code.delx.au - gnu-emacs/blob - lisp/net/shr.el

   1 ;;; shr.el --- Simple HTML Renderer
   2
   3 ;; Copyright (C) 2010-2015 Free Software Foundation, Inc.
   4
   5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   6 ;; Keywords: html
   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 ;; This package takes a HTML parse tree (as provided by
  26 ;; libxml-parse-html-region) and renders it in the current buffer.  It
  27 ;; does not do CSS, JavaScript or anything advanced: It's geared
  28 ;; towards rendering typical short snippets of HTML, like what you'd
  29 ;; find in HTML email and the like.
  30
  31 ;;; Code:
  32
  33 (eval-when-compile (require 'cl))
  34 (eval-when-compile (require 'url))      ;For url-filename's setf handler.
  35 (require 'browse-url)
  36 (require 'subr-x)
  37 (require 'dom)
  38
  39 (defgroup shr nil
  40   "Simple HTML Renderer"
  41   :version "25.1"
  42   :group 'web)
  43
  44 (defcustom shr-max-image-proportion 0.9
  45   "How big pictures displayed are in relation to the window they're in.
  46 A value of 0.7 means that they are allowed to take up 70% of the
  47 width and height of the window.  If they are larger than this,
  48 and Emacs supports it, then the images will be rescaled down to
  49 fit these criteria."
  50   :version "24.1"
  51   :group 'shr
  52   :type 'float)
  53
  54 (defcustom shr-blocked-images nil
  55   "Images that have URLs matching this regexp will be blocked."
  56   :version "24.1"
  57   :group 'shr
  58   :type '(choice (const nil) regexp))
  59
  60 (defcustom shr-use-fonts nil
  61   "If non-nil, use proportional fonts for text."
  62   :version "25.1"
  63   :group 'shr
  64   :type 'boolean)
  65
  66 (defcustom shr-table-horizontal-line nil
  67   "Character used to draw horizontal table lines.
  68 If nil, don't draw horizontal table lines."
  69   :group 'shr
  70   :type '(choice (const nil) character))
  71
  72 (defcustom shr-table-vertical-line ?\s
  73   "Character used to draw vertical table lines."
  74   :group 'shr
  75   :type 'character)
  76
  77 (defcustom shr-table-corner ?\s
  78   "Character used to draw table corners."
  79   :group 'shr
  80   :type 'character)
  81
  82 (defcustom shr-hr-line ?-
  83   "Character used to draw hr lines."
  84   :group 'shr
  85   :type 'character)
  86
  87 (defcustom shr-width nil
  88   "Frame width to use for rendering.
  89 May either be an integer specifying a fixed width in characters,
  90 or nil, meaning that the full width of the window should be
  91 used."
  92   :version "25.1"
  93   :type '(choice (integer :tag "Fixed width in characters")
  94                  (const   :tag "Use the width of the window" nil))
  95   :group 'shr)
  96
  97 (defcustom shr-bullet "* "
  98   "Bullet used for unordered lists.
  99 Alternative suggestions are:
 100 - \"  \"
 101 - \"  \""
 102   :version "24.4"
 103   :type 'string
 104   :group 'shr)
 105
 106 (defcustom shr-external-browser 'browse-url-default-browser
 107   "Function used to launch an external browser."
 108   :version "24.4"
 109   :group 'shr
 110   :type 'function)
 111
 112 (defcustom shr-image-animate t
 113   "Non nil means that images that can be animated will be."
 114   :version "24.4"
 115   :group 'shr
 116   :type 'boolean)
 117
 118 (defvar shr-content-function nil
 119   "If bound, this should be a function that will return the content.
 120 This is used for cid: URLs, and the function is called with the
 121 cid: URL as the argument.")
 122
 123 (defvar shr-put-image-function 'shr-put-image
 124   "Function called to put image and alt string.")
 125
 126 (defface shr-strike-through '((t (:strike-through t)))
 127   "Font for <s> elements."
 128   :group 'shr)
 129
 130 (defface shr-link
 131   '((t (:inherit link)))
 132   "Font for link elements."
 133   :group 'shr)
 134
 135 (defvar shr-inhibit-images nil
 136   "If non-nil, inhibit loading images.")
 137
 138 ;;; Internal variables.
 139
 140 (defvar shr-folding-mode nil)
 141 (defvar shr-start nil)
 142 (defvar shr-indentation 0)
 143 (defvar shr-internal-width nil)
 144 (defvar shr-list-mode nil)
 145 (defvar shr-content-cache nil)
 146 (defvar shr-kinsoku-shorten nil)
 147 (defvar shr-table-depth 0)
 148 (defvar shr-stylesheet nil)
 149 (defvar shr-base nil)
 150 (defvar shr-depth 0)
 151 (defvar shr-warning nil)
 152 (defvar shr-ignore-cache nil)
 153 (defvar shr-external-rendering-functions nil)
 154 (defvar shr-target-id nil)
 155 (defvar shr-inhibit-decoration nil)
 156 (defvar shr-table-separator-length 1)
 157 (defvar shr-table-separator-pixel-width 0)
 158 (defvar shr-table-id nil)
 159 (defvar shr-current-font nil)
 160 (defvar shr-internal-bullet nil)
 161
 162 (defvar shr-map
 163   (let ((map (make-sparse-keymap)))
 164     (define-key map "a" 'shr-show-alt-text)
 165     (define-key map "i" 'shr-browse-image)
 166     (define-key map "z" 'shr-zoom-image)
 167     (define-key map [?\t] 'shr-next-link)
 168     (define-key map [?\M-\t] 'shr-previous-link)
 169     (define-key map [follow-link] 'mouse-face)
 170     (define-key map [mouse-2] 'shr-browse-url)
 171     (define-key map "I" 'shr-insert-image)
 172     (define-key map "w" 'shr-copy-url)
 173     (define-key map "u" 'shr-copy-url)
 174     (define-key map "v" 'shr-browse-url)
 175     (define-key map "o" 'shr-save-contents)
 176     (define-key map "\r" 'shr-browse-url)
 177     map))
 178
 179 ;; Public functions and commands.
 180 (declare-function libxml-parse-html-region "xml.c"
 181                   (start end &optional base-url discard-comments))
 182
 183 (defun shr-render-buffer (buffer)
 184   "Display the HTML rendering of the current buffer."
 185   (interactive (list (current-buffer)))
 186   (or (fboundp 'libxml-parse-html-region)
 187       (error "This function requires Emacs to be compiled with libxml2"))
 188   (pop-to-buffer "*html*")
 189   (erase-buffer)
 190   (shr-insert-document
 191    (with-current-buffer buffer
 192      (libxml-parse-html-region (point-min) (point-max))))
 193   (goto-char (point-min)))
 194
 195 ;;;###autoload
 196 (defun shr-render-region (begin end &optional buffer)
 197   "Display the HTML rendering of the region between BEGIN and END."
 198   (interactive "r")
 199   (unless (fboundp 'libxml-parse-html-region)
 200     (error "This function requires Emacs to be compiled with libxml2"))
 201   (with-current-buffer (or buffer (current-buffer))
 202     (let ((dom (libxml-parse-html-region begin end)))
 203       (delete-region begin end)
 204       (goto-char begin)
 205       (shr-insert-document dom))))
 206
 207 ;;;###autoload
 208 (defun shr-insert-document (dom)
 209   "Render the parsed document DOM into the current buffer.
 210 DOM should be a parse tree as generated by
 211 `libxml-parse-html-region' or similar."
 212   (setq shr-content-cache nil)
 213   (let ((start (point))
 214         (shr-start nil)
 215         (shr-base nil)
 216         (shr-depth 0)
 217         (shr-table-id 0)
 218         (shr-warning nil)
 219         (shr-table-separator-pixel-width (shr-string-pixel-width "-"))
 220         (shr-internal-bullet (cons shr-bullet
 221                                    (shr-string-pixel-width shr-bullet)))
 222         (shr-internal-width (or (and shr-width
 223                                      (if (not shr-use-fonts)
 224                                          shr-width
 225                                        (* shr-width (frame-char-width))))
 226                                 (if (not shr-use-fonts)
 227                                     (- (window-width) 2)
 228                                   (- (window-pixel-width)
 229                                      (* (frame-fringe-width) 2))))))
 230     (shr-descend dom)
 231     (shr-fill-lines start (point))
 232     (shr-remove-trailing-whitespace start (point))
 233     (when shr-warning
 234       (message "%s" shr-warning))))
 235
 236 (defun shr-remove-trailing-whitespace (start end)
 237   (let ((width (window-width)))
 238     (save-restriction
 239       (narrow-to-region start end)
 240       (goto-char start)
 241       (while (not (eobp))
 242         (end-of-line)
 243         (when (> (shr-previous-newline-padding-width (current-column)) width)
 244           (dolist (overlay (overlays-at (point)))
 245             (when (overlay-get overlay 'before-string)
 246               (overlay-put overlay 'before-string nil))))
 247         (forward-line 1)))))
 248
 249 (defun shr-copy-url (&optional image-url)
 250   "Copy the URL under point to the kill ring.
 251 If IMAGE-URL (the prefix) is non-nil, or there is no link under
 252 point, but there is an image under point then copy the URL of the
 253 image under point instead.
 254 If called twice, then try to fetch the URL and see whether it
 255 redirects somewhere else."
 256   (interactive "P")
 257   (let ((url (or (get-text-property (point) 'shr-url)
 258                  (get-text-property (point) 'image-url))))
 259     (cond
 260      ((not url)
 261       (message "No URL under point"))
 262      ;; Resolve redirected URLs.
 263      ((equal url (car kill-ring))
 264       (url-retrieve
 265        url
 266        (lambda (a)
 267          (when (and (consp a)
 268                     (eq (car a) :redirect))
 269            (with-temp-buffer
 270              (insert (cadr a))
 271              (goto-char (point-min))
 272              ;; Remove common tracking junk from the URL.
 273              (when (re-search-forward ".utm_.*" nil t)
 274                (replace-match "" t t))
 275              (message "Copied %s" (buffer-string))
 276              (copy-region-as-kill (point-min) (point-max)))))
 277        nil t))
 278      ;; Copy the URL to the kill ring.
 279      (t
 280       (with-temp-buffer
 281         (insert (url-encode-url url))
 282         (copy-region-as-kill (point-min) (point-max))
 283         (message "Copied %s" (buffer-string)))))))
 284
 285 (defun shr-next-link ()
 286   "Skip to the next link."
