summaryrefslogtreecommitdiff
path: root/lisp/descr-text.el
blob: 65590a737fceee24f29b85064d3c87704694db7c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
;;; descr-text.el --- describe text mode

;; Copyright (C) 1994, 1995, 1996, 2001, 2002, 2003, 2004,
;;   2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.

;; Author: Boris Goldowsky <boris@gnu.org>
;; Maintainer: FSF
;; Keywords: faces, i18n, Unicode, multilingual

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;; Describe-Text Mode.

;;; Code:

(eval-when-compile (require 'quail))
(require 'help-mode)

;;; Describe-Text Utilities.

(defun describe-text-widget (widget)
  "Insert text to describe WIDGET in the current buffer."
  (insert-text-button
   (symbol-name (if (symbolp widget) widget (car widget)))
   'action `(lambda (&rest ignore)
	      (widget-browse ',widget))
   'help-echo "mouse-2, RET: browse this widget")
  (insert " ")
  (insert-text-button
   "(widget)Top" 'type 'help-info 'help-args '("(widget)Top")))

(defun describe-text-sexp (sexp)
  "Insert a short description of SEXP in the current buffer."
  (let ((pp (condition-case signal
		(pp-to-string sexp)
	      (error (prin1-to-string signal)))))
    (when (string-match-p "\n\\'" pp)
      (setq pp (substring pp 0 (1- (length pp)))))

    (if (and (not (string-match-p "\n" pp))
    	     (<= (length pp) (- (window-width) (current-column))))
	(insert pp)
      (insert-text-button
       "[Show]" 'action `(lambda (&rest ignore)
			   (with-output-to-temp-buffer
			       "*Pp Eval Output*"
			     (princ ',pp)))
       'help-echo "mouse-2, RET: pretty print value in another buffer"))))

(defun describe-property-list (properties)
  "Insert a description of PROPERTIES in the current buffer.
PROPERTIES should be a list of overlay or text properties.
The `category', `face' and `font-lock-face' properties are made
into help buttons that call `describe-text-category' or
`describe-face' when pushed."
  ;; Sort the properties by the size of their value.
  (dolist (elt (sort (let (ret)
		       (while properties
			 (push (list (pop properties) (pop properties)) ret))
		       ret)
		     (lambda (a b) (string< (prin1-to-string (nth 0 a) t)
					    (prin1-to-string (nth 0 b) t)))))
    (let ((key (nth 0 elt))
	  (value (nth 1 elt)))
      (insert (propertize (format "  %-20s " key)
			  'face 'help-argument-name))
      (cond ((eq key 'category)
	     (insert-text-button
	      (symbol-name value)
	      'action `(lambda (&rest ignore)
			 (describe-text-category ',value))
	      'follow-link t
	      'help-echo "mouse-2, RET: describe this category"))
            ((memq key '(face font-lock-face mouse-face))
	     (insert-text-button
	      (format "%S" value)
	      'type 'help-face 'help-args (list value)))
            ((widgetp value)
	     (describe-text-widget value))
	    (t
	     (describe-text-sexp value))))
    (insert "\n")))

;;; Describe-Text Commands.

(defun describe-text-category (category)
  "Describe a text property category."
  (interactive "SCategory: ")
  (help-setup-xref (list #'describe-text-category category)
		   (called-interactively-p 'interactive))
  (with-help-window (help-buffer)
    (with-current-buffer standard-output
      (insert "Category " (format "%S" category) ":\n\n")
      (describe-property-list (symbol-plist category))
      (goto-char (point-min)))))

