shr.el 36.8 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
;;; shr.el --- Simple HTML Renderer

;; Copyright (C) 2010 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: html

;; This file is part of GNU Emacs.

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

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

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

;;; Commentary:

;; This package takes a HTML parse tree (as provided by
;; libxml-parse-html-region) and renders it in the current buffer.  It
;; does not do CSS, JavaScript or anything advanced: It's geared
;; towards rendering typical short snippets of HTML, like what you'd
;; find in HTML email and the like.

;;; Code:

33
(eval-when-compile (require 'cl))
34 35
(require 'browse-url)

36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
(defgroup shr nil
  "Simple HTML Renderer"
  :group 'mail)

(defcustom shr-max-image-proportion 0.9
  "How big pictures displayed are in relation to the window they're in.
A value of 0.7 means that they are allowed to take up 70% of the
width and height of the window.  If they are larger than this,
and Emacs supports it, then the images will be rescaled down to
fit these criteria."
  :version "24.1"
  :group 'shr
  :type 'float)

(defcustom shr-blocked-images nil
  "Images that have URLs matching this regexp will be blocked."
  :version "24.1"
  :group 'shr
  :type 'regexp)

56 57 58 59 60 61 62
(defcustom shr-table-horizontal-line ?-
  "Character used to draw horizontal table lines."
  :group 'shr
  :type 'character)

(defcustom shr-table-vertical-line ?|
  "Character used to draw vertical table lines."
63
  :group 'shr
64
  :type 'character)
65 66

(defcustom shr-table-corner ?+
67
  "Character used to draw table corners."
68
  :group 'shr
69
  :type 'character)
70 71

(defcustom shr-hr-line ?-
72
  "Character used to draw hr lines."
73
  :group 'shr
74
  :type 'character)
75

76 77 78 79 80
(defcustom shr-width fill-column
  "Frame width to use for rendering."
  :type 'integer
  :group 'shr)

81 82 83 84 85
(defvar shr-content-function nil
  "If bound, this should be a function that will return the content.
This is used for cid: URLs, and the function is called with the
cid: URL as the argument.")

86 87
;;; Internal variables.

88 89 90
(defvar shr-folding-mode nil)
(defvar shr-state nil)
(defvar shr-start nil)
91
(defvar shr-indentation 0)
92
(defvar shr-inhibit-images nil)
93
(defvar shr-list-mode nil)
94
(defvar shr-content-cache nil)
95
(defvar shr-kinsoku-shorten nil)
96
(defvar shr-table-depth 0)
97
(defvar shr-stylesheet nil)
98

99 100 101 102 103 104 105
(defvar shr-map
  (let ((map (make-sparse-keymap)))
    (define-key map "a" 'shr-show-alt-text)
    (define-key map "i" 'shr-browse-image)
    (define-key map "I" 'shr-insert-image)
    (define-key map "u" 'shr-copy-url)
    (define-key map "v" 'shr-browse-url)
106
    (define-key map "o" 'shr-save-contents)
107 108 109
    (define-key map "\r" 'shr-browse-url)
    map))

110 111 112 113
;; Public functions and commands.

;;;###autoload
(defun shr-insert-document (dom)
114
  (setq shr-content-cache nil)
115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160
  (let ((shr-state nil)
	(shr-start nil))
    (shr-descend (shr-transform-dom dom))))

(defun shr-copy-url ()
  "Copy the URL under point to the kill ring.
If called twice, then try to fetch the URL and see whether it
redirects somewhere else."
  (interactive)
  (let ((url (get-text-property (point) 'shr-url)))
    (cond
     ((not url)
      (message "No URL under point"))
     ;; Resolve redirected URLs.
     ((equal url (car kill-ring))
      (url-retrieve
       url
       (lambda (a)
	 (when (and (consp a)
		    (eq (car a) :redirect))
	   (with-temp-buffer
	     (insert (cadr a))
	     (goto-char (point-min))
	     ;; Remove common tracking junk from the URL.
	     (when (re-search-forward ".utm_.*" nil t)
	       (replace-match "" t t))
	     (message "Copied %s" (buffer-string))
	     (copy-region-as-kill (point-min) (point-max)))))))
     ;; Copy the URL to the kill ring.
     (t
      (with-temp-buffer
	(insert url)
	(copy-region-as-kill (point-min) (point-max))
	(message "Copied %s" url))))))

(defun shr-show-alt-text ()
  "Show the ALT text of the image under point."
  (interactive)
  (let ((text (get-text-property (point) 'shr-alt)))
    (if (not text)
	(message "No image under point")
      (message "%s" text))))

(defun shr-browse-image ()
  "Browse the image under point."
  (interactive)
161
  (let ((url (get-text-property (point) 'image-url)))
162 163 164 165 166
    (if (not url)
	(message "No image under point")
      (message "Browsing %s..." url)
      (browse-url url))))

167 168 169
(defun shr-insert-image ()
  "Insert the image under point into the buffer."
  (interactive)
170
  (let ((url (get-text-property (point) 'image-url)))
171 172 173 174 175 176 177
    (if (not url)
	(message "No image under point")
      (message "Inserting %s..." url)
      (url-retrieve url 'shr-image-fetched
		    (list (current-buffer) (1- (point)) (point-marker))
		    t))))

178 179
;;; Utility functions.