 287   (interactive)
 288   (let ((skip (text-property-any (point) (point-max) 'help-echo nil)))
 289     (if (or (eobp)
 290             (not (setq skip (text-property-not-all skip (point-max)
 291                                                    'help-echo nil))))
 292         (message "No next link")
 293       (goto-char skip)
 294       (message "%s" (get-text-property (point) 'help-echo)))))
 295
 296 (defun shr-previous-link ()
 297   "Skip to the previous link."
 298   (interactive)
 299   (let ((start (point))
 300         (found nil))
 301     ;; Skip past the current link.
 302     (while (and (not (bobp))
 303                 (get-text-property (point) 'help-echo))
 304       (forward-char -1))
 305     ;; Find the previous link.
 306     (while (and (not (bobp))
 307                 (not (setq found (get-text-property (point) 'help-echo))))
 308       (forward-char -1))
 309     (if (not found)
 310         (progn
 311           (message "No previous link")
 312           (goto-char start))
 313       ;; Put point at the start of the link.
 314       (while (and (not (bobp))
 315                   (get-text-property (point) 'help-echo))
 316         (forward-char -1))
 317       (forward-char 1)
 318       (message "%s" (get-text-property (point) 'help-echo)))))
 319
 320 (defun shr-show-alt-text ()
 321   "Show the ALT text of the image under point."
 322   (interactive)
 323   (let ((text (get-text-property (point) 'shr-alt)))
 324     (if (not text)
 325         (message "No image under point")
 326       (message "%s" (shr-fill-text text)))))
 327
 328 (defun shr-browse-image (&optional copy-url)
 329   "Browse the image under point.
 330 If COPY-URL (the prefix if called interactively) is non-nil, copy
 331 the URL of the image to the kill buffer instead."
 332   (interactive "P")
 333   (let ((url (get-text-property (point) 'image-url)))
 334     (cond
 335      ((not url)
 336       (message "No image under point"))
 337      (copy-url
 338       (with-temp-buffer
 339         (insert url)
 340         (copy-region-as-kill (point-min) (point-max))
 341         (message "Copied %s" url)))
 342      (t
 343       (message "Browsing %s..." url)
 344       (browse-url url)))))
 345
 346 (defun shr-insert-image ()
 347   "Insert the image under point into the buffer."
 348   (interactive)
 349   (let ((url (get-text-property (point) 'image-url)))
 350     (if (not url)
 351         (message "No image under point")
 352       (message "Inserting %s..." url)
 353       (url-retrieve url 'shr-image-fetched
 354                     (list (current-buffer) (1- (point)) (point-marker))
 355                     t t))))
 356
 357 (defun shr-zoom-image ()
 358   "Toggle the image size.
 359 The size will be rotated between the default size, the original
 360 size, and full-buffer size."
 361   (interactive)
 362   (let ((url (get-text-property (point) 'image-url))
 363         (size (get-text-property (point) 'image-size))
 364         (buffer-read-only nil))
 365     (if (not url)
 366         (message "No image under point")
 367       ;; Delete the old picture.
 368       (while (get-text-property (point) 'image-url)
 369         (forward-char -1))
 370       (forward-char 1)
 371       (let ((start (point)))
 372         (while (get-text-property (point) 'image-url)
 373           (forward-char 1))
 374         (forward-char -1)
 375         (put-text-property start (point) 'display nil)
 376         (when (> (- (point) start) 2)
 377           (delete-region start (1- (point)))))
 378       (message "Inserting %s..." url)
 379       (url-retrieve url 'shr-image-fetched
 380                     (list (current-buffer) (1- (point)) (point-marker)
 381                           (list (cons 'size
 382                                       (cond ((or (eq size 'default)
 383                                                  (null size))
 384                                              'original)
 385                                             ((eq size 'original)
 386                                              'full)
 387                                             ((eq size 'full)
 388                                              'default)))))
 389                     t))))
 390
 391 ;;; Utility functions.
 392
 393 (defsubst shr-generic (dom)
 394   (dolist (sub (dom-children dom))
 395     (if (stringp sub)
 396         (shr-insert sub)
 397       (shr-descend sub))))
 398
 399 (defun shr-descend (dom)
 400   (let ((function
 401          (or
 402           ;; Allow other packages to override (or provide) rendering
 403           ;; of elements.
 404           (cdr (assq (dom-tag dom) shr-external-rendering-functions))
 405           (intern (concat "shr-tag-" (symbol-name (dom-tag dom))) obarray)))
 406         (style (dom-attr dom 'style))
 407         (shr-stylesheet shr-stylesheet)
 408         (shr-depth (1+ shr-depth))
 409         (start (point)))
 410     ;; shr uses about 12 frames per nested node.
 411     (if (> shr-depth (/ max-specpdl-size 12))
 412         (setq shr-warning "Too deeply nested to render properly; consider increasing `max-specpdl-size'")
 413       (when style
 414         (if (string-match "color\\|display\\|border-collapse" style)
 415             (setq shr-stylesheet (nconc (shr-parse-style style)
 416                                         shr-stylesheet))
 417           (setq style nil)))
 418       ;; If we have a display:none, then just ignore this part of the DOM.
 419       (unless (equal (cdr (assq 'display shr-stylesheet)) "none")
 420         (if (fboundp function)
 421             (funcall function dom)
 422           (shr-generic dom))
 423         (when (and shr-target-id
 424                    (equal (dom-attr dom 'id) shr-target-id))
 425           ;; If the element was empty, we don't have anything to put the
 426           ;; anchor on.  So just insert a dummy character.
 427           (when (= start (point))
 428             (insert "*"))
 429           (put-text-property start (1+ start) 'shr-target-id shr-target-id))
 430         ;; If style is set, then this node has set the color.
 431         (when style
 432           (shr-colorize-region
 433            start (point)
 434            (cdr (assq 'color shr-stylesheet))
 435            (cdr (assq 'background-color shr-stylesheet))))))))
 436
 437 (defun shr-fill-text (text)
 438   (if (zerop (length text))
 439       text
 440     (with-temp-buffer
 441       (let ((shr-indentation 0)
 442             (shr-start nil)
 443             (shr-internal-width (- (window-pixel-width)
 444                                    (* (frame-fringe-width) 2))))
 445         (shr-insert text)
 446         (buffer-string)))))
 447
 448 (define-inline shr-char-breakable-p (char)
 449   "Return non-nil if a line can be broken before and after CHAR."
 450   (inline-quote (aref fill-find-break-point-function-table ,char)))
 451 (define-inline shr-char-nospace-p (char)
 452   "Return non-nil if no space is required before and after CHAR."
 453   (inline-quote (aref fill-nospace-between-words-table ,char)))
 454
 455 ;; KINSOKU is a Japanese word meaning a rule that should not be violated.
 456 ;; In Emacs, it is a term used for characters, e.g. punctuation marks,
 457 ;; parentheses, and so on, that should not be placed in the beginning
 458 ;; of a line or the end of a line.
 459 (define-inline shr-char-kinsoku-bol-p (char)
 460   "Return non-nil if a line ought not to begin with CHAR."
 461   (inline-letevals (char)
 462     (inline-quote (and (not (eq ,char ?'))
 463                        (aref (char-category-set ,char) ?>)))))
 464 (define-inline shr-char-kinsoku-eol-p (char)
 465   "Return non-nil if a line ought not to end with CHAR."
 466   (inline-quote (aref (char-category-set ,char) ?<)))
 467 (unless (shr-char-kinsoku-bol-p (make-char 'japanese-jisx0208 33 35))
 468   (load "kinsoku" nil t))
 469
 470 (defun shr-pixel-column ()
 471   (if (not shr-use-fonts)
 472       (current-column)
 473     (if (not (get-buffer-window (current-buffer)))
 474         (save-window-excursion
 475           (set-window-buffer nil (current-buffer))
 476           (car (window-text-pixel-size nil (line-beginning-position) (point))))
 477       (car (window-text-pixel-size nil (line-beginning-position) (point))))))
 478
 479 (defun shr-pixel-region ()
 480   (- (shr-pixel-column)
 481      (save-excursion
 482        (goto-char (mark))
 483        (shr-pixel-column))))
 484
 485 (defun shr-string-pixel-width (string)
 486   (if (not shr-use-fonts)
 487       (length string)
 488     (with-temp-buffer
 489       (insert string)
 490       (shr-pixel-column))))
 491
 492 (defun shr-insert (text)
 493   (when (and (not (bolp))
 494              (get-text-property (1- (point)) 'image-url))
 495     (insert "\n"))
 496   (cond
 497    ((eq shr-folding-mode 'none)
 498     (let ((start (point)))
 499       (insert text)
 500       (save-restriction
 501         (narrow-to-region start (point))
 502         ;; Remove soft hyphens.
 503         (goto-char (point-min))
 504         (while (search-forward "" nil t)
 505           (replace-match "" t t))
 506         (goto-char (point-max)))))
 507    (t
 508     (let ((font-start (point)))
 509       (when (and (string-match "\\`[ \t\n\r ]" text)
 510                  (not (bolp))
 511                  (not (eq (char-after (1- (point))) ? )))
 512         (insert " "))
 513       (let ((start (point))
 514             (bolp (bolp)))
 515         (insert text)
 516         (save-restriction
 517           (narrow-to-region start (point))
 518           (goto-char start)
 519           (when (looking-at "[ \t\n\r ]+")
 520             (replace-match "" t t))
 521           (while (re-search-forward "[ \t\n\r ]+" nil t)
 522             (replace-match " " t t))
 523           ;; Remove soft hyphens.
 524           (goto-char (point-min))
 525           (while (search-forward "" nil t)
 526             (replace-match "" t t))
 527           (goto-char (point-max)))
 528         ;; We may have removed everything we inserted if if was just
 529         ;; spaces.
 530         (unless (= font-start (point))
 531           ;; Mark all lines that should possibly be folded afterwards.
