shr.el 53.4 KB
Newer Older
1 2
;;; shr.el --- Simple HTML Renderer

3
;; Copyright (C) 2010-2013 Free Software Foundation, Inc.
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

;; 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
(eval-when-compile (require 'url))      ;For url-filename's setf handler.
35 36
(require 'browse-url)

37 38
(defgroup shr nil
  "Simple HTML Renderer"
39
  :version "24.1"
40
  :group 'hypermedia)
41 42 43 44 45 46 47 48 49 50 51 52 53 54 55

(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
56
  :type '(choice (const nil) regexp))
57

58 59 60
(defcustom shr-table-horizontal-line nil
  "Character used to draw horizontal table lines.
If nil, don't draw horizontal table lines."
61
  :group 'shr
Glenn Morris's avatar
Glenn Morris committed
62
  :type '(choice (const nil) character))
63

64
(defcustom shr-table-vertical-line ?\s
65
  "Character used to draw vertical table lines."
66
  :group 'shr
67
  :type 'character)
68

69
(defcustom shr-table-corner ?\s
70
  "Character used to draw table corners."
71
  :group 'shr
72
  :type 'character)
73 74

(defcustom shr-hr-line ?-
75
  "Character used to draw hr lines."
76
  :group 'shr
77
  :type 'character)
78

79
(defcustom shr-width fill-column
80 81 82 83 84 85
  "Frame width to use for rendering.
May either be an integer specifying a fixed width in characters,
or nil, meaning that the full width of the window should be
used."
  :type '(choice (integer :tag "Fixed width in characters")
		 (const   :tag "Use the width of the window" nil))
86 87
  :group 'shr)

88 89 90 91 92 93 94 95
(defcustom shr-bullet "* "
  "Bullet used for unordered lists.
Alternative suggestions are:
- \"  \"
- \"  \""
  :type 'string
  :group 'shr)

96 97 98 99 100 101
(defcustom shr-external-browser 'browse-url-default-browser
  "Function used to launch an external browser."
  :version "24.4"
  :group 'shr
  :type 'function)

102 103 104 105 106
(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.")

107 108 109
(defvar shr-put-image-function 'shr-put-image
  "Function called to put image and alt string.")

110 111 112 113
(defface shr-strike-through '((t (:strike-through t)))
  "Font for <s> elements."
  :group 'shr)

114
(defface shr-link
115
  '((t (:inherit link)))
116
  "Font for link elements."
117 118
  :group 'shr)

119 120
;;; Internal variables.

121 122 123
(defvar shr-folding-mode nil)
(defvar shr-state nil)
(defvar shr-start nil)
124
(defvar shr-indentation 0)
125
(defvar shr-inhibit-images nil)
126
(defvar shr-list-mode nil)
127
(defvar shr-content-cache nil)
128
(defvar shr-kinsoku-shorten nil)
129
(defvar shr-table-depth 0)
130
(defvar shr-stylesheet nil)
131
(defvar shr-base nil)
132
(defvar shr-ignore-cache nil)
133
(defvar shr-external-rendering-functions nil)
134
(defvar shr-target-id nil)
135
(defvar shr-inhibit-decoration nil)
136
(defvar shr-table-separator-length 1)
137

138 139 140 141
(defvar shr-map
  (let ((map (make-sparse-keymap)))
    (define-key map "a" 'shr-show-alt-text)
    (define-key map "i" 'shr-browse-image)
142
    (define-key map "z" 'shr-zoom-image)
143 144
    (define-key map [tab] 'shr-next-link)
    (define-key map [backtab] 'shr-previous-link)
145
    (define-key map [follow-link] 'mouse-face)
146
    (define-key map [mouse-2] 'shr-browse-url)
147
    (define-key map "I" 'shr-insert-image)
148
    (define-key map "w" 'shr-copy-url)
149
    (define-key map "u" 'shr-copy-url)
150
    (define-key map "v" 'shr-browse-url)
151
    (define-key map "o" 'shr-save-contents)
152 153 154
    (define-key map "\r" 'shr-browse-url)
    map))

