lisp/descr-text.el

   1 ;;; descr-text.el --- describe text mode
   2
   3 ;; Copyright (C) 1994, 1995, 1996, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   5
   6 ;; Author: Boris Goldowsky <boris@gnu.org>
   7 ;; Maintainer: FSF
   8 ;; Keywords: faces, i18n, Unicode, multilingual
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;;; Describe-Text Mode.
  28
  29 ;;; Code:
  30
  31 (eval-when-compile (require 'quail))
  32 (require 'help-mode)
  33
  34 ;;; Describe-Text Utilities.
  35
  36 (defun describe-text-widget (widget)
  37   "Insert text to describe WIDGET in the current buffer."
  38   (insert-text-button
  39    (symbol-name (if (symbolp widget) widget (car widget)))
  40    'action `(lambda (&rest ignore)
  41               (widget-browse ',widget))
  42    'help-echo "mouse-2, RET: browse this widget")
  43   (insert " ")
  44   (insert-text-button
  45    "(widget)Top" 'type 'help-info 'help-args '("(widget)Top")))
  46
  47 (defun describe-text-sexp (sexp)
  48   "Insert a short description of SEXP in the current buffer."
  49   (let ((pp (condition-case signal
  50                 (pp-to-string sexp)
  51               (error (prin1-to-string signal)))))
  52     (when (string-match-p "\n\\'" pp)
  53       (setq pp (substring pp 0 (1- (length pp)))))
  54
  55     (if (and (not (string-match-p "\n" pp))
  56              (<= (length pp) (- (window-width) (current-column))))
  57         (insert pp)
  58       (insert-text-button
  59        "[Show]" 'action `(lambda (&rest ignore)
  60                            (with-output-to-temp-buffer
  61                                "*Pp Eval Output*"
  62                              (princ ',pp)))
  63        'help-echo "mouse-2, RET: pretty print value in another buffer"))))
  64
  65 (defun describe-property-list (properties)
  66   "Insert a description of PROPERTIES in the current buffer.
  67 PROPERTIES should be a list of overlay or text properties.
  68 The `category', `face' and `font-lock-face' properties are made
  69 into help buttons that call `describe-text-category' or
  70 `describe-face' when pushed."
  71   ;; Sort the properties by the size of their value.
  72   (dolist (elt (sort (let (ret)
  73                        (while properties
  74                          (push (list (pop properties) (pop properties)) ret))
  75                        ret)
  76                      (lambda (a b) (string< (prin1-to-string (nth 0 a) t)
  77                                             (prin1-to-string (nth 0 b) t)))))
  78     (let ((key (nth 0 elt))
  79           (value (nth 1 elt)))
  80       (insert (propertize (format "  %-20s " key)
  81                           'face 'help-argument-name))
  82       (cond ((eq key 'category)
  83              (insert-text-button
  84               (symbol-name value)
  85               'action `(lambda (&rest ignore)
  86                          (describe-text-category ',value))
  87               'follow-link t
  88               'help-echo "mouse-2, RET: describe this category"))
  89             ((memq key '(face font-lock-face mouse-face))
  90              (insert-text-button
  91               (format "%S" value)
  92               'type 'help-face 'help-args (list value)))
  93             ((widgetp value)
  94              (describe-text-widget value))
  95             (t
  96              (describe-text-sexp value))))
  97     (insert "\n")))
  98 \f
  99 ;;; Describe-Text Commands.
 100
 101 (defun describe-text-category (category)
 102   "Describe a text property category."
 103   (interactive "SCategory: ")
 104   (help-setup-xref (list #'describe-text-category category)
 105                    (called-interactively-p 'interactive))
 106   (with-help-window (help-buffer)
 107     (with-current-buffer standard-output
 108       (insert "Category " (format "%S" category) ":\n\n")
 109       (describe-property-list (symbol-plist category))
 110       (goto-char (point-min)))))
 111
 112 ;;;###autoload
 113 (defun describe-text-properties (pos &optional output-buffer buffer)
 114   "Describe widgets, buttons, overlays, and text properties at POS.