 532           (when bolp
 533             (shr-mark-fill start))
 534           (when shr-use-fonts
 535             (put-text-property font-start (point)
 536                                'face
 537                                (or shr-current-font 'variable-pitch)))))))))
 538
 539 (defun shr-fill-lines (start end)
 540   (if (<= shr-internal-width 0)
 541       nil
 542     (save-restriction
 543       (narrow-to-region start end)
 544       (goto-char start)
 545       (when (get-text-property (point) 'shr-indentation)
 546         (shr-fill-line))
 547       (while (setq start (next-single-property-change start 'shr-indentation))
 548         (goto-char start)
 549         (when (bolp)
 550           (shr-fill-line)))
 551       (goto-char (point-max)))))
 552
 553 (defun shr-vertical-motion (column)
 554   (if (not shr-use-fonts)
 555       (move-to-column column)
 556     (unless (eolp)
 557       (forward-char 1))
 558     (vertical-motion (cons (/ column (frame-char-width)) 0))
 559     (unless (eolp)
 560       (forward-char 1))))
 561
 562 (defun shr-fill-line ()
 563   (let ((shr-indentation (get-text-property (point) 'shr-indentation))
 564         (continuation (get-text-property
 565                        (point) 'shr-continuation-indentation))
 566         start)
 567     (put-text-property (point) (1+ (point)) 'shr-indentation nil)
 568     (let ((face (get-text-property (point) 'face))
 569           (background-start (point)))
 570       (shr-indent)
 571       (when face
 572         (put-text-property background-start (point) 'face
 573                            `,(shr-face-background face))))
 574     (setq start (point))
 575     (setq shr-indentation (or continuation shr-indentation))
 576     (shr-vertical-motion shr-internal-width)
 577     (when (looking-at " $")
 578       (delete-region (point) (line-end-position)))
 579     (while (not (eolp))
 580       ;; We have to do some folding.  First find the first
 581       ;; previous point suitable for folding.
 582       (if (or (not (shr-find-fill-point (line-beginning-position)))
 583               (= (point) start))
 584           ;; We had unbreakable text (for this width), so just go to
 585           ;; the first space and carry on.
 586           (progn
 587             (beginning-of-line)
 588             (skip-chars-forward " ")
 589             (search-forward " " (line-end-position) 'move)))
 590       ;; Success; continue.
 591       (when (= (preceding-char) ?\s)
 592         (delete-char -1))
 593       (let ((face (get-text-property (point) 'face))
 594             (background-start (point)))
 595         (insert "\n")
 596         (shr-indent)
 597         (when face
 598           (put-text-property background-start (point) 'face
 599                              `,(shr-face-background face))))
 600       (setq start (point))
 601       (shr-vertical-motion shr-internal-width)
 602       (when (looking-at " $")
 603         (delete-region (point) (line-end-position))))))
 604
 605 (defun shr-find-fill-point (start)
 606   (let ((bp (point))
 607         (end (point))
 608         failed)
 609     (while (not (or (setq failed (<= (point) start))
 610                     (eq (preceding-char) ? )
 611                     (eq (following-char) ? )
 612                     (shr-char-breakable-p (preceding-char))
 613                     (shr-char-breakable-p (following-char))
 614                     (and (shr-char-kinsoku-bol-p (preceding-char))
 615                          (shr-char-breakable-p (following-char))
 616                          (not (shr-char-kinsoku-bol-p (following-char))))
 617                     (shr-char-kinsoku-eol-p (following-char))
 618                     (bolp)))
 619       (backward-char 1))
 620     (if failed
 621         ;; There's no breakable point, so we give it up.
 622         (let (found)
 623           (goto-char bp)
 624           (unless shr-kinsoku-shorten
 625             (while (setq found (re-search-forward
 626                                 "\\(\\c>\\)\\| \\|\\c<\\|\\c|"
 627                                 (line-end-position) 'move)))
 628             (if (and found
 629                      (not (match-beginning 1)))
 630                 (goto-char (match-beginning 0)))))
 631       (or
 632        (eolp)
 633        ;; Don't put kinsoku-bol characters at the beginning of a line,
 634        ;; or kinsoku-eol characters at the end of a line.
 635        (cond
 636         (shr-kinsoku-shorten
 637          (while (and (not (memq (preceding-char) (list ?\C-@ ?\n ? )))
 638                      (shr-char-kinsoku-eol-p (preceding-char)))
 639            (backward-char 1))
 640          (when (setq failed (<= (point) start))
 641            ;; There's no breakable point that doesn't violate kinsoku,
 642            ;; so we look for the second best position.
 643            (while (and (progn
 644                          (forward-char 1)
 645                          (<= (point) end))
 646                        (progn
 647                          (setq bp (point))
 648                          (shr-char-kinsoku-eol-p (following-char)))))
 649            (goto-char bp)))
 650         ((shr-char-kinsoku-eol-p (preceding-char))
 651          ;; Find backward the point where kinsoku-eol characters begin.
 652          (let ((count 4))
 653            (while
 654                (progn
 655                  (backward-char 1)
 656                  (and (> (setq count (1- count)) 0)
 657                       (not (memq (preceding-char) (list ?\C-@ ?\n ? )))
 658                       (or (shr-char-kinsoku-eol-p (preceding-char))
 659                           (shr-char-kinsoku-bol-p (following-char)))))))
 660          (when (setq failed (<= (point) start))
 661            ;; There's no breakable point that doesn't violate kinsoku,
 662            ;; so we go to the second best position.
 663            (if (looking-at "\\(\\c<+\\)\\c<")
 664                (goto-char (match-end 1))
 665              (forward-char 1))))
 666         ((shr-char-kinsoku-bol-p (following-char))
 667          ;; Find forward the point where kinsoku-bol characters end.
 668          (let ((count 4))
 669            (while (progn
 670                     (forward-char 1)
 671                     (and (>= (setq count (1- count)) 0)
 672                          (shr-char-kinsoku-bol-p (following-char))
 673                          (shr-char-breakable-p (following-char))))))))
 674        (when (eq (following-char) ? )
 675          (forward-char 1))))
 676     (not failed)))
 677
 678 (defun shr-parse-base (url)
 679   ;; Always chop off anchors.
 680   (when (string-match "#.*" url)
 681     (setq url (substring url 0 (match-beginning 0))))
 682   ;; NB: <base href="" > URI may itself be relative to the document s URI
 683   (setq url (shr-expand-url url))
 684   (let* ((parsed (url-generic-parse-url url))
 685          (local (url-filename parsed)))
 686     (setf (url-filename parsed) "")
 687     ;; Chop off the bit after the last slash.
 688     (when (string-match "\\`\\(.*/\\)[^/]+\\'" local)
 689       (setq local (match-string 1 local)))
 690     ;; Always make the local bit end with a slash.
 691     (when (and (not (zerop (length local)))
 692                (not (eq (aref local (1- (length local))) ?/)))
 693       (setq local (concat local "/")))
 694     (list (url-recreate-url parsed)
 695           local
 696           (url-type parsed)
 697           url)))
 698
 699 (autoload 'url-expand-file-name "url-expand")
 700
 701 ;; FIXME This needs some tests writing.
 702 ;; Does it even need to exist, given that url-expand-file-name does?
 703 (defun shr-expand-url (url &optional base)
 704   (setq base
 705         (if base
 706             ;; shr-parse-base should never call this with non-nil base!
 707             (shr-parse-base base)
 708           ;; Bound by the parser.
 709           shr-base))
 710   (when (zerop (length url))
 711     (setq url nil))
 712   ;; Strip leading whitespace
 713   (and url (string-match "\\`\\s-+" url)
 714        (setq url (substring url (match-end 0))))
 715   (cond ((or (not url)
 716              (not base)
 717              (string-match "\\`[a-z]*:" url))
 718          ;; Absolute or empty URI
 719          (or url (nth 3 base)))
 720         ((eq (aref url 0) ?/)
 721          (if (and (> (length url) 1)
 722                   (eq (aref url 1) ?/))
 723              ;; //host...; just use the protocol
 724              (concat (nth 2 base) ":" url)
 725            ;; Just use the host name part.
 726            (concat (car base) url)))
 727         ((eq (aref url 0) ?#)
 728          ;; A link to an anchor.
 729          (concat (nth 3 base) url))
 730         (t
 731          ;; Totally relative.
 732          (url-expand-file-name url (concat (car base) (cadr base))))))
 733
 734 (defun shr-ensure-newline ()
 735   (unless (zerop (current-column))
 736     (insert "\n")))
 737
 738 (defun shr-ensure-paragraph ()
 739   (unless (bobp)
 740     (let ((prefix (get-text-property (line-beginning-position)
 741                                      'shr-prefix-length)))
 742       (cond
 743        ((and (bolp)
 744              (save-excursion
 745                (forward-line -1)
 746                (looking-at " *$")))
 747         ;; We're already at a new paragraph; do nothing.
 748         )
 749        ((and prefix
 750              (= prefix (- (point) (line-beginning-position))))
 751         ;; Do nothing; we're at the start of a <li>.
 752         )
 753        ((save-excursion
 754           (beginning-of-line)
 755           ;; If the current line is totally blank, and doesn't even
 756           ;; have any face properties set, then delete the blank
 757           ;; space.
 758           (and (looking-at " *$")
 759                (not (get-text-property (point) 'face))
 760                (not (= (next-single-property-change (point) 'face nil
 761                                                     (line-end-position))
 762                        (line-end-position)))))
 763         (delete-region (match-beginning 0) (match-end 0)))
 764        (t
 765         (insert "\n\n"))))))
 766
 767 (defun shr-indent ()
 768   (when (> shr-indentation 0)
 769     (insert
 770      (if (not shr-use-fonts)
 771          (make-string shr-indentation ?\s)
 772        (propertize " "
 773                    'display
 774                    `(space :width (,shr-indentation)))))))
 775
 776 (defun shr-fontize-dom (dom &rest types)
 777   (let ((start (point)))
 778     (shr-generic dom)
 779     (dolist (type types)
 780       (shr-add-font start (point) type))))
 781
 782 ;; Add face to the region, but avoid putting the font properties on
 783 ;; blank text at the start of the line, and the newline at the end, to
 784 ;; avoid ugliness.
 785 (defun shr-add-font (start end type)
 786   (unless shr-inhibit-decoration
 787     (save-excursion
 788       (goto-char start)
 789       (while (< (point) end)
 790         (when (bolp)
 791           (skip-chars-forward " "))
 792         (add-face-text-property (point) (min (line-end-position) end) type t)
 793         (if (< (line-end-position) end)
 794             (forward-line 1)
 795           (goto-char end))))))
 796
 797 (defun shr-mouse-browse-url (ev)
 798   "Browse the URL under the mouse cursor."
