todos-special-buffer-name buf files)))
 
 (defun todos-custom-items ()
   "Display todo items filtered by `todos-filter-function'.
 The items are those in the current Todos file."
   (interactive)
-  (todos-filter-items 'custom))
+  (let ((buf todos-custom-items-buffer)
+        (file todos-current-todos-file))
+    (todos-filter-items 'custom)
+    (todos-special-buffer-name buf file)))
 
-(defun todos-merged-custom-items ()
+(defun todos-custom-items-multifile (&optional arg)
   "Display todo items filtered by `todos-filter-function'.
-The items are those in the files listed in `todos-merged-files'."
+The items are those in the files listed in `todos-filter-files'."
+  (interactive "P")
+  (let ((buf todos-custom-items-buffer)
+        (files (if (or arg (null todos-filter-files))
+                   (todos-multiple-files)
+                 todos-filter-files)))
+    (todos-filter-items 'custom t)
+    (todos-special-buffer-name buf files)))
+
+(defun todos-print (&optional to-file)
+  "Produce a printable version of the current Todos buffer.
+This converts overlays and soft line wrapping and, depending on
+the value of `todos-print-function', includes faces.  With
+non-nil argument TO-FILE write the printable version to a file;
+otherwise, send it to the default printer."
   (interactive)
-  (todos-filter-items 'custom t))
+  (let ((buf todos-print-buffer)
+        (header (cond
+                 ((eq major-mode 'todos-mode)
+                  (concat "Todos File: "
+                          (todos-short-file-name todos-current-todos-file)
+                          "\nCategory: " (todos-current-category)))
+                 ((eq major-mode 'todos-filter-items-mode)
+                  "Todos Top Priorities")))
+        (prefix (propertize (concat todos-prefix " ")
+                            'face 'todos-prefix-string))
+        (num 0)
+        (fill-prefix (make-string todos-indent-to-here 32))
+        (content (buffer-string))
+        file)
+    (with-current-buffer (get-buffer-create buf)
+      (insert content)
+      (goto-char (point-min))
+      (while (not (eobp))
+        (let ((beg (point))
+              (end (save-excursion (todos-item-end))))
+          (when todos-number-prefix
+            (setq num (1+ num))
+            (setq prefix (propertize (concat (number-to-string num) " ")
+                                     'face 'todos-prefix-string)))
+          (insert prefix)
+          (fill-region beg end))
+        ;; Calling todos-forward-item infloops at todos-item-start due to
+        ;; non-overlay prefix, so search for item start instead.
+        (if (re-search-forward todos-item-start nil t)
+            (beginning-of-line)
+          (goto-char (point-max))))
+      (if (re-search-backward (concat "^" (regexp-quote todos-category-done))
+                              nil t)
+          (replace-match todos-done-separator))
+      (goto-char (point-min))
+      (insert header)
+      (newline 2)
+      (if to-file
+          (let ((file (read-file-name "Print to file: ")))
+            (funcall todos-print-function file))
+        (funcall todos-print-function)))
+    (kill-buffer buf)))
+
+(defun todos-print-to-file ()
+  "Save printable version of this Todos buffer to a file."
+  (interactive)
+  (todos-print t))
+
+(defun todos-convert-legacy-files ()
+  "Convert legacy Todo files to the current Todos format.
+The files `todo-file-do' and `todo-file-done' are converted and
+saved (the latter as a Todos Archive file) with a new name in
+`todos-files-directory'.  See also the documentation string of
+`todos-todo-mode-date-time-regexp' for further details."
+  (interactive)
+  (if (fboundp 'todo-mode)
+      (require 'todo-mode)
+    (error "Void function `todo-mode'"))
+  ;; Convert `todo-file-do'.
+  (if (file-exists-p todo-file-do)
+      (let ((default "todo-do-conv")
+            file archive-sexp)
+        (with-temp-buffer
+          (insert-file-contents todo-file-do)
+          (let ((end (search-forward ")" (line-end-position) t))
+                (beg (search-backward "(" (line-beginning-position) t)))
+            (setq todo-categories
+                  (read (buffer-substring-no-properties beg end))))
+          (todo-mode)
+          (delete-region (line-beginning-position) (1+ (line-end-position)))
+          (while (not (eobp))
+            (cond
+             ((looking-at (regexp-quote (concat todo-prefix todo-category-beg)))
+              (replace-match todos-category-beg))
+             ((looking-at (regexp-quote todo-category-end))
+              (replace-match ""))
+             ((looking-at (regexp-quote (concat todo-prefix " "
+                                                todo-category-sep)))
+              (replace-match todos-category-done))
+             ((looking-at (concat (regexp-quote todo-prefix) " "
+                                  todos-todo-mode-date-time-regexp " "
+                                  (regexp-quote todo-initials) ":"))
+              (todos-convert-legacy-date-time)))
+            (forward-line))
+          (setq file (concat todos-files-directory
+                             (read-string
+                              (format "Save file as (default \"%s\"): " default)
+                              nil nil default)
+                             ".todo"))
+          (write-region (point-min) (point-max) file nil 'nomessage nil t))
+        (with-temp-buffer
+          (insert-file-contents file)
+          (let ((todos-categories (todos-make-categories-list t)))
+            (todos-update-categories-sexp))
+          (write-region (point-min) (point-max) file nil 'nomessage))
+        ;; Convert `todo-file-done'.
+        (when (file-exists-p todo-file-done)
+          (with-temp-buffer
+            (insert-file-contents todo-file-done)
+            (let ((beg (make-marker))
+                  (end (make-marker))
+                  cat cats comment item)
+              (while (not (eobp))
+                (when (looking-at todos-todo-mode-date-time-regexp)
+                  (set-marker beg (point))
+                  (todos-convert-legacy-date-time)
+                  (set-marker end (point))
+                  (goto-char beg)
+                  (insert "[" todos-done-string)
+                  (goto-char end)
+                  (insert "]")
+                  (forward-char)
+                  (when (looking-at todos-todo-mode-date-time-regexp)
+                    (todos-convert-legacy-date-time))
+                  (when (looking-at (concat " " (regexp-quote todo-initials) ":"))
+                    (replace-match "")))
+                (if (re-search-forward
+                     (concat "^" todos-todo-mode-date-time-regexp) nil t)
+                    (goto-char (match-beginning 0))
+                  (goto-char (point-max)))
+                (backward-char)
+                (when (looking-back "\\[\\([^][]+\\)\\]")
+                  (setq cat (match-string 1))
+                  (goto-char (match-beginning 0))
+                  (replace-match ""))
+                ;; If the item ends with a non-comment parenthesis not
+                ;; followed by a period, we lose (but we inherit that problem
+                ;; from todo-mode.el).
+                (when (looking-back "(\\(.*\\)) ")
+                  (setq comment (match-string 1))
+                  (replace-match "")
+                  (insert "[" todos-comment-string ": " comment "]"))
+                (set-marker end (point))
+                (if (member cat cats)
+                    ;; If item is already in its category, leave it there.
+                    (unless (save-excursion
+                              (re-search-backward
+                               (concat "^" (regexp-quote todos-category-beg)
+                                       "\\(.*\\)$") nil t)
+                              (string= (match-string 1) cat))
+                      ;; Else move it to its category.
+                      (setq item (buffer-substring-no-properties beg end))
+                      (delete-region beg (1+ end))
+                      (set-marker beg (point))
+                      (re-search-backward
+                       (concat "^" (regexp-quote (concat todos-category-beg cat)))
+                       nil t)
+                      (forward-line)
+                      (if (re-search-forward
+                           (concat "^" (regexp-quote todos-category-beg)
+                                   "\\(.*\\)$") nil t)
+                          (progn (goto-char (match-beginning 0))
+                                 (newline)
+                                 (forward-line -1))
+                        (goto-char (point-max)))
+                      (insert item "\n")
+                      (goto-char beg))
+                  (push cat cats)
+                  (goto-char beg)
+                  (insert todos-category-beg cat "\n\n" todos-category-done "\n"))
+                (forward-line))
+              (set-marker beg nil)
+              (set-marker end nil))
+            (setq file (concat (file-name-sans-extension file) ".toda"))
+            (write-region (point-min) (point-max) file nil 'nomessage nil t))
+          (with-temp-buffer
+            (insert-file-contents file)
+            (let ((todos-categories (todos-make-categories-list t)))
+              (todos-update-categories-sexp))
+            (write-region (point-min) (point-max) file nil 'nomessage)
+            (setq archive-sexp (read (buffer-substring-no-properties
+                                      (line-beginning-position)
+                                      (line-end-position)))))
+          (setq file (concat (file-name-sans-extension file) ".todo"))
+          ;; Update categories sexp of converted Todos file again, adding
+          ;; counts of archived items.
+          (with-temp-buffer
+            (insert-file-contents file)
+            (let ((sexp (read (buffer-substring-no-properties
+                               (line-beginning-position)
+                               (line-end-position)))))
+              (dolist (cat sexp)
+                (let ((archive-cat (assoc (car cat) archive-sexp)))
+                  (if archive-cat
+                      (aset (cdr cat) 3 (aref (cdr archive-cat) 2)))))
+              (delete-region (line-beginning-position) (line-end-position))
+              (prin1 sexp (current-buffer)))
+            (write-region (point-min) (point-max) file nil 'nomessage)))
+          (todos-reevaluate-defcustoms)
+        (message "Format conversion done."))
+    (error "No legacy Todo file exists")))
 
-;;; Navigation
+;; ---------------------------------------------------------------------------
+;;; Navigation Commands
 
 (defun todos-forward-category (&optional back)
   "Visit the numerically next category in this Todos file.
-With non-nil argument BACK, visit the numerically previous
-category."
+If the current category is the highest numbered, visit the first
+category.  With non-nil argument BACK, visit the numerically
+previous category (the highest numbered one, if the current
+category is the first)."
   (interactive)
   (setq todos-category-number
         (1+ (mod (- todos-category-number (if back 2 0))
@@ -1487,20 +3164,22 @@ category."
   (goto-char (point-min)))
 
 (defun todos-backward-category ()
-  "Visit the numerically previous category in this Todos file."
+  "Visit the numerically previous category in this Todos file.
+If the current category is the highest numbered, visit the first
+category."
   (interactive)
   (todos-forward-category t))
 
-;; FIXME: autoload?
 (defun todos-jump-to-category (&optional cat other-file)
   "Jump to a category in this or another Todos file.
-Optional argument CAT provides the category name.  Otherwise,
-prompt for the category, with TAB completion on existing
-categories.  If a non-existing category name is entered, ask
-whether to add a new category with this name, if affirmed, do so,
-then jump to that category.  With non-nil argument OTHER-FILE,
-prompt for a Todos file, otherwise jump within the current Todos
-file."
+
+Programmatically, optional argument CAT provides the category
+name.  When nil (as in interactive calls), prompt for the
+category, with TAB completion on existing categories.  If a
+non-existing category name is entered, ask whether to add a new
+category with this name; if affirmed, add it, then jump to that
+category.  With non-nil argument OTHER-FILE, prompt for a Todos
+file, otherwise jump within the current Todos file."
   (interactive)
   (let ((file (or (and other-file
                        (todos-read-file-name "Choose a Todos file: " nil t))
@@ -1519,9 +3198,6 @@ file."
           (and other-file (setq todos-current-todos-file file))
           (let ((category (or (and (assoc cat todos-categories) cat)
                               (todos-read-category "Jump to category: "))))
-            ;; ;; FIXME: why is this needed?
-            ;; (if (string= "" category)
-            ;;  (setq category (todos-current-category)))
             ;; Clean up after selecting category in Todos Categories mode.
             (if (string= (buffer-name) todos-categories-buffer)
                 (kill-buffer))
@@ -1542,6 +3218,37 @@ The category is chosen by prompt, with TAB completion."
   (interactive)
   (todos-jump-to-category nil t))
 
+(defun todos-jump-to-item ()
+  "Jump to the file and category of the filtered item at point."
+  (interactive)
+  (let ((str (todos-item-string))
+        (buf (current-buffer))
+        cat file beg)
+    (string-match (concat todos-date-string-start todos-date-pattern
+                          "\\(?: " diary-time-regexp "\\)?"
+                          (regexp-quote todos-nondiary-end) "?"
+                          "\\(?3: \\[\\(?2:.*:\\)?\\(?1:.*\\)\\]\\).*$") str)
+    (setq cat (match-string 1 str))
+    (setq file (match-string 2 str))
+    (setq str (replace-match "" nil nil str 3))
+    (setq file (if file
+                   (concat todos-files-directory (substring file 0 -1) ".todo")
+                 todos-global-current-todos-file))
+    (find-file-noselect file)
+    (with-current-buffer (get-file-buffer file)
+      (widen)
+      (goto-char (point-min))
+      (re-search-forward
+       (concat "^" (regexp-quote (concat todos-category-beg cat))) nil t)
+      (search-forward str)
+      (setq beg (match-beginning 0)))
+    (kill-buffer buf)
+    (set-window-buffer (selected-window) (set-buffer (get-file-buffer file)))
+    (setq todos-current-todos-file file)
+    (setq todos-category-number (todos-category-number cat))
+    (todos-category-select)
+    (goto-char beg)))
+
 ;; FIXME ? disallow prefix arg value < 1 (re-search-* allows these)
 (defun todos-forward-item (&optional count)
   "Move point down to start of item with next lower priority.
@@ -1579,6 +3286,8 @@ With numerical prefix COUNT, move point COUNT items upward,"
       (re-search-forward (concat "^" (regexp-quote todos-category-done)) nil t)
       (forward-line -1))))
 
