lisp/tutorial.el

   1 ;;; tutorial.el --- tutorial for Emacs
   2
   3 ;; Copyright (C) 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: help, internal
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; Code for running the Emacs tutorial.
  26
  27 ;;; History:
  28
  29 ;; File was created 2006-09.
  30
  31 ;;; Code:
  32
  33 (require 'help-mode) ;; for function help-buffer
  34
  35 (defface tutorial-warning-face
  36   '((t :inherit font-lock-warning-face))
  37   "Face used to highlight warnings in the tutorial."
  38   :group 'help)
  39
  40 (defvar tutorial--point-before-chkeys 0
  41   "Point before display of key changes.")
  42 (make-variable-buffer-local 'tutorial--point-before-chkeys)
  43
  44 (defvar tutorial--point-after-chkeys 0
  45   "Point after display of key changes.")
  46 (make-variable-buffer-local 'tutorial--point-after-chkeys)
  47
  48 (defvar tutorial--lang nil
  49   "Tutorial language.")
  50 (make-variable-buffer-local 'tutorial--lang)
  51
  52 (defun tutorial--describe-nonstandard-key (value)
  53   "Give more information about a changed key binding.
  54 This is used in `help-with-tutorial'.  The information includes
  55 the key sequence that no longer has a default binding, the
  56 default binding and the current binding.  It also tells in what
  57 keymap the new binding has been done and how to access the
  58 function in the default binding from the keyboard.
  59
  60 For `cua-mode' key bindings that try to combine CUA key bindings
  61 with default Emacs bindings information about this is shown.
  62
  63 VALUE should have either of these formats:
  64
  65   \(cua-mode)
  66   \(current-binding KEY-FUN DEF-FUN KEY WHERE)
  67
  68 Where
  69   KEY         is a key sequence whose standard binding has been changed
  70   KEY-FUN     is the actual binding for KEY
  71   DEF-FUN     is the standard binding of KEY
  72   WHERE       is a text describing the key sequences to which DEF-FUN is
  73               bound now (or, if it is remapped, a key sequence
  74               for the function it is remapped to)"
  75   (with-output-to-temp-buffer (help-buffer)
  76     (help-setup-xref (list #'tutorial--describe-nonstandard-key value)
  77                      (called-interactively-p 'interactive))
  78     (with-current-buffer (help-buffer)
  79       (insert
  80        "Your Emacs customizations override the default binding for this key:"
  81        "\n\n")
  82       (let ((inhibit-read-only t))
  83         (cond
  84          ((eq (car value) 'cua-mode)
  85           (insert
  86            "CUA mode is enabled.
  87
  88 When CUA mode is enabled, you can use C-z, C-x, C-c, and C-v to
  89 undo, cut, copy, and paste in addition to the normal Emacs
  90 bindings.  The C-x and C-c keys only do cut and copy when the
  91 region is active, so in most cases, they do not conflict with the
  92 normal function of these prefix keys.
  93
  94 If you really need to perform a command which starts with one of
  95 the prefix keys even when the region is active, you have three
  96 options:
  97 - press the prefix key twice very quickly (within 0.2 seconds),
  98 - press the prefix key and the following key within 0.2 seconds, or
  99 - use the SHIFT key with the prefix key, i.e. C-S-x or C-S-c."))
 100          ((eq (car value) 'current-binding)
 101           (let ((cb    (nth 1 value))
 102                 (db    (nth 2 value))
 103                 (key   (nth 3 value))
 104                 (where (nth 4 value))
 105                 map
 106                 (maps (current-active-maps))
 107                 mapsym)
 108             ;; Look at the currently active keymaps and try to find
 109             ;; first the keymap where the current binding occurs:
 110             (while maps
 111               (let* ((m (car maps))
 112                      (mb (lookup-key m key t)))
 113                 (setq maps (cdr maps))
 114                 (when (eq mb cb)
 115                   (setq map m)
 116                   (setq maps nil))))
 117             ;; Now, if a keymap was found we must found the symbol
 118             ;; name for it to display to the user.  This can not
 119             ;; always be found since all keymaps does not have a
 120             ;; symbol pointing to them, but here they should have
 121             ;; that:
 122             (when map
 123               (mapatoms (lambda (s)
 124                           (and
 125                            ;; If not already found
 126                            (not mapsym)
 127                            ;; and if s is a keymap
 128                            (and (boundp s)
 129                                 (keymapp (symbol-value s)))
 130                            ;; and not the local symbol map
 131                            (not (eq s 'map))
 132                            ;; and the value of s is map
 133                            (eq map (symbol-value s))
 134                            ;; then save this value in mapsym
 135                            (setq mapsym s)))))
 136             (insert "The default Emacs binding for the key "
 137                     (key-description key)
 138                     " is the command `")
 139             (insert (format "%s" db))
 140             (insert "'.  "
 141                     "However, your customizations have "
 142                     (if cb
 143                         (format "rebound it to the command `%s'" cb)
 144                       "unbound it"))
 145             (insert ".")