 799   (interactive "e")
 800   (mouse-set-point ev)
 801   (shr-browse-url))
 802
 803 (defun shr-browse-url (&optional external mouse-event)
 804   "Browse the URL under point.
 805 If EXTERNAL, browse the URL using `shr-external-browser'."
 806   (interactive (list current-prefix-arg last-nonmenu-event))
 807   (mouse-set-point mouse-event)
 808   (let ((url (get-text-property (point) 'shr-url)))
 809     (cond
 810      ((not url)
 811       (message "No link under point"))
 812      ((string-match "^mailto:" url)
 813       (browse-url-mail url))
 814      (t
 815       (if external
 816           (funcall shr-external-browser url)
 817         (browse-url url))))))
 818
 819 (defun shr-save-contents (directory)
 820   "Save the contents from URL in a file."
 821   (interactive "DSave contents of URL to directory: ")
 822   (let ((url (get-text-property (point) 'shr-url)))
 823     (if (not url)
 824         (message "No link under point")
 825       (url-retrieve (shr-encode-url url)
 826                     'shr-store-contents (list url directory)
 827                     nil t))))
 828
 829 (defun shr-store-contents (status url directory)
 830   (unless (plist-get status :error)
 831     (when (or (search-forward "\n\n" nil t)
 832               (search-forward "\r\n\r\n" nil t))
 833       (write-region (point) (point-max)
 834                     (expand-file-name (file-name-nondirectory url)
 835                                       directory)))))
 836
 837 (defun shr-image-fetched (status buffer start end &optional flags)
 838   (let ((image-buffer (current-buffer)))
 839     (when (and (buffer-name buffer)
 840                (not (plist-get status :error)))
 841       (url-store-in-cache image-buffer)
 842       (when (or (search-forward "\n\n" nil t)
 843                 (search-forward "\r\n\r\n" nil t))
 844         (let ((data (shr-parse-image-data)))
 845           (with-current-buffer buffer
 846             (save-excursion
 847               (let ((alt (buffer-substring start end))
 848                     (properties (text-properties-at start))
 849                     (inhibit-read-only t))
 850                 (delete-region start end)
 851                 (goto-char start)
 852                 (funcall shr-put-image-function data alt flags)
 853                 (while properties
 854                   (let ((type (pop properties))
 855                         (value (pop properties)))
 856                     (unless (memq type '(display image-size))
 857                       (put-text-property start (point) type value))))))))))
 858     (kill-buffer image-buffer)))
 859
 860 (defun shr-image-from-data (data)
 861   "Return an image from the data: URI content DATA."
 862   (when (string-match
 863          "\\(\\([^/;,]+\\(/[^;,]+\\)?\\)\\(;[^;,]+\\)*\\)?,\\(.*\\)"
 864          data)
 865     (let ((param (match-string 4 data))
 866           (payload (url-unhex-string (match-string 5 data))))
 867       (when (string-match "^.*\\(;[ \t]*base64\\)$" param)
 868         (setq payload (base64-decode-string payload)))
 869       payload)))
 870
 871 ;; Behind display-graphic-p test.
 872 (declare-function image-size "image.c" (spec &optional pixels frame))
 873 (declare-function image-animate "image" (image &optional index limit))
 874
 875 (defun shr-put-image (spec alt &optional flags)
 876   "Insert image SPEC with a string ALT.  Return image.
 877 SPEC is either an image data blob, or a list where the first
 878 element is the data blob and the second element is the content-type."
 879   (if (display-graphic-p)
 880       (let* ((size (cdr (assq 'size flags)))
 881              (data (if (consp spec)
 882                        (car spec)
 883                      spec))
 884              (content-type (and (consp spec)
 885                                 (cadr spec)))
 886              (start (point))
 887              (image (cond
 888                      ((eq size 'original)
 889                       (create-image data nil t :ascent 100
 890                                     :format content-type))
 891                      ((eq content-type 'image/svg+xml)
 892                       (create-image data 'svg t :ascent 100))
 893                      ((eq size 'full)
 894                       (ignore-errors
 895                         (shr-rescale-image data content-type)))
 896                      (t
 897                       (ignore-errors
 898                         (shr-rescale-image data content-type))))))
 899         (when image
 900           ;; When inserting big-ish pictures, put them at the
 901           ;; beginning of the line.
 902           (when (and (> (current-column) 0)
 903                      (> (car (image-size image t)) 400))
 904             (insert "\n"))
 905           (if (eq size 'original)
 906               (insert-sliced-image image (or alt "*") nil 20 1)
 907             (insert-image image (or alt "*")))
 908           (put-text-property start (point) 'image-size size)
 909           (when (and shr-image-animate
 910                      (cond ((fboundp 'image-multi-frame-p)
 911                        ;; Only animate multi-frame things that specify a
 912                        ;; delay; eg animated gifs as opposed to
 913                        ;; multi-page tiffs.  FIXME?
 914                             (cdr (image-multi-frame-p image)))
 915                            ((fboundp 'image-animated-p)
 916                             (image-animated-p image))))
 917             (image-animate image nil 60)))
 918         image)
 919     (insert alt)))
 920
 921 (defun shr-rescale-image (data &optional content-type)
 922   "Rescale DATA, if too big, to fit the current buffer."
 923   (if (not (and (fboundp 'imagemagick-types)
 924                 (get-buffer-window (current-buffer))))
 925       (create-image data nil t :ascent 100)
 926     (let ((edges (window-inside-pixel-edges
 927                   (get-buffer-window (current-buffer)))))
 928       (create-image
 929        data 'imagemagick t
 930        :ascent 100
 931        :max-width (truncate (* shr-max-image-proportion
 932                                (- (nth 2 edges) (nth 0 edges))))
 933        :max-height (truncate (* shr-max-image-proportion
 934                                 (- (nth 3 edges) (nth 1 edges))))
 935        :format content-type))))
 936
 937 ;; url-cache-extract autoloads url-cache.
 938 (declare-function url-cache-create-filename "url-cache" (url))
 939 (autoload 'mm-disable-multibyte "mm-util")
 940 (autoload 'browse-url-mail "browse-url")
 941
 942 (defun shr-get-image-data (url)
 943   "Get image data for URL.
 944 Return a string with image data."
 945   (with-temp-buffer
 946     (mm-disable-multibyte)
 947     (when (ignore-errors
 948             (url-cache-extract (url-cache-create-filename (shr-encode-url url)))
 949             t)
 950       (when (or (search-forward "\n\n" nil t)
 951                 (search-forward "\r\n\r\n" nil t))
 952         (shr-parse-image-data)))))
 953
 954 (defun shr-parse-image-data ()
 955   (let ((data (buffer-substring (point) (point-max)))
 956         (content-type
 957          (save-excursion
 958            (save-restriction
 959              (narrow-to-region (point-min) (point))
 960              (let ((content-type (mail-fetch-field "content-type")))
 961                (and content-type
 962                     ;; Remove any comments in the type string.
 963                     (intern (replace-regexp-in-string ";.*" "" content-type)
 964                             obarray)))))))
 965     ;; SVG images may contain references to further images that we may
 966     ;; want to block.  So special-case these by parsing the XML data
 967     ;; and remove the blocked bits.
 968     (when (eq content-type 'image/svg+xml)
 969       (setq data
 970             (shr-dom-to-xml
 971              (libxml-parse-xml-region (point) (point-max)))))
 972     (list data content-type)))
 973
 974 (defun shr-image-displayer (content-function)
 975   "Return a function to display an image.
 976 CONTENT-FUNCTION is a function to retrieve an image for a cid url that
 977 is an argument.  The function to be returned takes three arguments URL,
 978 START, and END.  Note that START and END should be markers."
 979   `(lambda (url start end)
 980      (when url
 981        (if (string-match "\\`cid:" url)
 982            ,(when content-function
 983               `(let ((image (funcall ,content-function
 984                                      (substring url (match-end 0)))))
 985                  (when image
 986                    (goto-char start)
 987                    (funcall shr-put-image-function
 988                             image (buffer-substring start end))
 989                    (delete-region (point) end))))
 990          (url-retrieve url 'shr-image-fetched
 991                        (list (current-buffer) start end)
 992                        t t)))))
 993
 994 (defun shr-heading (dom &rest types)
 995   (shr-ensure-paragraph)
 996   (apply #'shr-fontize-dom dom types)
 997   (shr-ensure-paragraph))
 998
 999 (defun shr-urlify (start url &optional title)
1000   (shr-add-font start (point) 'shr-link)
1001   (add-text-properties
1002    start (point)
1003    (list 'shr-url url
1004          'help-echo (let ((iri (or (ignore-errors
1005                                      (decode-coding-string
1006                                       (url-unhex-string url)
1007                                       'utf-8 t))
1008                                    url)))
1009                       (if title (format "%s (%s)" iri title) iri))
1010          'follow-link t
1011          'mouse-face 'highlight
1012          'keymap shr-map)))
1013
1014 (defun shr-encode-url (url)
1015   "Encode URL."
1016   (browse-url-url-encode-chars url "[)$ ]"))
1017
1018 (autoload 'shr-color-visible "shr-color")
1019 (autoload 'shr-color->hexadecimal "shr-color")
1020
1021 (defun shr-color-check (fg bg)
1022   "Check that FG is visible on BG.
1023 Returns (fg bg) with corrected values.
1024 Returns nil if the colors that would be used are the default
1025 ones, in case fg and bg are nil."
1026   (when (or fg bg)
1027     (let ((fixed (cond ((null fg) 'fg)
1028                        ((null bg) 'bg))))
1029       ;; Convert colors to hexadecimal, or set them to default.