155
;; Public functions and commands.
156 157
(declare-function libxml-parse-html-region "xml.c"
		  (start end &optional base-url))
158

159 160 161
(defun shr-render-buffer (buffer)
  "Display the HTML rendering of the current buffer."
  (interactive (list (current-buffer)))
162 163
  (or (fboundp 'libxml-parse-html-region)
      (error "This function requires Emacs to be compiled with libxml2"))
164 165 166
  (pop-to-buffer "*html*")
  (erase-buffer)
  (shr-insert-document
167
   (with-current-buffer buffer
168 169
     (libxml-parse-html-region (point-min) (point-max))))
  (goto-char (point-min)))
170

171 172 173 174 175 176 177 178 179 180 181
(defun shr-render-region (begin end &optional buffer)
  "Display the HTML rendering of the region between BEGIN and END."
  (interactive "r")
  (unless (fboundp 'libxml-parse-html-region)
    (error "This function requires Emacs to be compiled with libxml2"))
  (with-current-buffer (or buffer (current-buffer))
    (let ((dom (libxml-parse-html-region begin end)))
      (delete-region begin end)
      (goto-char begin)
      (shr-insert-document dom))))

182 183
;;;###autoload
(defun shr-insert-document (dom)
184 185 186
  "Render the parsed document DOM into the current buffer.
DOM should be a parse tree as generated by
`libxml-parse-html-region' or similar."
187
  (setq shr-content-cache nil)
188 189
  (let ((start (point))
	(shr-state nil)
190
	(shr-start nil)
191
	(shr-base nil)
192
	(shr-width (or shr-width (1- (window-width)))))
193 194 195 196
    (shr-descend (shr-transform-dom dom))
    (shr-remove-trailing-whitespace start (point))))

(defun shr-remove-trailing-whitespace (start end)
197 198 199 200 201 202
  (let ((width (window-width)))
    (save-restriction
      (narrow-to-region start end)
      (goto-char start)
      (while (not (eobp))
	(end-of-line)
203
	(when (> (shr-previous-newline-padding-width (current-column)) width)
204 205 206 207
	  (dolist (overlay (overlays-at (point)))
	    (when (overlay-get overlay 'before-string)
	      (overlay-put overlay 'before-string nil))))
	(forward-line 1)))))
208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231

(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))
232 233
	     (copy-region-as-kill (point-min) (point-max)))))
       nil t))
234 235 236 237 238 239 240
     ;; 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))))))

241 242 243
(defun shr-next-link ()
  "Skip to the next link."
  (interactive)
244
  (let ((skip (text-property-any (point) (point-max) 'help-echo nil)))
245
    (if (not (setq skip (text-property-not-all skip (point-max)
246
					       'help-echo nil)))
247 248 249 250 251 252 253 254 255 256 257
	(message "No next link")
      (goto-char skip)
      (message "%s" (get-text-property (point) 'help-echo)))))

(defun shr-previous-link ()
  "Skip to the previous link."
  (interactive)
  (let ((start (point))
	(found nil))
    ;; Skip past the current link.
    (while (and (not (bobp))
258
		(get-text-property (point) 'help-echo))
259 260 261
      (forward-char -1))
    ;; Find the previous link.
    (while (and (not (bobp))
262
		(not (setq found (get-text-property (point) 'help-echo))))
263 264 265 266 267 268 269
      (forward-char -1))
    (if (not found)
	(progn
	  (message "No previous link")
	  (goto-char start))
      ;; Put point at the start of the link.
      (while (and (not (bobp))
270
		  (get-text-property (point) 'help-echo))
271 272 273 274
	(forward-char -1))
      (forward-char 1)
      (message "%s" (get-text-property (point) 'help-echo)))))