 146             (when mapsym
 147               (insert "  (For the more advanced user:"
 148                       " This binding is in the keymap `"
 149                       (format "%s" mapsym)
 150                       "'.)"))
 151             (if (string= where "")
 152                 (unless (keymapp db)
 153                   (insert "\n\nYou can use M-x "
 154                           (format "%s" db)
 155                           " RET instead."))
 156               (insert "\n\nWith your current key bindings"
 157                       " you can use "
 158                       (if (string-match "^the .*menus?$" where)
 159                           ""
 160                         "the key")
 161                       where
 162                       " to get the function `"
 163                       (format "%s" db)
 164                       "'.")))
 165           (fill-region (point-min) (point)))))
 166       (help-print-return-message))))
 167
 168 (defun tutorial--sort-keys (left right)
 169   "Sort predicate for use with `tutorial--default-keys'.
 170 This is a predicate function to `sort'.
 171
 172 The sorting is for presentation purpose only and is done on the
 173 key sequence.
 174
 175 LEFT and RIGHT are the elements to compare."
 176   (let ((x (append (cadr left)  nil))
 177         (y (append (cadr right) nil)))
 178     ;; Skip the front part of the key sequences if they are equal:
 179     (while (and x y
 180                 (listp x) (listp y)
 181                 (equal (car x) (car y)))
 182       (setq x (cdr x))
 183       (setq y (cdr y)))
 184     ;; Try to make a comparision that is useful for presentation (this
 185     ;; could be made nicer perhaps):
 186     (let ((cx (car x))
 187           (cy (car y)))
 188       ;;(message "x=%s, y=%s;;;; cx=%s, cy=%s" x y cx cy)
 189       (cond
 190        ;; Lists? Then call this again
 191        ((and cx cy
 192              (listp cx)
 193              (listp cy))
 194         (tutorial--sort-keys cx cy))
 195        ;; Are both numbers? Then just compare them
 196        ((and (wholenump cx)
 197              (wholenump cy))
 198         (> cx cy))
 199        ;; Is one of them a number? Let that be bigger then.
 200        ((wholenump cx)
 201         t)
 202        ((wholenump cy)
 203         nil)
 204        ;; Are both symbols? Compare the names then.
 205        ((and (symbolp cx)
 206              (symbolp cy))
 207         (string< (symbol-name cy)
 208                  (symbol-name cx)))))))
 209
 210 (defconst tutorial--default-keys
 211   ;; On window system, `suspend-emacs' is replaced in the default
 212   ;; keymap
 213   (let* ((suspend-emacs 'suspend-frame)
 214          (default-keys
 215            `((ESC-prefix [27])
 216              (Control-X-prefix [?\C-x])
 217              (mode-specific-command-prefix [?\C-c])
 218              (save-buffers-kill-terminal [?\C-x ?\C-c])
 219
 220              ;; * SUMMARY
 221              (scroll-up [?\C-v])
 222              (scroll-down [?\M-v])
 223              (recenter-top-bottom [?\C-l])
 224
 225              ;; * BASIC CURSOR CONTROL
 226              (forward-char [?\C-f])
 227              (backward-char [?\C-b])
 228              (forward-word [?\M-f])
 229              (backward-word [?\M-b])
 230              (next-line [?\C-n])
 231              (previous-line [?\C-p])
 232              (move-beginning-of-line [?\C-a])
 233              (move-end-of-line [?\C-e])
 234              (backward-sentence [?\M-a])
 235              (forward-sentence [?\M-e])
 236              (newline "\r")
 237              (beginning-of-buffer [?\M-<])
 238              (end-of-buffer [?\M->])
 239              (universal-argument [?\C-u])
 240
 241              ;; * WHEN EMACS IS HUNG
 242              (keyboard-quit [?\C-g])
 243
 244              ;; * DISABLED COMMANDS
 245              (downcase-region [?\C-x ?\C-l])
 246
 247              ;; * WINDOWS
 248              (delete-other-windows [?\C-x ?1])
 249              ;; C-u 0 C-l
 250              ;; Type CONTROL-h k CONTROL-f.
 251
 252              ;; * INSERTING AND DELETING
 253              ;; C-u 8 * to insert ********.
 254              (delete-backward-char "\d")
 255              (delete-char [?\C-d])
 256              (backward-kill-word [?\M-\d])
 257              (kill-word [?\M-d])
 258              (kill-line [?\C-k])
 259              (kill-sentence [?\M-k])
 260              (set-mark-command [?\C-@])
 261              (set-mark-command [?\C- ])
 262              (kill-region [?\C-w])
 263              (yank [?\C-y])
 264              (yank-pop [?\M-y])
 265
 266              ;; * UNDO
 267              (undo [?\C-x ?u])
 268
 269              ;; * FILES
 270              (find-file [?\C-x ?\C-f])
 271              (save-buffer [?\C-x ?\C-s])
 272
 273              ;; * BUFFERS
 274              (list-buffers [?\C-x ?\C-b])
 275              (switch-to-buffer [?\C-x ?b])
 276              (save-some-buffers [?\C-x ?s])
 277
 278              ;; * EXTENDING THE COMMAND SET
 279              ;; C-x     Character eXtend.  Followed by one character.