1030       (let ((fg (or (shr-color->hexadecimal fg)
1031                     (frame-parameter nil 'foreground-color)))
1032             (bg (or (shr-color->hexadecimal bg)
1033                     (frame-parameter nil 'background-color))))
1034         (cond ((eq fixed 'bg)
1035                ;; Only return the new fg
1036                (list nil (cadr (shr-color-visible bg fg t))))
1037               ((eq fixed 'fg)
1038                ;; Invert args and results and return only the new bg
1039                (list (cadr (shr-color-visible fg bg t)) nil))
1040               (t
1041                (shr-color-visible bg fg)))))))
1042
1043 (defun shr-colorize-region (start end fg &optional bg)
1044   (when (and (not shr-inhibit-decoration)
1045              (or fg bg))
1046     (let ((new-colors (shr-color-check fg bg)))
1047       (when new-colors
1048         (when fg
1049           (add-face-text-property start end
1050                                   (list :foreground (cadr new-colors))
1051                                   t))
1052         (when bg
1053           (add-face-text-property start end
1054                                   (list :background (car new-colors))
1055                                   t)))
1056       new-colors)))
1057
1058 (defun shr-previous-newline-padding-width (width)
1059   (let ((overlays (overlays-at (point)))
1060         (previous-width 0))
1061     (if (null overlays)
1062         width
1063       (dolist (overlay overlays)
1064         (setq previous-width
1065               (+ previous-width
1066                  (length (plist-get (overlay-properties overlay)
1067                                     'before-string)))))
1068       (+ width previous-width))))
1069
1070 ;;; Tag-specific rendering rules.
1071
1072 (defun shr-tag-body (dom)
1073   (let* ((start (point))
1074          (fgcolor (or (dom-attr dom 'fgcolor) (dom-attr dom 'text)))
1075          (bgcolor (dom-attr dom 'bgcolor))
1076          (shr-stylesheet (list (cons 'color fgcolor)
1077                                (cons 'background-color bgcolor))))
1078     (shr-generic dom)
1079     (shr-colorize-region start (point) fgcolor bgcolor)))
1080
1081 (defun shr-tag-style (_dom)
1082   )
1083
1084 (defun shr-tag-script (_dom)
1085   )
1086
1087 (defun shr-tag-comment (_dom)
1088   )
1089
1090 (defun shr-dom-to-xml (dom)
1091   (with-temp-buffer
1092     (shr-dom-print dom)
1093     (buffer-string)))
1094
1095 (defun shr-dom-print (dom)
1096   "Convert DOM into a string containing the xml representation."
1097   (insert (format "<%s" (dom-tag dom)))
1098   (dolist (attr (dom-attributes dom))
1099     ;; Ignore attributes that start with a colon because they are
1100     ;; private elements.
1101     (unless (= (aref (format "%s" (car attr)) 0) ?:)
1102       (insert (format " %s=\"%s\"" (car attr) (cdr attr)))))
1103   (insert ">")
1104   (let (url)
1105     (dolist (elem (dom-children dom))
1106       (cond
1107        ((stringp elem)
1108         (insert elem))
1109        ((eq (dom-tag elem) 'comment)
1110         )
1111        ((or (not (eq (dom-tag elem) 'image))
1112             ;; Filter out blocked elements inside the SVG image.
1113             (not (setq url (dom-attr elem ':xlink:href)))
1114             (not shr-blocked-images)
1115             (not (string-match shr-blocked-images url)))
1116         (insert " ")
1117         (shr-dom-print elem)))))
1118   (insert (format "</%s>" (dom-tag dom))))
1119
1120 (defun shr-tag-svg (dom)
1121   (when (and (image-type-available-p 'svg)
1122              (not shr-inhibit-images))
1123     (funcall shr-put-image-function (list (shr-dom-to-xml dom) 'image/svg+xml)
1124              "SVG Image")))
1125
1126 (defun shr-tag-sup (dom)
1127   (let ((start (point)))
1128     (shr-generic dom)
1129     (put-text-property start (point) 'display '(raise 0.5))))
1130
1131 (defun shr-tag-sub (dom)
1132   (let ((start (point)))
1133     (shr-generic dom)
1134     (put-text-property start (point) 'display '(raise -0.5))))
1135
1136 (defun shr-tag-label (dom)
1137   (shr-generic dom)
1138   (shr-ensure-paragraph))
1139
1140 (defun shr-tag-p (dom)
1141   (shr-ensure-paragraph)
1142   (shr-generic dom)
1143   (shr-ensure-paragraph))
1144
1145 (defun shr-tag-div (dom)
1146   (shr-ensure-newline)
1147   (shr-generic dom)
1148   (shr-ensure-newline))
1149
1150 (defun shr-tag-s (dom)
1151   (shr-fontize-dom dom 'shr-strike-through))
1152
1153 (defun shr-tag-del (dom)
1154   (shr-fontize-dom dom 'shr-strike-through))
1155
1156 (defun shr-tag-b (dom)
1157   (shr-fontize-dom dom 'bold))
1158
1159 (defun shr-tag-i (dom)
1160   (shr-fontize-dom dom 'italic))
1161
1162 (defun shr-tag-em (dom)
1163   (shr-fontize-dom dom 'italic))
1164
1165 (defun shr-tag-strong (dom)
1166   (shr-fontize-dom dom 'bold))
1167
1168 (defun shr-tag-u (dom)
1169   (shr-fontize-dom dom 'underline))
1170
1171 (defun shr-tag-tt (dom)
1172   (let ((shr-current-font 'default))
1173     (shr-generic dom)))
1174
1175 (defun shr-parse-style (style)
1176   (when style
1177     (save-match-data
1178       (when (string-match "\n" style)
1179         (setq style (replace-match " " t t style))))
1180     (let ((plist nil))
1181       (dolist (elem (split-string style ";"))
1182         (when elem
1183           (setq elem (split-string elem ":"))
1184           (when (and (car elem)
1185                      (cadr elem))
1186             (let ((name (replace-regexp-in-string "^ +\\| +$" "" (car elem)))
1187                   (value (replace-regexp-in-string "^ +\\| +$" "" (cadr elem))))
1188               (when (string-match " *!important\\'" value)
1189                 (setq value (substring value 0 (match-beginning 0))))
1190               (unless (equal value "inherit")
1191                 (push (cons (intern name obarray)
1192                             value)
1193                       plist))))))
1194       plist)))
1195
1196 (defun shr-tag-base (dom)
1197   (when-let (base (dom-attr dom 'href))
1198     (setq shr-base (shr-parse-base base)))
1199   (shr-generic dom))
1200
1201 (defun shr-tag-a (dom)
1202   (let ((url (dom-attr dom 'href))
1203         (title (dom-attr dom 'title))
1204         (start (point))
1205         shr-start)
1206     (shr-generic dom)
1207     (when (and shr-target-id
1208                (equal (dom-attr dom 'name) shr-target-id))
1209       ;; We have a zero-length <a name="foo"> element, so just
1210       ;; insert...  something.
1211       (when (= start (point))
1212         (shr-ensure-newline)
1213         (insert " "))
1214       (put-text-property start (1+ start) 'shr-target-id shr-target-id))
1215     (when (and url
1216                (not shr-inhibit-decoration))
1217       (shr-urlify (or shr-start start) (shr-expand-url url) title))))
1218
1219 (defun shr-tag-object (dom)
1220   (unless shr-inhibit-images
1221     (let ((start (point))
1222           url multimedia image)
1223       (when-let (type (dom-attr dom 'type))
1224         (when (string-match "\\`image/svg" type)
1225           (setq url (dom-attr dom 'data)
1226                 image t)))
1227       (dolist (child (dom-non-text-children dom))
1228         (cond
1229          ((eq (dom-tag child) 'embed)
1230           (setq url (or url (dom-attr child 'src))
1231                 multimedia t))
1232          ((and (eq (dom-tag child) 'param)
1233                (equal (dom-attr child 'name) "movie"))
1234           (setq url (or url (dom-attr child 'value))
1235                 multimedia t))))
1236       (when url
1237         (cond
1238          (image
1239           (shr-tag-img dom url)
1240           (setq dom nil))
1241          (multimedia
1242           (shr-insert " [multimedia] ")
1243           (shr-urlify start (shr-expand-url url)))))
1244       (when dom
1245         (shr-generic dom)))))
1246
1247 (defcustom shr-prefer-media-type-alist '(("webm" . 1.0)
1248                                          ("ogv"  . 1.0)
1249                                          ("ogg"  . 1.0)
1250                                          ("opus" . 1.0)
1251                                          ("flac" . 0.9)
1252                                          ("wav"  . 0.5))
1253   "Preferences for media types.
1254 The key element should be a regexp matched against the type of the source or
1255 url if no type is specified.  The value should be a float in the range 0.0 to
1256 1.0.  Media elements with higher value are preferred."
1257   :version "24.4"
1258   :group 'shr
1259   :type '(alist :key-type regexp :value-type float))
1260
1261 (defun shr--get-media-pref (elem)
1262   "Determine the preference for ELEM.
1263 The preference is a float determined from `shr-prefer-media-type'."
1264   (let ((type (dom-attr elem 'type))
1265         (p 0.0))
1266     (unless type
1267       (setq type (dom-attr elem 'src)))
1268     (when type
1269       (dolist (pref shr-prefer-media-type-alist)
1270         (when (and
1271                (> (cdr pref) p)
1272                (string-match-p (car pref) type))
1273           (setq p (cdr pref)))))
1274     p))
1275
1276 (defun shr--extract-best-source (dom &optional url pref)
1277   "Extract the best `:src' property from <source> blocks in DOM."
1278   (setq pref (or pref -1.0))
1279   (let (new-pref)
1280     (dolist (elem (dom-non-text-children dom))
1281       (when (and (eq (dom-tag elem) 'source)
1282                  (< pref
1283                     (setq new-pref
1284                           (shr--get-media-pref elem))))
1285         (setq pref new-pref
1286               url (dom-attr elem 'src))
1287         ;; libxml's html parser isn't HTML5 compliant and non terminated
1288         ;; source tags might end up as children.  So recursion it is...
1289         (dolist (child (dom-non-text-children elem))
1290           (when (eq (dom-tag child) 'source)
1291             (let ((ret (shr--extract-best-source (list child) url pref)))
1292               (when (< pref (cdr ret))
1293                 (setq url (car ret)
1294                       pref (cdr ret)))))))))
1295   (cons url pref))
1296
1297 (defun shr-tag-video (dom)
1298   (let ((image (dom-attr dom 'poster))
1299         (url (dom-attr dom 'src))
1300         (start (point)))
1301     (unless url
1302       (setq url (car (shr--extract-best-source dom))))
1303     (if image
1304         (shr-tag-img nil image)
1305       (shr-insert " [video] "))
1306     (shr-urlify start (shr-expand-url url))))
1307
1308 (defun shr-tag-audio (dom)
1309   (let ((url (dom-attr dom 'src))
1310         (start (point)))
1311     (unless url
1312       (setq url (car (shr--extract-best-source dom))))
1313     (shr-insert " [audio] ")
1314     (shr-urlify start (shr-expand-url url))))
1315
1316 (defun shr-tag-img (dom &optional url)
1317   (when (or url
1318             (and dom
1319                  (> (length (dom-attr dom 'src)) 0)))
1320     (when (> (current-column) 0)
1321       (insert "\n"))
1322     (let ((alt (dom-attr dom 'alt))
1323           (url (shr-expand-url (or url (dom-attr dom 'src)))))
1324       (let ((start (point-marker)))
1325         (when (zerop (length alt))
1326           (setq alt "*"))
1327         (cond
1328          ((or (member (dom-attr dom 'height) '("0" "1"))
1329               (member (dom-attr dom 'width) '("0" "1")))
1330           ;; Ignore zero-sized or single-pixel images.
