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1 ;;; shr.el --- Simple HTML Renderer
3 ;; Copyright (C) 2010-2011 Free Software Foundation, Inc.
5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
6 ;; Keywords: html
8 ;; This file is part of GNU Emacs.
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.
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.
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/>.
23 ;;; Commentary:
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.
31 ;;; Code:
33 (eval-when-compile (require 'cl))
34 (require 'browse-url)
36 (defgroup shr nil
37 "Simple HTML Renderer"
38 :group 'mail)
40 (defcustom shr-max-image-proportion 0.9
41 "How big pictures displayed are in relation to the window they're in.
42 A value of 0.7 means that they are allowed to take up 70% of the
43 width and height of the window. If they are larger than this,
44 and Emacs supports it, then the images will be rescaled down to
45 fit these criteria."
46 :version "24.1"
47 :group 'shr
48 :type 'float)
50 (defcustom shr-blocked-images nil
51 "Images that have URLs matching this regexp will be blocked."
52 :version "24.1"
53 :group 'shr
54 :type 'regexp)
56 (defcustom shr-table-horizontal-line ?
57 "Character used to draw horizontal table lines."
58 :group 'shr
59 :type 'character)
61 (defcustom shr-table-vertical-line ?
62 "Character used to draw vertical table lines."
63 :group 'shr
64 :type 'character)
66 (defcustom shr-table-corner ?
67 "Character used to draw table corners."
68 :group 'shr
69 :type 'character)
71 (defcustom shr-hr-line ?-
72 "Character used to draw hr lines."
73 :group 'shr
74 :type 'character)
76 (defcustom shr-width fill-column
77 "Frame width to use for rendering.
78 May either be an integer specifying a fixed width in characters,
79 or nil, meaning that the full width of the window should be
80 used."
81 :type '(choice (integer :tag "Fixed width in characters")
82 (const :tag "Use the width of the window" nil))
83 :group 'shr)
85 (defvar shr-content-function nil
86 "If bound, this should be a function that will return the content.
87 This is used for cid: URLs, and the function is called with the
88 cid: URL as the argument.")
90 ;;; Internal variables.
92 (defvar shr-folding-mode nil)
93 (defvar shr-state nil)
94 (defvar shr-start nil)
95 (defvar shr-indentation 0)
96 (defvar shr-inhibit-images nil)
97 (defvar shr-list-mode nil)
98 (defvar shr-content-cache nil)
99 (defvar shr-kinsoku-shorten nil)
100 (defvar shr-table-depth 0)
101 (defvar shr-stylesheet nil)
103 (defvar shr-map
104 (let ((map (make-sparse-keymap)))
105 (define-key map "a" 'shr-show-alt-text)
106 (define-key map "i" 'shr-browse-image)
107 (define-key map "I" 'shr-insert-image)
108 (define-key map "u" 'shr-copy-url)
109 (define-key map "v" 'shr-browse-url)
110 (define-key map "o" 'shr-save-contents)
111 (define-key map "\r" 'shr-browse-url)
112 map))
114 ;; Public functions and commands.
116 ;;;###autoload
117 (defun shr-insert-document (dom)
118 (setq shr-content-cache nil)
119 (let ((shr-state nil)
120 (shr-start nil)
121 (shr-width (or shr-width (window-width))))
122 (shr-descend (shr-transform-dom dom))))
124 (defun shr-copy-url ()
125 "Copy the URL under point to the kill ring.
126 If called twice, then try to fetch the URL and see whether it
127 redirects somewhere else."
128 (interactive)
129 (let ((url (get-text-property (point) 'shr-url)))
130 (cond
131 ((not url)
132 (message "No URL under point"))
133 ;; Resolve redirected URLs.
134 ((equal url (car kill-ring))
135 (url-retrieve
137 (lambda (a)
138 (when (and (consp a)
139 (eq (car a) :redirect))
140 (with-temp-buffer
141 (insert (cadr a))
142 (goto-char (point-min))
143 ;; Remove common tracking junk from the URL.
144 (when (re-search-forward ".utm_.*" nil t)
145 (replace-match "" t t))
146 (message "Copied %s" (buffer-string))
147 (copy-region-as-kill (point-min) (point-max)))))))
148 ;; Copy the URL to the kill ring.
150 (with-temp-buffer
151 (insert url)
152 (copy-region-as-kill (point-min) (point-max))
153 (message "Copied %s" url))))))
155 (defun shr-show-alt-text ()
156 "Show the ALT text of the image under point."
157 (interactive)
158 (let ((text (get-text-property (point) 'shr-alt)))
159 (if (not text)
160 (message "No image under point")
161 (message "%s" text))))
163 (defun shr-browse-image ()
164 "Browse the image under point."
165 (interactive)
166 (let ((url (get-text-property (point) 'image-url)))
167 (if (not url)
168 (message "No image under point")
169 (message "Browsing %s..." url)
170 (browse-url url))))
172 (defun shr-insert-image ()
173 "Insert the image under point into the buffer."
174 (interactive)
175 (let ((url (get-text-property (point) 'image-url)))
176 (if (not url)
177 (message "No image under point")
178 (message "Inserting %s..." url)
179 (url-retrieve url 'shr-image-fetched
180 (list (current-buffer) (1- (point)) (point-marker))
181 t))))
183 ;;; Utility functions.
185 (defun shr-transform-dom (dom)
186 (let ((result (list (pop dom))))
187 (dolist (arg (pop dom))
188 (push (cons (intern (concat ":" (symbol-name (car arg))) obarray)
189 (cdr arg))
190 result))
191 (dolist (sub dom)
192 (if (stringp sub)
193 (push (cons 'text sub) result)
194 (push (shr-transform-dom sub) result)))
195 (nreverse result)))
197 (defun shr-descend (dom)
198 (let ((function (intern (concat "shr-tag-" (symbol-name (car dom))) obarray))
199 (style (cdr (assq :style (cdr dom))))
200 (shr-stylesheet shr-stylesheet)
201 (start (point)))
202 (when style
203 (if (string-match "color" style)
204 (setq shr-stylesheet (nconc (shr-parse-style style)
205 shr-stylesheet))
206 (setq style nil)))
207 (if (fboundp function)
208 (funcall function (cdr dom))
209 (shr-generic (cdr dom)))
210 ;; If style is set, then this node has set the color.