180 181 182 183 184 185 186 187
(defun shr-transform-dom (dom)
  (let ((result (list (pop dom))))
    (dolist (arg (pop dom))
      (push (cons (intern (concat ":" (symbol-name (car arg))) obarray)
		  (cdr arg))
	    result))
    (dolist (sub dom)
      (if (stringp sub)
188
	  (push (cons 'text sub) result)
189 190 191 192
	(push (shr-transform-dom sub) result)))
    (nreverse result)))

(defun shr-descend (dom)
193 194
  (let ((function (intern (concat "shr-tag-" (symbol-name (car dom))) obarray))
	(style (cdr (assq :style (cdr dom))))
195
	(shr-stylesheet shr-stylesheet)
196
	(start (point)))
197 198 199 200 201
    (when style
      (if (string-match "color" style)
	  (setq shr-stylesheet (nconc (shr-parse-style style)
				      shr-stylesheet))
	(setq style nil)))
202 203
    (if (fboundp function)
	(funcall function (cdr dom))
204
      (shr-generic (cdr dom)))
205 206 207 208 209
    ;; If style is set, then this node has set the color.
    (when style
      (shr-colorize-region start (point)
			   (cdr (assq 'color shr-stylesheet))
			   (cdr (assq 'background-color shr-stylesheet))))))
210 211 212 213

(defun shr-generic (cont)
  (dolist (sub cont)
    (cond
214
     ((eq (car sub) 'text)
215
      (shr-insert (cdr sub)))
216
     ((listp (cdr sub))
217 218
      (shr-descend sub)))))

219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238
(defmacro shr-char-breakable-p (char)
  "Return non-nil if a line can be broken before and after CHAR."
  `(aref fill-find-break-point-function-table ,char))
(defmacro shr-char-nospace-p (char)
  "Return non-nil if no space is required before and after CHAR."
  `(aref fill-nospace-between-words-table ,char))

;; KINSOKU is a Japanese word meaning a rule that should not be violated.
;; In Emacs, it is a term used for characters, e.g. punctuation marks,
;; parentheses, and so on, that should not be placed in the beginning
;; of a line or the end of a line.
(defmacro shr-char-kinsoku-bol-p (char)
  "Return non-nil if a line ought not to begin with CHAR."
  `(aref (char-category-set ,char) ?>))
(defmacro shr-char-kinsoku-eol-p (char)
  "Return non-nil if a line ought not to end with CHAR."
  `(aref (char-category-set ,char) ?<))
(unless (shr-char-kinsoku-bol-p (make-char 'japanese-jisx0208 33 35))
  (load "kinsoku" nil t))

239
(defun shr-insert (text)
240 241
  (when (and (eq shr-state 'image)
	     (not (string-match "\\`[ \t\n]+\\'" text)))
242 243 244 245 246 247
    (insert "\n")
    (setq shr-state nil))
  (cond
   ((eq shr-folding-mode 'none)
    (insert text))
   (t
248 249 250 251 252 253 254 255 256 257 258 259 260 261
    (when (and (string-match "\\`[ \t\n]" text)
	       (not (bolp))
	       (not (eq (char-after (1- (point))) ? )))
      (insert " "))
    (dolist (elem (split-string text))
      (when (and (bolp)
		 (> shr-indentation 0))
	(shr-indent))
      ;; The shr-start is a special variable that is used to pass
      ;; upwards the first point in the buffer where the text really
      ;; starts.
      (unless shr-start
	(setq shr-start (point)))
      ;; No space is needed behind a wide character categorized as
262 263
      ;; kinsoku-bol, between characters both categorized as nospace,
      ;; or at the beginning of a line.
264
      (let (prev)
265 266
	(when (and (eq (preceding-char) ? )
		   (or (= (line-beginning-position) (1- (point)))
267 268 269 270 271
		       (and (shr-char-breakable-p
			     (setq prev (char-after (- (point) 2))))
			    (shr-char-kinsoku-bol-p prev))
		       (and (shr-char-nospace-p prev)
			    (shr-char-nospace-p (aref elem 0)))))
272 273
	  (delete-char -1)))
      (insert elem)
274 275 276 277
      (let (found)
	(while (and (> (current-column) shr-width)
		    (progn
		      (setq found (shr-find-fill-point))
278
		      (not (eolp))))
279 280 281 282
	  (when (eq (preceding-char) ? )
	    (delete-char -1))
	  (insert "\n")
	  (unless found
283 284 285 286 287 288 289 290
	    (put-text-property (1- (point)) (point) 'shr-break t)
	    ;; No space is needed at the beginning of a line.
	    (when (eq (following-char) ? )
	      (delete-char 1)))
	  (when (> shr-indentation 0)
	    (shr-indent))
	  (end-of-line))
	(insert " ")))
291 292
    (unless (string-match "[ \t\n]\\'" text)
      (delete-char -1)))))
293