;;;###autoload
(defun describe-text-properties (pos &optional output-buffer buffer)
  "Describe widgets, buttons, overlays, and text properties at POS.
POS is taken to be in BUFFER or in current buffer if nil.
Interactively, describe them for the character after point.
If optional second argument OUTPUT-BUFFER is non-nil,
insert the output into that buffer, and don't initialize or clear it
otherwise."
  (interactive "d")
  (let ((src-buf (current-buffer)))
    (if buffer (set-buffer buffer) (setq buffer (current-buffer)))
  (if (>= pos (point-max))
      (error "No character follows specified position"))
  (if output-buffer
      (describe-text-properties-1 pos output-buffer)
    (if (not (or (text-properties-at pos) (overlays-at pos)))
	(message "This is plain text.")
        (with-temp-buffer
	    (setq output-buffer (current-buffer))
	    (insert "Text content at position " (format "%d" pos) ":\n\n")
          (set-buffer buffer)
          (describe-text-properties-1 pos output-buffer)
          (set-buffer src-buf)
          (help-setup-xref (list 'describe-text-properties pos nil buffer)
                           (called-interactively-p 'interactive))
          (with-help-window (help-buffer)
            (with-current-buffer standard-output
              (buffer-swap-text output-buffer)
              (goto-char (point-min)))))))))

(defun describe-text-properties-1 (pos output-buffer)
  (let* ((properties (text-properties-at pos))
	 (overlays (overlays-at pos))
	 (wid-field (get-char-property pos 'field))
	 (wid-button (get-char-property pos 'button))
	 (wid-doc (get-char-property pos 'widget-doc))
	 ;; If button.el is not loaded, we have no buttons in the text.
	 (button (and (fboundp 'button-at) (button-at pos)))
	 (button-type (and button (button-type button)))
	 (button-label (and button (button-label button)))
	 (widget (or wid-field wid-button wid-doc)))
    (with-current-buffer output-buffer
      ;; Widgets
      (when (widgetp widget)
	(newline)
	(insert (cond (wid-field "This is an editable text area")
		      (wid-button "This is an active area")
		      (wid-doc "This is documentation text")))
	(insert " of a ")
	(describe-text-widget widget)
	(insert ".\n\n"))
      ;; Buttons
      (when (and button (not (widgetp wid-button)))
	(newline)
	(insert "Here is a `" (format "%S" button-type)
		"' button labeled `" button-label "'.\n\n"))
      ;; Overlays
      (when overlays
	(newline)
	(if (eq (length overlays) 1)
	    (insert "There is an overlay here:\n")
	  (insert "There are " (format "%d" (length overlays))
			 " overlays here:\n"))
	(dolist (overlay overlays)
	  (insert " From " (format "%d" (overlay-start overlay))
			 " to " (format "%d" (overlay-end overlay)) "\n")
	  (describe-property-list (overlay-properties overlay)))
	(insert "\n"))
      ;; Text properties
      (when properties
	(newline)
	(insert "There are text properties here:\n")
	(describe-property-list properties)))))

(defcustom describe-char-unidata-list
  '(name old-name general-category decomposition)
  "List of Unicode-based character property names shown by `describe-char'."
  :group 'mule
  :version "23.1"
  :type '(choice (const :tag "All properties" t)
          (set
           (const :tag "Unicode name" name)
           (const :tag "Unicode old name" old-name)
           (const :tag "Unicode general category " general-category)
           (const :tag "Unicode canonical combining class"
                  canonical-combining-class)
           (const :tag "Unicode bidi class" bidi-class)
           (const :tag "Unicode decomposition mapping" decomposition)
           (const :tag "Unicode decimal digit value" decimal-digit-value)
           (const :tag "Unicode digit value" digit-value)
           (const :tag "Unicode numeric value" numeric-value)
           (const :tag "Unicode mirrored" mirrored)
           (const :tag "Unicode ISO 10646 comment" iso-10646-comment)
           (const :tag "Unicode simple uppercase mapping" uppercase)
           (const :tag "Unicode simple lowercase mapping" lowercase)
           (const :tag "Unicode simple titlecase mapping" titlecase))))

(defcustom describe-char-unicodedata-file nil
  "Location of Unicode data file.
This is the UnicodeData.txt file from the Unicode Consortium, used for
diagnostics.  If it is non-nil `describe-char' will print data
looked up from it.  This facility is mostly of use to people doing
multilingual development.