211 (when style
212 (shr-colorize-region start (point)
213 (cdr (assq 'color shr-stylesheet))
214 (cdr (assq 'background-color shr-stylesheet))))))
216 (defun shr-generic (cont)
217 (dolist (sub cont)
218 (cond
219 ((eq (car sub) 'text)
220 (shr-insert (cdr sub)))
221 ((listp (cdr sub))
222 (shr-descend sub)))))
224 (defmacro shr-char-breakable-p (char)
225 "Return non-nil if a line can be broken before and after CHAR."
226 `(aref fill-find-break-point-function-table ,char))
227 (defmacro shr-char-nospace-p (char)
228 "Return non-nil if no space is required before and after CHAR."
229 `(aref fill-nospace-between-words-table ,char))
231 ;; KINSOKU is a Japanese word meaning a rule that should not be violated.
232 ;; In Emacs, it is a term used for characters, e.g. punctuation marks,
233 ;; parentheses, and so on, that should not be placed in the beginning
234 ;; of a line or the end of a line.
235 (defmacro shr-char-kinsoku-bol-p (char)
236 "Return non-nil if a line ought not to begin with CHAR."
237 `(aref (char-category-set ,char) ?>))
238 (defmacro shr-char-kinsoku-eol-p (char)
239 "Return non-nil if a line ought not to end with CHAR."
240 `(aref (char-category-set ,char) ?<))
241 (unless (shr-char-kinsoku-bol-p (make-char 'japanese-jisx0208 33 35))
242 (load "kinsoku" nil t))
244 (defun shr-insert (text)
245 (when (and (eq shr-state 'image)
246 (not (string-match "\\`[ \t\n]+\\'" text)))
247 (insert "\n")
248 (setq shr-state nil))
249 (cond
250 ((eq shr-folding-mode 'none)
251 (insert text))
253 (when (and (string-match "\\`[ \t\n]" text)
254 (not (bolp))
255 (not (eq (char-after (1- (point))) ? )))
256 (insert " "))
257 (dolist (elem (split-string text))
258 (when (and (bolp)
259 (> shr-indentation 0))
260 (shr-indent))
261 ;; No space is needed behind a wide character categorized as
262 ;; kinsoku-bol, between characters both categorized as nospace,
263 ;; or at the beginning of a line.
264 (let (prev)
265 (when (and (> (current-column) shr-indentation)
266 (eq (preceding-char) ? )
267 (or (= (line-beginning-position) (1- (point)))
268 (and (shr-char-breakable-p
269 (setq prev (char-after (- (point) 2))))
270 (shr-char-kinsoku-bol-p prev))
271 (and (shr-char-nospace-p prev)
272 (shr-char-nospace-p (aref elem 0)))))
273 (delete-char -1)))
274 ;; The shr-start is a special variable that is used to pass
275 ;; upwards the first point in the buffer where the text really
276 ;; starts.
277 (unless shr-start
278 (setq shr-start (point)))
279 (insert elem)
280 (let (found)
281 (while (and (> (current-column) shr-width)
282 (progn
283 (setq found (shr-find-fill-point))
284 (not (eolp))))
285 (when (eq (preceding-char) ? )
286 (delete-char -1))
287 (insert "\n")
288 (unless found
289 (put-text-property (1- (point)) (point) 'shr-break t)
290 ;; No space is needed at the beginning of a line.
291 (when (eq (following-char) ? )
292 (delete-char 1)))
293 (when (> shr-indentation 0)
294 (shr-indent))
295 (end-of-line))
296 (insert " ")))
297 (unless (string-match "[ \t\n]\\'" text)
298 (delete-char -1)))))
300 (defun shr-find-fill-point ()
301 (when (> (move-to-column shr-width) shr-width)
302 (backward-char 1))
303 (let ((bp (point))
304 failed)
305 (while (not (or (setq failed (= (current-column) shr-indentation))
306 (eq (preceding-char) ? )
307 (eq (following-char) ? )
308 (shr-char-breakable-p (preceding-char))
309 (shr-char-breakable-p (following-char))
310 (if (eq (preceding-char) ?')
311 (not (memq (char-after (- (point) 2))
312 (list nil ?\n ? )))
313 (and (shr-char-kinsoku-bol-p (preceding-char))
314 (shr-char-breakable-p (following-char))
315 (not (shr-char-kinsoku-bol-p (following-char)))))
316 (shr-char-kinsoku-eol-p (following-char))))
317 (backward-char 1))
318 (if (and (not (or failed (eolp)))
319 (eq (preceding-char) ?'))
320 (while (not (or (setq failed (eolp))
321 (eq (following-char) ? )
322 (shr-char-breakable-p (following-char))
323 (shr-char-kinsoku-eol-p (following-char))))
324 (forward-char 1)))
325 (if failed
326 ;; There's no breakable point, so we give it up.
327 (let (found)
328 (goto-char bp)
329 (unless shr-kinsoku-shorten
330 (while (and (setq found (re-search-forward
331 "\\(\\c>\\)\\| \\|\\c<\\|\\c|"
332 (line-end-position) 'move))
333 (eq (preceding-char) ?')))
334 (if (and found (not (match-beginning 1)))
335 (goto-char (match-beginning 0)))))
337 (eolp)
338 ;; Don't put kinsoku-bol characters at the beginning of a line,
339 ;; or kinsoku-eol characters at the end of a line.