294
(defun shr-find-fill-point ()
295 296
  (when (> (move-to-column shr-width) shr-width)
    (backward-char 1))
297 298 299 300 301 302 303
  (let ((bp (point))
	failed)
    (while (not (or (setq failed (= (current-column) shr-indentation))
		    (eq (preceding-char) ? )
		    (eq (following-char) ? )
		    (shr-char-breakable-p (preceding-char))
		    (shr-char-breakable-p (following-char))
304 305 306 307
		    (if (eq (preceding-char) ?')
			(not (memq (char-after (- (point) 2))
				   (list nil ?\n ? )))
		      (and (shr-char-kinsoku-bol-p (preceding-char))
308
			   (shr-char-breakable-p (following-char))
309
			   (not (shr-char-kinsoku-bol-p (following-char)))))
310
		    (shr-char-kinsoku-eol-p (following-char))))
311
      (backward-char 1))
312 313 314 315 316 317 318
    (if (and (not (or failed (eolp)))
	     (eq (preceding-char) ?'))
	(while (not (or (setq failed (eolp))
			(eq (following-char) ? )
			(shr-char-breakable-p (following-char))
			(shr-char-kinsoku-eol-p (following-char))))
	  (forward-char 1)))
319
    (if failed
320
	;; There's no breakable point, so we give it up.
321 322 323 324 325 326 327 328 329
	(let (found)
	  (goto-char bp)
	  (unless shr-kinsoku-shorten
	    (while (and (setq found (re-search-forward
				     "\\(\\c>\\)\\| \\|\\c<\\|\\c|"
				     (line-end-position) 'move))
			(eq (preceding-char) ?')))
	    (if (and found (not (match-beginning 1)))
		(goto-char (match-beginning 0)))))
330 331
      (or
       (eolp)
332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361
       ;; Don't put kinsoku-bol characters at the beginning of a line,
       ;; or kinsoku-eol characters at the end of a line.
       (cond
	(shr-kinsoku-shorten
	 (while (and (not (memq (preceding-char) (list ?\C-@ ?\n ? )))
		     (shr-char-kinsoku-eol-p (preceding-char)))
	   (backward-char 1))
	 (when (setq failed (= (current-column) shr-indentation))
	   ;; There's no breakable point that doesn't violate kinsoku,
	   ;; so we look for the second best position.
	   (while (and (progn
			 (forward-char 1)
			 (<= (current-column) shr-width))
		       (progn
			 (setq bp (point))
			 (shr-char-kinsoku-eol-p (following-char)))))
	   (goto-char bp)))
	((shr-char-kinsoku-eol-p (preceding-char))
	 (if (shr-char-kinsoku-eol-p (following-char))
	     ;; There are consecutive kinsoku-eol characters.
	     (setq failed t)
	   (let ((count 4))
	     (while
		 (progn
		   (backward-char 1)
		   (and (> (setq count (1- count)) 0)
			(not (memq (preceding-char) (list ?\C-@ ?\n ? )))
			(or (shr-char-kinsoku-eol-p (preceding-char))
			    (shr-char-kinsoku-bol-p (following-char)))))))
	   (if (setq failed (= (current-column) shr-indentation))
362
	       ;; There's no breakable point that doesn't violate kinsoku,
363 364 365 366 367 368 369 370
	       ;; so we go to the second best position.
	       (if (looking-at "\\(\\c<+\\)\\c<")
		   (goto-char (match-end 1))
		 (forward-char 1)))))
	(t
	 (if (shr-char-kinsoku-bol-p (preceding-char))
	     ;; There are consecutive kinsoku-bol characters.
	     (setq failed t)
371 372
	   (let ((count 4))
	     (while (and (>= (setq count (1- count)) 0)
373 374 375 376 377 378
			 (shr-char-kinsoku-bol-p (following-char))
			 (shr-char-breakable-p (following-char)))
	       (forward-char 1))))))
       (when (eq (following-char) ? )
	 (forward-char 1))))
    (not failed)))
379

380 381 382
(defun shr-ensure-newline ()
  (unless (zerop (current-column))
    (insert "\n")))
383 384 385

(defun shr-ensure-paragraph ()
  (unless (bobp)
386
    (if (<= (current-column) shr-indentation)
387 388 389
	(unless (save-excursion
		  (forward-line -1)
		  (looking-at " *$"))
390 391 392
	  (insert "\n"))
      (if (save-excursion
	    (beginning-of-line)
393
	    (looking-at " *$"))
394 395 396
	  (insert "\n")
	(insert "\n\n")))))

397
(defun shr-indent ()
398 399
  (when (> shr-indentation 0)
    (insert (make-string shr-indentation ? ))))
400

401
(defun shr-fontize-cont (cont &rest types)
402 403
  (let (shr-start)
    (shr-generic cont)
404 405
    (dolist (type types)
      (shr-add-font (or shr-start (point)) (point) type))))
406

407 408 409
;; Add an overlay in the region, but avoid putting the font properties
;; on blank text at the start of the line, and the newline at the end,
;; to avoid ugliness.
410
(defun shr-add-font (start end type)
411 412 413 414 415 416 417 418 419 420
  (save-excursion
    (goto-char start)
    (while (< (point) end)
      (when (bolp)
	(skip-chars-forward " "))
      (let ((overlay (make-overlay (point) (min (line-end-position) end))))
	(overlay-put overlay 'face type))
      (if (< (line-end-position) end)
	  (forward-line 1)
	(goto-char end)))))
421

422 423 424 425
(defun shr-browse-url ()
  "Browse the URL under point."
  (interactive)
  (let ((url (get-text-property (point) 'shr-url)))
426 427 428 429
    (cond
     ((not url)
      (message "No link under point"))
     ((string-match "^mailto:" url)
430
      (browse-url-mailto url))
431 432
     (t
      (browse-url url)))))
433

434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450
(defun shr-save-contents (directory)
  "Save the contents from URL in a file."
  (interactive "DSave contents of URL to directory: ")
  (let ((url (get-text-property (point) 'shr-url)))
    (if (not url)
	(message "No link under point")
      (url-retrieve (shr-encode-url url)
		    'shr-store-contents (list url directory)))))

(defun shr-store-contents (status url directory)
  (unless (plist-get status :error)
    (when (or (search-forward "\n\n" nil t)
	      (search-forward "\r\n\r\n" nil t))
      (write-region (point) (point-max)
		    (expand-file-name (file-name-nondirectory url)
				      directory)))))

451 452 453 454 455 456 457 458 459 460 461
(defun shr-image-fetched (status buffer start end)
  (when (and (buffer-name buffer)
	     (not (plist-get status :error)))
    (url-store-in-cache (current-buffer))
    (when (or (search-forward "\n\n" nil t)
	      (search-forward "\r\n\r\n" nil t))
      (let ((data (buffer-substring (point) (point-max))))
        (with-current-buffer buffer
          (let ((alt (buffer-substring start end))
		(inhibit-read-only t))
	    (delete-region start end)
462 463
	    (goto-char start)
	    (shr-put-image data alt))))))
464 465
  (kill-buffer (current-buffer)))