 115 POS is taken to be in BUFFER or in current buffer if nil.
 116 Interactively, describe them for the character after point.
 117 If optional second argument OUTPUT-BUFFER is non-nil,
 118 insert the output into that buffer, and don't initialize or clear it
 119 otherwise."
 120   (interactive "d")
 121   (let ((src-buf (current-buffer)))
 122     (if buffer (set-buffer buffer) (setq buffer (current-buffer)))
 123   (if (>= pos (point-max))
 124       (error "No character follows specified position"))
 125   (if output-buffer
 126       (describe-text-properties-1 pos output-buffer)
 127     (if (not (or (text-properties-at pos) (overlays-at pos)))
 128         (message "This is plain text.")
 129         (with-temp-buffer
 130             (setq output-buffer (current-buffer))
 131             (insert "Text content at position " (format "%d" pos) ":\n\n")
 132           (set-buffer buffer)
 133           (describe-text-properties-1 pos output-buffer)
 134           (set-buffer src-buf)
 135           (help-setup-xref (list 'describe-text-properties pos nil buffer)
 136                            (called-interactively-p 'interactive))
 137           (with-help-window (help-buffer)
 138             (with-current-buffer standard-output
 139               (buffer-swap-text output-buffer)
 140               (goto-char (point-min)))))))))
 141
 142 (defun describe-text-properties-1 (pos output-buffer)
 143   (let* ((properties (text-properties-at pos))
 144          (overlays (overlays-at pos))
 145          (wid-field (get-char-property pos 'field))
 146          (wid-button (get-char-property pos 'button))
 147          (wid-doc (get-char-property pos 'widget-doc))
 148          ;; If button.el is not loaded, we have no buttons in the text.
 149          (button (and (fboundp 'button-at) (button-at pos)))
 150          (button-type (and button (button-type button)))
 151          (button-label (and button (button-label button)))
 152          (widget (or wid-field wid-button wid-doc)))
 153     (with-current-buffer output-buffer
 154       ;; Widgets
 155       (when (widgetp widget)
 156         (newline)
 157         (insert (cond (wid-field "This is an editable text area")
 158                       (wid-button "This is an active area")
 159                       (wid-doc "This is documentation text")))
 160         (insert " of a ")
 161         (describe-text-widget widget)
 162         (insert ".\n\n"))
 163       ;; Buttons
 164       (when (and button (not (widgetp wid-button)))
 165         (newline)
 166         (insert "Here is a `" (format "%S" button-type)
 167                 "' button labeled `" button-label "'.\n\n"))
 168       ;; Overlays
 169       (when overlays
 170         (newline)
 171         (if (eq (length overlays) 1)
 172             (insert "There is an overlay here:\n")
 173           (insert "There are " (format "%d" (length overlays))
 174                          " overlays here:\n"))
 175         (dolist (overlay overlays)
 176           (insert " From " (format "%d" (overlay-start overlay))
 177                          " to " (format "%d" (overlay-end overlay)) "\n")
 178           (describe-property-list (overlay-properties overlay)))
 179         (insert "\n"))
 180       ;; Text properties
 181       (when properties
 182         (newline)
 183         (insert "There are text properties here:\n")
 184         (describe-property-list properties)))))
 185 \f
 186 (defcustom describe-char-unidata-list
 187   '(name old-name general-category decomposition)
 188   "List of Unicode-based character property names shown by `describe-char'."
 189   :group 'mule
 190   :version "23.1"
 191   :type '(choice (const :tag "All properties" t)
 192           (set
 193            (const :tag "Unicode name" name)
 194            (const :tag "Unicode old name" old-name)
 195            (const :tag "Unicode general category " general-category)
 196            (const :tag "Unicode canonical combining class"
 197                   canonical-combining-class)
 198            (const :tag "Unicode bidi class" bidi-class)
 199            (const :tag "Unicode decomposition mapping" decomposition)
 200            (const :tag "Unicode decimal digit value" decimal-digit-value)
 201            (const :tag "Unicode digit value" digit-value)
 202            (const :tag "Unicode numeric value" numeric-value)
 203            (const :tag "Unicode mirrored" mirrored)
 204            (const :tag "Unicode ISO 10646 comment" iso-10646-comment)
 205            (const :tag "Unicode simple uppercase mapping" uppercase)
 206            (const :tag "Unicode simple lowercase mapping" lowercase)
 207            (const :tag "Unicode simple titlecase mapping" titlecase))))
 208
 209 (defcustom describe-char-unicodedata-file nil
 210   "Location of Unicode data file.