340 (cond
341 (shr-kinsoku-shorten
342 (while (and (not (memq (preceding-char) (list ?\C-@ ?\n ? )))
343 (shr-char-kinsoku-eol-p (preceding-char)))
344 (backward-char 1))
345 (when (setq failed (= (current-column) shr-indentation))
346 ;; There's no breakable point that doesn't violate kinsoku,
347 ;; so we look for the second best position.
348 (while (and (progn
349 (forward-char 1)
350 (<= (current-column) shr-width))
351 (progn
352 (setq bp (point))
353 (shr-char-kinsoku-eol-p (following-char)))))
354 (goto-char bp)))
355 ((shr-char-kinsoku-eol-p (preceding-char))
356 (if (shr-char-kinsoku-eol-p (following-char))
357 ;; There are consecutive kinsoku-eol characters.
358 (setq failed t)
359 (let ((count 4))
360 (while
361 (progn
362 (backward-char 1)
363 (and (> (setq count (1- count)) 0)
364 (not (memq (preceding-char) (list ?\C-@ ?\n ? )))
365 (or (shr-char-kinsoku-eol-p (preceding-char))
366 (shr-char-kinsoku-bol-p (following-char)))))))
367 (if (setq failed (= (current-column) shr-indentation))
368 ;; There's no breakable point that doesn't violate kinsoku,
369 ;; so we go to the second best position.
370 (if (looking-at "\\(\\c<+\\)\\c<")
371 (goto-char (match-end 1))
372 (forward-char 1)))))
374 (if (shr-char-kinsoku-bol-p (preceding-char))
375 ;; There are consecutive kinsoku-bol characters.
376 (setq failed t)
377 (let ((count 4))
378 (while (and (>= (setq count (1- count)) 0)
379 (shr-char-kinsoku-bol-p (following-char))
380 (shr-char-breakable-p (following-char)))
381 (forward-char 1))))))
382 (when (eq (following-char) ? )
383 (forward-char 1))))
384 (not failed)))
386 (defun shr-ensure-newline ()
387 (unless (zerop (current-column))
388 (insert "\n")))
390 (defun shr-ensure-paragraph ()
391 (unless (bobp)
392 (if (<= (current-column) shr-indentation)
393 (unless (save-excursion
394 (forward-line -1)
395 (looking-at " *$"))
396 (insert "\n"))
397 (if (save-excursion
398 (beginning-of-line)
399 (looking-at " *$"))
400 (insert "\n")
401 (insert "\n\n")))))
403 (defun shr-indent ()
404 (when (> shr-indentation 0)
405 (insert (make-string shr-indentation ? ))))
407 (defun shr-fontize-cont (cont &rest types)
408 (let (shr-start)
409 (shr-generic cont)
410 (dolist (type types)
411 (shr-add-font (or shr-start (point)) (point) type))))
413 ;; Add an overlay in the region, but avoid putting the font properties
414 ;; on blank text at the start of the line, and the newline at the end,
415 ;; to avoid ugliness.
416 (defun shr-add-font (start end type)
417 (save-excursion
418 (goto-char start)
419 (while (< (point) end)
420 (when (bolp)
421 (skip-chars-forward " "))
422 (let ((overlay (make-overlay (point) (min (line-end-position) end))))
423 (overlay-put overlay 'face type))
424 (if (< (line-end-position) end)
425 (forward-line 1)
426 (goto-char end)))))
428 (defun shr-browse-url ()
429 "Browse the URL under point."
430 (interactive)
431 (let ((url (get-text-property (point) 'shr-url)))
432 (cond
433 ((not url)
434 (message "No link under point"))
435 ((string-match "^mailto:" url)
436 (browse-url-mailto url))
438 (browse-url url)))))
440 (defun shr-save-contents (directory)
441 "Save the contents from URL in a file."
442 (interactive "DSave contents of URL to directory: ")
443 (let ((url (get-text-property (point) 'shr-url)))
444 (if (not url)
445 (message "No link under point")
446 (url-retrieve (shr-encode-url url)
447 'shr-store-contents (list url directory)))))
449 (defun shr-store-contents (status url directory)
450 (unless (plist-get status :error)
451 (when (or (search-forward "\n\n" nil t)
452 (search-forward "\r\n\r\n" nil t))
453 (write-region (point) (point-max)
454 (expand-file-name (file-name-nondirectory url)
455 directory)))))
457 (defun shr-image-fetched (status buffer start end)
458 (when (and (buffer-name buffer)
459 (not (plist-get status :error)))
460 (url-store-in-cache (current-buffer))
461 (when (or (search-forward "\n\n" nil t)
462 (search-forward "\r\n\r\n" nil t))
463 (let ((data (buffer-substring (point) (point-max))))
464 (with-current-buffer buffer
465 (save-excursion
466 (let ((alt (buffer-substring start end))
467 (inhibit-read-only t))
468 (delete-region start end)
469 (goto-char start)
470 (shr-put-image data alt)))))))
471 (kill-buffer (current-buffer)))
473 (defun shr-put-image (data alt)
474 (if (display-graphic-p)
475 (let ((image (ignore-errors
476 (shr-rescale-image data))))
477 (when image
478 ;; When inserting big-ish pictures, put them at the
479 ;; beginning of the line.