 280              (execute-extended-command [?\M-x])
 281              ;; C-x C-f         Find file
 282              ;; C-x C-s         Save file
 283              ;; C-x s           Save some buffers
 284              ;; C-x C-b         List buffers
 285              ;; C-x b           Switch buffer
 286              ;; C-x C-c         Quit Emacs
 287              ;; C-x 1           Delete all but one window
 288              ;; C-x u           Undo
 289
 290              ;; * MODE LINE
 291              (describe-mode [?\C-h ?m])
 292              (set-fill-column [?\C-x ?f])
 293              (fill-paragraph [?\M-q])
 294
 295              ;; * SEARCHING
 296              (isearch-forward [?\C-s])
 297              (isearch-backward [?\C-r])
 298
 299              ;; * MULTIPLE WINDOWS
 300              (split-window-vertically [?\C-x ?2])
 301              (scroll-other-window [?\C-\M-v])
 302              (other-window [?\C-x ?o])
 303              (find-file-other-window [?\C-x ?4 ?\C-f])
 304
 305              ;; * RECURSIVE EDITING LEVELS
 306              (keyboard-escape-quit [27 27 27])
 307
 308              ;; * GETTING MORE HELP
 309              ;; The most basic HELP feature is C-h c
 310              (describe-key-briefly [?\C-h ?c])
 311              (describe-key [?\C-h ?k])
 312
 313              ;; * MORE FEATURES
 314              ;; F10
 315
 316              ;; * CONCLUSION
 317              ;;(iconify-or-deiconify-frame [?\C-z])
 318              (,suspend-emacs [?\C-z]))))
 319     (sort default-keys 'tutorial--sort-keys))
 320   "Default Emacs key bindings that the tutorial depends on.")
 321
 322 (defun tutorial--detailed-help (button)
 323   "Give detailed help about changed keys."
 324   (with-output-to-temp-buffer (help-buffer)
 325     (help-setup-xref (list #'tutorial--detailed-help button)
 326                      (called-interactively-p 'interactive))
 327     (with-current-buffer (help-buffer)
 328       (let* ((tutorial-buffer  (button-get button 'tutorial-buffer))
 329              (explain-key-desc (button-get button 'explain-key-desc))
 330              (changed-keys (with-current-buffer tutorial-buffer
 331                              (save-excursion
 332                                (goto-char (point-min))
 333                                (tutorial--find-changed-keys
 334                                 tutorial--default-keys)))))
 335         (when changed-keys
 336           (insert
 337            "The following key bindings used in the tutorial have been changed
 338 from the Emacs default:\n\n" )
 339           (let ((frm "   %-14s %-27s %-16s\n"))
 340             (insert (format frm
 341                             "Standard Key" "Command" "In Your Emacs")))
 342           (dolist (tk changed-keys)
 343             (let* ((def-fun     (nth 1 tk))
 344                    (key         (nth 0 tk))
 345                    (def-fun-txt (nth 2 tk))
 346                    (where       (nth 3 tk))
 347                    (remark      (nth 4 tk))
 348                    (rem-fun (command-remapping def-fun))
 349                    (key-txt (key-description key))
 350                    (key-fun (with-current-buffer tutorial-buffer (key-binding key)))
 351                    tot-len)
 352               (unless (eq def-fun key-fun)
 353                 ;; Insert key binding description:
 354                 (when (string= key-txt explain-key-desc)
 355                   (put-text-property 0 (length key-txt)
 356                                      'face 'tutorial-warning-face key-txt))
 357                 (insert "   " key-txt " ")
 358                 (indent-to 18)
 359                 ;; Insert a link describing the old binding:
 360                 (insert-button def-fun-txt
 361                                'value def-fun
 362                                'action
 363                                (lambda (button) (interactive)
 364                                  (describe-function
 365                                   (button-get button 'value)))
 366                                'follow-link t)
 367                 (indent-to 45)
 368                 (when (listp where)
 369                   (setq where "list"))
 370                 ;; Tell where the old binding is now:
 371                 (insert (format " %-16s "
 372                                 (if (string= "" where)
 373                                     (format "M-x %s" def-fun-txt)
 374                                   where)))
 375                 ;; Insert a link with more information, for example
 376                 ;; current binding and keymap or information about
 377                 ;; cua-mode replacements:
 378                 (insert-button (car remark)
 379                                'action
 380                                (lambda (b) (interactive)
 381                                  (let ((value (button-get b 'value)))
 382                                    (tutorial--describe-nonstandard-key value)))
 383                                'value (cdr remark)
 384                                'follow-link t)
 385                 (insert "\n")))))
 386
 387         (insert "
 388 It is OK to change key bindings, but changed bindings do not
 389 correspond to what the tutorial says.\n\n")
 390         (help-print-return-message)))))
 391
 392 (defun tutorial--find-changed-keys (default-keys)
 393   "Find the key bindings used in the tutorial that have changed.
