;;; Code:
+(require 'browse-url)
+
+(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)
+
+(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.")
+
+(defvar shr-width 70
+ "Frame width to use for rendering.")
+
+;;; Internal variables.
+
(defvar shr-folding-mode nil)
+(defvar shr-state nil)
+(defvar shr-start nil)
+(defvar shr-indentation 0)
+(defvar shr-inhibit-images nil)
+(defvar shr-list-mode nil)
+(defvar shr-content-cache nil)
+
+(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)
+ (define-key map "\r" 'shr-browse-url)
+ map))
+
+;; Public functions and commands.
+
+;;;###autoload
+(defun shr-insert-document (dom)
+ (setq shr-content-cache nil)
+ (let ((shr-state nil)
+ (shr-start nil))
+ (shr-descend (shr-transform-dom dom))))
-(defvar shr-width 70)
+(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)
+ (let ((url (get-text-property (point) 'shr-image)))
+ (if (not url)
+ (message "No image under point")
+ (message "Browsing %s..." url)
+ (browse-url url))))
+
+(defun shr-insert-image ()
+ "Insert the image under point into the buffer."
+ (interactive)
+ (let ((url (get-text-property (point) 'shr-image)))
+ (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))))
+
+;;; Utility functions.
(defun shr-transform-dom (dom)
(let ((result (list (pop dom))))
(push (shr-transform-dom sub) result)))
(nreverse result)))
-(defun shr-insert-document (dom)
- (setq dom (shr-transform-dom dom))
- (shr-descend dom))
-
(defun shr-descend (dom)
- (let ((function (intern (concat "shr-" (symbol-name (car dom))) obarray)))
+ (let ((function (intern (concat "shr-tag-" (symbol-name (car dom))) obarray)))
(if (fboundp function)
(funcall function (cdr dom))
(shr-generic (cdr dom)))))
(cond
((eq (car sub) :text)
(shr-insert (cdr sub)))
- ((consp (cdr sub))
+ ((listp (cdr sub))
(shr-descend sub)))))
-(defun shr-p (cont)
- (shr-ensure-newline)
- (insert "\n")
+(defun shr-insert (text)
+ (when (eq shr-state 'image)
+ (insert "\n")
+ (setq shr-state nil))
+ (cond
+ ((eq shr-folding-mode 'none)
+ (insert text))
+ (t
+ (let ((first t)
+ column)
+ (when (and (string-match "\\`[ \t\n]" text)
+ (not (bolp)))
+ (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)))
+ (insert elem)
+ (when (> (current-column) shr-width)
+ (if (not (search-backward " " (line-beginning-position) t))
+ (insert "\n")
+ (delete-char 1)
+ (insert "\n")
+ (put-text-property (1- (point)) (point) 'shr-break t)
+ (when (> shr-indentation 0)
+ (shr-indent))
+ (end-of-line)))
+ (insert " "))))))
+
+(defun shr-ensure-newline ()
+ (unless (zerop (current-column))
+ (insert "\n")))
+
+(defun shr-ensure-paragraph ()
+ (unless (bobp)
+ (if (bolp)
+ (unless (save-excursion
+ (forward-line -1)
+ (looking-at " *$"))
+ (insert "\n"))
+ (if (save-excursion
+ (beginning-of-line)
+ (looking-at " *$"))
+ (insert "\n")
+ (insert "\n\n")))))
+
+(defun shr-indent ()
+ (insert (make-string shr-indentation ? )))
+
+(defun shr-fontize-cont (cont &rest types)
+ (let (shr-start)
+ (shr-generic cont)
+ (dolist (type types)
+ (shr-add-font (or shr-start (point)) (point) type))))
+
+(defun shr-add-font (start end type)
+ (let ((overlay (make-overlay start end)))
+ (overlay-put overlay 'face type)))
+
+(defun shr-browse-url ()
+ "Browse the URL under point."
+ (interactive)
+ (let ((url (get-text-property (point) 'shr-url)))
+ (if (not url)
+ (message "No link under point")
+ (browse-url url))))
+
+(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)
+ (shr-put-image data start alt))))))
+ (kill-buffer (current-buffer)))
+
+(defun shr-put-image (data point alt)
+ (if (not (display-graphic-p))
+ (insert alt)
+ (let ((image (ignore-errors
+ (shr-rescale-image data))))
+ (when image
+ (put-image image point alt)))))
+
+(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))
+ (size (image-size image t))
+ (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)))
+
+(defun shr-get-image-data (url)
+ "Get image data for URL.