480 (when (and (> (current-column) 0)
481 (> (car (image-size image t)) 400))
482 (insert "\n"))
483 (insert-image image (or alt "*"))))
484 (insert alt)))
486 (defun shr-rescale-image (data)
487 (if (or (not (fboundp 'imagemagick-types))
488 (not (get-buffer-window (current-buffer))))
489 (create-image data nil t)
490 (let* ((image (create-image data nil t))
491 (size (image-size image t))
492 (width (car size))
493 (height (cdr size))
494 (edges (window-inside-pixel-edges
495 (get-buffer-window (current-buffer))))
496 (window-width (truncate (* shr-max-image-proportion
497 (- (nth 2 edges) (nth 0 edges)))))
498 (window-height (truncate (* shr-max-image-proportion
499 (- (nth 3 edges) (nth 1 edges)))))
500 scaled-image)
501 (when (> height window-height)
502 (setq image (or (create-image data 'imagemagick t
503 :height window-height)
504 image))
505 (setq size (image-size image t)))
506 (when (> (car size) window-width)
507 (setq image (or
508 (create-image data 'imagemagick t
509 :width window-width)
510 image)))
511 (when (and (fboundp 'create-animated-image)
512 (eq (image-type data nil t) 'gif))
513 (setq image (create-animated-image data 'gif t)))
514 image)))
516 ;; url-cache-extract autoloads url-cache.
517 (declare-function url-cache-create-filename "url-cache" (url))
518 (autoload 'mm-disable-multibyte "mm-util")
519 (autoload 'browse-url-mailto "browse-url")
521 (defun shr-get-image-data (url)
522 "Get image data for URL.
523 Return a string with image data."
524 (with-temp-buffer
525 (mm-disable-multibyte)
526 (when (ignore-errors
527 (url-cache-extract (url-cache-create-filename (shr-encode-url url)))
529 (when (or (search-forward "\n\n" nil t)
530 (search-forward "\r\n\r\n" nil t))
531 (buffer-substring (point) (point-max))))))
533 (defun shr-image-displayer (content-function)
534 "Return a function to display an image.
535 CONTENT-FUNCTION is a function to retrieve an image for a cid url that
536 is an argument. The function to be returned takes three arguments URL,
537 START, and END. Note that START and END should be merkers."
538 `(lambda (url start end)
539 (when url
540 (if (string-match "\\`cid:" url)
541 ,(when content-function
542 `(let ((image (funcall ,content-function
543 (substring url (match-end 0)))))
544 (when image
545 (goto-char start)
546 (shr-put-image image
547 (buffer-substring-no-properties start end))
548 (delete-region (point) end))))
549 (url-retrieve url 'shr-image-fetched
550 (list (current-buffer) start end)
551 t)))))
553 (defun shr-heading (cont &rest types)
554 (shr-ensure-paragraph)
555 (apply #'shr-fontize-cont cont types)
556 (shr-ensure-paragraph))
558 (autoload 'widget-convert-button "wid-edit")
560 (defun shr-urlify (start url &optional title)
561 (widget-convert-button
562 'url-link start (point)
563 :help-echo (if title (format "%s (%s)" url title) url)
564 :keymap shr-map
565 url)
566 (put-text-property start (point) 'shr-url url))
568 (defun shr-encode-url (url)
569 "Encode URL."
570 (browse-url-url-encode-chars url "[)$ ]"))
572 (autoload 'shr-color-visible "shr-color")
573 (autoload 'shr-color->hexadecimal "shr-color")
575 (defun shr-color-check (fg bg)
576 "Check that FG is visible on BG.
577 Returns (fg bg) with corrected values.
578 Returns nil if the colors that would be used are the default
579 ones, in case fg and bg are nil."
580 (when (or fg bg)
581 (let ((fixed (cond ((null fg) 'fg)
582 ((null bg) 'bg))))
583 ;; Convert colors to hexadecimal, or set them to default.
584 (let ((fg (or (shr-color->hexadecimal fg)
585 (frame-parameter nil 'foreground-color)))
586 (bg (or (shr-color->hexadecimal bg)
587 (frame-parameter nil 'background-color))))
588 (cond ((eq fixed 'bg)
589 ;; Only return the new fg
590 (list nil (cadr (shr-color-visible bg fg t))))
591 ((eq fixed 'fg)
592 ;; Invert args and results and return only the new bg
593 (list (cadr (shr-color-visible fg bg t)) nil))
595 (shr-color-visible bg fg)))))))
597 (defun shr-colorize-region (start end fg &optional bg)
598 (when (or fg bg)
599 (let ((new-colors (shr-color-check fg bg)))
600 (when new-colors
601 (when fg
602 (shr-put-color start end :foreground (cadr new-colors)))
603 (when bg
604 (shr-put-color start end :background (car new-colors))))
605 new-colors)))
607 ;; Put a color in the region, but avoid putting colors on on blank
608 ;; text at the start of the line, and the newline at the end, to avoid
609 ;; ugliness. Also, don't overwrite any existing color information,
610 ;; since this can be called recursively, and we want the "inner" color
611 ;; to win.
612 (defun shr-put-color (start end type color)
613 (save-excursion
614 (goto-char start)
615 (while (< (point) end)
616 (when (and (bolp)
617 (not (eq type :background)))
618 (skip-chars-forward " "))
619 (when (> (line-end-position) (point))
620 (shr-put-color-1 (point) (min (line-end-position) end) type color))
621 (if (< (line-end-position) end)
622 (forward-line 1)
623 (goto-char end)))
624 (when (and (eq type :background)
625 (= shr-table-depth 0))
626 (shr-expand-newlines start end color))))
628 (defun shr-expand-newlines (start end color)
629 (save-restriction
630 ;; Skip past all white space at the start and ends.