This is a fairly large file, not typically present on GNU systems.
At the time of writing it is at the URL
`http://www.unicode.org/Public/UNIDATA/UnicodeData.txt'."
  :group 'mule
  :version "22.1"
  :type '(choice (const :tag "None" nil)
		 file))

(defun describe-char-unicode-data (char)
  "Return a list of Unicode data for unicode CHAR.
Each element is a list of a property description and the property value.
The list is null if CHAR isn't found in `describe-char-unicodedata-file'.
This function is semi-obsolete.  Use `get-char-code-property'."
  (when describe-char-unicodedata-file
    (unless (file-exists-p describe-char-unicodedata-file)
      (error "`unicodedata-file' %s not found" describe-char-unicodedata-file))
    (with-current-buffer (get-buffer-create " *Unicode Data*")
      (when (zerop (buffer-size))
	;; Don't use -literally in case of DOS line endings.
	(insert-file-contents describe-char-unicodedata-file))
      (goto-char (point-min))
      (let ((hex (format "%04X" char))
	    found first last)
	(if (re-search-forward (concat "^" hex) nil t)
	    (setq found t)
	  ;; It's not listed explicitly.  Look for ranges, e.g. CJK
	  ;; ideographs, and check whether it's in one of them.
	  (while (and (re-search-forward "^\\([^;]+\\);[^;]+First>;" nil t)
		      (>= char (setq first
				     (string-to-number (match-string 1) 16)))
		      (progn
			(forward-line 1)
			(looking-at "^\\([^;]+\\);[^;]+Last>;")
			(> char
			   (setq last
				 (string-to-number (match-string 1) 16))))))
	  (if (and (>= char first)
		   (<= char last))
	      (setq found t)))
	(if found
	    (let ((fields (mapcar (lambda (elt)
				    (if (> (length elt) 0)
					elt))
				  (cdr (split-string
					(buffer-substring
					 (line-beginning-position)
					 (line-end-position))
					";")))))
	      ;; The length depends on whether the last field was empty.
	      (unless (or (= 13 (length fields))
			  (= 14 (length fields)))
		(error "Invalid contents in %s" describe-char-unicodedata-file))
	      ;; The field names and values lists are slightly
	      ;; modified from Mule-UCS unidata.el.
	      (list
	       (list "Name" (let ((name (nth 0 fields)))
			      ;; Check for <..., First>, <..., Last>
			      (if (string-match "\\`\\(<[^,]+\\)," name)
				  (concat (match-string 1 name) ">")
				name)))
	       (list "Category"
		     (let ((val (nth 1 fields)))
		       (or (char-code-property-description
			    'general-category (intern val))
			   val)))
	       (list "Combining class"
		     (let ((val (nth 1 fields)))
		       (or (char-code-property-description
			    'canonical-combining-class (intern val))
			   val)))
	       (list "Bidi category"
		     (let ((val (nth 1 fields)))
		       (or (char-code-property-description
			    'bidi-class (intern val))
			   val)))
	       (list
		"Decomposition"
		(if (nth 4 fields)
		    (let* ((parts (split-string (nth 4 fields)))
			   (info (car parts)))
		      (if (string-match "\\`<\\(.+\\)>\\'" info)
			  (setq info (match-string 1 info))
			(setq info nil))
		      (if info (setq parts (cdr parts)))
		      (setq parts (mapconcat
				   (lambda (arg)
				     (string (string-to-number arg 16)))
				   parts " "))
		      (concat info (if info " ") parts))))
	       (list "Decimal digit value"
		     (nth 5 fields))
	       (list "Digit value"
		     (nth 6 fields))
	       (list "Numeric value"
		     (nth 7 fields))
	       (list "Mirrored"
		     (if (equal "Y" (nth 8 fields))
			 "yes"))
	       (list "Old name" (nth 9 fields))
	       (list "ISO 10646 comment" (nth 10 fields))
	       (list "Uppercase" (and (nth 11 fields)
				      (string (string-to-number
					       (nth 11 fields) 16))))
	       (list "Lowercase" (and (nth 12 fields)
				      (string (string-to-number
					       (nth 12 fields) 16))))
	       (list "Titlecase" (and (nth 13 fields)
				      (string (string-to-number
					       (nth 13 fields) 16)))))))))))

;; Not defined on builds without X, but behind display-graphic-p.
(declare-function internal-char-font "fontset.c" (position &optional ch))