 394 Return a list with elements of the form
 395
 396   '(KEY DEF-FUN DEF-FUN-TXT WHERE REMARK QUIET)
 397
 398 where
 399
 400   KEY         is a key sequence whose standard binding has been changed
 401   DEF-FUN     is the standard binding of KEY
 402   DEF-FUN-TXT is a short descriptive text for DEF-FUN
 403   WHERE       is a text describing the key sequences to which DEF-FUN is
 404               bound now (or, if it is remapped, a key sequence
 405               for the function it is remapped to)
 406   REMARK      is a list with info about rebinding. It has either of
 407               these formats:
 408
 409                 \(TEXT cua-mode)
 410                 \(TEXT current-binding KEY-FUN DEF-FUN KEY WHERE)
 411
 412               Here TEXT is a link text to show to the user.  The
 413               rest of the list is used to show information when
 414               the user clicks the link.
 415
 416               KEY-FUN is the actual binding for KEY.
 417   QUIET       is t if this changed keybinding should be handled quietly.
 418               This is used by `tutorial--display-changes'."
 419   (let (changed-keys remark)
 420     ;; Look up the bindings in a Fundamental mode buffer
 421     ;; so we do not get fooled by some other major mode.
 422     (with-temp-buffer
 423       (fundamental-mode)
 424       (dolist (kdf default-keys)
 425         ;; The variables below corresponds to those with the same names
 426         ;; described in the doc string.
 427         (let* ((key     (nth 1 kdf))
 428                (def-fun (nth 0 kdf))
 429                (def-fun-txt (format "%s" def-fun))
 430                (rem-fun (command-remapping def-fun))
 431                ;; Handle prefix definitions specially
 432                ;; so that a mode that rebinds some subcommands
 433                ;; won't make it appear that the whole prefix is gone.
 434                (key-fun (if (eq def-fun 'ESC-prefix)
 435                             (lookup-key global-map [27])
 436                           (if (eq def-fun 'Control-X-prefix)
 437                               (lookup-key global-map [24])
 438                             (key-binding key))))
 439                (where (where-is-internal (if rem-fun rem-fun def-fun)))
 440                cwhere)
 441
 442           (if where
 443               (progn
 444                 (setq cwhere (car where)
 445                       where (key-description cwhere))
 446                 (when (and (< 10 (length where))
 447                            (string= (substring where 0 (length "<menu-bar>"))
 448                                     "<menu-bar>"))
 449                   (setq where
 450                         (if (and (vectorp cwhere)
 451                                  (setq cwhere (elt cwhere 1))
 452                                  (setq cwhere
 453                                        (cadr
 454                                         (assoc cwhere
 455                                                (lookup-key global-map
 456                                                            [menu-bar]))))
 457                                  (stringp cwhere))
 458                             (format "the `%s' menu" cwhere)
 459                           "the menus"))))
 460             (setq where ""))
 461           (setq remark nil)
 462           (unless
 463               (cond ((eq key-fun def-fun)
 464                      ;; No rebinding, return t
 465                      t)
 466                     ((and key-fun
 467                           (eq key-fun (command-remapping def-fun)))
 468                      ;; Just a remapping, return t
 469                      t)
 470                     ;; cua-mode specials:
 471                     ((and cua-mode
 472                           (or (and
 473                                (equal key [?\C-v])
 474                                (eq key-fun 'cua-paste))
 475                               (and
 476                                (equal key [?\C-z])
 477                                (eq key-fun 'undo))))
 478                      (setq remark (list "cua-mode, more info" 'cua-mode))
 479                      nil)
 480                     ((and cua-mode
 481                           (or (and (eq def-fun 'ESC-prefix)
 482                                    (equal key-fun
 483                                           `(keymap
 484                                             (118 . cua-repeat-replace-region)))
 485                                    (setq def-fun-txt "\"ESC prefix\""))
 486                               (and (eq def-fun 'mode-specific-command-prefix)
 487                                    (equal key-fun
 488                                           '(keymap
 489                                             (timeout . copy-region-as-kill)))
 490                                    (setq def-fun-txt "\"C-c prefix\""))
 491                               (and (eq def-fun 'Control-X-prefix)
 492                                    (equal key-fun
 493                                           '(keymap (timeout . kill-region)))
 494                                    (setq def-fun-txt "\"C-x prefix\""))))
 495                      (setq remark (list "cua-mode replacement" 'cua-mode))
 496                      (setq where "Same key")
 497                      nil)
 498                     ;; viper-mode specials:
 499                     ((and (boundp 'viper-mode-string)
 500                           (boundp 'viper-current-state)
 501                           (eq viper-current-state 'vi-state)
 502                           (or (and (eq def-fun 'isearch-forward)
 503                                    (eq key-fun 'viper-isearch-forward))
 504                               (and (eq def-fun 'isearch-backward)
 505                                    (eq key-fun 'viper-isearch-backward))))
 506                      ;; These bindings works as the default bindings,
 507                      ;; return t
 508                      t)
 509                     ((when normal-erase-is-backspace
 510                        (or (and (equal key [C-delete])
 511                                 (equal key-fun 'kill-word))
 512                            (and (equal key [C-backspace])
 513                                 (equal key-fun 'backward-kill-word))))
 514                      ;; This is the strange handling of C-delete and
 515                      ;; C-backspace, return t
 516                      t)
 517                     (t
 518                      ;; This key has indeed been rebound. Put information
 519                      ;; in `remark' and return nil
 520                      (setq remark
 521                            (list "more info" 'current-binding
 522                                  key-fun def-fun key where))
 523                      nil))
 524             (add-to-list 'changed-keys
 525                          (list key def-fun def-fun-txt where remark nil))))))
 526     changed-keys))
 527
 528 (defun tutorial--key-description (key)
 529   (let ((desc (key-description key)))
 530     (cond ((string= "ESC" desc) "<ESC>")
 531           ((string= "RET" desc) "<Return>")
 532           ((string= "DEL" desc) "<Delback>")
 533           (t desc))))
 534
 535 (defun tutorial--display-changes ()
 536   "Display changes to some default key bindings.