631 (goto-char start)
632 (skip-chars-forward " \t\n")
633 (beginning-of-line)
634 (setq start (point))
635 (goto-char end)
636 (skip-chars-backward " \t\n")
637 (forward-line 1)
638 (setq end (point))
639 (narrow-to-region start end)
640 (let ((width (shr-natural-width))
641 column)
642 (goto-char (point-min))
643 (while (not (eobp))
644 (end-of-line)
645 (when (and (< (setq column (current-column)) width)
646 (< (setq column (shr-previous-newline-padding-width column))
647 width))
648 (let ((overlay (make-overlay (point) (1+ (point)))))
649 (overlay-put overlay 'before-string
650 (concat
651 (mapconcat
652 (lambda (overlay)
653 (let ((string (plist-get
654 (overlay-properties overlay)
655 'before-string)))
656 (if (not string)
658 (overlay-put overlay 'before-string "")
659 string)))
660 (overlays-at (point))
662 (propertize (make-string (- width column) ? )
663 'face (list :background color))))))
664 (forward-line 1)))))
666 (defun shr-previous-newline-padding-width (width)
667 (let ((overlays (overlays-at (point)))
668 (previous-width 0))
669 (if (null overlays)
670 width
671 (dolist (overlay overlays)
672 (setq previous-width
673 (+ previous-width
674 (length (plist-get (overlay-properties overlay)
675 'before-string)))))
676 (+ width previous-width))))
678 (defun shr-put-color-1 (start end type color)
679 (let* ((old-props (get-text-property start 'face))
680 (do-put (not (memq type old-props)))
681 change)
682 (while (< start end)
683 (setq change (next-single-property-change start 'face nil end))
684 (when do-put
685 (put-text-property start change 'face
686 (nconc (list type color) old-props)))
687 (setq old-props (get-text-property change 'face))
688 (setq do-put (not (memq type old-props)))
689 (setq start change))
690 (when (and do-put
691 (> end start))
692 (put-text-property start end 'face
693 (nconc (list type color old-props))))))
695 ;;; Tag-specific rendering rules.
697 (defun shr-tag-body (cont)
698 (let* ((start (point))
699 (fgcolor (cdr (or (assq :fgcolor cont)
700 (assq :text cont))))
701 (bgcolor (cdr (assq :bgcolor cont)))
702 (shr-stylesheet (list (cons 'color fgcolor)
703 (cons 'background-color bgcolor))))
704 (shr-generic cont)
705 (shr-colorize-region start (point) fgcolor bgcolor)))
707 (defun shr-tag-style (cont)
710 (defun shr-tag-script (cont)
713 (defun shr-tag-label (cont)
714 (shr-generic cont)
715 (shr-ensure-paragraph))
717 (defun shr-tag-p (cont)
718 (shr-ensure-paragraph)
719 (shr-indent)
720 (shr-generic cont)
721 (shr-ensure-paragraph))
723 (defun shr-tag-div (cont)
724 (shr-ensure-newline)
725 (shr-indent)
726 (shr-generic cont)
727 (shr-ensure-newline))
729 (defun shr-tag-b (cont)
730 (shr-fontize-cont cont 'bold))
732 (defun shr-tag-i (cont)
733 (shr-fontize-cont cont 'italic))
735 (defun shr-tag-em (cont)
736 (shr-fontize-cont cont 'bold))
738 (defun shr-tag-strong (cont)
739 (shr-fontize-cont cont 'bold))
741 (defun shr-tag-u (cont)
742 (shr-fontize-cont cont 'underline))
744 (defun shr-tag-s (cont)
745 (shr-fontize-cont cont 'strike-through))
747 (defun shr-parse-style (style)
748 (when style
749 (save-match-data
750 (when (string-match "\n" style)
751 (setq style (replace-match " " t t style))))
752 (let ((plist nil))
753 (dolist (elem (split-string style ";"))
754 (when elem
755 (setq elem (split-string elem ":"))
756 (when (and (car elem)
757 (cadr elem))
758 (let ((name (replace-regexp-in-string "^ +\\| +$" "" (car elem)))
759 (value (replace-regexp-in-string "^ +\\| +$" "" (cadr elem))))
760 (when (string-match " *!important\\'" value)
761 (setq value (substring value 0 (match-beginning 0))))
762 (push (cons (intern name obarray)
763 value)
764 plist)))))
765 plist)))
767 (defun shr-tag-a (cont)
768 (let ((url (cdr (assq :href cont)))
769 (title (cdr (assq :title cont)))
770 (start (point))
771 shr-start)
772 (shr-generic cont)
773 (shr-urlify (or shr-start start) url title)))
775 (defun shr-tag-object (cont)
776 (let ((start (point))
777 url)
778 (dolist (elem cont)
779 (when (eq (car elem) 'embed)
780 (setq url (or url (cdr (assq :src (cdr elem))))))
781 (when (and (eq (car elem) 'param)
782 (equal (cdr (assq :name (cdr elem))) "movie"))
783 (setq url (or url (cdr (assq :value (cdr elem)))))))
784 (when url
785 (shr-insert " [multimedia] ")
786 (shr-urlify start url))
787 (shr-generic cont)))
789 (defun shr-tag-video (cont)
790 (let ((image (cdr (assq :poster cont)))
791 (url (cdr (assq :src cont)))
792 (start (point)))
793 (shr-tag-img nil image)
794 (shr-urlify start url)))
796 (defun shr-tag-img (cont &optional url)
797 (when (or url
798 (and cont
799 (cdr (assq :src cont))))
800 (when (and (> (current-column) 0)
801 (not (eq shr-state 'image)))
802 (insert "\n"))
803 (let ((alt (cdr (assq :alt cont)))
804 (url (or url (cdr (assq :src cont)))))
805 (let ((start (point-marker)))
806 (when (zerop (length alt))
807 (setq alt "*"))
808 (cond
809 ((or (member (cdr (assq :height cont)) '("0" "1"))
810 (member (cdr (assq :width cont)) '("0" "1")))
811 ;; Ignore zero-sized or single-pixel images.