275 276 277 278 279 280 281 282
(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))))

283 284 285 286 287
(defun shr-browse-image (&optional copy-url)
  "Browse the image under point.
If COPY-URL (the prefix if called interactively) is non-nil, copy
the URL of the image to the kill buffer instead."
  (interactive "P")
288
  (let ((url (get-text-property (point) 'image-url)))
289 290 291 292 293 294 295 296 297
    (cond
     ((not url)
      (message "No image under point"))
     (copy-url
      (with-temp-buffer
	(insert url)
	(copy-region-as-kill (point-min) (point-max))
	(message "Copied %s" url)))
     (t
298
      (message "Browsing %s..." url)
299
      (browse-url url)))))
300

301 302 303
(defun shr-insert-image ()
  "Insert the image under point into the buffer."
  (interactive)
304
  (let ((url (get-text-property (point) 'image-url)))
305 306 307 308 309
    (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))
310
		    t t))))
311

312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345
(defun shr-zoom-image ()
  "Toggle the image size.
The size will be rotated between the default size, the original
size, and full-buffer size."
  (interactive)
  (let ((url (get-text-property (point) 'image-url))
	(size (get-text-property (point) 'image-size))
	(buffer-read-only nil))
    (if (not url)
	(message "No image under point")
      ;; Delete the old picture.
      (while (get-text-property (point) 'image-url)
	(forward-char -1))
      (forward-char 1)
      (let ((start (point)))
	(while (get-text-property (point) 'image-url)
	  (forward-char 1))
	(forward-char -1)
	(put-text-property start (point) 'display nil)
	(when (> (- (point) start) 2)
	  (delete-region start (1- (point)))))
      (message "Inserting %s..." url)
      (url-retrieve url 'shr-image-fetched
		    (list (current-buffer) (1- (point)) (point-marker)
			  (list (cons 'size
				      (cond ((or (eq size 'default)
						 (null size))
					     'original)
					    ((eq size 'original)
					     'full)
					    ((eq size 'full)
					     'default)))))
		    t))))

346 347
;;; Utility functions.

348 349 350 351 352 353 354 355
(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)
356
	  (push (cons 'text sub) result)
357 358 359 360
	(push (shr-transform-dom sub) result)))
    (nreverse result)))

(defun shr-descend (dom)
361 362 363 364 365 366
  (let ((function
	 (or
	  ;; Allow other packages to override (or provide) rendering
	  ;; of elements.
	  (cdr (assq (car dom) shr-external-rendering-functions))
	  (intern (concat "shr-tag-" (symbol-name (car dom))) obarray)))
367
	(style (cdr (assq :style (cdr dom))))
368
	(shr-stylesheet shr-stylesheet)
369
	(start (point)))
370
    (when style
371
      (if (string-match "color\\|display\\|border-collapse" style)
372 373 374
	  (setq shr-stylesheet (nconc (shr-parse-style style)
				      shr-stylesheet))
	(setq style nil)))
375
    ;; If we have a display:none, then just ignore this part of the DOM.
376 377 378 379 380 381 382 383 384 385 386 387
    (unless (equal (cdr (assq 'display shr-stylesheet)) "none")
      (if (fboundp function)
	  (funcall function (cdr dom))
	(shr-generic (cdr dom)))
      (when (and shr-target-id
		 (equal (cdr (assq :id (cdr dom))) shr-target-id))
	(put-text-property start (1+ start) 'shr-target-id shr-target-id))
      ;; 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)))))))
388 389 390 391

(defun shr-generic (cont)
  (dolist (sub cont)
    (cond
392
     ((eq (car sub) 'text)
393
      (shr-insert (cdr sub)))
394
     ((listp (cdr sub))
395 396
      (shr-descend sub)))))

397 398 399 400 401 402 403 404 405 406 407 408 409
(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."
410 411 412
  `(let ((char ,char))
     (and (not (eq char ?'))
	  (aref (char-category-set char) ?>))))
413 414 415 416 417 418
(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))