+Return a string with image data."
+ (with-temp-buffer
+ (mm-disable-multibyte)
+ (when (ignore-errors
+ (url-cache-extract (url-cache-create-filename url))
+ t)
+ (when (or (search-forward "\n\n" nil t)
+ (search-forward "\r\n\r\n" nil t))
+ (buffer-substring (point) (point-max))))))
+
+(defun shr-heading (cont &rest types)
+ (shr-ensure-paragraph)
+ (apply #'shr-fontize-cont cont types)
+ (shr-ensure-paragraph))
+
+;;; Tag-specific rendering rules.
+
+(defun shr-tag-p (cont)
+ (shr-ensure-paragraph)
(shr-generic cont)
- (insert "\n"))
+ (shr-ensure-paragraph))
+
+(defun shr-tag-b (cont)
+ (shr-fontize-cont cont 'bold))
-(defun shr-pre (cont)
- (let ((shr-folding-mode nil))
+(defun shr-tag-i (cont)
+ (shr-fontize-cont cont 'italic))
+
+(defun shr-tag-em (cont)
+ (shr-fontize-cont cont 'bold))
+
+(defun shr-tag-u (cont)
+ (shr-fontize-cont cont 'underline))
+
+(defun shr-tag-s (cont)
+ (shr-fontize-cont cont 'strike-through))
+
+(defun shr-tag-a (cont)
+ (let ((url (cdr (assq :href cont)))
+ (start (point))
+ shr-start)
+ (shr-generic cont)
+ (widget-convert-button
+ 'link (or shr-start start) (point)
+ :help-echo url)
+ (put-text-property (or shr-start start) (point) 'keymap shr-map)
+ (put-text-property (or shr-start start) (point) 'shr-url url)))
+
+(defun shr-tag-img (cont)
+ (when (and (> (current-column) 0)
+ (not (eq shr-state 'image)))
+ (insert "\n"))
+ (let ((start (point-marker)))
+ (let ((alt (cdr (assq :alt cont)))
+ (url (cdr (assq :src cont))))
+ (when (zerop (length alt))
+ (setq alt "[img]"))
+ (cond
+ ((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)
+ (shr-put-image image (point) alt))))
+ ((or shr-inhibit-images
+ (and shr-blocked-images
+ (string-match shr-blocked-images url)))
+ (setq shr-start (point))
+ (let ((shr-state 'space))
+ (if (> (length alt) 8)
+ (shr-insert (substring alt 0 8))
+ (shr-insert alt))))
+ ((url-is-cached (browse-url-url-encode-chars url "[&)$ ]"))
+ (shr-put-image (shr-get-image-data url) (point) alt))
+ (t
+ (insert alt)
+ (ignore-errors
+ (url-retrieve url 'shr-image-fetched
+ (list (current-buffer) start (point-marker))
+ t))))
+ (insert " ")
+ (put-text-property start (point) 'keymap shr-map)
+ (put-text-property start (point) 'shr-alt alt)
+ (put-text-property start (point) 'shr-image url)
+ (setq shr-state 'image))))
+
+(defun shr-tag-pre (cont)
+ (let ((shr-folding-mode 'none))
(shr-ensure-newline)
(shr-generic cont)
(shr-ensure-newline)))
-(defun shr-blockquote (cont)
- (shr-pre cont))
+(defun shr-tag-blockquote (cont)
+ (shr-ensure-paragraph)
+ (let ((shr-indentation (+ shr-indentation 4)))
+ (shr-generic cont))
+ (shr-ensure-paragraph))
-(defun shr-ensure-newline ()
- (unless (zerop (current-column))
- (insert "\n")))
+(defun shr-tag-ul (cont)
+ (shr-ensure-paragraph)
+ (let ((shr-list-mode 'ul))
+ (shr-generic cont)))
-(defun shr-insert (text)
- (cond
- ((eq shr-folding-mode 'none)
- (insert t))
- (t
- (let (column)
- (dolist (elem (split-string text))
- (setq column (current-column))
- (if (zerop column)
- (insert elem)
- (if (> (+ column (length elem) 1) shr-width)
- (insert "\n" elem)
- (insert " " elem))))))))
+(defun shr-tag-ol (cont)
+ (let ((shr-list-mode 1))
+ (shr-generic cont)))
+
+(defun shr-tag-li (cont)
+ (shr-ensure-newline)
+ (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)))
+
+(defun shr-tag-br (cont)
+ (unless (bobp)
+ (insert "\n"))
+ (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))
+
+;;; Table rendering algorithm.