813 ((and (not shr-inhibit-images)
814 (string-match "\\`cid:" url))
815 (let ((url (substring url (match-end 0)))
816 image)
817 (if (or (not shr-content-function)
818 (not (setq image (funcall shr-content-function url))))
819 (insert alt)
820 (shr-put-image image alt))))
821 ((or shr-inhibit-images
822 (and shr-blocked-images
823 (string-match shr-blocked-images url)))
824 (setq shr-start (point))
825 (let ((shr-state 'space))
826 (if (> (string-width alt) 8)
827 (shr-insert (truncate-string-to-width alt 8))
828 (shr-insert alt))))
829 ((url-is-cached (shr-encode-url url))
830 (shr-put-image (shr-get-image-data url) alt))
832 (insert alt)
833 (ignore-errors
834 (url-retrieve (shr-encode-url url) 'shr-image-fetched
835 (list (current-buffer) start (point-marker))
836 t))))
837 (put-text-property start (point) 'keymap shr-map)
838 (put-text-property start (point) 'shr-alt alt)
839 (put-text-property start (point) 'image-url url)
840 (put-text-property start (point) 'image-displayer
841 (shr-image-displayer shr-content-function))
842 (put-text-property start (point) 'help-echo alt)
843 (setq shr-state 'image)))))
845 (defun shr-tag-pre (cont)
846 (let ((shr-folding-mode 'none))
847 (shr-ensure-newline)
848 (shr-indent)
849 (shr-generic cont)
850 (shr-ensure-newline)))
852 (defun shr-tag-blockquote (cont)
853 (shr-ensure-paragraph)
854 (shr-indent)
855 (let ((shr-indentation (+ shr-indentation 4)))
856 (shr-generic cont))
857 (shr-ensure-paragraph))
859 (defun shr-tag-ul (cont)
860 (shr-ensure-paragraph)
861 (let ((shr-list-mode 'ul))
862 (shr-generic cont))
863 (shr-ensure-paragraph))
865 (defun shr-tag-ol (cont)
866 (shr-ensure-paragraph)
867 (let ((shr-list-mode 1))
868 (shr-generic cont))
869 (shr-ensure-paragraph))
871 (defun shr-tag-li (cont)
872 (shr-ensure-paragraph)
873 (shr-indent)
874 (let* ((bullet
875 (if (numberp shr-list-mode)
876 (prog1
877 (format "%d " shr-list-mode)
878 (setq shr-list-mode (1+ shr-list-mode)))
879 "* "))
880 (shr-indentation (+ shr-indentation (length bullet))))
881 (insert bullet)
882 (shr-generic cont)))
884 (defun shr-tag-br (cont)
885 (unless (bobp)
886 (insert "\n")
887 (shr-indent))
888 (shr-generic cont))
890 (defun shr-tag-h1 (cont)
891 (shr-heading cont 'bold 'underline))
893 (defun shr-tag-h2 (cont)
894 (shr-heading cont 'bold))
896 (defun shr-tag-h3 (cont)
897 (shr-heading cont 'italic))
899 (defun shr-tag-h4 (cont)
900 (shr-heading cont))
902 (defun shr-tag-h5 (cont)
903 (shr-heading cont))
905 (defun shr-tag-h6 (cont)
906 (shr-heading cont))
908 (defun shr-tag-hr (cont)
909 (shr-ensure-newline)
910 (insert (make-string shr-width shr-hr-line) "\n"))
912 (defun shr-tag-title (cont)
913 (shr-heading cont 'bold 'underline))
915 (defun shr-tag-font (cont)
916 (let* ((start (point))
917 (color (cdr (assq :color cont)))
918 (shr-stylesheet (nconc (list (cons 'color color))
919 shr-stylesheet)))
920 (shr-generic cont)
921 (when color
922 (shr-colorize-region start (point) color
923 (cdr (assq 'background-color shr-stylesheet))))))
925 ;;; Table rendering algorithm.
927 ;; Table rendering is the only complicated thing here. We do this by
928 ;; first counting how many TDs there are in each TR, and registering
929 ;; how wide they think they should be ("width=45%", etc). Then we
930 ;; render each TD separately (this is done in temporary buffers, so
931 ;; that we can use all the rendering machinery as if we were in the
932 ;; main buffer). Now we know how much space each TD really takes, so
933 ;; we then render everything again with the new widths, and finally
934 ;; insert all these boxes into the main buffer.
935 (defun shr-tag-table-1 (cont)
936 (setq cont (or (cdr (assq 'tbody cont))
937 cont))
938 (let* ((shr-inhibit-images t)
939 (shr-table-depth (1+ shr-table-depth))
940 (shr-kinsoku-shorten t)
941 ;; Find all suggested widths.
942 (columns (shr-column-specs cont))
943 ;; Compute how many characters wide each TD should be.
944 (suggested-widths (shr-pro-rate-columns columns))
945 ;; Do a "test rendering" to see how big each TD is (this can
946 ;; be smaller (if there's little text) or bigger (if there's
947 ;; unbreakable text).
948 (sketch (shr-make-table cont suggested-widths))
949 (sketch-widths (shr-table-widths sketch suggested-widths)))
950 ;; This probably won't work very well.
951 (when (> (+ (loop for width across sketch-widths
952 summing (1+ width))
953 shr-indentation 1)
954 (frame-width))
955 (setq truncate-lines t))
956 ;; Then render the table again with these new "hard" widths.
957 (shr-insert-table (shr-make-table cont sketch-widths t) sketch-widths))
958 ;; Finally, insert all the images after the table. The Emacs buffer
959 ;; model isn't strong enough to allow us to put the images actually
960 ;; into the tables.