 537 If some of the default key bindings that the tutorial depends on
 538 have been changed then display the changes in the tutorial buffer
 539 with some explanatory links."
 540   (let* ((changed-keys (tutorial--find-changed-keys
 541                         tutorial--default-keys))
 542          ;; Alist of element (DESC . CK) where DESC is the
 543          ;; key-description of a changed key and CK is the
 544          ;; corresponding element in `changed-keys'.
 545          (changed-keys-alist
 546           (mapcar (lambda (ck) (cons (tutorial--key-description (car ck)) ck))
 547                   changed-keys))
 548          changed-key
 549          (start (point))
 550          (case-fold-search nil)
 551          (keybindings-regexp
 552           (concat "[[:space:]]\\("
 553                   (mapconcat (lambda (kdf) (regexp-quote
 554                                             (tutorial--key-description
 555                                              (nth 1 kdf))))
 556                              tutorial--default-keys
 557                              "\\|")
 558                   "\\)[[:punct:][:space:]]")))
 559     ;; Need the custom button face for viper buttons:
 560     (if (boundp 'viper-mode-string) (require 'cus-edit))
 561
 562     (if (or changed-keys (boundp 'viper-mode-string))
 563         (let ((head  (get-lang-string tutorial--lang 'tut-chgdhead))
 564               (head2 (get-lang-string tutorial--lang 'tut-chgdhead2)))
 565           (when (and head head2)
 566             (goto-char tutorial--point-before-chkeys)
 567             (insert head " [")
 568             (insert-button head2 'tutorial-buffer (current-buffer)
 569                            'action 'tutorial--detailed-help
 570                            'follow-link t 'face 'link)
 571             (insert "]\n\n")
 572             (add-text-properties tutorial--point-before-chkeys (point)
 573                                  '(tutorial-remark remark
 574                                    face tutorial-warning-face
 575                                    read-only t)))))
 576
 577     ;; Scan the tutorial for all key sequences.
 578     (goto-char (point-min))
 579     (while (re-search-forward keybindings-regexp (point-max) t)
 580       ;; Then highlight each rebound key sequence.
 581       ;; This avoids issuing a warning for, e.g., C-x C-b if C-b is rebound.
 582       (setq changed-key (assoc (match-string 1) changed-keys-alist))
 583       (and changed-key
 584            (not (get-text-property (match-beginning 1) 'tutorial-remark))
 585            (let* ((desc    (car changed-key))
 586                   (ck      (cdr changed-key))
 587                   (key     (nth 0 ck))
 588                   (def-fun (nth 1 ck))
 589                   (where   (nth 3 ck))
 590                   s1 s2 help-string)
 591              (unless (string= where "Same key")
 592                (when (string= where "")
 593                  (setq where (format "M-x %s" def-fun)))
 594                (setq tutorial--point-after-chkeys (point-marker)
 595                      s1 (get-lang-string tutorial--lang 'tut-chgdkey)
 596                      s2 (get-lang-string tutorial--lang 'tut-chgdkey2)
 597                      help-string (and s1 s2 (format s1 desc where)))
 598                (add-text-properties (match-beginning 1) (match-end 1)
 599                                     '(face tutorial-warning-face
 600                                       tutorial-remark key-sequence))
 601                (if help-string
 602                    (if (nth 5 ck)
 603                        ;; Put help string in the tooltip.
 604                        (put-text-property (match-beginning 1) (match-end 1)
 605                                           'help-echo help-string)
 606                      ;; Put help string in the buffer.
 607                      (save-excursion
 608                        (setcar (nthcdr 5 ck) t)
 609                        (forward-line)
 610                        ;; Two or more changed keys were on the same line.