+;; FIXME: (i) Extend search to other Todos files. (ii) Allow navigating among
+;; hits.
 (defun todos-search ()
   "Search for a regular expression in this Todos file.
 The search runs through the whole file and encompasses all and
@@ -1645,59 +3354,35 @@ face."
   (interactive)
   (remove-overlays 1 (1+ (buffer-size)) 'face 'todos-search))
 
-;;; Editing
+;; ---------------------------------------------------------------------------
+;;; Editing Commands
 
+;; FIXME: autoload?
+;; FIXME: should there also be command todos-delete-file or is it enough to
+;; delete empty file on deleting last category with todos-delete-category?
 (defun todos-add-file ()
   "Name and add a new Todos file.
 Interactively, prompt for a category and display it.
 Noninteractively, return the name of the new file."
   (interactive)
   (let ((default-file (if todos-default-todos-file
-                          (file-name-sans-extension
-                           (file-name-nondirectory todos-default-todos-file))))
-        file prompt shortname)
-    (while
-        (and
-         (cond
-          ((or (not file) (member file todos-files))
-           (setq prompt (concat "Enter name of new Todos file "
-                                "(TAB or SPC to see existing Todos files): ")))
-          ((string-equal file "")
-           (setq prompt "Enter a non-empty name: "))
-          ((string-match "\\`\\s-+\\'" file)
-           (setq prompt "Enter a name that is not only white space: ")))
-         (setq file (todos-read-file-name prompt))))
-    (setq shortname (file-name-sans-extension (file-name-nondirectory file)))
+                          (todos-short-file-name todos-default-todos-file)))
+        (prompt (concat "Enter name of new Todos file "
+                        "(TAB or SPC to see current names): "))
+        file shortname)
+    (setq file (todos-read-file-name prompt));))
+    (setq shortname (todos-short-file-name file))
     (with-current-buffer (get-buffer-create file)
       (erase-buffer)
       (write-region (point-min) (point-max) file nil 'nomessage nil t)
       (kill-buffer file))
-    ;; FIXME: todos-change-default-file yields a Custom mismatch
-    ;; (if (or (not default-file)
-    ;;      (yes-or-no-p (concat (format "Make \"%s\" new default Todos file "
-    ;;                                   shortname)
-    ;;                           (format "[current default is \"%s\"]? "
-    ;;                                   default-file))))
-    ;;  (todos-change-default-file file)
-    ;;   (message "\"%s\" remains the default Todos file." default-file))
+    (todos-reevaluate-defcustoms)
     (if (called-interactively-p)
         (progn
           (setq todos-current-todos-file file)
           (todos-show))
       file)))
 
-;; FIXME: omit this and just use defcustom?  Says "changed outside of Custom
-;; (mismatch)"
-(defun todos-change-default-file (&optional file)
-  ""
-  (interactive)
-  (let ((new-default (or file
-                         (todos-read-file-name "Choose new default Todos file: "
-                                               nil t))))
-    (customize-save-variable 'todos-default-todos-file new-default)
-    (message "\"%s\" is new default Todos file."
-             (file-name-sans-extension (file-name-nondirectory new-default)))))
-
 (defun todos-add-category (&optional cat)
   "Add a new category to the current Todos file.
 Called interactively, prompt for category name, then visit the
@@ -1716,8 +3401,11 @@ the category name, which is also the return value."
                   todos-current-todos-file)))
     (unless cat (setq cat (read-from-minibuffer "Enter new category name: ")))
     (with-current-buffer buf
-      (setq cat (todos-validate-category-name cat))
+      (setq cat (todos-validate-name cat 'category))
       (setq todos-categories (append todos-categories (list (cons cat counts))))
+      (if todos-categories-full
+          (setq todos-categories-full (append todos-categories-full
+                                              (list (cons cat counts)))))
       (widen)
       (goto-char (point-max))
       (save-excursion                   ; Save point for todos-category-select.
@@ -1738,7 +3426,7 @@ category there as well."
   (interactive)
   (let* ((cat (todos-current-category))
          (new (read-from-minibuffer (format "Rename category \"%s\" to: " cat))))
-    (setq new (todos-validate-category-name new))
+    (setq new (todos-validate-name new 'category))
     (let* ((ofile todos-current-todos-file)
            (archive (concat (file-name-sans-extension ofile) ".toda"))
            (buffers (append (list ofile)
@@ -1758,6 +3446,7 @@ category there as well."
                                            "\\(" (regexp-quote cat) "\\)\n")
                                    nil t)
                 (replace-match new t t nil 1)))))))
+    ;; FIXME: use force-mode-line-update instead?
     (setq mode-line-buffer-identification
           (funcall todos-mode-line-function new)))
   (save-excursion (todos-category-select)))
@@ -1771,42 +3460,58 @@ i.e. including all existing todo and done items."
          (todo (todos-get-count 'todo cat))
          (done (todos-get-count 'done cat))
          (archived (todos-get-count 'archived cat)))
-    (if (and (not arg)
-             (or (> todo 0) (> done 0)))
-        (message "To delete a non-empty category, type C-u D.")
-      (when (yes-or-no-p (concat "Permanently remove category \"" cat
-                                 "\"" (and arg " and all its entries") "? "))
-        ;; FIXME ? optionally delete archived category as well?
-        (when (and archived
-                   (y-or-n-p (concat "This category has archived items; "
-                                     "the archived category will remain\n"
-                                     "after deleting the todo category.  "
-                                     "Do you still want to delete it\n"
-                                     "(see 'todos-ignore-archived-categories' "
-                                     "for another option)? ")))
-          (widen)
-          (let ((buffer-read-only)
-                (beg (re-search-backward
-                      (concat "^" (regexp-quote (concat todos-category-beg cat))
-                              "\n") nil t))
-                (end (if (re-search-forward
-                          (concat "\n\\(" (regexp-quote todos-category-beg)
-                                  ".*\n\\)") nil t)
-                         (match-beginning 1)
-                       (point-max))))
-            (remove-overlays beg end)
-            (delete-region beg end)
-            (setq todos-categories (delete (assoc cat todos-categories)
-                                           todos-categories))
-            (todos-update-categories-sexp)
-            (setq todos-category-number
-                  (1+ (mod todos-category-number (length todos-categories))))
-            (todos-category-select)
-            (goto-char (point-min))
-            (message "Deleted category %s" cat)))))))
+    (when (or (> (length todos-categories) 1)
+              (y-or-n-p (concat "This is the only category in this file; "
+                                "deleting it will also delete the file.\n"
+                                "Do you want to proceed? ")))
+      (if (and (not arg)
+               (or (> todo 0) (> done 0)))
+          (message "To delete a non-empty category, type C-u %s."
+                   (key-description
+                    (car (where-is-internal 'todos-delete-category))))
+        (when (yes-or-no-p (concat "Permanently remove category \"" cat
+                                   "\"" (and arg " and all its entries") "? "))
+          (when (and archived
+                     (y-or-n-p (concat "This category has archived items; "
+                                       "the archived category will remain\n"
+                                       "after deleting the todo category.  "
+                                       "Do you still want to delete it\n"
+                                       "(see 'todos-ignore-archived-categories' "
+                                       "for another option)? ")))
+            (widen)
+            (let ((buffer-read-only)
+                  (beg (re-search-backward
+                        (concat "^" (regexp-quote (concat todos-category-beg cat))
+                                "\n") nil t))
+                  (end (if (re-search-forward
+                            (concat "\n\\(" (regexp-quote todos-category-beg)
+                                    ".*\n\\)") nil t)
+                           (match-beginning 1)
+                         (point-max))))
+              (remove-overlays beg end)
+              (delete-region beg end)
+              (if (= (length todos-categories) 1)
+                  ;; If deleted category was the only one, delete the file.
+                  (progn
+                    ;; FIXME: need this?
+                    (setq todos-categories nil)
+                    (todos-reevaluate-defcustoms)
+                    (delete-file todos-current-todos-file)
+                    (kill-buffer)
+                    (message "Deleted empty Todos file %s."
+                             todos-current-todos-file))
+                ;; FIXME: what about todos-categories-full ?
+                (setq todos-categories (delete (assoc cat todos-categories)
+                                               todos-categories))
+                (todos-update-categories-sexp)
+                (setq todos-category-number
+                      (1+ (mod todos-category-number (length todos-categories))))
+                (todos-category-select)
+                (goto-char (point-min))
+                (message "Deleted category %s." cat)))))))))
 
 (defun todos-raise-category (&optional lower)
-  "Raise priority of category point is on in Categories buffer.
+  "Raise priority of category point is on in Todos Categories buffer.
 With non-nil argument LOWER, lower the category's priority."
   (interactive)
   (let (num)
@@ -1846,7 +3551,7 @@ With non-nil argument LOWER, lower the category's priority."
         (forward-char col)))))
 
 (defun todos-lower-category ()
-  "Lower priority of category point is on in Categories buffer."
+  "Lower priority of category point is on in Todos Categories buffer."
   (interactive)
   (todos-raise-category t))
 
@@ -1892,8 +3597,7 @@ archive of the file moved to, creating it if it does not exist."
                  (if (member buf (funcall todos-files-function t))
                      (concat (file-name-sans-extension nfile) ".toda")
                    nfile))
-              (let* ((nfile-short (file-name-sans-extension
-                                   (file-name-nondirectory nfile)))
+              (let* ((nfile-short (todos-short-file-name nfile))
                      (prompt (concat
                               (format "Todos file \"%s\" already has "
                                       nfile-short)
@@ -1909,7 +3613,7 @@ archive of the file moved to, creating it if it does not exist."
                   (unless (member (file-truename (buffer-file-name))
                                   (funcall todos-files-function t))
                     (setq new (read-from-minibuffer prompt))
-                    (setq new (todos-validate-category-name new))))
+                    (setq new (todos-validate-name new 'category))))
                 ;; Replace old with new name in Todos and archive files.
                 (when new
                   (goto-char (point-max))
@@ -1941,7 +3645,9 @@ archive of the file moved to, creating it if it does not exist."
                   ;; Skip confirming killing the archive buffer.
                   (set-buffer-modified-p nil)
                   (delete-file todos-current-todos-file)
-                  (kill-buffer))
+                  (kill-buffer)
+                  (when (member todos-current-todos-file todos-files)
+                    (todos-reevaluate-defcustoms)))
               (setq todos-categories (delete (assoc cat todos-categories)
                                              todos-categories))
               (todos-update-categories-sexp)
@@ -1952,10 +3658,11 @@ archive of the file moved to, creating it if it does not exist."
       (todos-category-select))))
 
 (defun todos-merge-category ()
-  "Merge this category with chosen category in this file. The
-current category's todo and done items are appended to the chosen
-category's todo and done items, respectively, which becomes the
-current category, and the category moved from is deleted."
+  "Merge current category into another category in this file.
+The current category's todo and done items are appended to the
+chosen category's todo and done items, respectively, which
+becomes the current category, and the category moved from is
+deleted."
   (interactive)
   (let ((buffer-read-only nil)
         (cat (todos-current-category))
@@ -2022,15 +3729,13 @@ current category, and the category moved from is deleted."
     (widen)
   ))
 
-;; FIXME: make insertion options customizable per category
+;; FIXME: make insertion options customizable per category?
 ;;;###autoload
-;; (defun todos-insert-item (&optional arg use-point date-type time
-;;                                  diary nonmarking)
 (defun todos-insert-item (&optional arg diary nonmarking date-type time
                                     region-or-here)
   "Add a new Todo item to a category.
-See the note at the end of this document string about key
-bindings and convenience commands derived from this command.
+\(See the note at the end of this document string about key
+bindings and convenience commands derived from this command.)
 
 With no (or nil) prefix argument ARG, add the item to the current
 category; with one prefix argument (C-u), prompt for a category
@@ -2070,17 +3775,21 @@ mandatory date header string and how it is added:
   header contains the current date (in the format set by
   `calendar-date-display-form').
 
-With non-nil argument TIME prompt for a time string; this must
-either be empty or else match `diary-time-regexp'.  If TIME is
-nil, add or omit the current time according to value of the user
-option `todos-always-add-time-string'.
+With non-nil argument TIME prompt for a time string, which must
+match `diary-time-regexp'.  Typing `<return>' at the prompt
+returns the current time, if the user option
+`todos-always-add-time-string' is non-nil, otherwise the empty
+string (i.e., no time string).  If TIME is absent or nil, add or
+omit the current time string according as
+`todos-always-add-time-string' is non-nil or nil, respectively.
 