;; Return information about how CHAR is displayed at the buffer
;; position POS.  If the selected frame is on a graphic display,
;; return a string "FONT-DRIVER:FONT-NAME (GLYPH-CODE)" where:
;;   FONT-DRIVER is the font-driver name,
;;   FONT-NAME is the font name,
;;   GLYPH-CODE is a hexadigit string representing the glyph-ID.
;; Otherwise, return a string describing the terminal codes for the
;; character.
(defun describe-char-display (pos char)
  (if (display-graphic-p (selected-frame))
      (let ((char-font-info (internal-char-font pos char)))
	(if char-font-info
	    (let ((type (font-get (car char-font-info) :type))
		  (name (font-xlfd-name (car char-font-info)))
		  (code (cdr char-font-info)))
	       (if (integerp code)
		   (format "%s:%s (#x%02X)" type name code)
		 (format "%s:%s (#x%04X%04X)"
			 type name (car code) (cdr code))))))
    (let* ((charset (get-text-property pos 'charset))
	   (coding (or (terminal-coding-system) 'us-ascii))
	   (encoded (encode-coding-char char coding charset)))
      (if encoded
	  (encoded-string-description encoded coding)))))


;; Return a string of CH with composition for padding on both sides.
;; It is displayed without overlapping with the left/right columns.
(defsubst describe-char-padded-string (ch)
  (if (internal-char-font nil ch)
      (compose-string (string ch) 0 1 (format "\t%c\t" ch))
    (string ch)))

;; Return a nicely formated list of categories; extended category
;; description is added to the category name as a tooltip
(defsubst describe-char-categories (category-set)
  (let ((mnemonics (category-set-mnemonics category-set)))
    (unless (eq mnemonics "")
      (list (mapconcat
	     #'(lambda (x)
		 (let* ((c (category-docstring x))
			(doc (if (string-match "\\`\\(.*?\\)\n\\(.*\\)\\'" c)
				 (propertize (match-string 1 c)
					     'help-echo (match-string 2 c))
			       c)))
		   (format "%c:%s" x doc)))
	     mnemonics ", ")))))

;;;###autoload
(defun describe-char (pos &optional buffer)
  "Describe the character after POS (interactively, the character after point).
Is POS is taken to be in buffer BUFFER or current buffer if nil.
The information includes character code, charset and code points in it,
syntax, category, how the character is encoded in a file,
character composition information (if relevant),
as well as widgets, buttons, overlays, and text properties."
  (interactive "d")
  (unless (buffer-live-p buffer) (setq buffer (current-buffer)))
  (let ((src-buf (current-buffer)))
    (set-buffer buffer)
    (if (>= pos (point-max))
        (error "No character follows specified position"))
    (let* ((char (char-after pos))
           (eight-bit-p (and (not enable-multibyte-characters) (>= char 128)))
           (charset (if eight-bit-p 'eight-bit
                      (or (get-text-property pos 'charset)
                          (char-charset char))))
           (composition (find-composition pos nil nil t))
           (component-chars nil)
           (display-table (or (window-display-table)
                              buffer-display-table
                              standard-display-table))
           (disp-vector (and display-table (aref display-table char)))
           (multibyte-p enable-multibyte-characters)
           (overlays (mapcar #'(lambda (o) (overlay-properties o))
                             (overlays-at pos)))
           (char-description (if (not multibyte-p)
                                 (single-key-description char)
                               (if (< char 128)
                                   (single-key-description char)
                                 (string-to-multibyte
                                  (char-to-string char)))))
           (text-props-desc
            (let ((tmp-buf (generate-new-buffer " *text-props*")))
              (unwind-protect
                  (progn
                    (describe-text-properties pos tmp-buf)
                    (with-current-buffer tmp-buf (buffer-string)))
                (kill-buffer tmp-buf))))
           item-list max-width code)