466
(defun shr-put-image (data alt)
467 468 469 470
  (if (display-graphic-p)
      (let ((image (ignore-errors
                     (shr-rescale-image data))))
        (when image
471 472 473 474 475
	  ;; When inserting big-ish pictures, put them at the
	  ;; beginning of the line.
	  (when (and (> (current-column) 0)
		     (> (car (image-size image t)) 400))
	    (insert "\n"))
476 477
	  (insert-image image (or alt "*"))))
    (insert alt)))
478 479 480 481 482 483

(defun shr-rescale-image (data)
  (if (or (not (fboundp 'imagemagick-types))
	  (not (get-buffer-window (current-buffer))))
      (create-image data nil t)
    (let* ((image (create-image data nil t))
484
	   (size (image-size image t))
485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505
	   (width (car size))
	   (height (cdr size))
	   (edges (window-inside-pixel-edges
		   (get-buffer-window (current-buffer))))
	   (window-width (truncate (* shr-max-image-proportion
				      (- (nth 2 edges) (nth 0 edges)))))
	   (window-height (truncate (* shr-max-image-proportion
				       (- (nth 3 edges) (nth 1 edges)))))
	   scaled-image)
      (when (> height window-height)
	(setq image (or (create-image data 'imagemagick t
				      :height window-height)
			image))
	(setq size (image-size image t)))
      (when (> (car size) window-width)
	(setq image (or
		     (create-image data 'imagemagick t
				   :width window-width)
		     image)))
      image)))

Glenn Morris's avatar
Glenn Morris committed
506 507 508
;; url-cache-extract autoloads url-cache.
(declare-function url-cache-create-filename "url-cache" (url))
(autoload 'mm-disable-multibyte "mm-util")
509
(autoload 'browse-url-mailto "browse-url")
Glenn Morris's avatar
Glenn Morris committed
510

511 512 513 514 515
(defun shr-get-image-data (url)
  "Get image data for URL.
Return a string with image data."
  (with-temp-buffer
    (mm-disable-multibyte)
516
    (when (ignore-errors
517
	    (url-cache-extract (url-cache-create-filename (shr-encode-url url)))
518 519 520 521
	    t)
      (when (or (search-forward "\n\n" nil t)
		(search-forward "\r\n\r\n" nil t))
	(buffer-substring (point) (point-max))))))
522

523 524 525 526
(defun shr-image-displayer (content-function)
  "Return a function to display an image.
CONTENT-FUNCTION is a function to retrieve an image for a cid url that
is an argument.  The function to be returned takes three arguments URL,
527
START, and END.  Note that START and END should be merkers."
528
  `(lambda (url start end)
529 530 531 532 533 534 535 536
     (when url
       (if (string-match "\\`cid:" url)
	   ,(when content-function
	      `(let ((image (funcall ,content-function
				     (substring url (match-end 0)))))
		 (when image
		   (goto-char start)
		   (shr-put-image image
537 538
				  (buffer-substring-no-properties start end))
		   (delete-region (point) end))))
539 540 541
	 (url-retrieve url 'shr-image-fetched
		       (list (current-buffer) start end)
		       t)))))
542

543 544 545 546 547
(defun shr-heading (cont &rest types)
  (shr-ensure-paragraph)
  (apply #'shr-fontize-cont cont types)
  (shr-ensure-paragraph))

Glenn Morris's avatar
Glenn Morris committed
548 549
(autoload 'widget-convert-button "wid-edit")

550
(defun shr-urlify (start url &optional title)
551 552
  (widget-convert-button
   'url-link start (point)
553
   :help-echo (if title (format "%s (%s)" url title) url)
554 555 556 557 558 559 560 561
   :keymap shr-map
   url)
  (put-text-property start (point) 'shr-url url))

(defun shr-encode-url (url)
  "Encode URL."
  (browse-url-url-encode-chars url "[)$ ]"))

562 563
(autoload 'shr-color-visible "shr-color")
(autoload 'shr-color->hexadecimal "shr-color")
564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586

(defun shr-color-check (fg bg)
  "Check that FG is visible on BG.
Returns (fg bg) with corrected values.
Returns nil if the colors that would be used are the default
ones, in case fg and bg are nil."
  (when (or fg bg)
    (let ((fixed (cond ((null fg) 'fg)
                       ((null bg) 'bg))))
      ;; Convert colors to hexadecimal, or set them to default.
      (let ((fg (or (shr-color->hexadecimal fg)
                    (frame-parameter nil 'foreground-color)))
            (bg (or (shr-color->hexadecimal bg)
                    (frame-parameter nil 'background-color))))
        (cond ((eq fixed 'bg)
               ;; Only return the new fg
               (list nil (cadr (shr-color-visible bg fg t))))
              ((eq fixed 'fg)
               ;; Invert args and results and return only the new bg
               (list (cadr (shr-color-visible fg bg t)) nil))
              (t
               (shr-color-visible bg fg)))))))

587
(defun shr-colorize-region (start end fg &optional bg)
588
  (when (or fg bg)
589
    (let ((new-colors (shr-color-check fg bg)))
590
      (when new-colors
591 592
	(when fg
	  (shr-put-color start end :foreground (cadr new-colors)))
593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628
	(when bg
	  (shr-put-color start end :background (car new-colors)))))))

;; Put a color in the region, but avoid putting colors on on blank
;; text at the start of the line, and the newline at the end, to avoid
;; ugliness.  Also, don't overwrite any existing color information,
;; since this can be called recursively, and we want the "inner" color
;; to win.
(defun shr-put-color (start end type color)
  (save-excursion
    (goto-char start)
    (while (< (point) end)
      (when (bolp)
	(skip-chars-forward " "))
      (when (> (line-end-position) (point))
	(shr-put-color-1 (point) (min (line-end-position) end) type color))
      (if (< (line-end-position) end)
	  (forward-line 1)
	(goto-char end)))))

(defun shr-put-color-1 (start end type color)
  (let* ((old-props (get-text-property start 'face))
	 (do-put (not (memq type old-props)))
	 change)
    (while (< start end)
      (setq change (next-single-property-change start 'face nil end))
      (when do-put
	(put-text-property start change 'face
			   (nconc (list type color) old-props)))
      (setq old-props (get-text-property change 'face))
      (setq do-put (not (memq type old-props)))
      (setq start change))
    (when (and do-put
	       (> end start))
      (put-text-property start end 'face
			 (nconc (list type color old-props))))))
629

630 631
;;; Tag-specific rendering rules.