 The argument REGION-OR-HERE determines the source and location of
 the new item:
 - If the REGION-OR-HERE is the symbol `here', prompt for the text
   of the new item and insert it directly above the todo item at
-  point, or if point is on the empty line below the last todo
-  item, insert the new item there.  An error is signalled if
+  point (hence lowering the priority of the remaining items), or
+  if point is on the empty line below the last todo item, insert
+  the new item there.  An error is signalled if
   `todos-insert-item' is invoked with `here' outside of the
   current category.
 - If REGION-OR-HERE is the symbol `region', use the region of the
@@ -2099,11 +3808,18 @@ the new item:
 To facilitate using these arguments when inserting a new todo
 item, convenience commands have been defined for all admissible
 combinations (96 in all!) together with mnenomic key bindings
-based on on the name of the arguments and their order: _h_ere or
-_r_egion - _c_alendar or _d_ate or day_n_ame - _t_ime - diar_y_ -
-nonmar_k_ing.  An alternative interface for customizing key
-binding is also provided with the function
-`todos-insertion-bindings'."            ;FIXME
+based on on the name of the arguments and their order in the
+command's argument list: diar_y_ - nonmar_k_ing - _c_alendar or
+_d_ate or day_n_ame - _t_ime - _r_egion or _h_ere.  These key
+combinations are appended to the basic insertion key (i) and keys
+that allow a following key must be doubled when used finally.
+For example, `iyh' will insert a new item with today's date,
+marked according to the DIARY argument described above, and with
+priority according to the HERE argument; while `iyy' does the
+same except the priority is not given by HERE but by prompting."
+;;   An alternative interface for customizing key
+;; binding is also provided with the function
+;; `todos-insertion-bindings'."         ;FIXME
   (interactive "P")
   (let ((region (eq region-or-here 'region))
         (here (eq region-or-here 'here)))
@@ -2127,15 +3843,8 @@ binding is also provided with the function
                           (todos-read-dayname))
                          ((eq date-type 'calendar)
                           (setq todos-date-from-calendar t)
-                          (let (calendar-view-diary-initially-flag)
-                            (calendar))
-                          (with-current-buffer "*Calendar*"
-                            (todos-set-date-from-calendar))
-                          todos-date-from-calendar)
+                          (todos-set-date-from-calendar))
                          (t (calendar-date-string (calendar-current-date) t t))))
-           ;; FIXME: should TIME override `todos-always-add-time-string'?  But
-           ;; then add another option to use current time or prompt for time
-           ;; string?
            (time-string (or (and time (todos-read-time))
                             (and todos-always-add-time-string
                                  (substring (current-time-string) 11 16)))))
@@ -2159,7 +3868,8 @@ binding is also provided with the function
                           todos-nondiary-start
                         (when (and nonmarking (not todos-diary-nonmarking))
                           diary-nonmarking-symbol))
-                      date-string (when time-string
+                      date-string (unless (and time-string
+                                               (string= time-string ""))
                                     (concat " " time-string))
                       (when (not (and diary (not todos-include-in-diary)))
                         todos-nondiary-end)
@@ -2185,6 +3895,25 @@ binding is also provided with the function
         (if (or diary todos-include-in-diary) (todos-set-count 'diary 1))
         (todos-update-categories-sexp)))))
 
+(defvar todos-date-from-calendar nil
+  "Helper variable for setting item date from the Emacs Calendar.")
+
+(defun todos-set-date-from-calendar ()
+  "Return string of date chosen from Calendar."
+  (when todos-date-from-calendar
+    (let (calendar-view-diary-initially-flag)
+      (calendar))
+    ;; *Calendar* is now current buffer.
+    (local-set-key (kbd "RET") 'exit-recursive-edit)
+    (message "Put cursor on a date and type <return> to set it.")
+    ;; FIXME: is there a better way than recursive-edit?
+    ;; FIXME: use unwind-protect?  Check recursive-depth?
+    (recursive-edit)
+    (setq todos-date-from-calendar
+          (calendar-date-string (calendar-cursor-to-date t) t t))
+    (calendar-exit)
+    todos-date-from-calendar))
+
 ;; FIXME: autoload when key-binding is defined in calendar.el
 (defun todos-insert-item-from-calendar ()
   ""
@@ -2201,19 +3930,6 @@ binding is also provided with the function
           ;; (lambda ()
             (define-key calendar-mode-map "it" 'todos-insert-item-from-calendar);))
 
-(defvar todos-date-from-calendar nil)
-(defun todos-set-date-from-calendar ()
-  ""
-  (when todos-date-from-calendar
-    (local-set-key (kbd "RET") 'exit-recursive-edit)
-    (message "Put cursor on a date and type <return> to set it.")
-    ;; FIXME: is there a better way than recursive-edit?
-    ;; FIXME: use unwind-protect?  Check recursive-depth?
-    (recursive-edit)
-    (setq todos-date-from-calendar
-          (calendar-date-string (calendar-cursor-to-date t) t t))
-    (calendar-exit)))
-
 (defun todos-delete-item ()
   "Delete at least one item in this category.
 
@@ -2237,7 +3953,7 @@ the item at point."
       (and marked (goto-char (point-min)))
       (catch 'done
         (while (not (eobp))
-          (if (or (and marked (todos-item-marked-p)) item)
+          (if (or (and marked (todos-marked-item-p)) item)
               (progn
                 (if (todos-done-item-p)
                     (todos-set-count 'done -1)
@@ -2261,7 +3977,9 @@ the item at point."
     (if ov (delete-overlay ov))))
 
 (defun todos-edit-item ()
-  "Edit current Todo item in the minibuffer."
+  "Edit the Todo item at point.
+If the item consists of only one logical line, edit it in the
+minibuffer; otherwise, edit it in Todos Edit mode."
   (interactive)
   (when (todos-item-string)
     (let* ((buffer-read-only)
@@ -2277,7 +3995,7 @@ the item at point."
            (multiline (> (length (split-string item "\n")) 1))
            (opoint (point)))
       (if multiline
-          (todos-edit-multiline)
+          (todos-edit-multiline t)
         (let ((new (read-string "Edit: " (cons item item-beg))))
           (while (not (string-match
                        (concat todos-date-string-start todos-date-pattern) new))
@@ -2293,29 +4011,50 @@ the item at point."
           (todos-remove-item)
           (todos-insert-with-overlays new)
           (move-to-column item-beg))))))
-  
-;; FIXME: run todos-check-format on exiting buffer (or check for date string
-;; and indentation)
-(defun todos-edit-multiline ()
+
+(defun todos-edit-multiline-item ()
   "Edit current Todo item in Todos Edit mode.
 Use of newlines invokes `todos-indent' to insure compliance with
 the format of Diary entries."
   (interactive)
+  (todos-edit-multiline t))
+
+(defun todos-edit-multiline (&optional item)
+  ""
+  (interactive)
+  ;; FIXME: should there be only one live Todos Edit buffer?
+  ;; (let ((buffer-name todos-edit-buffer))
   (let ((buffer-name (generate-new-buffer-name todos-edit-buffer)))
     (set-window-buffer
      (selected-window)
      (set-buffer (make-indirect-buffer
                   (file-name-nondirectory todos-current-todos-file)
                   buffer-name)))
-    (narrow-to-region (todos-item-start) (todos-item-end))
+    (if item
+        (narrow-to-region (todos-item-start) (todos-item-end))
+      (widen))
     (todos-edit-mode)
-    (message "Type %s to return to Todos mode."
-             (key-description (car (where-is-internal 'todos-edit-quit))))))
+    ;; (message (concat "Type %s to check file format validity and "
+    ;;               "return to Todos mode.\n")
+    ;;       (key-description (car (where-is-internal 'todos-edit-quit))))
+    (message "%s" (substitute-command-keys
+                   (concat "Type \\[todos-edit-quit] to check file format "
+                           "validity and return to Todos mode.\n")))))
 
 (defun todos-edit-quit ()
-  "Return from Todos Edit mode to Todos mode."
+  "Return from Todos Edit mode to Todos mode.
+
+If the whole file was in Todos Edit mode, check before returning
+whether the file is still a valid Todos file and if so, also
+recalculate the Todos categories sexp, in case changes were made
+in the number or names of categories."
   (interactive)
+  ;; FIXME: worth doing this only if file was actually changed?
+  (when (eq (buffer-size) (- (point-max) (point-min)))
+    (when (todos-check-format)
+      (todos-make-categories-list t)))
   (kill-buffer)
+  ;; In case next buffer is not the one holding todos-current-todos-file.
   (todos-show))
 
 (defun todos-edit-item-header (&optional what)
@@ -2323,21 +4062,23 @@ the format of Diary entries."
 
 Interactively, ask whether to edit year, month and day or day of
 the week, as well as time.  If there are marked items, apply the
-changes to all of these; otherwise, edit just the item at point.
+changes to all of these; otherwise, edit just the item at point.  
 
-Non-interactively, argument WHAT specifies whether to edit only
-the date or only the time, or to set the date to today."
+Non-interactively, argument WHAT specifies whether to set the
+date from the Calendar or to today, or whether to edit only the
+date or day, or only the time."
   (interactive)
   (let* ((cat (todos-current-category))
          (marked (assoc cat todos-categories-with-marks))
-         (first t)
+         (first t)                      ; Match only first of marked items.
+         (todos-date-from-calendar t)
          ndate ntime nheader)
     (save-excursion
       (or (and marked (goto-char (point-min))) (todos-item-start))
       (catch 'stop
         (while (not (eobp))
           (and marked
-               (while (not (todos-item-marked-p))
+               (while (not (todos-marked-item-p))
                  (todos-forward-item)
                  (and (eobp) (throw 'stop nil))))
           (re-search-forward (concat todos-date-string-start "\\(?1:"
@@ -2347,38 +4088,51 @@ the date or only the time, or to set the date to today."
           (let* ((odate (match-string-no-properties 1))
                  (otime (match-string-no-properties 2))
                  (buffer-read-only))
-            (if (eq what 'today)
-                (progn
-                  (setq ndate (calendar-date-string (calendar-current-date) t t))
-                  (replace-match ndate nil nil nil 1))
-              (unless (eq what 'timeonly)
-                (when first
-                  (setq ndate (if (save-match-data (string-match "[0-9]+" odate))
-                                  (if (y-or-n-p "Change date? ")
-                                      (todos-read-date)
-                                    (todos-read-dayname))
-                                (if (y-or-n-p "Change day? ")
-                                    (todos-read-dayname)
-                                  (todos-read-date)))))
-                (replace-match ndate nil nil nil 1))
-              (unless (eq what 'dateonly)
-                (when first
-                  (setq ntime (save-match-data (todos-read-time)))
-                  (when (< 0 (length ntime)) (setq ntime (concat " " ntime))))
-                (if otime
-                    (replace-match ntime nil nil nil 2)
-                  (goto-char (match-end 1))
-                  (insert ntime))))
+            (cond ((eq what 'today)
+                   (progn
+                     (setq ndate (calendar-date-string
+                                  (calendar-current-date) t t))
+                     (replace-match ndate nil nil nil 1)))
+                  ((eq what 'calendar)
+                   (setq ndate (save-match-data (todos-set-date-from-calendar)))
+                   (replace-match ndate nil nil nil 1))
+                  (t
+                   (unless (eq what 'timeonly)
+                     (when first
+                       (setq ndate (if (save-match-data
+                                         (string-match "[0-9]+" odate))
+                                       (if (y-or-n-p "Change date? ")
+                                           (todos-read-date)
+                                         (todos-read-dayname))
+                                     (if (y-or-n-p "Change day? ")
+                                         (todos-read-dayname)
+                                       (todos-read-date)))))
+                     (replace-match ndate nil nil nil 1))
+                   (unless (eq what 'dateonly)
+                     (when first
+                       (setq ntime (save-match-data (todos-read-time)))
+                       (when (< 0 (length ntime))
+                         (setq ntime (concat " " ntime))))
+                     (if otime
+                         (replace-match ntime nil nil nil 2)
+                       (goto-char (match-end 1))
+                       (insert ntime)))))
+            (setq todos-date-from-calendar nil)
             (setq first nil))
           (if marked
               (todos-forward-item)
             (goto-char (point-max))))))))
 
 (defun todos-edit-item-date ()
-  "Prompt For and apply changes to current item's date."
+  "Prompt for and apply changes to current item's date."
   (interactive)
   (todos-edit-item-header 'dateonly))
 
+(defun todos-edit-item-date-from-calendar ()
+  "Prompt for changes to current item's date and apply from Calendar."
+  (interactive)
+  (todos-edit-item-header 'calendar))
+
 (defun todos-edit-item-date-is-today ()
   "Set item date to today's date."
   (interactive)
@@ -2389,12 +4143,134 @@ the date or only the time, or to set the date to today."
   (interactive)
   (todos-edit-item-header 'timeonly))
 