 211 This is the UnicodeData.txt file from the Unicode Consortium, used for
 212 diagnostics.  If it is non-nil `describe-char' will print data
 213 looked up from it.  This facility is mostly of use to people doing
 214 multilingual development.
 215
 216 This is a fairly large file, not typically present on GNU systems.
 217 At the time of writing it is at the URL
 218 `http://www.unicode.org/Public/UNIDATA/UnicodeData.txt'."
 219   :group 'mule
 220   :version "22.1"
 221   :type '(choice (const :tag "None" nil)
 222                  file))
 223
 224 (defun describe-char-unicode-data (char)
 225   "Return a list of Unicode data for unicode CHAR.
 226 Each element is a list of a property description and the property value.
 227 The list is null if CHAR isn't found in `describe-char-unicodedata-file'.
 228 This function is semi-obsolete.  Use `get-char-code-property'."
 229   (when describe-char-unicodedata-file
 230     (unless (file-exists-p describe-char-unicodedata-file)
 231       (error "`unicodedata-file' %s not found" describe-char-unicodedata-file))
 232     (with-current-buffer (get-buffer-create " *Unicode Data*")
 233       (when (zerop (buffer-size))
 234         ;; Don't use -literally in case of DOS line endings.
 235         (insert-file-contents describe-char-unicodedata-file))
 236       (goto-char (point-min))
 237       (let ((hex (format "%04X" char))
 238             found first last)
 239         (if (re-search-forward (concat "^" hex) nil t)
 240             (setq found t)
 241           ;; It's not listed explicitly.  Look for ranges, e.g. CJK
 242           ;; ideographs, and check whether it's in one of them.
 243           (while (and (re-search-forward "^\\([^;]+\\);[^;]+First>;" nil t)
 244                       (>= char (setq first
 245                                      (string-to-number (match-string 1) 16)))
 246                       (progn
 247                         (forward-line 1)
 248                         (looking-at "^\\([^;]+\\);[^;]+Last>;")
 249                         (> char
 250                            (setq last
 251                                  (string-to-number (match-string 1) 16))))))
 252           (if (and (>= char first)
 253                    (<= char last))
 254               (setq found t)))
 255         (if found
 256             (let ((fields (mapcar (lambda (elt)
 257                                     (if (> (length elt) 0)
 258                                         elt))
 259                                   (cdr (split-string
 260                                         (buffer-substring
 261                                          (line-beginning-position)
 262                                          (line-end-position))
 263                                         ";")))))
 264               ;; The length depends on whether the last field was empty.
 265               (unless (or (= 13 (length fields))
 266                           (= 14 (length fields)))
 267                 (error "Invalid contents in %s" describe-char-unicodedata-file))
 268               ;; The field names and values lists are slightly
 269               ;; modified from Mule-UCS unidata.el.