632
(defun shr-tag-body (cont)
633 634 635
  (let* ((start (point))
	 (fgcolor (cdr (assq :fgcolor cont)))
	 (bgcolor (cdr (assq :bgcolor cont)))
636 637
	 (shr-stylesheet (list (cons 'color fgcolor)
			       (cons 'background-color bgcolor))))
638
    (shr-generic cont)
639
    (shr-colorize-region start (point) fgcolor bgcolor)))
640

641 642 643
(defun shr-tag-style (cont)
  )

644 645 646
(defun shr-tag-script (cont)
  )

647 648
(defun shr-tag-p (cont)
  (shr-ensure-paragraph)
649
  (shr-indent)
650 651 652
  (shr-generic cont)
  (shr-ensure-paragraph))

Katsumi Yamaoka's avatar
Katsumi Yamaoka committed
653 654 655 656 657 658
(defun shr-tag-div (cont)
  (shr-ensure-newline)
  (shr-indent)
  (shr-generic cont)
  (shr-ensure-newline))

659 660 661 662 663 664 665 666 667
(defun shr-tag-b (cont)
  (shr-fontize-cont cont 'bold))

(defun shr-tag-i (cont)
  (shr-fontize-cont cont 'italic))

(defun shr-tag-em (cont)
  (shr-fontize-cont cont 'bold))

668 669 670
(defun shr-tag-strong (cont)
  (shr-fontize-cont cont 'bold))

671 672 673 674 675 676
(defun shr-tag-u (cont)
  (shr-fontize-cont cont 'underline))

(defun shr-tag-s (cont)
  (shr-fontize-cont cont 'strike-through))

677 678
(defun shr-parse-style (style)
  (when style
679 680 681
    (save-match-data
      (when (string-match "\n" style)
        (setq style (replace-match " " t t style))))
682 683 684 685 686 687 688 689
    (let ((plist nil))
      (dolist (elem (split-string style ";"))
	(when elem
	  (setq elem (split-string elem ":"))
	  (when (and (car elem)
		     (cadr elem))
	    (let ((name (replace-regexp-in-string "^ +\\| +$" "" (car elem)))
		  (value (replace-regexp-in-string "^ +\\| +$" "" (cadr elem))))
690 691
	      (when (string-match " *!important\\'" value)
		(setq value (substring value 0 (match-beginning 0))))
692 693 694 695 696
	      (push (cons (intern name obarray)
			  value)
		    plist)))))
      plist)))

697 698
(defun shr-tag-a (cont)
  (let ((url (cdr (assq :href cont)))
699
        (title (cdr (assq :title cont)))
700 701 702
	(start (point))
	shr-start)
    (shr-generic cont)
703
    (shr-urlify (or shr-start start) url title)))
704 705

(defun shr-tag-object (cont)
706 707 708 709 710 711 712 713
  (let ((start (point))
	url)
    (dolist (elem cont)
      (when (eq (car elem) 'embed)
	(setq url (or url (cdr (assq :src (cdr elem))))))
      (when (and (eq (car elem) 'param)
		 (equal (cdr (assq :name (cdr elem))) "movie"))
	(setq url (or url (cdr (assq :value (cdr elem)))))))
714 715
    (when url
      (shr-insert " [multimedia] ")
716 717 718 719 720 721 722 723 724
      (shr-urlify start url))
    (shr-generic cont)))

(defun shr-tag-video (cont)
  (let ((image (cdr (assq :poster cont)))
	(url (cdr (assq :src cont)))
	(start (point)))
    (shr-tag-img nil image)
    (shr-urlify start url)))
725

726 727 728 729
(defun shr-tag-img (cont &optional url)
  (when (or url
	    (and cont
		 (cdr (assq :src cont))))
730 731 732 733
    (when (and (> (current-column) 0)
	       (not (eq shr-state 'image)))
      (insert "\n"))
    (let ((alt (cdr (assq :alt cont)))
734
	  (url (or url (cdr (assq :src cont)))))
735 736
      (let ((start (point-marker)))
	(when (zerop (length alt))
737
	  (setq alt "*"))
738
	(cond
739 740 741 742
	 ((or (member (cdr (assq :height cont)) '("0" "1"))
	      (member (cdr (assq :width cont)) '("0" "1")))
	  ;; Ignore zero-sized or single-pixel images.
	  )
743 744 745 746 747 748 749
	 ((and (not shr-inhibit-images)
	       (string-match "\\`cid:" url))
	  (let ((url (substring url (match-end 0)))
		image)
	    (if (or (not shr-content-function)
		    (not (setq image (funcall shr-content-function url))))
		(insert alt)
750
	      (shr-put-image image alt))))
751 752 753 754 755
	 ((or shr-inhibit-images
	      (and shr-blocked-images
		   (string-match shr-blocked-images url)))
	  (setq shr-start (point))
	  (let ((shr-state 'space))
756 757
	    (if (> (string-width alt) 8)
		(shr-insert (truncate-string-to-width alt 8))
758 759
	      (shr-insert alt))))
	 ((url-is-cached (shr-encode-url url))
760
	  (shr-put-image (shr-get-image-data url) alt))
761 762 763 764 765 766 767 768
	 (t
	  (insert alt)
	  (ignore-errors
	    (url-retrieve (shr-encode-url url) 'shr-image-fetched
			  (list (current-buffer) start (point-marker))
			  t))))
	(put-text-property start (point) 'keymap shr-map)
	(put-text-property start (point) 'shr-alt alt)
769 770
	(put-text-property start (point) 'image-url url)
	(put-text-property start (point) 'image-displayer
771
			   (shr-image-displayer shr-content-function))
772
	(put-text-property start (point) 'help-echo alt)
773
	(setq shr-state 'image)))))
774 775 776 777