1331           )
1332          ((and (not shr-inhibit-images)
1333                (string-match "\\`data:" url))
1334           (let ((image (shr-image-from-data (substring url (match-end 0)))))
1335             (if image
1336                 (funcall shr-put-image-function image alt)
1337               (insert alt))))
1338          ((and (not shr-inhibit-images)
1339                (string-match "\\`cid:" url))
1340           (let ((url (substring url (match-end 0)))
1341                 image)
1342             (if (or (not shr-content-function)
1343                     (not (setq image (funcall shr-content-function url))))
1344                 (insert alt)
1345               (funcall shr-put-image-function image alt))))
1346          ((or shr-inhibit-images
1347               (and shr-blocked-images
1348                    (string-match shr-blocked-images url)))
1349           (setq shr-start (point))
1350           (if (> (string-width alt) 8)
1351               (shr-insert (truncate-string-to-width alt 8))
1352             (shr-insert alt)))
1353          ((and (not shr-ignore-cache)
1354                (url-is-cached (shr-encode-url url)))
1355           (funcall shr-put-image-function (shr-get-image-data url) alt))
1356          (t
1357           (insert alt " ")
1358           (when (and shr-ignore-cache
1359                      (url-is-cached (shr-encode-url url)))
1360             (let ((file (url-cache-create-filename (shr-encode-url url))))
1361               (when (file-exists-p file)
1362                 (delete-file file))))
1363           (url-queue-retrieve
1364            (shr-encode-url url) 'shr-image-fetched
1365            (list (current-buffer) start (set-marker (make-marker) (1- (point))))
1366            t t)))
1367         (when (zerop shr-table-depth) ;; We are not in a table.
1368           (put-text-property start (point) 'keymap shr-map)
1369           (put-text-property start (point) 'shr-alt alt)
1370           (put-text-property start (point) 'image-url url)
1371           (put-text-property start (point) 'image-displayer
1372                              (shr-image-displayer shr-content-function))
1373           (put-text-property start (point) 'help-echo
1374                              (shr-fill-text
1375                               (or (dom-attr dom 'title) alt))))))))
1376
1377 (defun shr-tag-pre (dom)
1378   (let ((shr-folding-mode 'none)
1379         (shr-current-font 'default))
1380     (shr-ensure-newline)
1381     (shr-generic dom)
1382     (shr-ensure-newline)))
1383
1384 (defun shr-tag-blockquote (dom)
1385   (shr-ensure-paragraph)
1386   (let ((start (point))
1387         (shr-indentation (+ shr-indentation
1388                             (* 4 shr-table-separator-pixel-width))))
1389     (shr-generic dom)
1390     (shr-ensure-paragraph)
1391     (shr-mark-fill start)))
1392
1393 (defun shr-tag-dl (dom)
1394   (shr-ensure-paragraph)
1395   (shr-generic dom)
1396   (shr-ensure-paragraph))
1397
1398 (defun shr-tag-dt (dom)
1399   (shr-ensure-newline)
1400   (shr-generic dom)
1401   (shr-ensure-newline))
1402
1403 (defun shr-tag-dd (dom)
1404   (shr-ensure-newline)
1405   (let ((shr-indentation (+ shr-indentation
1406                             (* 4 shr-table-separator-pixel-width))))
1407     (shr-generic dom)))
1408
1409 (defun shr-tag-ul (dom)
1410   (shr-ensure-paragraph)
1411   (let ((shr-list-mode 'ul))
1412     (shr-generic dom))
1413   (shr-ensure-paragraph))
1414
1415 (defun shr-tag-ol (dom)
1416   (shr-ensure-paragraph)
1417   (let ((shr-list-mode 1))
1418     (shr-generic dom))
1419   (shr-ensure-paragraph))
1420
1421 (defun shr-tag-li (dom)
1422   (shr-ensure-newline)
1423   (let ((start (point)))
1424     (let* ((bullet
1425             (if (numberp shr-list-mode)
1426                 (prog1
1427                     (format "%d " shr-list-mode)
1428                   (setq shr-list-mode (1+ shr-list-mode)))
1429               (car shr-internal-bullet)))
1430            (width (if (numberp shr-list-mode)
1431                       (shr-string-pixel-width bullet)
1432                     (cdr shr-internal-bullet))))
1433       (insert bullet)
1434       (shr-mark-fill start)
1435       (let ((shr-indentation (+ shr-indentation width)))
1436         (put-text-property start (1+ start)
1437                            'shr-continuation-indentation shr-indentation)
1438         (put-text-property start (1+ start) 'shr-prefix-length (length bullet))
1439         (shr-generic dom)))))
1440
1441 (defun shr-mark-fill (start)
1442   ;; We may not have inserted any text to fill.
1443   (unless (= start (point))
1444     (put-text-property start (1+ start)
1445                        'shr-indentation shr-indentation)))
1446
1447 (defun shr-tag-br (dom)
1448   (when (and (not (bobp))
1449              ;; Only add a newline if we break the current line, or
1450              ;; the previous line isn't a blank line.
1451              (or (not (bolp))
1452                  (and (> (- (point) 2) (point-min))
1453                       (not (= (char-after (- (point) 2)) ?\n)))))
1454     (insert "\n"))
1455   (shr-generic dom))
1456
1457 (defun shr-tag-span (dom)
1458   (shr-generic dom))
1459
1460 (defun shr-tag-h1 (dom)
1461   (shr-heading dom (if shr-use-fonts
1462                        '(variable-pitch (:height 1.3 :weight bold))
1463                      'bold)))
1464
1465 (defun shr-tag-h2 (dom)
1466   (shr-heading dom 'bold))
1467
1468 (defun shr-tag-h3 (dom)
1469   (shr-heading dom 'italic))
1470
1471 (defun shr-tag-h4 (dom)
1472   (shr-heading dom))
1473
1474 (defun shr-tag-h5 (dom)
1475   (shr-heading dom))
1476
1477 (defun shr-tag-h6 (dom)
1478   (shr-heading dom))
1479
1480 (defun shr-tag-hr (_dom)
1481   (shr-ensure-newline)
1482   (insert (make-string (if (not shr-use-fonts)
1483                            shr-internal-width
1484                          (1+ (/ shr-internal-width
1485                                 shr-table-separator-pixel-width)))
1486                        shr-hr-line)
1487           "\n"))
1488
1489 (defun shr-tag-title (dom)
1490   (shr-heading dom 'bold 'underline))
1491
1492 (defun shr-tag-font (dom)
1493   (let* ((start (point))
1494          (color (dom-attr dom 'color))
1495          (shr-stylesheet (nconc (list (cons 'color color))
1496                                 shr-stylesheet)))
1497     (shr-generic dom)
1498     (when color
1499       (shr-colorize-region start (point) color
1500                            (cdr (assq 'background-color shr-stylesheet))))))
1501
1502 ;;; Table rendering algorithm.
1503
1504 ;; Table rendering is the only complicated thing here.  We do this by
1505 ;; first counting how many TDs there are in each TR, and registering
1506 ;; how wide they think they should be ("width=45%", etc).  Then we
1507 ;; render each TD separately (this is done in temporary buffers, so
1508 ;; that we can use all the rendering machinery as if we were in the
1509 ;; main buffer).  Now we know how much space each TD really takes, so
1510 ;; we then render everything again with the new widths, and finally
1511 ;; insert all these boxes into the main buffer.
1512 (defun shr-tag-table-1 (dom)
1513   (setq dom (or (dom-child-by-tag dom 'tbody) dom))
1514   (let* ((shr-inhibit-images t)
1515          (shr-table-depth (1+ shr-table-depth))
1516          (shr-kinsoku-shorten t)
1517          ;; Find all suggested widths.
1518          (columns (shr-column-specs dom))
1519          ;; Compute how many pixels wide each TD should be.
1520          (suggested-widths (shr-pro-rate-columns columns))
1521          ;; Do a "test rendering" to see how big each TD is (this can
1522          ;; be smaller (if there's little text) or bigger (if there's
1523          ;; unbreakable text).
1524          (elems (or (dom-attr dom 'shr-suggested-widths)
1525                     (shr-make-table dom suggested-widths nil
1526                                     'shr-suggested-widths)))
1527          (sketch (loop for line in elems
1528                        collect (mapcar #'car line)))
1529          (natural (loop for line in elems
1530                         collect (mapcar #'cdr line)))
1531          (sketch-widths (shr-table-widths sketch natural suggested-widths)))
1532     ;; This probably won't work very well.
1533     (when (> (+ (loop for width across sketch-widths
1534                       summing (1+ width))
1535                 shr-indentation shr-table-separator-pixel-width)
1536              (frame-width))
1537       (setq truncate-lines t))
1538     ;; Then render the table again with these new "hard" widths.
1539     (shr-insert-table (shr-make-table dom sketch-widths t) sketch-widths)))
1540
1541 (defun shr-tag-table (dom)
1542   (shr-ensure-paragraph)
1543   (let* ((caption (dom-children (dom-child-by-tag dom 'caption)))
1544          (header (dom-non-text-children (dom-child-by-tag dom 'thead)))
1545          (body (dom-non-text-children (or (dom-child-by-tag dom 'tbody)
1546                                           dom)))
1547          (footer (dom-non-text-children (dom-child-by-tag dom 'tfoot)))
1548          (bgcolor (dom-attr dom 'bgcolor))
1549          (start (point))
1550          (shr-stylesheet (nconc (list (cons 'background-color bgcolor))
1551                                 shr-stylesheet))
1552          (nheader (if header (shr-max-columns header)))
1553          (nbody (if body (shr-max-columns body)))
1554          (nfooter (if footer (shr-max-columns footer))))
1555     (if (and (not caption)
1556              (not header)
1557              (not (dom-child-by-tag dom 'tbody))
1558              (not (dom-child-by-tag dom 'tr))
1559              (not footer))
1560         ;; The table is totally invalid and just contains random junk.