      (if multibyte-p
          (or (setq code (encode-char char charset))
              (setq charset (char-charset char)
                    code (encode-char char charset)))
        (setq code char))
      (when composition
        ;; When the composition is trivial (i.e. composed only with the
        ;; current character itself without any alternate characters),
        ;; we don't show the composition information.  Otherwise, store
        ;; two descriptive strings in the first two elements of
        ;; COMPOSITION.
        (or (catch 'tag
              (let ((from (car composition))
                    (to (nth 1 composition))
                    (components (nth 2 composition))
                    ch)
                (if (and (vectorp components) (vectorp (aref components 0)))
                    (let ((idx (- pos from))
                          (nglyphs (lgstring-glyph-len components))
                          (i 0) j glyph glyph-from)
                      ;; COMPONENTS is a gstring.  Find a grapheme
                      ;; cluster containing the current character.
                      (while (and (< i nglyphs)
                                  (setq glyph (lgstring-glyph components i))
                                  (< (lglyph-to glyph) idx))
                        (setq i (1+ i)))
                      (if (or (not glyph) (= i nglyphs))
                          ;; The composition is broken.
                          (throw 'tag nil))
                      (setq glyph-from (lglyph-from glyph)
                            to (+ from (lglyph-to glyph) 1)
                            from (+ from glyph-from)
                            j i)
                      (while (and (< j nglyphs)
                                  (setq glyph (lgstring-glyph components j))
                                  (= (lglyph-from glyph) glyph-from))
                        (setq j (1+ j)))
                      (if (and (= to (1+ from))
                               (= i (1- j))
                               (setq glyph (lgstring-glyph components i))
                               (= char (lglyph-char glyph)))
                          ;; The composition is trivial.
                          (throw 'tag nil))
                      (nconc composition (list i (1- j))))
                  (dotimes (i (length components))
                    (if (integerp (setq ch (aref components i)))
                        (push (cons ch (describe-char-display pos ch))
                              component-chars)))
                  (setq component-chars (nreverse component-chars)))
                (if (< from pos)
                    (if (< (1+ pos) to)
                        (setcar composition
                                (concat
                                 " with the surrounding characters \""
                                 (mapconcat 'describe-char-padded-string
                                            (buffer-substring from pos) "")
                                 "\" and \""
                                 (mapconcat 'describe-char-padded-string
                                            (buffer-substring (1+ pos) to) "")
                                 "\""))
                      (setcar composition
                              (concat
                               " with the preceding character(s) \""
                               (mapconcat 'describe-char-padded-string
                                          (buffer-substring from pos) "")
                               "\"")))
                  (if (< (1+ pos) to)
                      (setcar composition
                              (concat
                               " with the following character(s) \""
                               (mapconcat 'describe-char-padded-string
                                          (buffer-substring (1+ pos) to) "")
                               "\""))
                    (setcar composition nil)))
                (setcar (cdr composition)
                        (format "composed to form \"%s\" (see below)"
                                (buffer-substring from to)))))
            (setq composition nil)))