 611                        (while (eq (get-text-property (point) 'tutorial-remark)
 612                                   'remark)
 613                          (forward-line))
 614                        (setq start (point))
 615                        (insert "** " help-string " [")
 616                        (insert-button s2 'tutorial-buffer (current-buffer)
 617                                       'action 'tutorial--detailed-help
 618                                       'explain-key-desc desc 'follow-link t
 619                                       'face 'link)
 620                        (insert "] **\n")
 621                        (add-text-properties start (point)
 622                                             '(tutorial-remark remark
 623                                               rear-nonsticky t
 624                                               face tutorial-warning-face
 625                                               read-only t)))))))))))
 626
 627 (defun tutorial--saved-dir ()
 628   "Directory to which tutorials are saved."
 629   (locate-user-emacs-file "tutorial/"))
 630
 631 (defun tutorial--saved-file ()
 632   "File name in which to save tutorials."
 633   (let ((file-name tutorial--lang)
 634         (ext (file-name-extension tutorial--lang)))
 635     (when (or (not ext)
 636               (string= ext ""))
 637       (setq file-name (concat file-name ".tut")))
 638     (expand-file-name file-name (tutorial--saved-dir))))
 639
 640 (defun tutorial--remove-remarks ()
 641   "Remove the remark lines that was added to the tutorial buffer."
 642   (save-excursion
 643     (goto-char (point-min))
 644     (let (prop-start
 645           prop-end
 646           prop-val)
 647       ;; Catch the case when we already are on a remark line
 648       (while (if (get-text-property (point) 'tutorial-remark)
 649                  (setq prop-start (point))
 650                (setq prop-start (next-single-property-change (point) 'tutorial-remark)))
 651         (setq prop-end (next-single-property-change prop-start 'tutorial-remark))
 652         (setq prop-val (get-text-property prop-start 'tutorial-remark))
 653         (unless prop-end
 654           (setq prop-end (point-max)))
 655         (goto-char prop-end)
 656         (unless (eq prop-val 'key-sequence)
 657           (delete-region prop-start prop-end))))))
 658
 659 (defun tutorial--save-tutorial ()
 660   "Save the tutorial buffer.
 661 This saves the part of the tutorial before and after the area
 662 showing changed keys.  It also saves the point position and the
 663 position where the display of changed bindings was inserted."
 664   ;; This runs in a hook so protect it:
 665   (condition-case err
 666       (if (y-or-n-p "Save your position in the tutorial? ")
 667           (tutorial--save-tutorial-to (tutorial--saved-file))
 668         (message "Tutorial position not saved"))
 669     (error (message "Error saving tutorial state: %s"
 670                     (error-message-string err)))))
 671
 672 (defun tutorial--save-tutorial-to (saved-file)
 673   "Save the tutorial buffer to SAVED-FILE.
 674 See `tutorial--save-tutorial' for more information."
 675   ;; Anything to save?
 676   (when (or (buffer-modified-p)
 677             (< 1 (point)))
 678     (let ((tutorial-dir (tutorial--saved-dir))
 679           save-err)
 680       ;; The tutorial is saved in a subdirectory in the user home
 681       ;; directory. Create this subdirectory first.
 682       (unless (file-directory-p tutorial-dir)
 683         (condition-case err
 684             (make-directory tutorial-dir nil)
 685           (error (setq save-err t)
 686                  (warn "Could not create directory %s: %s" tutorial-dir
 687                        (error-message-string err)))))
 688       ;; Make sure we have that directory.
 689       (if (file-directory-p tutorial-dir)
 690           (let ((tut-point (if (= 0 tutorial--point-after-chkeys)
 691                                ;; No info about changed keys is
 692                                ;; displayed.
 693                                (point)
 694                              (if (< (point) tutorial--point-after-chkeys)
 695                                  (- (point))
 696                                (- (point) tutorial--point-after-chkeys))))
 697                 (old-point (point))
 698                 ;; Use a special undo list so that we easily can undo
 699                 ;; the changes we make to the tutorial buffer.  This is
 700                 ;; currently not needed since we now delete the buffer
 701                 ;; after saving, but kept for possible future use of
 702                 ;; this function.
 703                 buffer-undo-list
 704                 (inhibit-read-only t))
 705             ;; Delete the area displaying info about changed keys.
 706             ;;             (when (< 0 tutorial--point-after-chkeys)
 707             ;;               (delete-region tutorial--point-before-chkeys
 708             ;;                              tutorial--point-after-chkeys))
 709             ;; Delete the remarks:
 710             (tutorial--remove-remarks)
 711             ;; Put the value of point first in the buffer so it will
 712             ;; be saved with the tutorial.
 713             (goto-char (point-min))
 714             (insert (number-to-string tut-point)
 715                     "\n"
 716                     (number-to-string (marker-position
 717                                        tutorial--point-before-chkeys))
 718                     "\n")
 719             (condition-case err
 720                 (write-region nil nil saved-file)
 721               (error (setq save-err t)
 722                      (warn "Could not save tutorial to %s: %s"
 723                            saved-file
 724                            (error-message-string err))))
 725             ;; An error is raised here?? Is this a bug?
 726             (condition-case err
 727                 (undo-only)
 728               (error nil))
 729             ;; Restore point
 730             (goto-char old-point)
 731             (if save-err
 732                 (message "Could not save tutorial state.")