 270               (list
 271                (list "Name" (let ((name (nth 0 fields)))
 272                               ;; Check for <..., First>, <..., Last>
 273                               (if (string-match "\\`\\(<[^,]+\\)," name)
 274                                   (concat (match-string 1 name) ">")
 275                                 name)))
 276                (list "Category"
 277                      (let ((val (nth 1 fields)))
 278                        (or (char-code-property-description
 279                             'general-category (intern val))
 280                            val)))
 281                (list "Combining class"
 282                      (let ((val (nth 1 fields)))
 283                        (or (char-code-property-description
 284                             'canonical-combining-class (intern val))
 285                            val)))
 286                (list "Bidi category"
 287                      (let ((val (nth 1 fields)))
 288                        (or (char-code-property-description
 289                             'bidi-class (intern val))
 290                            val)))
 291                (list
 292                 "Decomposition"
 293                 (if (nth 4 fields)
 294                     (let* ((parts (split-string (nth 4 fields)))
 295                            (info (car parts)))
 296                       (if (string-match "\\`<\\(.+\\)>\\'" info)
 297                           (setq info (match-string 1 info))
 298                         (setq info nil))
 299                       (if info (setq parts (cdr parts)))
 300                       (setq parts (mapconcat
 301                                    (lambda (arg)
 302                                      (string (string-to-number arg 16)))
 303                                    parts " "))
 304                       (concat info parts))))
 305                (list "Decimal digit value"
 306                      (nth 5 fields))
 307                (list "Digit value"
 308                      (nth 6 fields))
 309                (list "Numeric value"
 310                      (nth 7 fields))
 311                (list "Mirrored"
 312                      (if (equal "Y" (nth 8 fields))
 313                          "yes"))
 314                (list "Old name" (nth 9 fields))
 315                (list "ISO 10646 comment" (nth 10 fields))
 316                (list "Uppercase" (and (nth 11 fields)
 317                                       (string (string-to-number
 318                                                (nth 11 fields) 16))))
 319                (list "Lowercase" (and (nth 12 fields)
 320                                       (string (string-to-number
 321                                                (nth 12 fields) 16))))
 322                (list "Titlecase" (and (nth 13 fields)
 323                                       (string (string-to-number
 324                                                (nth 13 fields) 16)))))))))))
 325
 326 ;; Not defined on builds without X, but behind display-graphic-p.
 327 (declare-function internal-char-font "fontset.c" (position &optional ch))
 328
 329 ;; Return information about how CHAR is displayed at the buffer
 330 ;; position POS.  If the selected frame is on a graphic display,
 331 ;; return a string "FONT-DRIVER:FONT-NAME (GLYPH-CODE)" where:
 332 ;;   FONT-DRIVER is the font-driver name,
 333 ;;   FONT-NAME is the font name,
 334 ;;   GLYPH-CODE is a hexadigit string representing the glyph-ID.
 335 ;; Otherwise, return a string describing the terminal codes for the
 336 ;; character.
 337 (defun describe-char-display (pos char)
 338   (if (display-graphic-p (selected-frame))
 339       (let ((char-font-info (internal-char-font pos char)))
 340         (if char-font-info
 341             (let ((type (font-get (car char-font-info) :type))
 342                   (name (font-xlfd-name (car char-font-info)))
 343                   (code (cdr char-font-info)))
 344                (if (integerp code)
 345                    (format "%s:%s (#x%02X)" type name code)
 346                  (format "%s:%s (#x%04X%04X)"
 347                          type name (car code) (cdr code))))))
 348     (let* ((charset (get-text-property pos 'charset))
 349            (coding (or (terminal-coding-system) 'us-ascii))
 350            (encoded (encode-coding-char char coding charset)))
 351       (if encoded
 352           (encoded-string-description encoded coding)))))
 353
 354 \f
 355 ;; Return a string of CH with composition for padding on both sides.
 356 ;; It is displayed without overlapping with the left/right columns.
 357 (defsubst describe-char-padded-string (ch)
 358   (if (internal-char-font nil ch)
 359       (compose-string (string ch) 0 1 (format "\t%c\t" ch))
 360     (string ch)))
 361
 362 ;; Return a nicely formated list of categories; extended category
 363 ;; description is added to the category name as a tooltip
 364 (defsubst describe-char-categories (category-set)
 365   (let ((mnemonics (category-set-mnemonics category-set)))
 366     (unless (eq mnemonics "")
 367       (list (mapconcat
 368              #'(lambda (x)
 369                  (let* ((c (category-docstring x))
 370                         (doc (if (string-match "\\`\\(.*?\\)\n\\(.*\\)\\'" c)
 371                                  (propertize (match-string 1 c)
 372                                              'help-echo (match-string 2 c))
 373                                c)))
 374                    (format "%c:%s" x doc)))
 375              mnemonics ", ")))))
 376
 377 ;;;###autoload
 378 (defun describe-char (pos &optional buffer)
 379   "Describe the character after POS (interactively, the character after point).
 380 Is POS is taken to be in buffer BUFFER or current buffer if nil.
 381 The information includes character code, charset and code points in it,
 382 syntax, category, how the character is encoded in a file,
 383 character composition information (if relevant),
 384 as well as widgets, buttons, overlays, and text properties."