(defun shr-tag-pre (cont)
  (let ((shr-folding-mode 'none))
    (shr-ensure-newline)
778
    (shr-indent)
779 780 781 782 783
    (shr-generic cont)
    (shr-ensure-newline)))

(defun shr-tag-blockquote (cont)
  (shr-ensure-paragraph)
784
  (shr-indent)
785 786 787
  (let ((shr-indentation (+ shr-indentation 4)))
    (shr-generic cont))
  (shr-ensure-paragraph))
788 789 790 791

(defun shr-tag-ul (cont)
  (shr-ensure-paragraph)
  (let ((shr-list-mode 'ul))
792 793
    (shr-generic cont))
  (shr-ensure-paragraph))
794 795

(defun shr-tag-ol (cont)
796
  (shr-ensure-paragraph)
797
  (let ((shr-list-mode 1))
798 799
    (shr-generic cont))
  (shr-ensure-paragraph))
800 801

(defun shr-tag-li (cont)
802 803
  (shr-ensure-paragraph)
  (shr-indent)
804 805 806 807 808 809 810 811 812
  (let* ((bullet
	  (if (numberp shr-list-mode)
	      (prog1
		  (format "%d " shr-list-mode)
		(setq shr-list-mode (1+ shr-list-mode)))
	    "* "))
	 (shr-indentation (+ shr-indentation (length bullet))))
    (insert bullet)
    (shr-generic cont)))
813 814

(defun shr-tag-br (cont)
815
  (unless (bobp)
816 817
    (insert "\n")
    (shr-indent))
818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
  (shr-generic cont))

(defun shr-tag-h1 (cont)
  (shr-heading cont 'bold 'underline))

(defun shr-tag-h2 (cont)
  (shr-heading cont 'bold))

(defun shr-tag-h3 (cont)
  (shr-heading cont 'italic))

(defun shr-tag-h4 (cont)
  (shr-heading cont))

(defun shr-tag-h5 (cont)
  (shr-heading cont))

(defun shr-tag-h6 (cont)
  (shr-heading cont))

838 839
(defun shr-tag-hr (cont)
  (shr-ensure-newline)
840
  (insert (make-string shr-width shr-hr-line) "\n"))
841

842 843 844
(defun shr-tag-title (cont)
  (shr-heading cont 'bold 'underline))

845
(defun shr-tag-font (cont)
846 847 848 849
  (let* ((start (point))
         (color (cdr (assq :color cont)))
         (shr-stylesheet (nconc (list (cons 'color color))
				shr-stylesheet)))
850
    (shr-generic cont)
851 852 853
    (when color
      (shr-colorize-region start (point) color
			   (cdr (assq 'background-color shr-stylesheet))))))
854

855
;;; Table rendering algorithm.
856

857 858 859 860 861 862 863 864
;; Table rendering is the only complicated thing here.  We do this by
;; first counting how many TDs there are in each TR, and registering
;; how wide they think they should be ("width=45%", etc).  Then we
;; render each TD separately (this is done in temporary buffers, so
;; that we can use all the rendering machinery as if we were in the
;; main buffer).  Now we know how much space each TD really takes, so
;; we then render everything again with the new widths, and finally
;; insert all these boxes into the main buffer.
865
(defun shr-tag-table-1 (cont)
866 867
  (setq cont (or (cdr (assq 'tbody cont))
		 cont))
868
  (let* ((shr-inhibit-images t)
869
	 (shr-table-depth (1+ shr-table-depth))
870
	 (shr-kinsoku-shorten t)
871
	 ;; Find all suggested widths.
872
	 (columns (shr-column-specs cont))
873
	 ;; Compute how many characters wide each TD should be.
874
	 (suggested-widths (shr-pro-rate-columns columns))
875 876 877
	 ;; Do a "test rendering" to see how big each TD is (this can
	 ;; be smaller (if there's little text) or bigger (if there's
	 ;; unbreakable text).
878
	 (sketch (shr-make-table cont suggested-widths))
879
	 (sketch-widths (shr-table-widths sketch suggested-widths)))
880
    ;; This probably won't work very well.
881 882 883
    (when (> (+ (loop for width across sketch-widths
		      summing (1+ width))
		shr-indentation 1)
884 885
	     (frame-width))
      (setq truncate-lines t))
886
    ;; Then render the table again with these new "hard" widths.
887
    (shr-insert-table (shr-make-table cont sketch-widths t) sketch-widths))
888 889 890
  ;; Finally, insert all the images after the table.  The Emacs buffer
  ;; model isn't strong enough to allow us to put the images actually
  ;; into the tables.
891 892 893
  (when (zerop shr-table-depth)
    (dolist (elem (shr-find-elements cont 'img))
      (shr-tag-img (cdr elem)))))
894