419
(defun shr-insert (text)
420
  (when (and (eq shr-state 'image)
421
	     (not (bolp))
422
	     (not (string-match "\\`[ \t\n]+\\'" text)))
423 424 425 426 427 428
    (insert "\n")
    (setq shr-state nil))
  (cond
   ((eq shr-folding-mode 'none)
    (insert text))
   (t
429
    (when (and (string-match "\\`[ \t\n ]" text)
430 431 432
	       (not (bolp))
	       (not (eq (char-after (1- (point))) ? )))
      (insert " "))
433
    (dolist (elem (split-string text "[ \f\t\n\r\v ]+" t))
434 435 436 437
      (when (and (bolp)
		 (> shr-indentation 0))
	(shr-indent))
      ;; No space is needed behind a wide character categorized as
438 439
      ;; kinsoku-bol, between characters both categorized as nospace,
      ;; or at the beginning of a line.
440
      (let (prev)
441 442
	(when (and (> (current-column) shr-indentation)
		   (eq (preceding-char) ? )
443
		   (or (= (line-beginning-position) (1- (point)))
444 445 446 447 448
		       (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)))))
449
	  (delete-char -1)))
450 451 452 453 454
      ;; 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)))
455
      (insert elem)
456
      (setq shr-state nil)
457
      (let (found)
458 459 460 461
	(while (and (> (current-column) shr-width)
		    (progn
		      (setq found (shr-find-fill-point))
		      (not (eolp))))
462 463 464 465
	  (when (eq (preceding-char) ? )
	    (delete-char -1))
	  (insert "\n")
	  (unless found
466 467 468 469 470 471 472
	    ;; 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 " ")))
473
    (unless (string-match "[ \t\r\n ]\\'" text)
474
      (delete-char -1)))))
475

476
(defun shr-find-fill-point ()
477 478
  (when (> (move-to-column shr-width) shr-width)
    (backward-char 1))
479 480
  (let ((bp (point))
	failed)
481
    (while (not (or (setq failed (< (current-column) shr-indentation))
482 483 484 485
		    (eq (preceding-char) ? )
		    (eq (following-char) ? )
		    (shr-char-breakable-p (preceding-char))
		    (shr-char-breakable-p (following-char))
486 487 488
		    (and (shr-char-kinsoku-bol-p (preceding-char))
			 (shr-char-breakable-p (following-char))
			 (not (shr-char-kinsoku-bol-p (following-char))))
489
		    (shr-char-kinsoku-eol-p (following-char))))
490 491
      (backward-char 1))
    (if failed
492
	;; There's no breakable point, so we give it up.
493 494 495
	(let (found)
	  (goto-char bp)
	  (unless shr-kinsoku-shorten
496 497 498
	    (while (setq found (re-search-forward
				"\\(\\c>\\)\\| \\|\\c<\\|\\c|"
				(line-end-position) 'move)))
499 500
	    (if (and found
		     (not (match-beginning 1)))
501
		(goto-char (match-beginning 0)))))
502 503
      (or
       (eolp)
504 505 506 507 508 509 510
       ;; 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))
511
	 (when (setq failed (< (current-column) shr-indentation))
512 513 514 515 516 517 518 519 520 521
	   ;; 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))
522 523 524 525 526 527 528 529 530
	 ;; Find backward the point where kinsoku-eol characters begin.
	 (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)))))))
531
	 (when (setq failed (< (current-column) shr-indentation))
532 533 534 535 536
	   ;; There's no breakable point that doesn't violate kinsoku,
	   ;; so we go to the second best position.
	   (if (looking-at "\\(\\c<+\\)\\c<")
	       (goto-char (match-end 1))
	     (forward-char 1))))
537
	((shr-char-kinsoku-bol-p (following-char))
538 539 540 541 542
	 ;; Find forward the point where kinsoku-bol characters end.
	 (let ((count 4))
	   (while (progn
		    (forward-char 1)
		    (and (>= (setq count (1- count)) 0)
543
			 (shr-char-kinsoku-bol-p (following-char))
544
			 (shr-char-breakable-p (following-char))))))))
545 546 547
       (when (eq (following-char) ? )
	 (forward-char 1))))
    (not failed)))
548