 385   (interactive "d")
 386   (unless (buffer-live-p buffer) (setq buffer (current-buffer)))
 387   (let ((src-buf (current-buffer)))
 388     (set-buffer buffer)
 389     (if (>= pos (point-max))
 390         (error "No character follows specified position"))
 391     (let* ((char (char-after pos))
 392            (eight-bit-p (and (not enable-multibyte-characters) (>= char 128)))
 393            (charset (if eight-bit-p 'eight-bit
 394                       (or (get-text-property pos 'charset)
 395                           (char-charset char))))
 396            (composition (find-composition pos nil nil t))
 397            (component-chars nil)
 398            (display-table (or (window-display-table)
 399                               buffer-display-table
 400                               standard-display-table))
 401            (disp-vector (and display-table (aref display-table char)))
 402            (multibyte-p enable-multibyte-characters)
 403            (overlays (mapcar #'(lambda (o) (overlay-properties o))
 404                              (overlays-at pos)))
 405            (char-description (if (not multibyte-p)
 406                                  (single-key-description char)
 407                                (if (< char 128)
 408                                    (single-key-description char)
 409                                  (string-to-multibyte
 410                                   (char-to-string char)))))
 411            (text-props-desc
 412             (let ((tmp-buf (generate-new-buffer " *text-props*")))
 413               (unwind-protect
 414                   (progn
 415                     (describe-text-properties pos tmp-buf)
 416                     (with-current-buffer tmp-buf (buffer-string)))
 417                 (kill-buffer tmp-buf))))
 418            item-list max-width code)
 419
 420       (if multibyte-p
 421           (or (setq code (encode-char char charset))
 422               (setq charset (char-charset char)
 423                     code (encode-char char charset)))
 424         (setq code char))
 425       (when composition
 426         ;; When the composition is trivial (i.e. composed only with the
 427         ;; current character itself without any alternate characters),
 428         ;; we don't show the composition information.  Otherwise, store
 429         ;; two descriptive strings in the first two elments of
 430         ;; COMPOSITION.
 431         (or (catch 'tag
 432               (let ((from (car composition))
 433                     (to (nth 1 composition))
 434                     (components (nth 2 composition))
 435                     ch)
 436                 (if (and (vectorp components) (vectorp (aref components 0)))
 437                     (let ((idx (- pos from))
 438                           (nglyphs (lgstring-glyph-len components))
 439                           (i 0) j glyph glyph-from)
 440                       ;; COMPONENTS is a gstring.  Find a grapheme
 441                       ;; cluster containing the current character.
 442                       (while (and (< i nglyphs)
 443                                   (setq glyph (lgstring-glyph components i))
 444                                   (< (lglyph-to glyph) idx))
 445                         (setq i (1+ i)))
 446                       (if (or (not glyph) (= i nglyphs))
 447                           ;; The composition is broken.
 448                           (throw 'tag nil))
 449                       (setq glyph-from (lglyph-from glyph)
 450                             to (+ from (lglyph-to glyph) 1)
 451                             from (+ from glyph-from)
 452                             j i)
 453                       (while (and (< j nglyphs)
 454                                   (setq glyph (lgstring-glyph components j))
 455                                   (= (lglyph-from glyph) glyph-from))
 456                         (setq j (1+ j)))
 457                       (if (and (= to (1+ from))
 458                                (= i (1- j))
 459                                (setq glyph (lgstring-glyph components i))
 460                                (= char (lglyph-char glyph)))
 461                           ;; The composition is trivial.