1561         ;; Try to output it anyway.
1562         (shr-generic dom)
1563       ;; It's a real table, so render it.
1564       (if (dom-attr dom 'shr-fixed-table)
1565           (shr-tag-table-1 dom)
1566         ;; Only fix up the table once.
1567         (let ((table
1568                (nconc
1569                 (list 'table nil)
1570                 (if caption `((tr nil (td nil ,@caption))))
1571                 (cond
1572                  (header
1573                   (if footer
1574                       ;; header + body + footer
1575                       (if (= nheader nbody)
1576                           (if (= nbody nfooter)
1577                               `((tr nil (td nil (table nil
1578                                                        (tbody nil ,@header
1579                                                               ,@body ,@footer)))))
1580                             (nconc `((tr nil (td nil (table nil
1581                                                             (tbody nil ,@header
1582                                                                    ,@body)))))
1583                                    (if (= nfooter 1)
1584                                        footer
1585                                      `((tr nil (td nil (table
1586                                                         nil (tbody
1587                                                              nil ,@footer))))))))
1588                         (nconc `((tr nil (td nil (table nil (tbody
1589                                                              nil ,@header)))))
1590                                (if (= nbody nfooter)
1591                                    `((tr nil (td nil (table
1592                                                       nil (tbody nil ,@body
1593                                                                  ,@footer)))))
1594                                  (nconc `((tr nil (td nil (table
1595                                                            nil (tbody nil
1596                                                                       ,@body)))))
1597                                         (if (= nfooter 1)
1598                                             footer
1599                                           `((tr nil (td nil (table
1600                                                              nil
1601                                                              (tbody
1602                                                               nil
1603                                                               ,@footer))))))))))
1604                     ;; header + body
1605                     (if (= nheader nbody)
1606                         `((tr nil (td nil (table nil (tbody nil ,@header
1607                                                             ,@body)))))
1608                       (if (= nheader 1)
1609                           `(,@header (tr nil (td nil (table
1610                                                       nil (tbody nil ,@body)))))
1611                         `((tr nil (td nil (table nil (tbody nil ,@header))))
1612                           (tr nil (td nil (table nil (tbody nil ,@body)))))))))
1613                  (footer
1614                   ;; body + footer
1615                   (if (= nbody nfooter)
1616                       `((tr nil (td nil (table
1617                                          nil (tbody nil ,@body ,@footer)))))
1618                     (nconc `((tr nil (td nil (table nil (tbody nil ,@body)))))
1619                            (if (= nfooter 1)
1620                                footer
1621                              `((tr nil (td nil (table
1622                                                 nil (tbody nil ,@footer)))))))))
1623                  (caption
1624                   `((tr nil (td nil (table nil (tbody nil ,@body))))))
1625                  (body)))))
1626           (dom-set-attribute table 'shr-fixed-table t)
1627           (setcdr dom (cdr table))
1628           (shr-tag-table-1 dom))))
1629     (when bgcolor
1630       (shr-colorize-region start (point) (cdr (assq 'color shr-stylesheet))
1631                            bgcolor))
1632     ;; Finally, insert all the images after the table.  The Emacs buffer
1633     ;; model isn't strong enough to allow us to put the images actually
1634     ;; into the tables.
1635     (when (zerop shr-table-depth)
1636       (save-excursion
1637         (shr-expand-alignments start (point)))
1638       (dolist (elem (dom-by-tag dom 'object))
1639         (shr-tag-object elem))
1640       (dolist (elem (dom-by-tag dom 'img))
1641         (shr-tag-img elem)))))
1642
1643 (defun shr-insert-table (table widths)
1644   (let* ((collapse (equal (cdr (assq 'border-collapse shr-stylesheet))
1645                           "collapse"))
1646          (shr-table-separator-length (if collapse 0 1))
1647          (shr-table-vertical-line (if collapse "" shr-table-vertical-line))
1648          (start (point)))
1649     (setq shr-table-id (1+ shr-table-id))
1650     (unless collapse
1651       (shr-insert-table-ruler widths))
1652     (dolist (row table)
1653       (let ((start (point))
1654             (align 0)
1655             (column-number 0)
1656             (height (let ((max 0))
1657                       (dolist (column row)
1658                         (setq max (max max (nth 2 column))))
1659                       max)))
1660         (dotimes (i (max height 1))
1661           (shr-indent)
1662           (insert shr-table-vertical-line "\n"))
1663         (dolist (column row)
1664           (when (> (nth 2 column) -1)
1665             (goto-char start)
1666             ;; Sum up all the widths from the column.  (There may be
1667             ;; more than one if this is a "colspan" column.)
1668             (dotimes (i (nth 4 column))
1669               ;; The colspan directive may be wrong and there may not be
1670               ;; that number of columns.
1671               (when (<= column-number (1- (length widths)))
1672                 (setq align (+ align
1673                                (aref widths column-number)
1674                                (* 2 shr-table-separator-pixel-width))))
1675               (setq column-number (1+ column-number)))
1676             (let ((lines (nth 3 column))
1677                   (pixel-align (if (not shr-use-fonts)
1678                                    (* align (frame-char-width))
1679                                  align)))
1680               (dolist (line lines)
1681                 (end-of-line)
1682                 (let ((start (point)))
1683                   (insert
1684                    line
1685                    (propertize " "
1686                                'display `(space :align-to (,pixel-align))
1687                                'face (and (> (length line) 0)
1688                                           (shr-face-background
1689                                            (get-text-property
1690                                             (1- (length line)) 'face line)))
1691                                'shr-table-indent shr-table-id)
1692                    shr-table-vertical-line)
1693                   (shr-colorize-region
1694                    start (1- (point)) (nth 5 column) (nth 6 column)))
1695                 (forward-line 1))
1696               ;; Add blank lines at padding at the bottom of the TD,
1697               ;; possibly.
1698               (dotimes (i (- height (length lines)))
1699                 (end-of-line)
1700                 (let ((start (point)))
1701                   (insert (propertize " "
1702                                       'display `(space :align-to (,pixel-align))
1703                                       'shr-table-indent shr-table-id)
1704                           shr-table-vertical-line)
1705                   (shr-colorize-region
1706                    start (1- (point)) (nth 5 column) (nth 6 column)))
1707                 (forward-line 1))))))
1708       (unless collapse
1709         (shr-insert-table-ruler widths)))
1710     (unless (= start (point))
1711       (put-text-property start (1+ start) 'shr-table-id shr-table-id))))
1712
1713 (defun shr-face-background (face)
1714   (and (consp face)
1715        (let ((background nil))
1716          (dolist (elem face)
1717            (when (and (consp elem)
1718                       (eq (car elem) :background))
1719              (setq background (cadr elem))))
1720          (and background
1721               (list :background background)))))
1722
1723 (defun shr-expand-alignments (start end)
1724   (while (< (setq start (next-single-property-change
1725                          start 'shr-table-id nil end))
1726             end)
1727     (goto-char start)
1728     (let* ((shr-use-fonts t)
1729            (id (get-text-property (point) 'shr-table-id))
1730            (base (shr-pixel-column))
1731            elem)
1732       (when id
1733         (save-excursion
1734           (while (setq elem (text-property-any
1735                              (point) end 'shr-table-indent id))
1736             (goto-char elem)
1737             (let ((align (get-text-property (point) 'display)))
1738               (put-text-property (point) (1+ (point)) 'display
1739                                  `(space :align-to (,(+ (car (nth 2 align))
1740                                                         base)))))
1741             (forward-char 1)))))
1742     (setq start (1+ start))))
1743
1744 (defun shr-insert-table-ruler (widths)
1745   (when shr-table-horizontal-line
1746     (when (and (bolp)
1747                (> shr-indentation 0))
1748       (shr-indent))
1749     (insert shr-table-corner)
1750     (let ((total-width 0))
1751       (dotimes (i (length widths))
1752         (setq total-width (+ total-width (aref widths i)
1753                              (* shr-table-separator-pixel-width 2)))
1754         (insert (make-string (1+ (/ (aref widths i)
1755                                     shr-table-separator-pixel-width))
1756                              shr-table-horizontal-line)
1757                 (propertize " "
1758                             'display `(space :align-to (,total-width))
1759                             'shr-table-indent shr-table-id)
1760                 shr-table-corner)))
1761     (insert "\n")))
1762
1763 (defun shr-table-widths (table natural-table suggested-widths)
1764   (let* ((length (length suggested-widths))
1765          (widths (make-vector length 0))
1766          (natural-widths (make-vector length 0)))
1767     (dolist (row table)
1768       (let ((i 0))
1769         (dolist (column row)
1770           (aset widths i (max (aref widths i) column))
1771           (setq i (1+ i)))))
1772     (dolist (row natural-table)
1773       (let ((i 0))
1774         (dolist (column row)
1775           (aset natural-widths i (max (aref natural-widths i) column))
1776           (setq i (1+ i)))))
1777     (let ((extra (- (apply '+ (append suggested-widths nil))
1778                     (apply '+ (append widths nil))
1779                     (* shr-table-separator-pixel-width (1+ (length widths)))))
1780           (expanded-columns 0))
1781       ;; We have extra, unused space, so divide this space amongst the
1782       ;; columns.
1783       (when (> extra 0)
1784         ;; If the natural width is wider than the rendered width, we
1785         ;; want to allow the column to expand.