      (setq item-list
            `(("character"
               ,(format "%s (%d, #o%o, #x%x)"
                        (apply 'propertize char-description
                               (text-properties-at pos))
                        char char char))
              ("preferred charset"
               ,`(insert-text-button
                  ,(symbol-name charset)
                  'type 'help-character-set 'help-args '(,charset))
               ,(format "(%s)" (charset-description charset)))
              ("code point"
               ,(let ((str (if (integerp code)
                               (format (if (< code 256) "0x%02X" "0x%04X")
                                       code)
                             (format "0x%04X%04X" (car code) (cdr code)))))
                  (if (<= (charset-dimension charset) 2)
                      `(insert-text-button
                        ,str
                        'action (lambda (&rest ignore)
                                  (list-charset-chars ',charset)
                                  (with-selected-window
                                      (get-buffer-window "*Character List*" 0)
                                    (goto-char (point-min))
                                    (forward-line 2) ;Skip the header.
                                    (let ((case-fold-search nil))
                                      (if (search-forward
                                           ,(char-to-string char) nil t)
                                          (goto-char (match-beginning 0))))))
                        'follow-link t
                        'help-echo
                        "mouse-2, RET: show this character in its character set")
                    str)))
              ("syntax"
               ,(let ((syntax (syntax-after pos)))
                  (with-temp-buffer
                    (internal-describe-syntax-value syntax)
                    (buffer-string))))
              ("category"
               ,@(if (not eight-bit-p)
                     (let ((category-set (char-category-set char)))
                       (if category-set
                           (describe-char-categories category-set)
                         '("-- none --")))))
              ("to input"
               ,@(if (not eight-bit-p)
                     (let ((key-list (and (eq input-method-function
                                              'quail-input-method)
                                          (quail-find-key char))))
                       (if (consp key-list)
                           (list "type"
                                 (concat "\""
                                         (mapconcat 'identity
                                                    key-list "\" or \"")
                                         "\"")
                                 "with"
                                 `(insert-text-button
                                   ,current-input-method
                                   'type 'help-input-method
                                   'help-args '(,current-input-method)))))))
              ("buffer code"
               ,(if multibyte-p
                    (encoded-string-description
                     (string-as-unibyte (char-to-string char)) nil)
                  (format "#x%02X" char)))
              ("file code"
               ,@(if multibyte-p
                     (let* ((coding buffer-file-coding-system)
                            (encoded (encode-coding-char char coding charset)))
                       (if encoded
                           (list (encoded-string-description encoded coding)
                                 (format "(encoded by coding system %S)"
                                         coding))
                         (list "not encodable by coding system"
                               (symbol-name coding))))
                   (list (format "#x%02X" char))))
              ("display"
               ,(cond
                 (disp-vector
                  (setq disp-vector (copy-sequence disp-vector))
                  (dotimes (i (length disp-vector))
                    (aset disp-vector i
                          (cons (aref disp-vector i)
                                (describe-char-display
                                 pos (glyph-char (aref disp-vector i))))))
                  (format "by display table entry [%s] (see below)"
                          (mapconcat
                           #'(lambda (x)
                               (format "?%c" (glyph-char (car x))))
                           disp-vector " ")))
                 (composition
                  (cadr composition))
                 (t
                  (let ((display (describe-char-display pos char)))
                    (if (display-graphic-p (selected-frame))
                        (if display
                            (concat "by this font (glyph code)\n    " display)
                          "no font available")
                      (if display
                          (format "terminal code %s" display)
                        "not encodable for terminal"))))))
              ,@(let ((face
                       (if (not (or disp-vector composition))
                           (cond
                            ((and show-trailing-whitespace
                                  (save-excursion (goto-char pos)
                                                  (looking-at-p "[ \t]+$")))
                             'trailing-whitespace)
                            ((and nobreak-char-display char (eq char '#xa0))
                             'nobreak-space)
                            ((and nobreak-char-display char (eq char '#xad))
                             'escape-glyph)
                            ((and (< char 32) (not (memq char '(9 10))))
                             'escape-glyph)))))
                  (if face (list (list "hardcoded face"
                                       `(insert-text-button
                                         ,(symbol-name face)
                                         'type 'help-face
                                         'help-args '(,face))))))
              ,@(if (not eight-bit-p)
                    (let ((unicodedata (describe-char-unicode-data char)))
                      (if unicodedata
                          (cons (list "Unicode data" "") unicodedata))))))
      (setq max-width (apply 'max (mapcar (lambda (x)
                                            (if (cadr x) (length (car x)) 0))
                                          item-list)))
      (set-buffer src-buf)
      (help-setup-xref (list 'describe-char pos buffer)
                       (called-interactively-p 'interactive))
      (with-help-window (help-buffer)
        (with-current-buffer standard-output
          (set-buffer-multibyte multibyte-p)
          (let ((formatter (format "%%%ds:" max-width)))
            (dolist (elt item-list)
              (when (cadr elt)
                (insert (format formatter (car elt)))
                (dolist (clm (cdr elt))
                  (if (eq (car-safe clm) 'insert-text-button)
                      (progn (insert " ") (eval clm))
                    (when (>= (+ (current-column)
                                 (or (string-match-p "\n" clm)
                                     (string-width clm))
                                 1)
                              (window-width))
                      (insert "\n")
                      (indent-to (1+ max-width)))
                    (unless (zerop (length clm))
                      (insert " " clm))))
                (insert "\n"))))

          (when overlays
            (save-excursion
              (goto-char (point-min))
              (re-search-forward "character:[ \t\n]+")
              (let ((end (+ (point) (length char-description))))
                (mapc #'(lambda (props)
                          (let ((o (make-overlay (point) end)))
                            (while props
                              (overlay-put o (car props) (nth 1 props))
                              (setq props (cddr props)))))
                      overlays))))