 462                           (throw 'tag nil))
 463                       (nconc composition (list i (1- j))))
 464                   (dotimes (i (length components))
 465                     (if (integerp (setq ch (aref components i)))
 466                         (push (cons ch (describe-char-display pos ch))
 467                               component-chars)))
 468                   (setq component-chars (nreverse component-chars)))
 469                 (if (< from pos)
 470                     (if (< (1+ pos) to)
 471                         (setcar composition
 472                                 (concat
 473                                  " with the surrounding characters \""
 474                                  (mapconcat 'describe-char-padded-string
 475                                             (buffer-substring from pos) "")
 476                                  "\" and \""
 477                                  (mapconcat 'describe-char-padded-string
 478                                             (buffer-substring (1+ pos) to) "")
 479                                  "\""))
 480                       (setcar composition
 481                               (concat
 482                                " with the preceding character(s) \""
 483                                (mapconcat 'describe-char-padded-string
 484                                           (buffer-substring from pos) "")
 485                                "\"")))
 486                   (if (< (1+ pos) to)
 487                       (setcar composition
 488                               (concat
 489                                " with the following character(s) \""
 490                                (mapconcat 'describe-char-padded-string
 491                                           (buffer-substring (1+ pos) to) "")
 492                                "\""))
 493                     (setcar composition nil)))
 494                 (setcar (cdr composition)
 495                         (format "composed to form \"%s\" (see below)"
 496                                 (buffer-substring from to)))))
 497             (setq composition nil)))
 498
 499       (setq item-list
 500             `(("character"
 501                ,(format "%s (%d, #o%o, #x%x)"
 502                         (apply 'propertize char-description
 503                                (text-properties-at pos))
 504                         char char char))
 505               ("preferred charset"
 506                ,`(insert-text-button
 507                   ,(symbol-name charset)
 508                   'type 'help-character-set 'help-args '(,charset))
 509                ,(format "(%s)" (charset-description charset)))
 510               ("code point"
 511                ,(let ((str (if (integerp code)
 512                                (format (if (< code 256) "0x%02X" "0x%04X")
 513                                        code)
 514                              (format "0x%04X%04X" (car code) (cdr code)))))
 515                   (if (<= (charset-dimension charset) 2)
 516                       `(insert-text-button
 517                         ,str
 518                         'action (lambda (&rest ignore)
 519                                   (list-charset-chars ',charset)
 520                                   (with-selected-window
 521                                       (get-buffer-window "*Character List*" 0)
 522                                     (goto-char (point-min))
 523                                     (forward-line 2) ;Skip the header.
 524                                     (let ((case-fold-search nil))
 525                                       (if (search-forward
 526                                            ,(char-to-string char) nil t)
 527                                           (goto-char (match-beginning 0))))))
 528                         'follow-link t
 529                         'help-echo
 530                         "mouse-2, RET: show this character in its character set")
 531                     str)))
 532               ("syntax"
 533                ,(let ((syntax (syntax-after pos)))
 534                   (with-temp-buffer
 535                     (internal-describe-syntax-value syntax)
 536                     (buffer-string))))
 537               ("category"
 538                ,@(if (not eight-bit-p)
 539                      (let ((category-set (char-category-set char)))
 540                        (if category-set
 541                            (describe-char-categories category-set)
 542                          '("-- none --")))))
 543               ("to input"
 544                ,@(if (not eight-bit-p)
 545                      (let ((key-list (and (eq input-method-function
 546                                               'quail-input-method)
 547                                           (quail-find-key char))))
 548                        (if (consp key-list)
 549                            (list "type"
 550                                  (concat "\""
 551                                          (mapconcat 'identity
 552                                                     key-list "\" or \"")
 553                                          "\"")
 554                                  "with"
 555                                  `(insert-text-button
 556                                    ,current-input-method
 557                                    'type 'help-input-method
 558                                    'help-args '(,current-input-method)))))))
 559               ("buffer code"
 560                ,(if multibyte-p
 561                     (encoded-string-description