549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593
(defun shr-parse-base (url)
  ;; Always chop off anchors.
  (when (string-match "#.*" url)
    (setq url (substring url 0 (match-beginning 0))))
  (let* ((parsed (url-generic-parse-url url))
	 (local (url-filename parsed)))
    (setf (url-filename parsed) "")
    ;; Chop off the bit after the last slash.
    (when (string-match "\\`\\(.*/\\)[^/]+\\'" local)
      (setq local (match-string 1 local)))
    ;; Always make the local bit end with a slash.
    (when (and (not (zerop (length local)))
	       (not (eq (aref local (1- (length local))) ?/)))
      (setq local (concat local "/")))
    (list (url-recreate-url parsed)
	  local
	  (url-type parsed)
	  url)))

(defun shr-expand-url (url &optional base)
  (setq base
	(if base
	    (shr-parse-base base)
	  ;; Bound by the parser.
	  shr-base))
  (when (zerop (length url))
    (setq url nil))
  (cond ((or (not url)
	     (not base)
	     (string-match "\\`[a-z]*:" url))
	 ;; Absolute URL.
	 (or url (car base)))
	((eq (aref url 0) ?/)
	 (if (and (> (length url) 1)
		  (eq (aref url 1) ?/))
	     ;; //host...; just use the protocol
	     (concat (nth 2 base) ":" url)
	   ;; Just use the host name part.
	   (concat (car base) url)))
	((eq (aref url 0) ?#)
	 ;; A link to an anchor.
	 (concat (nth 3 base) url))
	(t
	 ;; Totally relative.
	 (concat (car base) (cadr base) url))))
594

595 596 597
(defun shr-ensure-newline ()
  (unless (zerop (current-column))
    (insert "\n")))
598 599 600

(defun shr-ensure-paragraph ()
  (unless (bobp)
601
    (if (<= (current-column) shr-indentation)
602 603 604
	(unless (save-excursion
		  (forward-line -1)
		  (looking-at " *$"))
605 606 607
	  (insert "\n"))
      (if (save-excursion
	    (beginning-of-line)
608 609 610 611 612 613 614 615
	    ;; If the current line is totally blank, and doesn't even
	    ;; have any face properties set, then delete the blank
	    ;; space.
	    (and (looking-at " *$")
		 (not (get-text-property (point) 'face))
		 (not (= (next-single-property-change (point) 'face nil
						      (line-end-position))
			 (line-end-position)))))
616
	  (delete-region (match-beginning 0) (match-end 0))
617 618
	(insert "\n\n")))))

619
(defun shr-indent ()
620 621
  (when (> shr-indentation 0)
    (insert (make-string shr-indentation ? ))))
622

623
(defun shr-fontize-cont (cont &rest types)
624 625
  (let (shr-start)
    (shr-generic cont)
626 627
    (dolist (type types)
      (shr-add-font (or shr-start (point)) (point) type))))
628

629 630 631
;; Add face to 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.
632
(defun shr-add-font (start end type)
633 634 635 636 637 638 639 640 641 642
  (unless shr-inhibit-decoration
    (save-excursion
      (goto-char start)
      (while (< (point) end)
	(when (bolp)
	  (skip-chars-forward " "))
	(add-face-text-property (point) (min (line-end-position) end) type t)
	(if (< (line-end-position) end)
	    (forward-line 1)
	  (goto-char end))))))
643

644 645 646 647 648 649
(defun shr-mouse-browse-url (ev)
  "Browse the URL under the mouse cursor."
  (interactive "e")
  (mouse-set-point ev)
  (shr-browse-url))