 733               (message "Saved tutorial state.")))
 734         (message "Can't save tutorial: %s is not a directory"
 735                  tutorial-dir)))))
 736
 737
 738 ;;;###autoload
 739 (defun help-with-tutorial (&optional arg dont-ask-for-revert)
 740   "Select the Emacs learn-by-doing tutorial.
 741 If there is a tutorial version written in the language
 742 of the selected language environment, that version is used.
 743 If there's no tutorial in that language, `TUTORIAL' is selected.
 744 With ARG, you are asked to choose which language.
 745 If DONT-ASK-FOR-REVERT is non-nil the buffer is reverted without
 746 any question when restarting the tutorial.
 747
 748 If any of the standard Emacs key bindings that are used in the
 749 tutorial have been changed then an explanatory note about this is
 750 shown in the beginning of the tutorial buffer.
 751
 752 When the tutorial buffer is killed the content and the point
 753 position in the buffer is saved so that the tutorial may be
 754 resumed later."
 755   (interactive "P")
 756   (if (boundp 'viper-current-state)
 757       (let ((prompt1
 758              "You can not run the Emacs tutorial directly because you have \
 759 enabled Viper.")
 760             (prompt2 "\nThere is however a Viper tutorial you can run instead.
 761 Run the Viper tutorial? "))
 762         (if (fboundp 'viper-tutorial)
 763             (if (y-or-n-p (concat prompt1 prompt2))
 764                 (progn (message "")
 765                        (funcall 'viper-tutorial 0))
 766               (message "Tutorial aborted by user"))
 767           (message prompt1)))
 768     (let* ((lang (if arg
 769                      (let ((minibuffer-setup-hook minibuffer-setup-hook))
 770                        (add-hook 'minibuffer-setup-hook
 771                                  'minibuffer-completion-help)
 772                        (read-language-name 'tutorial "Language: " "English"))
 773                    (if (get-language-info current-language-environment 'tutorial)
 774                        current-language-environment
 775                      "English")))
 776            (filename (get-language-info lang 'tutorial))
 777            (tut-buf-name filename)
 778            (old-tut-buf (get-buffer tut-buf-name))
 779            (old-tut-win (when old-tut-buf (get-buffer-window old-tut-buf t)))
 780            (old-tut-is-ok (when old-tut-buf
 781                             (not (buffer-modified-p old-tut-buf))))
 782            old-tut-file
 783            (old-tut-point 1))
 784       (setq tutorial--point-after-chkeys (point-min))
 785       ;; Try to display the tutorial buffer before asking to revert it.
 786       ;; If the tutorial buffer is shown in some window make sure it is
 787       ;; selected and displayed:
 788       (if old-tut-win
 789           (raise-frame
 790            (window-frame
 791             (select-window (get-buffer-window old-tut-buf t))))
 792         ;; Else, is there an old tutorial buffer? Then display it:
 793         (when old-tut-buf
 794           (switch-to-buffer old-tut-buf)))
 795       ;; Use whole frame for tutorial
 796       (delete-other-windows)
 797       ;; If the tutorial buffer has been changed then ask if it should
 798       ;; be reverted:
 799       (when (and old-tut-buf
 800                  (not old-tut-is-ok))
 801         (setq old-tut-is-ok
 802               (if dont-ask-for-revert
 803                   nil
 804                 (not (y-or-n-p
 805                       "You have changed the Tutorial buffer.  Revert it? ")))))
 806       ;; (Re)build the tutorial buffer if it is not ok
 807       (unless old-tut-is-ok
 808         (switch-to-buffer (get-buffer-create tut-buf-name))
 809         ;; (unless old-tut-buf (text-mode))
 810         (unless lang (error "Variable lang is nil"))
 811         (setq tutorial--lang lang)
 812         (setq old-tut-file (file-exists-p (tutorial--saved-file)))
 813         (let ((inhibit-read-only t))
 814           (erase-buffer))
 815         (message "Preparing tutorial ...") (sit-for 0)
 816
 817         ;; Do not associate the tutorial buffer with a file. Instead use
 818         ;; a hook to save it when the buffer is killed.
 819         (setq buffer-auto-save-file-name nil)
 820         (add-hook 'kill-buffer-hook 'tutorial--save-tutorial nil t)
 821
 822         ;; Insert the tutorial. First offer to resume last tutorial
 823         ;; editing session.
 824         (when dont-ask-for-revert
 825           (setq old-tut-file nil))
 826         (when old-tut-file
 827           (setq old-tut-file
 828                 (y-or-n-p "Resume your last saved tutorial? ")))
 829         (if old-tut-file
 830             (progn
 831               (insert-file-contents (tutorial--saved-file))
 832               (goto-char (point-min))
 833               (setq old-tut-point
 834                     (string-to-number
 835                      (buffer-substring-no-properties
 836                       (line-beginning-position) (line-end-position))))
 837               (forward-line)
 838               (setq tutorial--point-before-chkeys
 839                     (string-to-number
 840                      (buffer-substring-no-properties
 841                       (line-beginning-position) (line-end-position))))
 842               (forward-line)
 843               (delete-region (point-min) (point))
 844               (goto-char tutorial--point-before-chkeys)
 845               (setq tutorial--point-before-chkeys (point-marker)))
 846           (insert-file-contents (expand-file-name filename tutorial-directory))
 847           (forward-line)
 848           (setq tutorial--point-before-chkeys (point-marker)))
 849
 850         (tutorial--display-changes)
 851
 852         ;; Clear message:
 853         (unless dont-ask-for-revert
 854           (message "") (sit-for 0))
 855
 856
 857         (if old-tut-file
 858             ;; Just move to old point in saved tutorial.