 562                      (string-as-unibyte (char-to-string char)) nil)
 563                   (format "#x%02X" char)))
 564               ("file code"
 565                ,@(if multibyte-p
 566                      (let* ((coding buffer-file-coding-system)
 567                             (encoded (encode-coding-char char coding charset)))
 568                        (if encoded
 569                            (list (encoded-string-description encoded coding)
 570                                  (format "(encoded by coding system %S)"
 571                                          coding))
 572                          (list "not encodable by coding system"
 573                                (symbol-name coding))))
 574                    (list (format "#x%02X" char))))
 575               ("display"
 576                ,(cond
 577                  (disp-vector
 578                   (setq disp-vector (copy-sequence disp-vector))
 579                   (dotimes (i (length disp-vector))
 580                     (aset disp-vector i
 581                           (cons (aref disp-vector i)
 582                                 (describe-char-display
 583                                  pos (glyph-char (aref disp-vector i))))))
 584                   (format "by display table entry [%s] (see below)"
 585                           (mapconcat
 586                            #'(lambda (x)
 587                                (format "?%c" (glyph-char (car x))))
 588                            disp-vector " ")))
 589                  (composition
 590                   (cadr composition))
 591                  (t
 592                   (let ((display (describe-char-display pos char)))
 593                     (if (display-graphic-p (selected-frame))
 594                         (if display
 595                             (concat "by this font (glyph code)\n    " display)
 596                           "no font available")
 597                       (if display
 598                           (format "terminal code %s" display)
 599                         "not encodable for terminal"))))))
 600               ,@(let ((face
 601                        (if (not (or disp-vector composition))
 602                            (cond
 603                             ((and show-trailing-whitespace
 604                                   (save-excursion (goto-char pos)
 605                                                   (looking-at-p "[ \t]+$")))
 606                              'trailing-whitespace)
 607                             ((and nobreak-char-display char (eq char '#xa0))
 608                              'nobreak-space)
 609                             ((and nobreak-char-display char (eq char '#xad))
 610                              'escape-glyph)
 611                             ((and (< char 32) (not (memq char '(9 10))))
 612                              'escape-glyph)))))
 613                   (if face (list (list "hardcoded face"
 614                                        `(insert-text-button
 615                                          ,(symbol-name face)
 616                                          'type 'help-face
 617                                          'help-args '(,face))))))
 618               ,@(if (not eight-bit-p)
 619                     (let ((unicodedata (describe-char-unicode-data char)))
 620                       (if unicodedata
 621                           (cons (list "Unicode data" " ") unicodedata))))))
 622       (setq max-width (apply 'max (mapcar (lambda (x)
 623                                             (if (cadr x) (length (car x)) 0))
 624                                           item-list)))
 625       (set-buffer src-buf)
 626       (help-setup-xref (list 'describe-char pos buffer)
 627                        (called-interactively-p 'interactive))
 628       (with-help-window (help-buffer)
 629         (with-current-buffer standard-output
 630           (set-buffer-multibyte multibyte-p)
 631           (let ((formatter (format "%%%ds:" max-width)))
 632             (dolist (elt item-list)
 633               (when (cadr elt)
 634                 (insert (format formatter (car elt)))
 635                 (dolist (clm (cdr elt))
 636                   (if (eq (car-safe clm) 'insert-text-button)
 637                       (progn (insert " ") (eval clm))
 638                     (when (>= (+ (current-column)
 639                                  (or (string-match-p "\n" clm)
 640                                      (string-width clm))
 641                                  1)
 642                               (window-width))
 643                       (insert "\n")
 644                       (indent-to (1+ max-width)))
 645                     (insert " " clm)))
 646                 (insert "\n"))))
 647
 648           (when overlays
 649             (save-excursion
 650               (goto-char (point-min))
 651               (re-search-forward "character:[ \t\n]+")
 652               (let ((end (+ (point) (length char-description))))
 653                 (mapc #'(lambda (props)
 654                           (let ((o (make-overlay (point) end)))
 655                             (while props
 656                               (overlay-put o (car props) (nth 1 props))
 657                               (setq props (cddr props)))))
 658                       overlays))))
 659
 660           (when disp-vector
 661             (insert
 662              "\nThe display table entry is displayed by ")
 663             (if (display-graphic-p (selected-frame))
 664                 (progn
 665                   (insert "these fonts (glyph codes):\n")
 666                   (dotimes (i (length disp-vector))