650
(defun shr-browse-url (&optional external mouse-event)
651 652
  "Browse the URL under point.
If EXTERNAL, browse the URL using `shr-external-browser'."
653 654
  (interactive (list current-prefix-arg last-nonmenu-event))
  (mouse-set-point mouse-event)
655
  (let ((url (get-text-property (point) 'shr-url)))
656 657 658 659
    (cond
     ((not url)
      (message "No link under point"))
     ((string-match "^mailto:" url)
660
      (browse-url-mail url))
661
     (t
662 663 664
      (if external
	  (funcall shr-external-browser url)
	(browse-url url))))))
665

666 667 668 669 670 671 672
(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)
673 674
		    'shr-store-contents (list url directory)
		    nil t))))
675 676 677 678 679 680 681 682 683

(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)))))

684
(defun shr-image-fetched (status buffer start end &optional flags)
685 686 687 688 689 690
  (let ((image-buffer (current-buffer)))
    (when (and (buffer-name buffer)
	       (not (plist-get status :error)))
      (url-store-in-cache image-buffer)
      (when (or (search-forward "\n\n" nil t)
		(search-forward "\r\n\r\n" nil t))
691
	(let ((data (shr-parse-image-data)))
692 693 694
	  (with-current-buffer buffer
	    (save-excursion
	      (let ((alt (buffer-substring start end))
695
		    (properties (text-properties-at start))
696 697 698
		    (inhibit-read-only t))
		(delete-region start end)
		(goto-char start)
699 700 701 702 703 704
		(funcall shr-put-image-function data alt flags)
		(while properties
		  (let ((type (pop properties))
			(value (pop properties)))
		    (unless (memq type '(display image-size))
		      (put-text-property start (point) type value))))))))))
705
    (kill-buffer image-buffer)))
706

707 708 709 710 711 712 713 714 715 716 717
(defun shr-image-from-data (data)
  "Return an image from the data: URI content DATA."
  (when (string-match
	 "\\(\\([^/;,]+\\(/[^;,]+\\)?\\)\\(;[^;,]+\\)*\\)?,\\(.*\\)"
	 data)
    (let ((param (match-string 4 data))
	  (payload (url-unhex-string (match-string 5 data))))
      (when (string-match "^.*\\(;[ \t]*base64\\)$" param)
	(setq payload (base64-decode-string payload)))
      payload)))

718 719 720 721
;; Behind display-graphic-p test.
(declare-function image-size "image.c" (spec &optional pixels frame))
(declare-function image-animate "image" (image &optional index limit))

722 723 724 725
(defun shr-put-image (spec alt &optional flags)
  "Insert image SPEC with a string ALT.  Return image.
SPEC is either an image data blob, or a list where the first
element is the data blob and the second element is the content-type."
726
  (if (display-graphic-p)
727
      (let* ((size (cdr (assq 'size flags)))
728 729 730 731 732
	     (data (if (consp spec)
		       (car spec)
		     spec))
	     (content-type (and (consp spec)
				(cadr spec)))
733 734 735
	     (start (point))
	     (image (cond
		     ((eq size 'original)
736
		      (create-image data nil t :ascent 100
737
				    :format content-type))
738 739
		     ((eq size 'full)
		      (ignore-errors
740
			(shr-rescale-image data content-type)))
741 742
		     (t
		      (ignore-errors
743
			(shr-rescale-image data content-type))))))
744
        (when image
745 746 747 748 749
	  ;; 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"))
750
	  (if (eq size 'original)
751
	      (insert-sliced-image image (or alt "*") nil 20 1)
752 753
	    (insert-image image (or alt "*")))
	  (put-text-property start (point) 'image-size size)
754 755 756 757 758 759 760
	  (when (cond ((fboundp 'image-multi-frame-p)
		       ;; Only animate multi-frame things that specify a
		       ;; delay; eg animated gifs as opposed to
		       ;; multi-page tiffs.  FIXME?
		       (cdr (image-multi-frame-p image)))
		      ((fboundp 'image-animated-p)
		       (image-animated-p image)))
761
	    (image-animate image nil 60)))
762
	image)
763
    (insert alt)))
764