+(defun todos-edit-item-diary-inclusion ()
+  "Change diary status of one or more todo items in this category.
+That is, insert `todos-nondiary-marker' if the candidate items
+lack this marking; otherwise, remove it.
+
+If there are marked todo items, change the diary status of all
+and only these, otherwise change the diary status of the item at
+point."
+  (interactive)
+  (let ((buffer-read-only)
+        (marked (assoc (todos-current-category)
+                       todos-categories-with-marks)))
+    (catch 'stop
+      (save-excursion
+        (when marked (goto-char (point-min)))
+        (while (not (eobp))
+          (if (todos-done-item-p)
+              (throw 'stop (message "Done items cannot be edited"))
+            (unless (and marked (not (todos-marked-item-p)))
+              (let* ((beg (todos-item-start))
+                     (lim (save-excursion (todos-item-end)))
+                     (end (save-excursion
+                            (or (todos-time-string-matcher lim)
+                                (todos-date-string-matcher lim)))))
+                (if (looking-at (regexp-quote todos-nondiary-start))
+                    (progn
+                      (replace-match "")
+                      (search-forward todos-nondiary-end (1+ end) t)
+                      (replace-match "")
+                      (todos-set-count 'diary 1))
+                  (when end
+                    (insert todos-nondiary-start)
+                    (goto-char (1+ end))
+                    (insert todos-nondiary-end)
+                    (todos-set-count 'diary -1)))))
+            (unless marked (throw 'stop nil))
+            (todos-forward-item)))))
+    (todos-update-categories-sexp)))
+
+(defun todos-edit-category-diary-inclusion (arg)
+  "Make all items in this category diary items.
+With prefix ARG, make all items in this category non-diary
+items."
+  (interactive "P")
+  (save-excursion
+    (goto-char (point-min))
+    (let ((todo-count (todos-get-count 'todo))
+          (diary-count (todos-get-count 'diary))
+          (buffer-read-only))
+      (catch 'stop
+        (while (not (eobp))
+          (if (todos-done-item-p)       ; We've gone too far.
+              (throw 'stop nil)
+            (let* ((beg (todos-item-start))
+                   (lim (save-excursion (todos-item-end)))
+                   (end (save-excursion
+                          (or (todos-time-string-matcher lim)
+                              (todos-date-string-matcher lim)))))
+              (if arg
+                  (unless (looking-at (regexp-quote todos-nondiary-start))
+                    (insert todos-nondiary-start)
+                    (goto-char (1+ end))
+                    (insert todos-nondiary-end))
+                (when (looking-at (regexp-quote todos-nondiary-start))
+                  (replace-match "")
+                  (search-forward todos-nondiary-end (1+ end) t)
+                  (replace-match "")))))
+          (todos-forward-item))
+        (unless (if arg (zerop diary-count) (= diary-count todo-count))
+          (todos-set-count 'diary (if arg
+                                      (- diary-count)
+                                    (- todo-count diary-count))))
+        (todos-update-categories-sexp)))))
+
+(defun todos-edit-item-diary-nonmarking ()
+  "Change non-marking of one or more diary items in this category.
+That is, insert `diary-nonmarking-symbol' if the candidate items
+lack this marking; otherwise, remove it.
+
+If there are marked todo items, change the non-marking status of
+all and only these, otherwise change the non-marking status of
+the item at point."
+  (interactive)
+  (let ((buffer-read-only)
+        (marked (assoc (todos-current-category)
+                       todos-categories-with-marks)))
+    (catch 'stop
+      (save-excursion
+        (when marked (goto-char (point-min)))
+        (while (not (eobp))
+          (if (todos-done-item-p)
+              (throw 'stop (message "Done items cannot be edited"))
+            (unless (and marked (not (todos-marked-item-p)))
+              (todos-item-start)
+              (unless (looking-at (regexp-quote todos-nondiary-start))
+                (if (looking-at (regexp-quote diary-nonmarking-symbol))
+                    (replace-match "")
+                  (insert diary-nonmarking-symbol))))
+            (unless marked (throw 'stop nil))
+            (todos-forward-item)))))))
+
+(defun todos-edit-category-diary-nonmarking (arg)
+  "Add `diary-nonmarking-symbol' to all diary items in this category.
+With prefix ARG, remove `diary-nonmarking-symbol' from all diary
+items in this category."
+  (interactive "P")
+  (save-excursion
+    (goto-char (point-min))
+    (let (buffer-read-only)
+      (catch 'stop
+      (while (not (eobp))
+        (if (todos-done-item-p)         ; We've gone too far.
+            (throw 'stop nil)
+          (unless (looking-at (regexp-quote todos-nondiary-start))
+            (if arg
+                (when (looking-at (regexp-quote diary-nonmarking-symbol))
+                  (replace-match ""))
+              (unless (looking-at (regexp-quote diary-nonmarking-symbol))
+                (insert diary-nonmarking-symbol))))
+        (todos-forward-item)))))))
+
 (defun todos-raise-item-priority (&optional lower)
   "Raise priority of current item by moving it up by one item.
 With non-nil argument LOWER lower item's priority."
   (interactive)
   (unless (or (todos-done-item-p)
-              (looking-at "^$"))        ; We're between todo and done items.
+              ;; Point is between todo and done items.
+              (looking-at "^$"))
     (let (buffer-read-only)
       (if (or (and lower
                    (save-excursion
@@ -2402,10 +4278,10 @@ With non-nil argument LOWER lower item's priority."
                      (todos-forward-item)
                      (and (looking-at todos-item-start)
                           (not (todos-done-item-p)))))
-              ;; Can't raise or lower only todo item.
+              ;; Can't raise or lower todo item when it's the only one.
               (> (count-lines (point-min) (point)) 0))
           (let ((item (todos-item-string))
-                (marked (todos-item-marked-p)))
+                (marked (todos-marked-item-p)))
             ;; In Todos Top Priorities mode, an item's priority can be changed
             ;; wrt items in another category, but not wrt items in the same
             ;; category.
@@ -2441,6 +4317,7 @@ With non-nil argument LOWER lower item's priority."
   (todos-raise-item-priority t))
 
 ;; FIXME: incorporate todos-(raise|lower)-item-priority ?
+;; FIXME: does this DTRT in todos-categories-mode?
 (defun todos-set-item-priority (item cat &optional new)
   "Set todo ITEM's priority in category CAT, moving item as needed.
 Interactively, the item and the category are the current ones,
@@ -2473,7 +4350,6 @@ priority is one more than the number of items in CAT."
       (unless (= priority 1) (todos-forward-item (1- priority))))
     (todos-insert-with-overlays item)))
 
-;; FIXME: apply to marked items?
 (defun todos-move-item (&optional file)
   "Move at least one todo item to another category.
 
@@ -2488,7 +4364,8 @@ then it is created and the item(s) become(s) the first
 entry/entries in that category."
   (interactive)
   (unless (or (todos-done-item-p)
-              (looking-at "^$"))        ; We're between todo and done items.
+              ;; Point is between todo and done items.
+              (looking-at "^$"))
     (let* ((buffer-read-only)
            (file1 todos-current-todos-file)
            (cat1 (todos-current-category))
@@ -2523,7 +4400,7 @@ entry/entries in that category."
            (setq item nil)
            (goto-char (point-min))
            (while (not (eobp))
-             (when (todos-item-marked-p)
+             (when (todos-marked-item-p)
                (setq item (concat item (todos-item-string) "\n"))
                (setq count (1+ count))
                (when (todos-diary-item-p)
@@ -2558,7 +4435,7 @@ entry/entries in that category."
                   (setq end (match-beginning 0))
                   (goto-char beg)
                   (while (< (point) end)
-                    (if (todos-item-marked-p)
+                    (if (todos-marked-item-p)
                         (todos-remove-item)
                       (todos-forward-item))))
               (todos-remove-item))))
@@ -2576,40 +4453,82 @@ entry/entries in that category."
   (interactive)
   (todos-move-item t))
 
-;; FIXME: apply to marked items?
+(defun todos-move-item-to-diary ()
+  "Move one or more items in current category to the diary file.
+
+If there are marked items, move all of these; otherwise, move
+the item at point."
+  (interactive)
+  ;; FIXME
+  )
+
+;; FIXME: make adding date customizable, and make this and time customization
+;; overridable via double prefix arg ??
 (defun todos-item-done (&optional arg)
-  "Tag this item as done and move it to category's done section.
-With prefix argument ARG prompt for a comment and append it to the
-done item."
+  "Tag at least one item in this category as done and hide it.
+
+With prefix argument ARG prompt for a comment and append it to
+the done item; this is only possible if there are no marked
+items.  If there are marked items, tag all of these with
+`todos-done-string' plus the current date and, if
+`todos-always-add-time-string' is non-nil, the current time;
+otherwise, just tag the item at point.  Items tagged as done are
+relocated to the category's (by default hidden) done section."
   (interactive "P")
-  (unless (or (todos-done-item-p)
-              (looking-at "^$"))
-    (let* ((buffer-read-only)
-           (item (todos-item-string))
-           (diary-item (todos-diary-item-p))
-           (date-string (calendar-date-string (calendar-current-date) t t))
-           (time-string (if todos-always-add-time-string ;FIXME: delete condition
-                            (concat " " (substring (current-time-string) 11 16))
-                          ""))
-           ;; FIXME: todos-nondiary-* ?
-           (done-item (concat "[" todos-done-string date-string time-string "] "
-                              item))
-           (comment (and arg (read-string "Enter a comment: "))))
-      (todos-remove-item)
-      (unless (zerop (length comment))
-        (setq done-item (concat done-item " [" todos-comment-string ": "
-                                comment "]")))
-      (save-excursion
-        (widen)
-        (re-search-forward (concat "^" (regexp-quote todos-category-done)) nil t)
-        (forward-char)
-        (todos-insert-with-overlays done-item))
-      (todos-set-count 'todo -1)
-      (todos-set-count 'done 1)
-      (and diary-item (todos-set-count 'diary -1))
-      (todos-update-categories-sexp)
-      (save-excursion (todos-category-select)))))
-
+  (let* ((cat (todos-current-category))
+         (marked (assoc cat todos-categories-with-marks)))
+    (unless (or (todos-done-item-p) 
+                (and (looking-at "^$") (not marked)))
+      (let* ((date-string (calendar-date-string (calendar-current-date) t t))
+             (time-string (if todos-always-add-time-string
+                              (concat " " (substring (current-time-string) 11 16))
+                            ""))
+             (done-prefix (concat "[" todos-done-string date-string time-string
+                                  "] "))
+             (comment (and arg (not marked) (read-string "Enter a comment: ")))
+             (item-count 0)
+             (diary-count 0)
+             item done-item
+             (buffer-read-only))
+        (and marked (goto-char (point-min)))
+        (catch 'done
+          (while (not (eobp))
+            (if (or (not marked) (and marked (todos-marked-item-p)))
+                (progn
+                  (setq item (todos-item-string))
+                  (setq done-item (cond (marked
+                                         (concat done-item done-prefix item "\n"))
+                                        (comment
+                                         (concat done-prefix item " ["
+                                                 todos-comment-string
+                                                 ": " comment "]"))
+                                        (t
+                                         (concat done-prefix item))))
+                  (setq item-count (1+ item-count))
+                  (when (todos-diary-item-p)
+                    (setq diary-count (1+ diary-count)))
+                  (todos-remove-item)
+                  (unless marked (throw 'done nil)))
+              (todos-forward-item))))
+        (when marked
+          ;; Chop off last newline of done item string.
+          (setq done-item (substring done-item 0 -1))
+          (remove-overlays (point-min) (point-max) 'before-string todos-item-mark)
+          (setq todos-categories-with-marks
+                (assq-delete-all cat todos-categories-with-marks)))
+        (save-excursion
+          (widen)
+          (re-search-forward
+           (concat "^" (regexp-quote todos-category-done)) nil t)
+          (forward-char)
+          (insert done-item "\n"))
+        (todos-set-count 'todo (- item-count))
+        (todos-set-count 'done item-count)
+        (todos-set-count 'diary (- diary-count))
+        (todos-update-categories-sexp)
+        (save-excursion (todos-category-select))))))
+
+;; FIXME: only if there's no comment, or edit an existing comment?
 (defun todos-comment-done-item ()
   "Add a comment to this done item."
   (interactive)
@@ -2668,7 +4587,7 @@ If the archive of this file does not exist, it is created.  If
 this category does not exist in the archive, it is created."
   (interactive)
   (when (not (member (buffer-file-name) (funcall todos-files-function t)))
-    (if (and all (zerop (todos-get-count 'done cat)))
+    (if (and all (zerop (todos-get-count 'done)))
         (message "No done items in this category")
       (catch 'end
         (let* ((cat (todos-current-category))
@@ -2697,7 +4616,7 @@ this category does not exist in the archive, it is created."
             (save-excursion
               (goto-char (point-min))
               (while (not (eobp))
-                (if (todos-item-marked-p)
+                (if (todos-marked-item-p)
                     (if (not (todos-done-item-p))
                         (throw 'end (message "Only done items can be archived"))
                       (concat marked-items (todos-item-string) "\n")
@@ -2751,7 +4670,7 @@ this category does not exist in the archive, it is created."
                      (and marked (goto-char (point-min)))
                      (catch 'done
                        (while (not (eobp))
-                         (if (or (and marked (todos-item-marked-p)) item)
+                         (if (or (and marked (todos-marked-item-p)) item)
                              (progn
                                (todos-remove-item)
                                (todos-set-count 'done -1)
@@ -2816,7 +4735,7 @@ archive, the archive file is deleted."
         (save-excursion
           (goto-char (point-min))
           (while (not (eobp))
-            (when (todos-item-marked-p)
+            (when (todos-marked-item-p)
               (concat marked-items (todos-item-string) "\n")
               (setq marked-count (1+ marked-count)))
             (todos-forward-item)))
@@ -2854,7 +4773,7 @@ archive, the archive file is deleted."
                (and marked (goto-char (point-min)))
                (catch 'done
                  (while (not (eobp))
-                   (if (or (and marked (todos-item-marked-p)) item)
+                   (if (or (and marked (todos-marked-item-p)) item)
                        (progn
                          (todos-remove-item)
                          (todos-set-count 'done -1)
@@ -2905,1191 +4824,11 @@ archive, the archive file is deleted."
   (interactive)
   (todos-unarchive-items t))
 