1786         (dotimes (i length)
1787           (when (> (aref natural-widths i) (aref widths i))
1788             (setq expanded-columns (1+ expanded-columns))))
1789         (dotimes (i length)
1790           (when (> (aref natural-widths i) (aref widths i))
1791             (aset widths i (min
1792                             (aref natural-widths i)
1793                             (+ (/ extra expanded-columns)
1794                                (aref widths i))))))))
1795     widths))
1796
1797 (defun shr-make-table (dom widths &optional fill storage-attribute)
1798   (or (cadr (assoc (list dom widths fill) shr-content-cache))
1799       (let ((data (shr-make-table-1 dom widths fill)))
1800         (push (list (list dom widths fill) data)
1801               shr-content-cache)
1802         (when storage-attribute
1803           (dom-set-attribute dom storage-attribute data))
1804         data)))
1805
1806 (defun shr-make-table-1 (dom widths &optional fill)
1807   (let ((trs nil)
1808         (shr-inhibit-decoration (not fill))
1809         (rowspans (make-vector (length widths) 0))
1810         (colspan-remaining 0)
1811         colspan-width colspan-count
1812         width colspan)
1813     (dolist (row (dom-non-text-children dom))
1814       (when (eq (dom-tag row) 'tr)
1815         (let ((tds nil)
1816               (columns (dom-non-text-children row))
1817               (i 0)
1818               (width-column 0)
1819               column)
1820           (while (< i (length widths))
1821             ;; If we previously had a rowspan definition, then that
1822             ;; means that we now have a "missing" td/th element here.
1823             ;; So just insert a dummy, empty one to (sort of) emulate
1824             ;; rowspan.
1825             (setq column
1826                   (if (zerop (aref rowspans i))
1827                       (pop columns)
1828                     (aset rowspans i (1- (aref rowspans i)))
1829                     '(td)))
1830             (when (and (not (stringp column))
1831                        (or (memq (dom-tag column) '(td th))
1832                            (not column)))
1833               (when-let (span (dom-attr column 'rowspan))
1834                 (aset rowspans i (+ (aref rowspans i)
1835                                     (1- (string-to-number span)))))
1836               ;; Sanity check for invalid column-spans.
1837               (when (>= width-column (length widths))
1838                 (setq width-column 0))
1839               (setq width
1840                     (if column
1841                         (aref widths width-column)
1842                       (* 10 shr-table-separator-pixel-width)))
1843               (when (setq colspan (dom-attr column 'colspan))
1844                 (setq colspan (min (string-to-number colspan)
1845                                    ;; The colspan may be wrong, so
1846                                    ;; truncate it to the length of the
1847                                    ;; remaining columns.
1848                                    (- (length widths) i)))
1849                 (dotimes (j (1- colspan))
1850                   (setq width
1851                         (if (> (+ i 1 j) (1- (length widths)))
1852                             ;; If we have a colspan spec that's longer
1853                             ;; than the table is wide, just use the last
1854                             ;; width as the width.
1855                             (aref widths (1- (length widths)))
1856                           ;; Sum up the widths of the columns we're
1857                           ;; spanning.
1858                           (+ width
1859                              shr-table-separator-length
1860                              (aref widths (+ i 1 j))))))
1861                 (setq width-column (+ width-column (1- colspan))
1862                       colspan-count colspan
1863                       colspan-remaining colspan))
1864               (when column
1865                 (let ((data (shr-render-td column width fill)))
1866                   (if (and (not fill)
1867                            (> colspan-remaining 0))
1868                       (progn
1869                         (setq colspan-width (car data))
1870                         (let ((this-width (/ colspan-width colspan-count)))
1871                           (push (cons this-width (cadr data)) tds)
1872                           (setq colspan-remaining (1- colspan-remaining))))
1873                     (if (not fill)
1874                         (push (cons (car data) (cadr data)) tds)
1875                       (push data tds)))))
1876               (when (and colspan
1877                          (> colspan 1))
1878                 (dotimes (c (1- colspan))
1879                   (setq i (1+ i))
1880                   (push
1881                    (if fill
1882                        (list 0 0 -1 nil 1 nil nil)
1883                      '(0 . 0))
1884                    tds)))
1885               (setq i (1+ i)
1886                     width-column (1+ width-column))))
1887           (push (nreverse tds) trs))))
1888     (nreverse trs)))
1889
1890 (defun shr-pixel-buffer-width ()
1891   (if (not shr-use-fonts)
1892       (save-excursion
1893         (goto-char (point-min))
1894         (let ((max 0))
1895           (while (not (eobp))
1896             (end-of-line)
1897             (setq max (max max (current-column)))
1898             (forward-line 1))
1899           max))
1900     (if (get-buffer-window)
1901         (car (window-text-pixel-size nil (point-min) (point-max)))
1902       (save-window-excursion
1903         (set-window-buffer nil (current-buffer))
1904         (car (window-text-pixel-size nil (point-min) (point-max)))))))
1905
1906 (defun shr-render-td (dom width fill)
1907   (let ((cache (intern (format "shr-td-cache-%s-%s" width fill))))
1908     (or (dom-attr dom cache)
1909         (and fill
1910              (let (result)
1911                (dolist (attr (dom-attributes dom))
1912                  (let ((name (symbol-name (car attr))))
1913                    (when (string-match "shr-td-cache-\\([0-9]+\\)-nil" name)
1914                      (let ((cache-width (string-to-number
1915                                          (match-string 1 name))))
1916                        (when (and (>= cache-width width)
1917                                   (<= (car (cdr attr)) width))
1918                          (setq result (cdr attr)))))))
1919                result))
1920         (let ((result (shr-render-td-1 dom width fill)))
1921           (dom-set-attribute dom cache result)
1922           result))))
1923
1924 (defun shr-render-td-1 (dom width fill)
1925   (with-temp-buffer
1926     (let ((bgcolor (dom-attr dom 'bgcolor))
1927           (fgcolor (dom-attr dom 'fgcolor))
1928           (style (dom-attr dom 'style))
1929           (shr-stylesheet shr-stylesheet)
1930           (max-width 0)
1931           natural-width)
1932       (when style
1933         (setq style (and (string-match "color" style)
1934                          (shr-parse-style style))))
1935       (when bgcolor
1936         (setq style (nconc (list (cons 'background-color bgcolor))
1937                            style)))
1938       (when fgcolor
1939         (setq style (nconc (list (cons 'color fgcolor)) style)))
1940       (when style
1941         (setq shr-stylesheet (append style shr-stylesheet)))
1942       (let ((shr-internal-width width)
1943             (shr-indentation 0))
1944         (shr-descend dom))
1945       (save-window-excursion
1946         (set-window-buffer nil (current-buffer))
1947         (unless fill
1948           (setq natural-width
1949                 (or (dom-attr dom 'shr-td-cache-natural)
1950                     (let ((natural (max (shr-pixel-buffer-width)
1951                                         (shr-dom-max-natural-width dom 0))))
1952                       (dom-set-attribute dom 'shr-td-cache-natural natural)
1953                       natural))))
1954         (if (and natural-width
1955                  (<= natural-width width))
1956             (setq max-width natural-width)
1957           (let ((shr-internal-width width))
1958             (shr-fill-lines (point-min) (point-max))
1959             (setq max-width (shr-pixel-buffer-width)))))
1960       (goto-char (point-max))
1961       ;; Delete padding at the bottom of the TDs.
1962       (delete-region
1963        (point)
1964        (progn
1965          (skip-chars-backward " \t\n")
1966          (end-of-line)
1967          (point)))
1968       (goto-char (point-min))
1969       (list max-width
1970             natural-width
1971             (count-lines (point-min) (point-max))
1972             (split-string (buffer-string) "\n")
1973             (if (dom-attr dom 'colspan)
1974                 (string-to-number (dom-attr dom 'colspan))
1975               1)
1976             (cdr (assq 'color shr-stylesheet))
1977             (cdr (assq 'background-color shr-stylesheet))))))
1978
1979 (defun shr-dom-max-natural-width (dom max)
1980   (if (eq (dom-tag dom) 'table)
1981       (max max (or
1982                 (loop for line in (dom-attr dom 'shr-suggested-widths)
1983                       maximize (+
1984                                 shr-table-separator-length
1985                                 (loop for elem in line
1986                                       summing
1987                                       (+ (cdr elem)
1988                                          (* 2 shr-table-separator-length)))))
1989                 0))
1990     (dolist (child (dom-children dom))
1991       (unless (stringp child)
1992         (setq max (max (shr-dom-max-natural-width child max)))))
1993     max))
1994
1995 (defun shr-buffer-width ()
1996   (goto-char (point-min))
1997   (let ((max 0))
1998     (while (not (eobp))
1999       (end-of-line)
2000       (setq max (max max (current-column)))
2001       (forward-line 1))
2002     max))
2003
2004 (defun shr-pro-rate-columns (columns)
2005   (let ((total-percentage 0)
2006         (widths (make-vector (length columns) 0)))
2007     (dotimes (i (length columns))
2008       (setq total-percentage (+ total-percentage (aref columns i))))
2009     (setq total-percentage (/ 1.0 total-percentage))
2010     (dotimes (i (length columns))
2011       (aset widths i (max (truncate (* (aref columns i)
2012                                        total-percentage
2013                                        (- shr-internal-width
2014                                           (* (1+ (length columns))
2015                                              shr-table-separator-pixel-width))))
2016                           10)))
2017     widths))
2018
2019 ;; Return a summary of the number and shape of the TDs in the table.
2020 (defun shr-column-specs (dom)
2021   (let ((columns (make-vector (shr-max-columns dom) 1)))
2022     (dolist (row (dom-non-text-children dom))
2023       (when (eq (dom-tag row) 'tr)
2024         (let ((i 0))
2025           (dolist (column (dom-non-text-children row))
2026             (when (memq (dom-tag column) '(td th))
2027               (let ((width (dom-attr column 'width)))
2028                 (when (and width
2029                            (string-match "\\([0-9]+\\)%" width)
2030                            (not (zerop (setq width (string-to-number
2031                                                     (match-string 1 width))))))
2032                   (aset columns i (/ width 100.0))))
2033               (setq i (1+ i)))))))
2034     columns))
2035
2036 (defun shr-count (dom elem)
2037   (let ((i 0))
2038     (dolist (sub (dom-children dom))
2039       (when (and (not (stringp sub))
2040                  (eq (dom-tag sub) elem))
2041         (setq i (1+ i))))
2042     i))
2043
2044 (defun shr-max-columns (dom)
2045   (let ((max 0))
2046     (dolist (row (dom-children dom))
2047       (when (and (not (stringp row))
2048                  (eq (dom-tag row) 'tr))
2049         (setq max (max max (+ (shr-count row 'td)
2050                               (shr-count row 'th))))))
2051     max))
2052
2053 (provide 'shr)
2054
2055 ;; Local Variables:
2056 ;; coding: utf-8
2057 ;; End:
2058
2059 ;;; shr.el ends here