765 766 767 768
(defun shr-rescale-image (data &optional content-type)
  "Rescale DATA, if too big, to fit the current buffer."
  (if (not (and (fboundp 'imagemagick-types)
                (get-buffer-window (current-buffer))))
769 770 771 772 773 774 775 776 777
      (create-image data nil t :ascent 100)
    (let ((edges (window-inside-pixel-edges
		  (get-buffer-window (current-buffer)))))
      (create-image
       data 'imagemagick t
       :ascent 100
       :max-width (truncate (* shr-max-image-proportion
			       (- (nth 2 edges) (nth 0 edges))))
       :max-height (truncate (* shr-max-image-proportion
778
				(- (nth 3 edges) (nth 1 edges))))
779
       :format content-type))))
780

Glenn Morris's avatar
Glenn Morris committed
781 782 783
;; url-cache-extract autoloads url-cache.
(declare-function url-cache-create-filename "url-cache" (url))
(autoload 'mm-disable-multibyte "mm-util")
784
(autoload 'browse-url-mail "browse-url")
Glenn Morris's avatar
Glenn Morris committed
785

786 787 788 789 790
(defun shr-get-image-data (url)
  "Get image data for URL.
Return a string with image data."
  (with-temp-buffer
    (mm-disable-multibyte)
791
    (when (ignore-errors
792
	    (url-cache-extract (url-cache-create-filename (shr-encode-url url)))
793 794 795
	    t)
      (when (or (search-forward "\n\n" nil t)
		(search-forward "\r\n\r\n" nil t))
796 797 798 799 800 801 802 803 804 805 806
	(shr-parse-image-data)))))

(defun shr-parse-image-data ()
  (list
   (buffer-substring (point) (point-max))
   (save-excursion
     (save-restriction
       (narrow-to-region (point-min) (point))
       (let ((content-type (mail-fetch-field "content-type")))
	 (and content-type
	      (intern content-type obarray)))))))
807

808 809 810 811
(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,
Paul Eggert's avatar
Paul Eggert committed
812
START, and END.  Note that START and END should be markers."
813
  `(lambda (url start end)
814 815 816 817 818 819 820
     (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)
821
		   (funcall shr-put-image-function
822
			    image (buffer-substring start end))
823
		   (delete-region (point) end))))
824 825
	 (url-retrieve url 'shr-image-fetched
		       (list (current-buffer) start end)
826
		       t t)))))
827

828 829 830 831 832
(defun shr-heading (cont &rest types)
  (shr-ensure-paragraph)
  (apply #'shr-fontize-cont cont types)
  (shr-ensure-paragraph))

833
(defun shr-urlify (start url &optional title)
834
  (shr-add-font start (point) 'shr-link)
835 836 837
  (add-text-properties
   start (point)
   (list 'shr-url url
838
	 'help-echo (if title (format "%s (%s)" url title) url)
839
	 'follow-link t
840
	 'mouse-face 'highlight
841
	 'keymap shr-map)))
842 843 844 845 846

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

847 848
(autoload 'shr-color-visible "shr-color")
(autoload 'shr-color->hexadecimal "shr-color")
849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871

(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)))))))

872
(defun shr-colorize-region (start end fg &optional bg)
873 874
  (when (and (not shr-inhibit-decoration)
	     (or fg bg))
875
    (let ((new-colors (shr-color-check fg bg)))
876
      (when new-colors
877
	(when fg
878 879 880
	  (add-face-text-property start end
				  (list :foreground (cadr new-colors))
				  t))
881
	(when bg
882 883 884
	  (add-face-text-property start end
				  (list :background (car new-colors))
				  t)))
885
      new-colors)))
886