 859             (let ((old-point
 860                    (if (> 0 old-tut-point)
 861                        (- old-tut-point)
 862                      (+ old-tut-point tutorial--point-after-chkeys))))
 863               (when (< old-point 1)
 864                 (setq old-point 1))
 865               (goto-char old-point))
 866           ;; Delete the arch-tag line, so as not to confuse readers.
 867           (goto-char (point-max))
 868           (if (search-backward ";;; arch-tag: " nil t)
 869               (delete-region (point) (point-max)))
 870           (goto-char (point-min))
 871           (search-forward "\n<<")
 872           (beginning-of-line)
 873           ;; Convert the <<...>> line to the proper [...] line,
 874           ;; or just delete the <<...>> line if a [...] line follows.
 875           (cond ((save-excursion
 876                    (forward-line 1)
 877                    (looking-at "\\["))
 878                  (delete-region (point) (progn (forward-line 1) (point))))
 879                 ((looking-at "<<Blank lines inserted.*>>")
 880                  (replace-match "[Middle of page left blank for didactic purposes.   Text continues below]"))
 881                 (t
 882                  (looking-at "<<")
 883                  (replace-match "[")
 884                  (search-forward ">>")
 885                  (replace-match "]")))
 886           (beginning-of-line)
 887           (let ((n (- (window-height (selected-window))
 888                       (count-lines (point-min) (point))
 889                       6)))
 890             (if (< n 8)
 891                 (progn
 892                   ;; For a short gap, we don't need the [...] line,
 893                   ;; so delete it.
 894                   (delete-region (point) (progn (end-of-line) (point)))
 895                   (newline n))
 896               ;; Some people get confused by the large gap.
 897               (newline (/ n 2))
 898
 899               ;; Skip the [...] line (don't delete it).
 900               (forward-line 1)
 901               (newline (- n (/ n 2)))))
 902           (goto-char (point-min)))
 903         (setq buffer-undo-list nil)
 904         (set-buffer-modified-p nil)))))
 905
 906
 907 ;; Below is some attempt to handle language specific strings. These
 908 ;; are currently only used in the tutorial.
 909
 910 (defconst lang-strings
 911   '(("English" .
 912      ((tut-chgdkey . "%s has been rebound, but you can use %s instead")
 913       (tut-chgdkey2 . "More")
 914       (tut-chgdhead . "
 915  NOTICE: The main purpose of the Emacs tutorial is to teach you
 916  the most important standard Emacs commands (key bindings).
 917  However, your Emacs has been customized by changing some of
 918  these basic editing commands, so it doesn't correspond to the
 919  tutorial.  We have inserted colored notices where the altered
 920  commands have been introduced.")
 921       (tut-chgdhead2 . "More"))))
 922   "Language specific strings for Emacs.
 923 This is an association list with the keys equal to the strings
 924 that can be returned by `read-language-name'.  The elements in
 925 the list are themselves association lists with keys that are
 926 string ids and values that are the language specific strings.
 927
 928 See `get-lang-string' for more information.")
 929
 930 (defun get-lang-string (lang stringid &optional no-eng-fallback)
 931   "Get a language specific string for Emacs.
 932 In certain places Emacs can replace a string shown to the user with
 933 a language specific string.  This function retrieves such strings.
 934
 935 LANG is the language specification.  It should be one of those
 936 strings that can be returned by `read-language-name'.  STRINGID
 937 is a symbol that specifies the string to retrieve.
 938
 939 If no string is found for STRINGID in the chosen language then
 940 the English string is returned unless NO-ENG-FALLBACK is non-nil.
 941
 942 See `lang-strings' for more information.
 943
 944 Currently this feature is only used in `help-with-tutorial'."
 945   (let ((my-lang-strings (assoc lang lang-strings))
 946         (found-string))
 947     (when my-lang-strings
 948       (let ((entry (assoc stringid (cdr my-lang-strings))))
 949         (when entry
 950           (setq found-string (cdr entry)))))
 951     ;; Fallback to English strings
 952     (unless (or found-string
 953                 no-eng-fallback)
 954       (setq found-string (get-lang-string "English" stringid t)))
 955     found-string))
 956
 957 ;;(get-lang-string "English" 'tut-chgdkey)
 958
 959 (provide 'tutorial)
 960
 961 ;; arch-tag: c8e80aef-c3bb-4ffb-8af6-22171bf0c100
 962 ;;; tutorial.el ends here