895 896 897 898 899 900
(defun shr-tag-table (cont)
  (shr-ensure-paragraph)
  (let* ((caption (cdr (assq 'caption cont)))
	 (header (cdr (assq 'thead cont)))
	 (body (or (cdr (assq 'tbody cont)) cont))
	 (footer (cdr (assq 'tfoot cont)))
901
         (bgcolor (cdr (assq :bgcolor cont)))
902 903 904
	 (start (point))
	 (shr-stylesheet (nconc (list (cons 'background-color bgcolor))
				shr-stylesheet))
905 906 907 908
	 (nheader (if header (shr-max-columns header)))
	 (nbody (if body (shr-max-columns body)))
	 (nfooter (if footer (shr-max-columns footer))))
    (shr-tag-table-1
909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939
     (nconc
      (if caption `((tr (td ,@caption))))
      (if header
	  (if footer
	      ;; hader + body + footer
	      (if (= nheader nbody)
		  (if (= nbody nfooter)
		      `((tr (td (table (tbody ,@header ,@body ,@footer)))))
		    (nconc `((tr (td (table (tbody ,@header ,@body)))))
			   (if (= nfooter 1)
			       footer
			     `((tr (td (table (tbody ,@footer))))))))
		(nconc `((tr (td (table (tbody ,@header)))))
		       (if (= nbody nfooter)
			   `((tr (td (table (tbody ,@body ,@footer)))))
			 (nconc `((tr (td (table (tbody ,@body)))))
				(if (= nfooter 1)
				    footer
				  `((tr (td (table (tbody ,@footer))))))))))
	    ;; header + body
	    (if (= nheader nbody)
		`((tr (td (table (tbody ,@header ,@body)))))
	      (if (= nheader 1)
		  `(,@header (tr (td (table (tbody ,@body)))))
		`((tr (td (table (tbody ,@header))))
		  (tr (td (table (tbody ,@body))))))))
	(if footer
	    ;; body + footer
	    (if (= nbody nfooter)
		`((tr (td (table (tbody ,@body ,@footer)))))
	      (nconc `((tr (td (table (tbody ,@body)))))
940
		     (if (= nfooter 1)
941 942 943 944
			 footer
		       `((tr (td (table (tbody ,@footer))))))))
	  (if caption
	      `((tr (td (table (tbody ,@body)))))
945 946 947 948
	    body)))))
    (when bgcolor
      (shr-colorize-region start (point) (cdr (assq 'color shr-stylesheet))
			   bgcolor))))
949

950 951 952 953 954 955 956 957
(defun shr-find-elements (cont type)
  (let (result)
    (dolist (elem cont)
      (cond ((eq (car elem) type)
	     (push elem result))
	    ((consp (cdr elem))
	     (setq result (nconc (shr-find-elements (cdr elem) type) result)))))
    (nreverse result)))
958 959 960 961 962 963 964 965 966 967 968

(defun shr-insert-table (table widths)
  (shr-insert-table-ruler widths)
  (dolist (row table)
    (let ((start (point))
	  (height (let ((max 0))
		    (dolist (column row)
		      (setq max (max max (cadr column))))
		    max)))
      (dotimes (i height)
	(shr-indent)
969
	(insert shr-table-vertical-line "\n"))
970 971
      (dolist (column row)
	(goto-char start)
972
	(let ((lines (nth 2 column))
973 974
	      (overlay-lines (nth 3 column))
	      overlay overlay-line)
975
	  (dolist (line lines)
976
	    (setq overlay-line (pop overlay-lines))
977
	    (end-of-line)
978
	    (insert line shr-table-vertical-line)
979 980 981 982 983 984 985
	    (dolist (overlay overlay-line)
	      (let ((o (make-overlay (- (point) (nth 0 overlay) 1)
				     (- (point) (nth 1 overlay) 1)))
		    (properties (nth 2 overlay)))
		(while properties
		  (overlay-put o (pop properties) (pop properties)))))
	    (forward-line 1))
986 987 988 989
	  ;; Add blank lines at padding at the bottom of the TD,
	  ;; possibly.
	  (dotimes (i (- height (length lines)))
	    (end-of-line)
990 991
	    (insert (make-string (string-width (car lines)) ? )
		    shr-table-vertical-line)
992 993 994 995
	    (forward-line 1)))))
    (shr-insert-table-ruler widths)))

(defun shr-insert-table-ruler (widths)
996 997 998
  (when (and (bolp)
	     (> shr-indentation 0))
    (shr-indent))
999
  (insert shr-table-corner)
1000
  (dotimes (i (length widths))
1001 1002
    (insert (make-string (aref widths i) shr-table-horizontal-line)
	    shr-table-corner))
1003 1004
  (insert "\n"))

1005 1006 1007 1008
(defun shr-table-widths (table suggested-widths)
  (let* ((length (length suggested-widths))
	 (widths (make-vector length 0))
	 (natural-widths (make-vector length 0)))
1009 1010 1011 1012 1013
    (dolist (row table)
      (let ((i 0))
	(dolist (column row)
	  (aset widths i (max (aref widths i)
			      (car column)))
1014 1015 1016
	  (aset natural-widths i (max (aref natural-widths i)
				      (cadr column)))
	  (setq i (1+ i)))))
1017 1018
    (let ((extra (- (apply '+ (append suggested-widths nil))
		    (apply '+ (append widths nil))))
1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031
	  (expanded-columns 0))
      (when (> extra 0)
	(dotimes (i length)
	  ;; If the natural width is wider than the rendered width, we
	  ;; want to allow the column to expand.
	  (when (> (aref natural-widths i) (aref widths i))
	    (setq expanded-columns (1+ expanded-columns))))
	(dotimes (i length)
	  (when (> (aref natural-widths i) (aref widths i))
	    (aset widths i (min
			    (1+ (aref natural-widths i))
			    (+ (/ extra expanded-columns)
			       (aref widths i))))))))
1032 1033 1034 1035 1036 1037
    widths))

