lisp/tutorial.el

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