          (when disp-vector
            (insert
             "\nThe display table entry is displayed by ")
            (if (display-graphic-p (selected-frame))
                (progn
                  (insert "these fonts (glyph codes):\n")
                  (dotimes (i (length disp-vector))
                    (insert (glyph-char (car (aref disp-vector i))) ?:
                            (propertize " " 'display '(space :align-to 5))
                            (or (cdr (aref disp-vector i)) "-- no font --")
                            "\n")
                    (let ((face (glyph-face (car (aref disp-vector i)))))
                      (when face
                        (insert (propertize " " 'display '(space :align-to 5))
                                "face: ")
                        (insert (concat "`" (symbol-name face) "'"))
                        (insert "\n")))))
              (insert "these terminal codes:\n")
              (dotimes (i (length disp-vector))
                (insert (car (aref disp-vector i))
                        (propertize " " 'display '(space :align-to 5))
                        (or (cdr (aref disp-vector i)) "-- not encodable --")
                        "\n"))))

          (when composition
            (insert "\nComposed")
            (if (car composition)
                (insert (car composition)))
            (if (and (vectorp (nth 2 composition))
                     (vectorp (aref (nth 2 composition) 0)))
                (let* ((gstring (nth 2 composition))
                       (font (lgstring-font gstring))
                       (from (nth 3 composition))
                       (to (nth 4 composition))
                       glyph)
                  (if (fontp font)
                      (progn
                        (insert " using this font:\n  "
                                (symbol-name (font-get font :type))
                                ?:
                                (aref (query-font font) 0)
                                "\nby these glyphs:\n")
                        (while (and (<= from to)
                                    (setq glyph (lgstring-glyph gstring from)))
                          (insert (format "  %S\n" glyph))
                          (setq from (1+ from))))
                    (insert " by these characters:\n")
                    (while (and (<= from to)
                                (setq glyph (lgstring-glyph gstring from)))
                      (insert (format " %c (#x%d)\n"
                                      (lglyph-char glyph) (lglyph-char glyph)))
                      (setq from (1+ from)))))
              (insert " by the rule:\n\t(")
              (let ((first t))
                (mapc (lambda (x)
                        (if first (setq first nil)
                          (insert " "))
                        (if (consp x) (insert (format "%S" x))
                          (if (= x ?\t) (insert (single-key-description x))
                            (insert ??)
                            (insert (describe-char-padded-string x)))))
                      (nth 2 composition)))
              (insert  ")\nThe component character(s) are displayed by ")
              (if (display-graphic-p (selected-frame))
                  (progn
                    (insert "these fonts (glyph codes):")
                    (dolist (elt component-chars)
                      (if (/= (car elt) ?\t)
                          (insert "\n "
                                  (describe-char-padded-string (car elt))
                                  ?:
                                  (propertize " "
                                              'display '(space :align-to 5))
                                  (or (cdr elt) "-- no font --")))))
                (insert "these terminal codes:")
                (dolist (elt component-chars)
                  (insert "\n  " (car elt) ":"
                          (propertize " " 'display '(space :align-to 4))
                          (or (cdr elt) "-- not encodable --"))))
              (insert "\nSee the variable `reference-point-alist' for "
                      "the meaning of the rule.\n")))

          (unless eight-bit-p
            (insert (if (not describe-char-unidata-list)
                        "\nCharacter code properties are not shown: "
                      "\nCharacter code properties: "))
            (insert-text-button
             "customize what to show"
             'action (lambda (&rest ignore)
                       (customize-variable
                        'describe-char-unidata-list))
             'follow-link t)
            (insert "\n")
            (dolist (elt (if (eq describe-char-unidata-list t)
                             (nreverse (mapcar 'car char-code-property-alist))
                           describe-char-unidata-list))
              (let ((val (get-char-code-property char elt))
                    description)
                (when val
                  (setq description (char-code-property-description elt val))
                  (insert (if description
                              (format "  %s: %s (%s)\n" elt val description)
                            (format "  %s: %s\n" elt val)))))))

          (if text-props-desc (insert text-props-desc))
          (toggle-read-only 1))))))

(define-obsolete-function-alias 'describe-char-after 'describe-char "22.1")

(provide 'descr-text)

;;; descr-text.el ends here