-(defun todos-toggle-diary-inclusion (&optional all)
-  "Toggle diary status of one or more todo items in this category.
-
-If a candidate item is marked with `todos-nondiary-marker',
-remove this marker; otherwise, insert it.
-
-With non-nil argument ALL toggle the diary status of all todo
-items in this category; otherwise, if there are marked todo
-items, toggle the diary status of all and only these, otherwise
-toggle the diary status of the item at point.  "
-  (interactive)
-  (let ((marked (assoc (todos-current-category)
-                       todos-categories-with-marks)))
-    (catch 'stop
-      (save-excursion
-        (save-restriction
-          (when (or marked all) (goto-char (point-min)))
-          (while (not (eobp))
-            (if (todos-done-item-p)
-                (throw 'stop (message "Done items cannot be changed"))
-              (unless (and marked (not (todos-item-marked-p)))
-                (save-excursion
-                  (let* ((buffer-read-only)
-                         (beg (todos-item-start))
-                         (lim (save-excursion (todos-item-end)))
-                         (end (save-excursion
-                               (or (todos-time-string-matcher lim)
-                                   (todos-date-string-matcher lim)))))
-                    (if (looking-at (regexp-quote todos-nondiary-start))
-                        (progn
-                          (replace-match "")
-                          (search-forward todos-nondiary-end (1+ end) t)
-                          (replace-match "")
-                          (todos-set-count 'diary 1))
-                      (when end
-                        (insert todos-nondiary-start)
-                        (goto-char (1+ end))
-                        (insert todos-nondiary-end)
-                        (todos-set-count 'diary -1))))))
-              (unless (or marked all) (throw 'stop nil))
-              (todos-forward-item))))))
-    (todos-update-categories-sexp)))
-
-(defun todos-toggle-item-diary-nonmarking ()
-  "Mark or unmark this todos diary item for calendar display.
-See `diary-nonmarking-symbol'."
-  (interactive)
-  (let ((buffer-read-only))
-    (save-excursion
-      (todos-item-start)
-      (unless (looking-at (regexp-quote todos-nondiary-start))
-        (if (looking-at (regexp-quote diary-nonmarking-symbol))
-            (replace-match "")
-          (insert diary-nonmarking-symbol))))))
-
-(defun todos-toggle-diary-nonmarking ()
-  "Mark or unmark this category's todos diary items for calendar.
-See `diary-nonmarking-symbol'."
-  (interactive)
-  (save-excursion
-    (goto-char (point-min))
-    (while (not (eobp))
-      (todos-toggle-item-diary-nonmarking)
-      (todos-forward-item))))
-
-(defun todos-print (&optional to-file)
-  "Produce a printable version of the current Todos buffer.
-This includes overlays, indentation, and, depending on the value
-of `todos-print-function', faces.  With non-nil argument TO-FILE
-write the printable version to a file; otherwise, send it to the
-default printer."
-  (interactive)
-  (let ((buf todos-tmp-buffer-name)     ;FIXME
-        (header (cond
-                 ((eq major-mode 'todos-mode)
-                  (concat "Todos File: "
-                          (file-name-sans-extension
-                           (file-name-nondirectory todos-current-todos-file))
-                          "\nCategory: " (todos-current-category)))
-                 ((eq major-mode 'todos-filter-items-mode)
-                  "Todos Top Priorities")))
-        (prefix (propertize (concat todos-prefix " ")
-                            'face 'todos-prefix-string))
-        (num 0)
-        (fill-prefix (make-string todos-indent-to-here 32))
-        (content (buffer-string))
-        file)
-    (with-current-buffer (get-buffer-create buf)
-      (insert content)
-      (goto-char (point-min))
-      (while (not (eobp))
-        (let ((beg (point))
-              (end (save-excursion (todos-item-end))))
-          (when todos-number-prefix
-            (setq num (1+ num))
-            (setq prefix (propertize (concat (number-to-string num) " ")
-                                     'face 'todos-prefix-string)))
-          (insert prefix)
-          (fill-region beg end))
-        ;; Calling todos-forward-item infloops at todos-item-start due to
-        ;; non-overlay prefix, so search for item start instead.
-        (if (re-search-forward todos-item-start nil t)
-            (beginning-of-line)
-          (goto-char (point-max))))
-      (if (re-search-backward (concat "^" (regexp-quote todos-category-done))
-                              nil t)
-          (replace-match todos-done-separator))
-      (goto-char (point-min))
-      (insert header)
-      (newline 2)
-      (if to-file
-          (let ((file (read-file-name "Print to file: ")))
-            (funcall todos-print-function file))
-        (funcall todos-print-function)))
-    (kill-buffer buf)))
-
-(defun todos-print-to-file ()
-  "Save printable version of this Todos buffer to a file."
-  (interactive)
-  (todos-print t))
-
-;; ---------------------------------------------------------------------------
-
-;;; Internals
-
-(defvar todos-date-pattern              ;FIXME: start with "^" ?
-  (let ((dayname (diary-name-pattern calendar-day-name-array nil t)))
-    (concat "\\(?:" dayname "\\|"
-            (let ((dayname)
-                  (monthname (format "\\(?:%s\\|\\*\\)"
-                                     (diary-name-pattern
-                                      calendar-month-name-array
-                                      calendar-month-abbrev-array t)))
-                  (month "\\(?:[0-9]+\\|\\*\\)")
-                  (day "\\(?:[0-9]+\\|\\*\\)")
-                  (year "-?\\(?:[0-9]+\\|\\*\\)"))
-              (mapconcat 'eval calendar-date-display-form ""))
-            "\\)"))
-  "Regular expression matching a Todos date header.")
-
-(defvar todos-date-string-start
-  ;; FIXME: with ? matches anything
-  (concat "^\\(" (regexp-quote todos-nondiary-start) "\\|"
-          (regexp-quote diary-nonmarking-symbol) "\\)?")
-  "Regular expression matching part of item header before the date.")
-
-(defvar todos-done-string-start
-  (concat "^\\[" (regexp-quote todos-done-string))
-  "Regular expression matching start of done item.")
-
-(defun todos-date-string-matcher (lim)
-  "Search for Todos date strings within LIM for font-locking."
-  (re-search-forward
-   (concat todos-date-string-start "\\(?1:" todos-date-pattern "\\)") lim t))
-
-(defun todos-time-string-matcher (lim)
-  "Search for Todos time strings within LIM for font-locking."
-  (re-search-forward (concat todos-date-string-start todos-date-pattern
-                             " \\(?1:" diary-time-regexp "\\)") lim t))
-
-(defun todos-done-string-matcher (lim)
-  "Search for Todos done headers within LIM for font-locking."
-  (re-search-forward (concat todos-done-string-start
-                      "[^][]+]")
-                     lim t))
-
-(defun todos-comment-string-matcher (lim)
-  "Search for Todos done comment within LIM for font-locking."
-  (re-search-forward (concat "\\[\\(?1:" todos-comment-string "\\):")
-                     lim t))
-
-(defun todos-category-string-matcher (lim)
-  "Search for Todos category headers within LIM for font-locking."
-  (if (eq major-mode 'todos-filter-items-mode)
-      (re-search-forward
-       ;; (concat "^\\(?1:" (regexp-quote todos-category-beg) ".*\\)$")
-       (concat "\\(?:^\\[?" todos-date-pattern "\\(?: " diary-time-regexp
-               "\\)?\\]?\\) \\(?1:\\[.+\\]\\)") lim t)))
-
-(defun todos-check-format ()
-  "Signal an error if the current Todos file is ill-formatted."
-  (save-excursion
-    (save-restriction
-      (widen)
-      (goto-char (point-min))
-      (let ((legit (concat "^\\(" (regexp-quote todos-category-beg) "\\)"
-                           "\\|\\(\\[?" todos-date-pattern "\\)"
-                           "\\|\\([ \t]+[^ \t]*\\)"
-                           "\\|$")))
-        (while (not (eobp))
-          (unless (looking-at legit)
-            (error "Illegitimate Todos file format at line %d"
-                   (line-number-at-pos (point))))
-          (forward-line)))))
-  (message "This Todos file is well-formatted."))
-
-(defun todos-after-find-file ()
-  "Show Todos files correctly when visited from outside of Todos mode."
-  (and (member this-command todos-visit-files-commands)
-       (= (- (point-max) (point-min)) (buffer-size))
-       (member major-mode '(todos-mode todos-archive-mode))
-       (todos-category-select)))
-
-(defun todos-wrap-and-indent ()
-  "Use word wrapping on long lines and indent with a wrap prefix.
-The amount of indentation is given by user option
-`todos-indent-to-here'."
-  (set (make-local-variable 'word-wrap) t)
-  (set (make-local-variable 'wrap-prefix) (make-string todos-indent-to-here 32))
-  (unless (member '(continuation) fringe-indicator-alist)
-    (push '(continuation) fringe-indicator-alist)))
-
-(defun todos-indent ()
-  "Indent from point to `todos-indent-to-here'."
-  (indent-to todos-indent-to-here todos-indent-to-here))
-
-(defun todos-prefix-overlays ()
-  "Put before-string overlay in front of this category's items.
-The overlay's value is the string `todos-prefix' or with non-nil
-`todos-number-prefix' an integer in the sequence from 1 to the
-number of todo or done items in the category indicating the
-item's priority.  Todo and done items are numbered independently
-of each other."
-  (when (or todos-number-prefix
-            (not (string-match "^[[:space:]]*$" todos-prefix)))
-    (let ((prefix (propertize (concat todos-prefix " ")
-                              'face 'todos-prefix-string))
-          (num 0))
-      (save-excursion
-        (goto-char (point-min))
-        (while (not (eobp))
-          (when (or (todos-date-string-matcher (line-end-position))
-                    (todos-done-string-matcher (line-end-position)))
-            (goto-char (match-beginning 0))
-            (when todos-number-prefix
-              (setq num (1+ num))
-              ;; Reset number for done items.
-              (when
-                  ;; FIXME: really need this?
-                  ;; If last not done item is multiline, then
-                  ;; todos-done-string-matcher skips empty line, so have
-                  ;; to look back.
-                  (and (looking-at todos-done-string-start)
-                       (looking-back (concat "^"
-                                             (regexp-quote todos-category-done)
-                                             "\n")))
-                (setq num 1))
-              (setq prefix (propertize (concat (number-to-string num) " ")
-                                       'face 'todos-prefix-string)))
-            (let ((ovs (overlays-in (point) (point)))
-                  marked ov-pref)
-              (if ovs
-                  (dolist (ov ovs)
-                    (let ((val (overlay-get ov 'before-string)))
-                      (if (equal val "*")
-                          (setq marked t)
-                        (setq ov-pref val)))))
-              (unless (equal ov-pref prefix)
-                (remove-overlays (point) (point)) ; 'before-string) doesn't work
-                (overlay-put (make-overlay (point) (point))
-                             'before-string prefix)
-                (and marked (overlay-put (make-overlay (point) (point))
-                                         'before-string todos-item-mark)))))
-          (forward-line))))))
-
-(defun todos-reset-prefix (symbol value)
-  "The :set function for `todos-prefix' and `todos-number-prefix'."
-  (let ((oldvalue (symbol-value symbol))
-        (files (append todos-files todos-archives)))
-    (custom-set-default symbol value)
-    (when (not (equal value oldvalue))
-      (dolist (f files)
-        (with-current-buffer (find-file-noselect f)
-          (save-window-excursion
-            (todos-show)
-            (save-excursion
-              (widen)
-              (goto-char (point-min))
-              (while (not (eobp))
-                (remove-overlays (point) (point)); 'before-string prefix)
-                (forward-line)))
-            ;; Activate the new setting (save-restriction does not help).
-            (save-excursion (todos-category-select))))))))
-
-(defun todos-reset-nondiary-marker (symbol value)
-  "The :set function for user option `todos-nondiary-marker'."
-  (let ((oldvalue (symbol-value symbol))
-        (files (append todos-files todos-archives)))
-    (custom-set-default symbol value)
-    ;; Need to reset these to get font-locking right.
-    (setq todos-nondiary-start (nth 0 todos-nondiary-marker)
-          todos-nondiary-end (nth 1 todos-nondiary-marker)
-          todos-date-string-start
-          ;; FIXME: with ? matches anything
-          (concat "^\\(" (regexp-quote todos-nondiary-start) "\\|"
-                  (regexp-quote diary-nonmarking-symbol) "\\)?"))
-    (when (not (equal value oldvalue))
-      (dolist (f files)
-        (with-current-buffer (find-file-noselect f)
-          (let (buffer-read-only)
-            (widen)
-            (goto-char (point-min))
-            (while (not (eobp))
-              (if (re-search-forward
-                   (concat "^\\(" todos-done-string-start "[^][]+] \\)?"
-                           "\\(?1:" (regexp-quote (car oldvalue))
-                           "\\)" todos-date-pattern "\\( "
-                           diary-time-regexp "\\)?\\(?2:"