 667                     (insert (glyph-char (car (aref disp-vector i))) ?:
 668                             (propertize " " 'display '(space :align-to 5))
 669                             (or (cdr (aref disp-vector i)) "-- no font --")
 670                             "\n")
 671                     (let ((face (glyph-face (car (aref disp-vector i)))))
 672                       (when face
 673                         (insert (propertize " " 'display '(space :align-to 5))
 674                                 "face: ")
 675                         (insert (concat "`" (symbol-name face) "'"))
 676                         (insert "\n")))))
 677               (insert "these terminal codes:\n")
 678               (dotimes (i (length disp-vector))
 679                 (insert (car (aref disp-vector i))
 680                         (propertize " " 'display '(space :align-to 5))
 681                         (or (cdr (aref disp-vector i)) "-- not encodable --")
 682                         "\n"))))
 683
 684           (when composition
 685             (insert "\nComposed")
 686             (if (car composition)
 687                 (insert (car composition)))
 688             (if (and (vectorp (nth 2 composition))
 689                      (vectorp (aref (nth 2 composition) 0)))
 690                 (let* ((gstring (nth 2 composition))
 691                        (font (lgstring-font gstring))
 692                        (from (nth 3 composition))
 693                        (to (nth 4 composition))
 694                        glyph)
 695                   (if (fontp font)
 696                       (progn
 697                         (insert " using this font:\n  "
 698                                 (symbol-name (font-get font :type))
 699                                 ?:
 700                                 (aref (query-font font) 0)
 701                                 "\nby these glyphs:\n")
 702                         (while (and (<= from to)
 703                                     (setq glyph (lgstring-glyph gstring from)))
 704                           (insert (format "  %S\n" glyph))
 705                           (setq from (1+ from))))
 706                     (insert " by these characters:\n")
 707                     (while (and (<= from to)
 708                                 (setq glyph (lgstring-glyph gstring from)))
 709                       (insert (format " %c (#x%d)\n"
 710                                       (lglyph-char glyph) (lglyph-char glyph)))
 711                       (setq from (1+ from)))))
 712               (insert " by the rule:\n\t(")
 713               (let ((first t))
 714                 (mapc (lambda (x)
 715                         (if first (setq first nil)
 716                           (insert " "))
 717                         (if (consp x) (insert (format "%S" x))
 718                           (if (= x ?\t) (insert (single-key-description x))
 719                             (insert ??)
 720                             (insert (describe-char-padded-string x)))))
 721                       (nth 2 composition)))
 722               (insert  ")\nThe component character(s) are displayed by ")
 723               (if (display-graphic-p (selected-frame))
 724                   (progn
 725                     (insert "these fonts (glyph codes):")
 726                     (dolist (elt component-chars)
 727                       (if (/= (car elt) ?\t)
 728                           (insert "\n "
 729                                   (describe-char-padded-string (car elt))
 730                                   ?:
 731                                   (propertize " "
 732                                               'display '(space :align-to 5))
 733                                   (or (cdr elt) "-- no font --")))))
 734                 (insert "these terminal codes:")
 735                 (dolist (elt component-chars)
 736                   (insert "\n  " (car elt) ":"
 737                           (propertize " " 'display '(space :align-to 4))
 738                           (or (cdr elt) "-- not encodable --"))))
 739               (insert "\nSee the variable `reference-point-alist' for "
 740                       "the meaning of the rule.\n")))
 741
 742           (unless eight-bit-p
 743             (insert (if (not describe-char-unidata-list)
 744                         "\nCharacter code properties are not shown: "
 745                       "\nCharacter code properties: "))
 746             (insert-text-button
 747              "customize what to show"
 748              'action (lambda (&rest ignore)
 749                        (customize-variable
 750                         'describe-char-unidata-list))
 751              'follow-link t)
 752             (insert "\n")
 753             (dolist (elt (if (eq describe-char-unidata-list t)
 754                              (nreverse (mapcar 'car char-code-property-alist))
 755                            describe-char-unidata-list))
 756               (let ((val (get-char-code-property char elt))
 757                     description)
 758                 (when val
 759                   (setq description (char-code-property-description elt val))
 760                   (insert (if description
 761                               (format "  %s: %s (%s)\n" elt val description)
 762                             (format "  %s: %s\n" elt val)))))))
 763
 764           (if text-props-desc (insert text-props-desc))
 765           (toggle-read-only 1))))))
 766
 767 (define-obsolete-function-alias 'describe-char-after 'describe-char "22.1")
 768
 769 (provide 'descr-text)
 770
 771 ;; arch-tag: fc55a498-f3e9-4312-b5bd-98cc02480af1
 772 ;;; descr-text.el ends here