+
+;; 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.
+(defun shr-tag-table (cont)
+ (shr-ensure-paragraph)
+ (setq cont (or (cdr (assq 'tbody cont))
+ cont))
+ (let* ((shr-inhibit-images t)
+ ;; Find all suggested widths.
+ (columns (shr-column-specs cont))
+ ;; Compute how many characters wide each TD should be.
+ (suggested-widths (shr-pro-rate-columns columns))
+ ;; 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).
+ (sketch (shr-make-table cont suggested-widths))
+ (sketch-widths (shr-table-widths sketch suggested-widths)))
+ ;; Then render the table again with these new "hard" widths.
+ (shr-insert-table (shr-make-table cont sketch-widths t) sketch-widths))
+ ;; 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.
+ (dolist (elem (shr-find-elements cont 'img))
+ (shr-tag-img (cdr elem))))
+
+(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)))
+
+(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)
+ (insert "|\n"))
+ (dolist (column row)
+ (goto-char start)
+ (let ((lines (nth 2 column))
+ (overlay-lines (nth 3 column))
+ overlay overlay-line)
+ (dolist (line lines)
+ (setq overlay-line (pop overlay-lines))
+ (when (> (length line) 0)
+ (end-of-line)
+ (insert line "|")
+ (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)))
+ ;; Add blank lines at padding at the bottom of the TD,
+ ;; possibly.
+ (dotimes (i (- height (length lines)))
+ (end-of-line)
+ (insert (make-string (length (car lines)) ? ) "|")
+ (forward-line 1)))))
+ (shr-insert-table-ruler widths)))
+
+(defun shr-insert-table-ruler (widths)
+ (shr-indent)
+ (insert "+")
+ (dotimes (i (length widths))
+ (insert (make-string (aref widths i) ?-) ?+))
+ (insert "\n"))
+
+(defun shr-table-widths (table suggested-widths)
+ (let* ((length (length suggested-widths))
+ (widths (make-vector length 0))
+ (natural-widths (make-vector length 0)))
+ (dolist (row table)
+ (let ((i 0))
+ (dolist (column row)
+ (aset widths i (max (aref widths i)
+ (car column)))
+ (aset natural-widths i (max (aref natural-widths i)
+ (cadr column)))
+ (setq i (1+ i)))))
+ (let ((extra (- (reduce '+ suggested-widths)
+ (reduce '+ widths)))
+ (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))))))))
+ widths))
+
+(defun shr-make-table (cont widths &optional fill)
+ (let ((trs nil))
+ (dolist (row cont)
+ (when (eq (car row) 'tr)
+ (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))
+ (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)
+ (with-temp-buffer
+ (let ((cache (cdr (assoc (cons width cont) shr-content-cache))))
+ (if cache
+ (insert cache)
+ (let ((shr-width width)
+ (shr-indentation 0))
+ (shr-generic cont))
+ (delete-region
+ (point)
+ (+ (point)
+ (skip-chars-backward " \t\n")))
+ (push (cons (cons width cont) (buffer-string))
+ 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))))
+ (if fill
+ (list max
+ (count-lines (point-min) (point-max))
+ (split-string (buffer-string) "\n")
+ (shr-collect-overlays))
+ (list max
+ (shr-natural-width))))))
+
+(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))
+
+(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)))
+
+(defun shr-pro-rate-columns (columns)
+ (let ((total-percentage 0)
+ (widths (make-vector (length columns) 0)))
+ (dotimes (i (length columns))
+ (setq total-percentage (+ total-percentage (aref columns i))))
+ (setq total-percentage (/ 1.0 total-percentage))
+ (dotimes (i (length columns))
+ (aset widths i (max (truncate (* (aref columns i)
+ total-percentage
+ (- shr-width (1+ (length columns)))))
+ 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))
+ 100.0))))
+ (setq i (1+ i)))))))
+ 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)
+ (setq max (max max (+ (shr-count (cdr row) 'td)
+ (shr-count (cdr row) 'th))))))
+ max))
(provide 'shr)
projects / gnus / blobdiff