-                           (regexp-quote (cadr oldvalue)) "\\)")
-                   nil t)
-                  (progn
-                    (replace-match (nth 0 value) t t nil 1)
-                    (replace-match (nth 1 value) t t nil 2))
-                (forward-line)))
-            (todos-category-select)))))))
-
-(defun todos-reset-done-string (symbol value)
-  "The :set function for user option `todos-done-string'."
-  (let ((oldvalue (symbol-value symbol))
-        (files (append todos-files todos-archives)))
-    (custom-set-default symbol value)
-    ;; Need to reset this to get font-locking right.
-    (setq todos-done-string-start
-          (concat "^\\[" (regexp-quote todos-done-string)))
-    (when (not (equal value oldvalue))
-      (dolist (f files)
-        (with-current-buffer (find-file-noselect f)
-          (let (buffer-read-only)
-            (widen)
-            (goto-char (point-min))
-            (while (not (eobp))
-              (if (re-search-forward
-                   (concat "^" (regexp-quote todos-nondiary-start)
-                           "\\(" (regexp-quote oldvalue) "\\)")
-                   nil t)
-                  (replace-match value t t nil 1)
-                (forward-line)))
-            (todos-category-select)))))))
-
-(defun todos-reset-comment-string (symbol value)
-  "The :set function for user option `todos-comment-string'."
-  (let ((oldvalue (symbol-value symbol))
-        (files (append todos-files todos-archives)))
-    (custom-set-default symbol value)
-    (when (not (equal value oldvalue))
-      (dolist (f files)
-        (with-current-buffer (find-file-noselect f)
-          (let (buffer-read-only)
-            (save-excursion
-              (widen)
-              (goto-char (point-min))
-              (while (not (eobp))
-                (if (re-search-forward
-                     (concat
-                             "\\[\\(" (regexp-quote oldvalue) "\\): [^]]*\\]")
-                     nil t)
-                    (replace-match value t t nil 1)
-                  (forward-line)))
-              (todos-category-select))))))))
-
-(defun todos-reset-categories (symbol value)
-  "The :set function for `todos-ignore-archived-categories'."
-  (custom-set-default symbol value)
-  (dolist (f (funcall todos-files-function))
-    (with-current-buffer (find-file-noselect f)
-      (if value
-          (setq todos-categories-full todos-categories
-                todos-categories (todos-truncate-categories-list))
-        (setq todos-categories todos-categories-full
-              todos-categories-full nil))
-      (todos-category-select))))
-
-(defun todos-toggle-show-current-file (symbol value)
-  "The :set function for user option `todos-show-current-file'."
-  (custom-set-default symbol value)
-  (if value
-      (add-hook 'pre-command-hook 'todos-show-current-file nil t)
-    (remove-hook 'pre-command-hook 'todos-show-current-file t)))
-
-(defun todos-show-current-file ()
-  "Visit current instead of default Todos file with `todos-show'.
-This function is added to `pre-command-hook' when user option
-`todos-show-current-file' is set to non-nil."
-  (setq todos-global-current-todos-file todos-current-todos-file))
-  ;; (and (eq major-mode 'todos-mode)
-       ;; (setq todos-global-current-todos-file (buffer-file-name))))
-
-;; FIXME: rename to todos-set-category-number ?
-(defun todos-category-number (cat)
-  "Set and return buffer-local value of `todos-category-number'.
-This value is one more than the index of category CAT, starting
-with one instead of zero, so that the highest priority
-category (see `todos-display-categories') has the number one."
-  (let ((categories (mapcar 'car todos-categories)))
-    (setq todos-category-number
-          (1+ (- (length categories)
-                 (length (member cat categories)))))))
-
-(defun todos-current-category ()
-  "Return the name of the current category."
-  (car (nth (1- todos-category-number) todos-categories)))
-
-(defun todos-category-select ()
-  "Display the current category correctly.
-
-With non-nil user option `todos-show-done-only' display only the
-category's done (but not archived) items; else (the default)
-display just the todo items, or with non-nil user option
-`todos-show-with-done' also display the category's done items
-below the todo items."
-  (let ((name (todos-current-category))
-        cat-begin cat-end done-start done-sep-start done-end)
-    (widen)
-    (goto-char (point-min))
-    (re-search-forward
-     (concat "^" (regexp-quote (concat todos-category-beg name)) "$") nil t)
-    (setq cat-begin (1+ (line-end-position)))
-    (setq cat-end (if (re-search-forward
-                       (concat "^" (regexp-quote todos-category-beg)) nil t)
-                      (match-beginning 0)
-                    (point-max)))
-    (setq mode-line-buffer-identification
-          (funcall todos-mode-line-function name))
-    (narrow-to-region cat-begin cat-end)
-    (todos-prefix-overlays)
-    (goto-char (point-min))
-    (if (re-search-forward (concat "\n\\(" (regexp-quote todos-category-done)
-                                   "\\)") nil t)
-        (progn
-          (setq done-start (match-beginning 0))
-          (setq done-sep-start (match-beginning 1))
-          (setq done-end (match-end 0)))
-      (error "Category %s is missing todos-category-done string" name))
-    (if todos-show-done-only
-        (narrow-to-region (1+ done-end) (point-max))
-      ;; Display or hide done items as per todos-show-with-done.
-      ;; FIXME: use todos-done-string-start ?
-      (when (re-search-forward (concat "\n\\(\\["
-                                       (regexp-quote todos-done-string)
-                                       "\\)") nil t)
-        (let (done-sep prefix ov-pref ov-done)
-          ;; FIXME: delete overlay when not viewing done items?
-          (when todos-show-with-done
-            (setq done-sep todos-done-separator)
-            (setq done-start cat-end)
-            (setq ov-pref (make-overlay done-sep-start done-end))
-            (overlay-put ov-pref 'display done-sep))))
-      (narrow-to-region (point-min) done-start))))
-
-(defun todos-insert-with-overlays (item)
-  "Insert ITEM and update prefix/priority number overlays."
-  (todos-item-start)
-  (insert item "\n")
-  (todos-backward-item)
-  (todos-prefix-overlays))
-
-(defvar todos-item-start ;; (concat "^\\(\\[\\(" (regexp-quote todos-done-string)
-                         ;;      "\\)?\\)?" todos-date-pattern)
-  (concat "\\(" todos-date-string-start "\\|" todos-done-string-start
-          "\\)" todos-date-pattern)
-  "String identifying start of a Todos item.")
-
-(defun todos-item-start ()
-  "Move to start of current Todos item and return its position."
-  (unless (or
-           ;; Point is either on last item in this category or on the empty
-           ;; line between done and not done items.
-           (looking-at "^$")
-           ;; There are no done items in this category yet.
-           (looking-at (regexp-quote todos-category-beg)))
-    (goto-char (line-beginning-position))
-    (while (not (looking-at todos-item-start))
-      (forward-line -1))
-    (point)))
-
-(defun todos-item-end ()
-  "Move to end of current Todos item and return its position."
-  ;; Items cannot end with a blank line.
-  (unless (looking-at "^$")
-    (let ((done (todos-done-item-p)))
-      (todos-forward-item)
-      ;; Adjust if item is last unfinished one before displayed done items.
-      (when (and (not done) (todos-done-item-p))
-        (forward-line -1))
-      (backward-char))
-    (point)))
-
-(defun todos-remove-item ()
-  "Internal function called in editing, deleting or moving items."
-  (let* ((beg (todos-item-start))
-         (end (progn (todos-item-end) (1+ (point))))
-         (ovs (overlays-in beg beg)))
-    ;; There can be both prefix/number and mark overlays.
-    (while ovs (delete-overlay (car ovs)) (pop ovs))
-    (delete-region beg end)))
-
-(defun todos-item-string ()
-  "Return bare text of current item as a string."
-  (let ((opoint (point))
-        (start (todos-item-start))
-        (end (todos-item-end)))
-    (goto-char opoint)
-    (and start end (buffer-substring-no-properties start end))))
-
-(defun todos-diary-item-p ()
-  "Return non-nil if item at point is marked for diary inclusion."
-  (save-excursion
-    (todos-item-start)
-    (looking-at todos-date-pattern)))
-
-(defun todos-done-item-p ()
-  "Return non-nil if item at point is a done item."
-  (save-excursion
-    (todos-item-start)
-    (looking-at todos-done-string-start)))
-
-(defvar todos-item-mark (propertize (if (equal todos-prefix "*") "@" "*")
-                                    'face 'todos-mark)
-  "String used to mark items.")
-
-(defun todos-item-marked-p ()
-  "If this item is marked, return mark overlay."
-  (let ((ovs (overlays-in (line-beginning-position) (line-beginning-position)))
-        (mark todos-item-mark)
-        ov marked)
-    (catch 'stop
-      (while ovs
-        (setq ov (pop ovs))
-        (and (equal (overlay-get ov 'before-string) mark)
-             (throw 'stop (setq marked t)))))
-    (when marked ov)))
-
-(defvar todos-categories-with-marks nil
-  "Alist of categories and number of marked items they contain.")
-
-(defun todos-get-count (type &optional category)
-  "Return count of TYPE items in CATEGORY.
-If CATEGORY is nil, default to the current category."
-  (let* ((cat (or category (todos-current-category)))
-         (counts (cdr (assoc cat todos-categories)))
-         (idx (cond ((eq type 'todo) 0)
-                    ((eq type 'diary) 1)
-                    ((eq type 'done) 2)
-                    ((eq type 'archived) 3))))
-    (aref counts idx)))
-
-(defun todos-set-count (type increment &optional category)
-  "Increment count of TYPE items in CATEGORY by INCREMENT.
-If CATEGORY is nil, default to the current category."
-  (let* ((cat (or category (todos-current-category)))
-         (counts (cdr (assoc cat todos-categories)))
-         (idx (cond ((eq type 'todo) 0)
-                    ((eq type 'diary) 1)
-                    ((eq type 'done) 2)
-                    ((eq type 'archived) 3))))
-    (aset counts idx (+ increment (aref counts idx)))))
-
-;; (defun todos-item-counts (operation &optional cat1 cat2)
-;;   "Update item counts in category CAT1 changed by OPERATION.
-;; If CAT1 is nil, update counts from the current category.  With
-;; non-nil CAT2 include specified counts from that category in the
-;; calculation for CAT1.
-;; After updating the item counts, update the `todos-categories' sexp."
-;;   (let* ((cat (or cat1 (todos-current-category))))
-;;     (cond ((eq type 'insert)
-;;         (todos-set-count 'todo 1 cat))
-;;        ((eq type 'diary)
-;;         (todos-set-count 'diary 1 cat))
-;;        ((eq type 'nondiary)
-;;         (todos-set-count 'diary -1 cat))
-;;        ((eq type 'delete)
-;;         ;; FIXME: ok if last done item was deleted?
-;;         (if (save-excursion
-;;               (re-search-backward (concat "^" (regexp-quote
-;;                                                todos-category-done)) nil t))
-;;             (todos-set-count 'done -1 cat)
-;;           (todos-set-count 'todo -1 cat)))
-;;        ((eq type 'done)
-;;         (unless (member (buffer-file-name) (funcall todos-files-function t))
-;;           (todos-set-count 'todo -1 cat))
-;;         (todos-set-count 'done 1 cat))
-;;        ((eq type 'undo)
-;;         (todos-set-count 'todo 1 cat)
-;;         (todos-set-count 'done -1 cat))
-;;        ((eq type 'archive1)
-;;         (todos-set-count 'archived 1 cat)
-;;         (todos-set-count 'done -1 cat))
-;;        ((eq type 'archive)
-;;         (if (member (buffer-file-name) (funcall todos-files-function t))
-;;             ;; In Archive file augment done count with cat's previous
-;;             ;; done count,
-;;             (todos-set-count 'done (todos-get-count 'done cat) cat)
-;;           ;; In Todos file augment archive count with cat's previous
-;;           ;; done count, and make the latter zero.
-;;           (todos-set-count 'archived (todos-get-count 'done cat) cat)
-;;           (todos-set-count 'done (- (todos-get-count 'done cat)) cat)))
-;;        ((eq type 'merge)
-;;         ;; Augment todo and done counts of cat by those of cat2.
-;;         (todos-set-count 'todo (todos-get-count 'todo cat2) cat)
-;;         (todos-set-count 'done (todos-get-count 'done cat2) cat)))
-;;     (todos-update-categories-sexp)))
-
-(defun todos-set-categories ()
-  "Set `todos-categories' from the sexp at the top of the file."
-  ;; New archive files created by `todos-move-category' are empty, which would
-  ;; make the sexp test fail and raise an error, so in this case we skip it.
-  (unless (zerop (buffer-size))
-    (save-excursion
-      (save-restriction
-        (widen)
-        (goto-char (point-min))
-        ;; todos-truncate-categories-list needs non-nil todos-categories.
-        (setq todos-categories-full
-              (if (looking-at "\(\(\"")
-                  (read (buffer-substring-no-properties
-                         (line-beginning-position)
-                         (line-end-position)))
-                (error "Invalid or missing todos-categories sexp"))
-              todos-categories todos-categories-full)))
-    (if (and todos-ignore-archived-categories
-             (eq major-mode 'todos-mode))
-        (todos-truncate-categories-list)
-      todos-categories-full)))
-
-;; FIXME: currently unused -- make this a command to rebuild a corrupted
-;; todos-cats sexp ?