961 (when (zerop shr-table-depth)
962 (dolist (elem (shr-find-elements cont 'img))
963 (shr-tag-img (cdr elem)))))
965 (defun shr-tag-table (cont)
966 (shr-ensure-paragraph)
967 (let* ((caption (cdr (assq 'caption cont)))
968 (header (cdr (assq 'thead cont)))
969 (body (or (cdr (assq 'tbody cont)) cont))
970 (footer (cdr (assq 'tfoot cont)))
971 (bgcolor (cdr (assq :bgcolor cont)))
972 (start (point))
973 (shr-stylesheet (nconc (list (cons 'background-color bgcolor))
974 shr-stylesheet))
975 (nheader (if header (shr-max-columns header)))
976 (nbody (if body (shr-max-columns body)))
977 (nfooter (if footer (shr-max-columns footer))))
978 (shr-tag-table-1
979 (nconc
980 (if caption `((tr (td ,@caption))))
981 (if header
982 (if footer
983 ;; hader + body + footer
984 (if (= nheader nbody)
985 (if (= nbody nfooter)
986 `((tr (td (table (tbody ,@header ,@body ,@footer)))))
987 (nconc `((tr (td (table (tbody ,@header ,@body)))))
988 (if (= nfooter 1)
989 footer
990 `((tr (td (table (tbody ,@footer))))))))
991 (nconc `((tr (td (table (tbody ,@header)))))
992 (if (= nbody nfooter)
993 `((tr (td (table (tbody ,@body ,@footer)))))
994 (nconc `((tr (td (table (tbody ,@body)))))
995 (if (= nfooter 1)
996 footer
997 `((tr (td (table (tbody ,@footer))))))))))
998 ;; header + body
999 (if (= nheader nbody)
1000 `((tr (td (table (tbody ,@header ,@body)))))
1001 (if (= nheader 1)
1002 `(,@header (tr (td (table (tbody ,@body)))))
1003 `((tr (td (table (tbody ,@header))))
1004 (tr (td (table (tbody ,@body))))))))
1005 (if footer
1006 ;; body + footer
1007 (if (= nbody nfooter)
1008 `((tr (td (table (tbody ,@body ,@footer)))))
1009 (nconc `((tr (td (table (tbody ,@body)))))
1010 (if (= nfooter 1)
1011 footer
1012 `((tr (td (table (tbody ,@footer))))))))
1013 (if caption
1014 `((tr (td (table (tbody ,@body)))))
1015 body)))))
1016 (when bgcolor
1017 (shr-colorize-region start (point) (cdr (assq 'color shr-stylesheet))
1018 bgcolor))))
1020 (defun shr-find-elements (cont type)
1021 (let (result)
1022 (dolist (elem cont)
1023 (cond ((eq (car elem) type)
1024 (push elem result))
1025 ((consp (cdr elem))
1026 (setq result (nconc (shr-find-elements (cdr elem) type) result)))))
1027 (nreverse result)))
1029 (defun shr-insert-table (table widths)
1030 (shr-insert-table-ruler widths)
1031 (dolist (row table)
1032 (let ((start (point))
1033 (height (let ((max 0))
1034 (dolist (column row)
1035 (setq max (max max (cadr column))))
1036 max)))
1037 (dotimes (i height)
1038 (shr-indent)
1039 (insert shr-table-vertical-line "\n"))
1040 (dolist (column row)
1041 (goto-char start)
1042 (let ((lines (nth 2 column))
1043 (overlay-lines (nth 3 column))
1044 overlay overlay-line)
1045 (dolist (line lines)
1046 (setq overlay-line (pop overlay-lines))
1047 (end-of-line)
1048 (insert line shr-table-vertical-line)
1049 (dolist (overlay overlay-line)
1050 (let ((o (make-overlay (- (point) (nth 0 overlay) 1)
1051 (- (point) (nth 1 overlay) 1)))
1052 (properties (nth 2 overlay)))
1053 (while properties
1054 (overlay-put o (pop properties) (pop properties)))))
1055 (forward-line 1))
1056 ;; Add blank lines at padding at the bottom of the TD,
1057 ;; possibly.
1058 (dotimes (i (- height (length lines)))
1059 (end-of-line)
1060 (let ((start (point)))
1061 (insert (make-string (string-width (car lines)) ? )
1062 shr-table-vertical-line)
1063 (when (nth 4 column)
1064 (shr-put-color start (1- (point)) :background (nth 4 column))))
1065 (forward-line 1)))))
1066 (shr-insert-table-ruler widths)))
1068 (defun shr-insert-table-ruler (widths)
1069 (when (and (bolp)
1070 (> shr-indentation 0))
1071 (shr-indent))
1072 (insert shr-table-corner)
1073 (dotimes (i (length widths))
1074 (insert (make-string (aref widths i) shr-table-horizontal-line)
1075 shr-table-corner))
1076 (insert "\n"))
1078 (defun shr-table-widths (table suggested-widths)
1079 (let* ((length (length suggested-widths))
1080 (widths (make-vector length 0))
1081 (natural-widths (make-vector length 0)))
1082 (dolist (row table)
1083 (let ((i 0))
1084 (dolist (column row)
1085 (aset widths i (max (aref widths i)
1086 (car column)))
1087 (aset natural-widths i (max (aref natural-widths i)
1088 (cadr column)))
1089 (setq i (1+ i)))))
1090 (let ((extra (- (apply '+ (append suggested-widths nil))
1091 (apply '+ (append widths nil))))
1092 (expanded-columns 0))
1093 (when (> extra 0)
1094 (dotimes (i length)
1095 ;; If the natural width is wider than the rendered width, we
1096 ;; want to allow the column to expand.