(defun shr-make-table (cont widths &optional fill)
  (let ((trs nil))
    (dolist (row cont)
      (when (eq (car row) 'tr)
1038 1039 1040 1041 1042 1043 1044 1045
	(let ((tds nil)
	      (columns (cdr row))
	      (i 0)
	      column)
	  (while (< i (length widths))
	    (setq column (pop columns))
	    (when (or (memq (car column) '(td th))
		      (null column))
1046 1047 1048 1049 1050 1051 1052
	      (push (shr-render-td (cdr column) (aref widths i) fill)
		    tds)
	      (setq i (1+ i))))
	  (push (nreverse tds) trs))))
    (nreverse trs)))

(defun shr-render-td (cont width fill)
1053
  (with-temp-buffer
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118
    (let ((bgcolor (cdr (assq :bgcolor cont)))
	  (fgcolor (cdr (assq :fgcolor cont)))
	  (style (cdr (assq :style cont)))
	  (shr-stylesheet shr-stylesheet)
	  overlays)
      (when style
	(setq style (and (string-match "color" style)
			 (shr-parse-style style))))
      (when bgcolor
	(setq style (nconc (list (cons 'background-color bgcolor)) style)))
      (when fgcolor
	(setq style (nconc (list (cons 'color fgcolor)) style)))
      (when style
	(setq shr-stylesheet (append style shr-stylesheet)))
      (let ((cache (cdr (assoc (cons width cont) shr-content-cache))))
	(if cache
	    (progn
	      (insert (car cache))
	      (let ((end (length (car cache))))
		(dolist (overlay (cadr cache))
		  (let ((new-overlay
			 (make-overlay (1+ (- end (nth 0 overlay)))
				       (1+ (- end (nth 1 overlay)))))
			(properties (nth 2 overlay)))
		    (while properties
		      (overlay-put new-overlay
				   (pop properties) (pop properties)))))))
	  (let ((shr-width width)
		(shr-indentation 0))
	    (shr-descend (cons 'td cont)))
	  (delete-region
	   (point)
	   (+ (point)
	      (skip-chars-backward " \t\n")))
	  (push (list (cons width cont) (buffer-string)
		      (shr-overlays-in-region (point-min) (point-max)))
		shr-content-cache)))
      (goto-char (point-min))
      (let ((max 0))
	(while (not (eobp))
	  (end-of-line)
	  (setq max (max max (current-column)))
	  (forward-line 1))
	(when fill
	  (goto-char (point-min))
	  ;; If the buffer is totally empty, then put a single blank
	  ;; line here.
	  (if (zerop (buffer-size))
	      (insert (make-string width ? ))
	    ;; Otherwise, fill the buffer.
	    (while (not (eobp))
	      (end-of-line)
	      (when (> (- width (current-column)) 0)
		(insert (make-string (- width (current-column)) ? )))
	      (forward-line 1))))
	(when style
	  (shr-colorize-region
	   (point-min) (point-max)
	   (cdr (assq 'color shr-stylesheet))
	   (cdr (assq 'background-color shr-stylesheet))))
	(if fill
	    (list max
		  (count-lines (point-min) (point-max))
		  (split-string (buffer-string) "\n")
		  (shr-collect-overlays))
1119
	  (list max
1120
		(shr-natural-width)))))))
1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133

(defun shr-natural-width ()
  (goto-char (point-min))
  (let ((current 0)
	(max 0))
    (while (not (eobp))
      (end-of-line)
      (setq current (+ current (current-column)))
      (unless (get-text-property (point) 'shr-break)
	(setq max (max max current)
	      current 0))
      (forward-line 1))
    max))
1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156

(defun shr-collect-overlays ()
  (save-excursion
    (goto-char (point-min))
    (let ((overlays nil))
      (while (not (eobp))
	(push (shr-overlays-in-region (point) (line-end-position))
	      overlays)
	(forward-line 1))
      (nreverse overlays))))

(defun shr-overlays-in-region (start end)
  (let (result)
    (dolist (overlay (overlays-in start end))
      (push (list (if (> start (overlay-start overlay))
		      (- end start)
		    (- end (overlay-start overlay)))
		  (if (< end (overlay-end overlay))
		      0
		    (- end (overlay-end overlay)))
		  (overlay-properties overlay))
	    result))
    (nreverse result)))
1157 1158 1159 1160 1161

(defun shr-pro-rate-columns (columns)
  (let ((total-percentage 0)
	(widths (make-vector (length columns) 0)))
    (dotimes (i (length columns))
1162
      (setq total-percentage (+ total-percentage (aref columns i))))
1163 1164 1165 1166
    (setq total-percentage (/ 1.0 total-percentage))
    (dotimes (i (length columns))
      (aset widths i (max (truncate (* (aref columns i)
				       total-percentage
1167
				       (- shr-width (1+ (length columns)))))
1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183
			  10)))
    widths))

;; Return a summary of the number and shape of the TDs in the table.
(defun shr-column-specs (cont)
  (let ((columns (make-vector (shr-max-columns cont) 1)))
    (dolist (row cont)
      (when (eq (car row) 'tr)
	(let ((i 0))
	  (dolist (column (cdr row))
	    (when (memq (car column) '(td th))
	      (let ((width (cdr (assq :width (cdr column)))))
		(when (and width
			   (string-match "\\([0-9]+\\)%" width))
		  (aset columns i
			(/ (string-to-number (match-string 1 width))
1184 1185
			   100.0))))
	      (setq i (1+ i)))))))
1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198
    columns))

(defun shr-count (cont elem)
  (let ((i 0))
    (dolist (sub cont)
      (when (eq (car sub) elem)
	(setq i (1+ i))))
    i))

(defun shr-max-columns (cont)
  (let ((max 0))
    (dolist (row cont)
      (when (eq (car row) 'tr)
1199 1200
	(setq max (max max (+ (shr-count (cdr row) 'td)
			      (shr-count (cdr row) 'th))))))
1201 1202
    max))

1203
(provide 'shr)
1204 1205

;;; shr.el ends here