-(defun todos-make-categories-list (&optional force)
-  "Return an alist of Todos categories and their item counts.
-With non-nil argument FORCE parse the entire file to build the
-list; otherwise, get the value by reading the sexp at the top of
-the file."
-  (setq todos-categories nil)
-  (save-excursion
-    (save-restriction
-      (widen)
-      (goto-char (point-min))
-      (let (counts cat archive)
-        ;; FIXME: can todos-archives be too old here?
-        (unless (member buffer-file-name (funcall todos-files-function t))
-          (setq archive (concat (file-name-sans-extension
-                                 todos-current-todos-file) ".toda")))
-        (while (not (eobp))
-          (cond ((looking-at (concat (regexp-quote todos-category-beg)
-                                     "\\(.*\\)\n"))
-                 (setq cat (match-string-no-properties 1))
-                 ;; Counts for each category: [todo diary done archive]
-                 (setq counts (make-vector 4 0))
-                 (setq todos-categories
-                       (append todos-categories (list (cons cat counts))))
-                 ;; todos-archives may be too old here (e.g. during
-                 ;; todos-move-category).
-                 (when (member archive (funcall todos-files-function t))
-                   (with-current-buffer (find-file-noselect archive)
-                     (widen)
-                     (goto-char (point-min))
-                     (when (re-search-forward
-                            (concat (regexp-quote todos-category-beg) cat)
-                            (point-max) t)
-                       (forward-line)
-                       (while (not (or (looking-at
-                                        (concat
-                                         (regexp-quote todos-category-beg)
-                                         "\\(.*\\)\n"))
-                                       (eobp)))
-                         (when (looking-at todos-done-string-start)
-                           (todos-set-count 'archived 1 cat))
-                         (forward-line))))))
-                ((looking-at todos-done-string-start)
-                 (todos-set-count 'done 1 cat))
-                ((looking-at (concat "^\\("
-                                     (regexp-quote diary-nonmarking-symbol)
-                                     "\\)?" todos-date-pattern))
-                 (todos-set-count 'diary 1 cat)
-                 (todos-set-count 'todo 1 cat))
-                ((looking-at (concat todos-date-string-start todos-date-pattern))
-                 (todos-set-count 'todo 1 cat))
-                ;; If first line is todos-categories list, use it and end loop
-                ;; unless forced by non-nil parameter `force' to scan whole file.
-                ((bobp)
-                 (unless force
-                   (setq todos-categories (read (buffer-substring-no-properties
-                                                 (line-beginning-position)
-                                                 (line-end-position))))
-                   (goto-char (1- (point-max))))))
-          (forward-line)))))
-  todos-categories)
-
-(defun todos-truncate-categories-list ()
-  "Return a truncated alist of Todos categories plus item counts.
-Categories containing only archived items are omitted.  This list
-is used in Todos mode when `todos-ignore-archived-categories' is
-non-nil."
-  (let (cats)
-    (dolist (catcons todos-categories-full cats)
-      (let ((cat (car catcons)))
-        (setq cats
-              (append cats
-                      (unless (and (zerop (todos-get-count 'todo cat))
-                                   (zerop (todos-get-count 'done cat))
-                                   (not (zerop (todos-get-count 'archived cat))))
-                        (list catcons))))))))
-
-(defun todos-update-categories-sexp ()
-  "Update the `todos-categories' sexp at the top of the file."
-  (let (buffer-read-only)
-    (save-excursion
-      (save-restriction
-        (widen)
-        (goto-char (point-min))
-        (if (looking-at (concat "^" (regexp-quote todos-category-beg)))
-            (progn (newline) (goto-char (point-min)))
-          ;; With empty buffer (e.g. with new archive in
-          ;; `todos-move-category') `kill-line' signals end of buffer.
-          (kill-region (line-beginning-position) (line-end-position)))
-        ;; FIXME
-        ;; (prin1 todos-categories (current-buffer))))))
-        (prin1 todos-categories-full (current-buffer))))))
-
-(defun todos-read-file-name (prompt &optional archive mustmatch)
-  "Choose and return the name of a Todos file, prompting with PROMPT.
-Show completions with TAB or SPC; the names are shown in short
-form but the absolute truename is returned.  With non-nil ARCHIVE
-return the absolute truename of a Todos archive file.  With non-nil
-MUSTMATCH the name of an existing file must be chosen;
-otherwise, a new file name is allowed." ;FIXME: is this possible?
-  (unless (file-exists-p todos-files-directory)
-    (make-directory todos-files-directory))
-  (let* ((completion-ignore-case t)
-         (files (mapcar 'file-name-sans-extension
-                        (directory-files todos-files-directory nil
-                                         (if archive "\.toda$" "\.todo$"))))
-         (file (concat todos-files-directory
-                       (completing-read prompt files nil mustmatch)
-                       (if archive ".toda" ".todo"))))
-    (file-truename file)))
-
-(defun todos-read-category (prompt &optional mustmatch)
-  "Choose and return a category name, prompting with PROMPT.
-Show completions with TAB or SPC.  With non-nil MUSTMATCH the
-name must be that of an existing category; otherwise, a new
-category name is allowed, after checking its validity."
-  ;; Allow SPC to insert spaces, for adding new category names.
-  (let ((map minibuffer-local-completion-map))
-    (define-key map " " nil)
-    ;; Make a copy of todos-categories in case history-delete-duplicates is
-    ;; non-nil, which makes completing-read alter todos-categories.
-    (let* ((categories (copy-sequence todos-categories))
-           (history (cons 'todos-categories (1+ todos-category-number)))
-           (completion-ignore-case todos-completion-ignore-case)
-           (category (completing-read prompt todos-categories nil
-                                      mustmatch nil history
-                                      (if todos-categories
-                                          (todos-current-category)
-                                        ;; Trigger prompt for initial category
-                                        ""))))
-      ;; FIXME: let "" return todos-current-category
-      (unless mustmatch
-        (when (and (not (assoc category categories))
-                   (y-or-n-p (format (concat "There is no category \"%s\" in "
-                                             "this file; add it? ") category)))
-          (todos-validate-category-name category)
-          (todos-add-category category)))
-      ;; Restore the original value of todos-categories.
-      (setq todos-categories categories)
-      category)))
-
-(defun todos-validate-category-name (cat)
-  "Check new category name CAT and when valid return it."
-  (let (prompt)
-    (while
-        (and (cond ((string= "" cat)
-                    ;; (if todos-categories
-                    ;;  (setq prompt "Enter a non-empty category name: ")
-                      ;; Prompt for initial category of a new Todos file.
-                      (setq prompt (concat "Initial category name ["
-                                           todos-initial-category "]: ")));)
-                   ((string-match "\\`\\s-+\\'" cat)
-                    (setq prompt
-                          "Enter a category name that is not only white space: "))
-                   ;; FIXME: add completion
-                   ((assoc cat todos-categories)
-                    (setq prompt "Enter a non-existing category name: ")))
-             (setq cat (if todos-categories
-                           (read-from-minibuffer prompt)
-                         ;; Offer default initial category name.
-                         (prin1-to-string
-                          (read-from-minibuffer prompt nil nil t nil
-                                                (list todos-initial-category))))))))
-  cat)
-
-;; (defun todos-read-category (prompt)
-;;   "Prompt with PROMPT for an existing category name and return it.
-;; Show completions with TAB or SPC."
-;;   ;; Make a copy of todos-categories in case history-delete-duplicates is
-;;   ;; non-nil, which makes completing-read alter todos-categories.
-;;   (let* ((categories (copy-sequence todos-categories))
-;;       (history (cons 'todos-categories (1+ todos-category-number)))
-;;       (completion-ignore-case todos-completion-ignore-case)
-;;       (category (completing-read prompt todos-categories nil
-;;                                  mustmatch nil history)))
-;;     (setq category (completing-read prompt todos-categories nil t))
-;;     ;; Restore the original value of todos-categories.
-;;     (setq todos-categories categories)
-;;     category))
-
-;; (defun todos-new-category-name (prompt)
-;;   "Prompt with PROMPT for a new category name and return it."
-;;   (let ((map minibuffer-local-completion-map)
-;;      prompt-n)
-;;     ;; Allow SPC to insert spaces, for adding new category names.
-;;     (define-key map " " nil)
-;;     (while
-;;      ;; Validate entered category name.
-;;      (and (cond ((string= "" cat)
-;;                  (setq prompt-n
-;;                        (if todos-categories
-;;                            "Enter a non-empty category name: "
-;;                          ;; Prompt for initial category of a new Todos file.
-;;                          (concat "Initial category name ["
-;;                                  todos-initial-category "]: "))))
-;;                 ((string-match "\\`\\s-+\\'" cat)
-;;                  (setq prompt-n
-;;                        "Enter a category name that is not only white space: "))
-;;                 ((assoc cat todos-categories)
-;;                  (setq prompt-n "Enter a non-existing category name: ")))
-;;           (setq cat (if todos-categories
-;;                         (read-from-minibuffer prompt)
-;;                       ;; Offer default initial category name.
-;;                       (prin1-to-string
-;;                        (read-from-minibuffer
-;;                         (or prompt prompt-n) nil nil t nil
-;;                         (list todos-initial-category))))))
-;;       (setq prompt nil)))
-;;   cat)
-
-;; ;; Adapted from calendar-read-date and calendar-date-string.
-(defun todos-read-date ()
-  "Prompt for Gregorian date and return it in the current format.
-Also accepts `*' as an unspecified month, day, or year."
-  (let* ((year (calendar-read
-                ;; FIXME: maybe better like monthname with RET for current month
-                "Year (>0 or * for any year): "
-                (lambda (x) (or (eq x '*) (> x 0)))
-                (number-to-string (calendar-extract-year
-                                   (calendar-current-date)))))
-         (month-array (vconcat calendar-month-name-array (vector "*")))
-         (abbrevs (vconcat calendar-month-abbrev-array (vector "*")))
-         (completion-ignore-case t)
-         (monthname (completing-read
-                     "Month name (RET for current month, * for any month): "
-                     (mapcar 'list (append month-array nil))
-                     nil t nil nil
-                     (calendar-month-name (calendar-extract-month
-                                           (calendar-current-date)) t)))
-         (month (cdr (assoc-string
-                      monthname (calendar-make-alist month-array nil nil
-                                                     abbrevs))))
-         (last (if (= month 13)
-                   31                   ; FIXME: what about shorter months?
-                 (let ((yr (if (eq year '*)
-                               1999     ; FIXME: no Feb. 29
-                             year)))
-                   (calendar-last-day-of-month month yr))))
-         day dayname)
-    (while (if (numberp day) (or (< day 0) (< last day)) (not (eq day '*)))
-      (setq day (read-from-minibuffer
-                 (format "Day (1-%d or RET for today or * for any day): " last)
-                 nil nil t nil
-                 (number-to-string
-                  (calendar-extract-day (calendar-current-date))))))
-    (setq year (if (eq year '*) (symbol-name '*) (number-to-string year)))
-    (setq day (if (eq day '*) (symbol-name '*) (number-to-string day)))
-    ;; FIXME: make abbreviation customizable
-    (setq monthname
-          (or (and (= month 13) "*")
-              (calendar-month-name (calendar-extract-month (list month day year))
-                                   t)))
-    (mapconcat 'eval calendar-date-display-form "")))
-
-(defun todos-read-dayname ()
-  "Choose name of a day of the week with completion and return it."
-  (let ((completion-ignore-case t))
-    (completing-read "Enter a day name: "
-                     (append calendar-day-name-array nil)
-                     nil t)))
-  
-(defun todos-read-time ()
-  "Prompt for and return a valid clock time as a string.
-Valid time strings are those matching `diary-time-regexp'."
-  (let (valid answer)
-    (while (not valid)
-      (setq answer (read-from-minibuffer