1097 (when (> (aref natural-widths i) (aref widths i))
1098 (setq expanded-columns (1+ expanded-columns))))
1099 (dotimes (i length)
1100 (when (> (aref natural-widths i) (aref widths i))
1101 (aset widths i (min
1102 (1+ (aref natural-widths i))
1103 (+ (/ extra expanded-columns)
1104 (aref widths i))))))))
1105 widths))
1107 (defun shr-make-table (cont widths &optional fill)
1108 (let ((trs nil))
1109 (dolist (row cont)
1110 (when (eq (car row) 'tr)
1111 (let ((tds nil)
1112 (columns (cdr row))
1113 (i 0)
1114 column)
1115 (while (< i (length widths))
1116 (setq column (pop columns))
1117 (when (or (memq (car column) '(td th))
1118 (null column))
1119 (push (shr-render-td (cdr column) (aref widths i) fill)
1120 tds)
1121 (setq i (1+ i))))
1122 (push (nreverse tds) trs))))
1123 (nreverse trs)))
1125 (defun shr-render-td (cont width fill)
1126 (with-temp-buffer
1127 (let ((bgcolor (cdr (assq :bgcolor cont)))
1128 (fgcolor (cdr (assq :fgcolor cont)))
1129 (style (cdr (assq :style cont)))
1130 (shr-stylesheet shr-stylesheet)
1131 overlays actual-colors)
1132 (when style
1133 (setq style (and (string-match "color" style)
1134 (shr-parse-style style))))
1135 (when bgcolor
1136 (setq style (nconc (list (cons 'background-color bgcolor)) style)))
1137 (when fgcolor
1138 (setq style (nconc (list (cons 'color fgcolor)) style)))
1139 (when style
1140 (setq shr-stylesheet (append style shr-stylesheet)))
1141 (let ((cache (cdr (assoc (cons width cont) shr-content-cache))))
1142 (if cache
1143 (progn
1144 (insert (car cache))
1145 (let ((end (length (car cache))))
1146 (dolist (overlay (cadr cache))
1147 (let ((new-overlay
1148 (make-overlay (1+ (- end (nth 0 overlay)))
1149 (1+ (- end (nth 1 overlay)))))
1150 (properties (nth 2 overlay)))
1151 (while properties
1152 (overlay-put new-overlay
1153 (pop properties) (pop properties)))))))
1154 (let ((shr-width width)
1155 (shr-indentation 0))
1156 (shr-descend (cons 'td cont)))
1157 (delete-region
1158 (point)
1159 (+ (point)
1160 (skip-chars-backward " \t\n")))
1161 (push (list (cons width cont) (buffer-string)
1162 (shr-overlays-in-region (point-min) (point-max)))
1163 shr-content-cache)))
1164 (goto-char (point-min))
1165 (let ((max 0))
1166 (while (not (eobp))
1167 (end-of-line)
1168 (setq max (max max (current-column)))
1169 (forward-line 1))
1170 (when fill
1171 (goto-char (point-min))
1172 ;; If the buffer is totally empty, then put a single blank
1173 ;; line here.
1174 (if (zerop (buffer-size))
1175 (insert (make-string width ? ))
1176 ;; Otherwise, fill the buffer.
1177 (while (not (eobp))
1178 (end-of-line)
1179 (when (> (- width (current-column)) 0)
1180 (insert (make-string (- width (current-column)) ? )))
1181 (forward-line 1)))
1182 (when style
1183 (setq actual-colors
1184 (shr-colorize-region
1185 (point-min) (point-max)
1186 (cdr (assq 'color shr-stylesheet))
1187 (cdr (assq 'background-color shr-stylesheet))))))
1188 (if fill
1189 (list max
1190 (count-lines (point-min) (point-max))
1191 (split-string (buffer-string) "\n")
1192 (shr-collect-overlays)
1193 (car actual-colors))
1194 (list max
1195 (shr-natural-width)))))))
1197 (defun shr-natural-width ()
1198 (goto-char (point-min))
1199 (let ((current 0)
1200 (max 0))
1201 (while (not (eobp))
1202 (end-of-line)
1203 (setq current (+ current (current-column)))
1204 (unless (get-text-property (point) 'shr-break)
1205 (setq max (max max current)
1206 current 0))
1207 (forward-line 1))
1208 max))
1210 (defun shr-collect-overlays ()
1211 (save-excursion
1212 (goto-char (point-min))
1213 (let ((overlays nil))
1214 (while (not (eobp))
1215 (push (shr-overlays-in-region (point) (line-end-position))
1216 overlays)
1217 (forward-line 1))
1218 (nreverse overlays))))
1220 (defun shr-overlays-in-region (start end)
1221 (let (result)
1222 (dolist (overlay (overlays-in start end))
1223 (push (list (if (> start (overlay-start overlay))
1224 (- end start)
1225 (- end (overlay-start overlay)))
1226 (if (< end (overlay-end overlay))
1228 (- end (overlay-end overlay)))
1229 (overlay-properties overlay))
1230 result))
1231 (nreverse result)))
1233 (defun shr-pro-rate-columns (columns)
1234 (let ((total-percentage 0)
1235 (widths (make-vector (length columns) 0)))
1236 (dotimes (i (length columns))
1237 (setq total-percentage (+ total-percentage (aref columns i))))
1238 (setq total-percentage (/ 1.0 total-percentage))
1239 (dotimes (i (length columns))
1240 (aset widths i (max (truncate (* (aref columns i)
1241 total-percentage
1242 (- shr-width (1+ (length columns)))))
1243 10)))
1244 widths))
1246 ;; Return a summary of the number and shape of the TDs in the table.
1247 (defun shr-column-specs (cont)
1248 (let ((columns (make-vector (shr-max-columns cont) 1)))
1249 (dolist (row cont)
1250 (when (eq (car row) 'tr)
1251 (let ((i 0))
1252 (dolist (column (cdr row))
1253 (when (memq (car column) '(td th))
1254 (let ((width (cdr (assq :width (cdr column)))))
1255 (when (and width
1256 (string-match "\\([0-9]+\\)%" width))
1257 (aset columns i
1258 (/ (string-to-number (match-string 1 width))
1259 100.0))))
1260 (setq i (1+ i)))))))
1261 columns))
1263 (defun shr-count (cont elem)
1264 (let ((i 0))
1265 (dolist (sub cont)
1266 (when (eq (car sub) elem)
1267 (setq i (1+ i))))
1270 (defun shr-max-columns (cont)
1271 (let ((max 0))
1272 (dolist (row cont)
1273 (when (eq (car row) 'tr)
1274 (setq max (max max (+ (shr-count (cdr row) 'td)
1275 (shr-count (cdr row) 'th))))))
1276 max))
1278 (provide 'shr)
1280 ;;; shr.el ends here