887 888
(defun shr-expand-newlines (start end color)
  (save-restriction
889 890 891 892 893 894 895 896 897
    ;; Skip past all white space at the start and ends.
    (goto-char start)
    (skip-chars-forward " \t\n")
    (beginning-of-line)
    (setq start (point))
    (goto-char end)
    (skip-chars-backward " \t\n")
    (forward-line 1)
    (setq end (point))
898
    (narrow-to-region start end)
899
    (let ((width (shr-buffer-width))
900 901 902 903
	  column)
      (goto-char (point-min))
      (while (not (eobp))
	(end-of-line)
904 905
	(when (and (< (setq column (current-column)) width)
		   (< (setq column (shr-previous-newline-padding-width column))
906
		      width))
907
	  (let ((overlay (make-overlay (point) (1+ (point)))))
908
	    (overlay-put overlay 'before-string
909 910 911
			 (concat
			  (mapconcat
			   (lambda (overlay)
912 913 914
			     (let ((string (plist-get
					    (overlay-properties overlay)
					    'before-string)))
915 916 917 918 919 920
			       (if (not string)
				   ""
				 (overlay-put overlay 'before-string "")
				 string)))
			   (overlays-at (point))
			   "")
921
			  (propertize (make-string (- width column) ? )
922
				      'face (list :background color))))))
923
	(forward-line 1)))))
924

925 926 927 928 929 930 931 932
(defun shr-previous-newline-padding-width (width)
  (let ((overlays (overlays-at (point)))
	(previous-width 0))
    (if (null overlays)
	width
      (dolist (overlay overlays)
	(setq previous-width
	      (+ previous-width
933 934
		 (length (plist-get (overlay-properties overlay)
				    'before-string)))))
935 936
      (+ width previous-width))))

937 938
;;; Tag-specific rendering rules.

939
(defun shr-tag-body (cont)
940
  (let* ((start (point))
941 942
	 (fgcolor (cdr (or (assq :fgcolor cont)
                           (assq :text cont))))
943
	 (bgcolor (cdr (assq :bgcolor cont)))
944 945
	 (shr-stylesheet (list (cons 'color fgcolor)
			       (cons 'background-color bgcolor))))
946
    (shr-generic cont)
947
    (shr-colorize-region start (point) fgcolor bgcolor)))
948

949
(defun shr-tag-style (_cont)
950 951
  )

952
(defun shr-tag-script (_cont)
953 954
  )

955
(defun shr-tag-comment (_cont)
956 957
  )

958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977
(defun shr-dom-to-xml (dom)
  "Convert DOM into a string containing the xml representation."
  (let ((arg " ")
        (text ""))
    (dolist (sub (cdr dom))
      (cond
       ((listp (cdr sub))
        (setq text (concat text (shr-dom-to-xml sub))))
       ((eq (car sub) 'text)
        (setq text (concat text (cdr sub))))
       (t
        (setq arg (concat arg (format "%s=\"%s\" "
                                      (substring (symbol-name (car sub)) 1)
                                      (cdr sub)))))))
    (format "<%s%s>%s</%s>"
            (car dom)
            (substring arg 0 (1- (length arg)))
            text
            (car dom))))

978
(defun shr-tag-svg (cont)
979 980 981 982
  (when (image-type-available-p 'svg)
    (funcall shr-put-image-function
             (shr-dom-to-xml (cons 'svg cont))
             "SVG Image")))
983

984 985 986 987 988 989 990 991 992 993
(defun shr-tag-sup (cont)
  (let ((start (point)))
    (shr-generic cont)
    (put-text-property start (point) 'display '(raise 0.5))))

(defun shr-tag-sub (cont)
  (let ((start (point)))
    (shr-generic cont)
    (put-text-property start (point) 'display '(raise -0.5))))