-                    "Enter a clock time (or return for none): "))
-      (when (or (string= "" answer)
-                (string-match diary-time-regexp answer))
-        (setq valid t)))
-    answer))
-
-;;; Sorting and display routines for todos-categories-mode.
-
-(defun todos-display-categories (&optional sortkey)
-  "Display a table of the current file's categories and item counts.
-
-In the initial display the categories are numbered, indicating
-their current order for navigating by \\[todos-forward-category]
-and \\[todos-backward-category].  You can persistantly change the
-order of the category at point by typing \\[todos-raise-category]
-or \\[todos-lower-category].
-
-The labels above the category names and item counts are buttons,
-and clicking these changes the display: sorted by category name
-or by the respective item counts (alternately descending or
-ascending).  In these displays the categories are not numbered
-and \\[todos-raise-category] and \\[todos-lower-category] are
-disabled.  (Programmatically, the sorting is triggered by passing
-a non-nil SORTKEY argument.)
-
-In addition, the lines with the category names and item counts
-are buttonized, and pressing one of these button jumps to the
-category in Todos mode (or Todos Archive mode, for categories
-containing only archived items, provided user option
-`todos-ignore-archived-categories' is non-nil.  These categories
-are shown in `todos-archived-only' face."
-  (interactive)
-  (unless (eq major-mode 'todos-categories-mode)
-    (setq todos-global-current-todos-file (or todos-current-todos-file
-                                              todos-default-todos-file)))
-  (let* ((cats0 (if (and todos-ignore-archived-categories
-                         (not (eq major-mode 'todos-categories-mode)))
-                    todos-categories-full
-                  todos-categories))
-         (cats (todos-sort cats0 sortkey))
-         (archive (member todos-current-todos-file todos-archives))
-         ;; `num' is used by todos-insert-category-line.
-         (num 0))
-    (set-window-buffer (selected-window)
-                       (set-buffer (get-buffer-create todos-categories-buffer)))
-    (let (buffer-read-only)
-      (erase-buffer)
-      (kill-all-local-variables)
-      (todos-categories-mode)
-      ;; FIXME: add usage tips?
-      (insert (format "Category counts for Todos file \"%s\"."
-                      (file-name-sans-extension
-                       (file-name-nondirectory todos-current-todos-file))))
-      (newline 2)
-      ;; Make space for the column of category numbers.
-      (insert (make-string (+ 4 (length todos-categories-number-separator)) 32))
-      ;; Add the category and item count buttons (if this is the list of
-      ;; categories in an archive, show only done item counts).
-      (save-excursion
-        (todos-insert-sort-button todos-categories-category-label)
-        (if (member todos-current-todos-file todos-archives)
-            (insert (concat (make-string 6 32)
-                            (format "%s" todos-categories-archived-label)))
-          (insert (make-string 3 32))
-          (todos-insert-sort-button todos-categories-todo-label)
-          (insert (make-string 2 32))
-          (todos-insert-sort-button todos-categories-diary-label)
-          (insert (make-string 2 32))
-          (todos-insert-sort-button todos-categories-done-label)
-          (insert (make-string 2 32))
-          (todos-insert-sort-button todos-categories-archived-label))
-        (newline 2)
-        ;; Fill in the table with buttonized lines, each showing a category and
-        ;; its item counts.
-        (mapc (lambda (cat) (todos-insert-category-line cat sortkey))
-              (mapcar 'car cats))
-        (newline)
-        ;; Add a line showing item count totals.
-        (insert (make-string (+ 4 (length todos-categories-number-separator)) 32)
-                (todos-padded-string todos-categories-totals-label)
-                (mapconcat
-                 (lambda (elt)
-                   (concat
-                    (make-string (1+ (/ (length (car elt)) 2)) 32)
-                    (format "%3d" (nth (cdr elt) (todos-total-item-counts)))
-                    ;; Add an extra space if label length is odd (using
-                    ;; definition of oddp from cl.el).
-                    (if (eq (logand (length (car elt)) 1) 1) " ")))
-                 (if archive
-                     (list (cons todos-categories-done-label 2))
-                   (list (cons todos-categories-todo-label 0)
-                         (cons todos-categories-diary-label 1)
-                         (cons todos-categories-done-label 2)
-                         (cons todos-categories-archived-label 3)))
-                 ""))))
-    (setq buffer-read-only t)))
-
-;; ;; FIXME: make this toggle with todos-display-categories
-;; (defun todos-display-categories-alphabetically ()
-;;   ""
-;;   (interactive)
-;;   (todos-display-sorted 'alpha))
-
-;; ;; FIXME: provide key bindings for these or delete them
-;; (defun todos-display-categories-sorted-by-todo ()
-;;   ""
-;;   (interactive)
-;;   (todos-display-sorted 'todo))
-
-;; (defun todos-display-categories-sorted-by-diary ()
-;;   ""
-;;   (interactive)
-;;   (todos-display-sorted 'diary))
-
-;; (defun todos-display-categories-sorted-by-done ()
-;;   ""
-;;   (interactive)
-;;   (todos-display-sorted 'done))
-
-;; (defun todos-display-categories-sorted-by-archived ()
-;;   ""
-;;   (interactive)
-;;   (todos-display-sorted 'archived))
-
-(defun todos-longest-category-name-length (categories)
-  "Return the length of the longest name in list CATEGORIES."
-  (let ((longest 0))
-    (dolist (c categories longest)
-      (setq longest (max longest (length c))))))
-
-(defun todos-padded-string (str)
-  "Return string STR padded with spaces.
-The placement of the padding is determined by the value of user
-option `todos-categories-align'."
-  (let* ((categories (mapcar 'car todos-categories))
-         (len (max (todos-longest-category-name-length categories)
-                   (length todos-categories-category-label)))
-         (strlen (length str))
-         (strlen-odd (eq (logand strlen 1) 1)) ; oddp from cl.el
-         (padding (max 0 (/ (- len strlen) 2)))
-         (padding-left (cond ((eq todos-categories-align 'left) 0)
-                             ((eq todos-categories-align 'center) padding)
-                             ((eq todos-categories-align 'right)
-                              (if strlen-odd (1+ (* padding 2)) (* padding 2)))))
-         (padding-right (cond ((eq todos-categories-align 'left)
-                               (if strlen-odd (1+ (* padding 2)) (* padding 2)))
-                              ((eq todos-categories-align 'center)
-                               (if strlen-odd (1+ padding) padding))
-                              ((eq todos-categories-align 'right) 0))))
-    (concat (make-string padding-left 32) str (make-string padding-right 32))))
-
-(defvar todos-descending-counts nil
-  "List of keys for category counts sorted in descending order.")
-
-(defun todos-sort (list &optional key)
-  "Return a copy of LIST, possibly sorted according to KEY."
-  (let* ((l (copy-sequence list))
-         (fn (if (eq key 'alpha)
-                   (lambda (x) (upcase x)) ; Alphabetize case insensitively.
-                 (lambda (x) (todos-get-count key x))))
-         (descending (member key todos-descending-counts))
-         (cmp (if (eq key 'alpha)
-                  'string<
-                (if descending '< '>)))
-         (pred (lambda (s1 s2) (let ((t1 (funcall fn (car s1)))
-                                     (t2 (funcall fn (car s2))))
-                                 (funcall cmp t1 t2)))))
-    (when key
-      (setq l (sort l pred))
-      (if descending
-          (setq todos-descending-counts
-                (delete key todos-descending-counts))
-        (push key todos-descending-counts)))
-    l))
-
-(defun todos-display-sorted (type)
-  "Keep point on the TYPE count sorting button just clicked."
-  (let ((opoint (point)))
-    (todos-display-categories type)
-    (goto-char opoint)))
-
-(defun todos-label-to-key (label)
-  "Return symbol for sort key associated with LABEL."
-  (let (key)
-    (cond ((string= label todos-categories-category-label)
-           (setq key 'alpha))
-          ((string= label todos-categories-todo-label)
-           (setq key 'todo))
-          ((string= label todos-categories-diary-label)
-           (setq key 'diary))
-          ((string= label todos-categories-done-label)
-           (setq key 'done))
-          ((string= label todos-categories-archived-label)
-           (setq key 'archived)))
-    key))
-
-(defun todos-insert-sort-button (label)
-  "Insert button for displaying categories sorted by item counts.
-LABEL determines which type of count is sorted."
-  (setq str (if (string= label todos-categories-category-label)
-                (todos-padded-string label)
-              label))
-  (setq beg (point))
-  (setq end (+ beg (length str)))
-  (insert-button str 'face nil
-                 'action
-                 `(lambda (button)
-                    (let ((key (todos-label-to-key ,label)))
-                      (if (and (member key todos-descending-counts)
-                               (eq key 'alpha))
-                          (progn
-                            (todos-display-categories)
-                            (setq todos-descending-counts
-                                  (delete key todos-descending-counts)))
-                        (todos-display-sorted key)))))
-  (setq ovl (make-overlay beg end))
-  (overlay-put ovl 'face 'todos-button))
-
-(defun todos-total-item-counts ()
-  "Return a list of total item counts for the current file."
-  (mapcar (lambda (i) (apply '+ (mapcar (lambda (l) (aref l i))
-                                        (mapcar 'cdr todos-categories))))
-          (list 0 1 2 3)))
-
-(defun todos-insert-category-line (cat &optional nonum)
-  "Insert button displaying category CAT's name and item counts.
-With non-nil argument NONUM show only these; otherwise, insert a
-number in front of the button indicating the category's priority.
-The number and the category name are separated by the string
-which is the value of the user option
-`todos-categories-number-separator'."
-  (let* ((archive (member todos-current-todos-file todos-archives))
-        (str (todos-padded-string cat))
-        (opoint (point)))
-    ;; num is declared in caller.
-    (setq num (1+ num))
-    (insert-button
-     (concat (if nonum
-                 (make-string (+ 4 (length todos-categories-number-separator))
-                              32)
-               (format " %3d%s" num todos-categories-number-separator))
-             str
-             (mapconcat (lambda (elt)
-                          (concat
-                           (make-string (1+ (/ (length (car elt)) 2)) 32) ; label
-                           (format "%3d" (todos-get-count (cdr elt) cat)) ; count
-                           ;; Add an extra space if label length is odd
-                           ;; (using def of oddp from cl.el).
-                           (if (eq (logand (length (car elt)) 1) 1) " ")))
-                        (if archive
-                            (list (cons todos-categories-done-label 'done))
-                          (list (cons todos-categories-todo-label 'todo)
-                                (cons todos-categories-diary-label 'diary)
-                                (cons todos-categories-done-label 'done)
-                                (cons todos-categories-archived-label
-                                      'archived)))
-                          ""))
-     'face (if (and todos-ignore-archived-categories
-                    (zerop (todos-get-count 'todo cat))
-                    (zerop (todos-get-count 'done cat))
-                    (not (zerop (todos-get-count 'archived cat))))
-               'todos-archived-only
-             nil)
-     'action `(lambda (button) (let ((buf (current-buffer)))
-                                 (todos-jump-to-category ,cat)
-                                 (kill-buffer buf))))
-    ;; Highlight the sorted count column.
-    (let* ((beg (+ opoint 6 (length str)))
-           end ovl)
-      (cond ((eq nonum 'todo)
-             (setq beg (+ beg 1 (/ (length todos-categories-todo-label) 2))))
-            ((eq nonum 'diary)
-             (setq beg (+ beg 1 (length todos-categories-todo-label)
-                           2 (/ (length todos-categories-diary-label) 2))))
-            ((eq nonum 'done)
-             (setq beg (+ beg 1 (length todos-categories-todo-label)
-                           2 (length todos-categories-diary-label)
-                           2 (/ (length todos-categories-done-label) 2))))
-            ((eq nonum 'archived)
-             (setq beg (+ beg 1 (length todos-categories-todo-label)
-                           2 (length todos-categories-diary-label)
-                           2 (length todos-categories-done-label)
-                           2 (/ (length todos-categories-archived-label) 2)))))
-      (unless (= beg (+ opoint 6 (length str)))
-        (setq end (+ beg 4))
-        (setq ovl (make-overlay beg end))
-        (overlay-put ovl 'face 'todos-sorted-column)))
-    (newline)))
-
 (provide 'todos)
 
 ;;; todos.el ends here
 
+;; ---------------------------------------------------------------------------
 ;;; necessitated adaptations to diary-lib.el
 
 ;; (defun diary-goto-entry (button)