;;; gnus-html.el --- Quoted-Printable functions
;; Copyright (C) 2010 Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen
;; Keywords: html, web
;; 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 .
;;; Commentary:
;; The idea is to provide a simple, fast and pretty minimal way to
;; render HTML (including links and images) in a buffer, based on an
;; external HTML renderer (i.e., w3m).
;;; Code:
(eval-when-compile (require 'cl))
(eval-when-compile (require 'mm-decode))
(require 'mm-url)
(defcustom gnus-html-cache-directory (nnheader-concat gnus-directory "html-cache/")
"Where Gnus will cache images it downloads from the web."
:version "24.1"
:group 'gnus-art
:type 'directory)
(defcustom gnus-html-cache-size 500000000
"The size of the Gnus image cache."
:version "24.1"
:group 'gnus-art
:type 'integer)
(defcustom gnus-html-frame-width 70
"What width to use when rendering HTML."
:version "24.1"
:group 'gnus-art
:type 'integer)
(defcustom gnus-blocked-images "."
"Images that have URLs matching this regexp will be blocked."
:version "24.1"
:group 'gnus-art
:type 'regexp)
;;;###autoload
(defun gnus-article-html (handle)
(let ((article-buffer (current-buffer)))
(save-restriction
(narrow-to-region (point) (point))
(save-excursion
(mm-with-part handle
(let* ((coding-system-for-read 'utf-8)
(coding-system-for-write 'utf-8)
(default-process-coding-system
(cons coding-system-for-read coding-system-for-write)))
(call-process-region (point-min) (point-max)
"w3m"
nil article-buffer nil
"-halfdump"
"-no-cookie"
"-I" "UTF-8"
"-O" "UTF-8"
"-o" "ext_halfdump=1"
"-o" "pre_conv=1"
"-t" (format "%s" tab-width)
"-cols" (format "%s" gnus-html-frame-width)
"-o" "display_image=off"
"-T" "text/html"))))
(gnus-html-wash-tags))))
(defvar gnus-article-mouse-face)
(defun gnus-html-wash-tags ()
(let (tag parameters string start end images url)
(mm-url-decode-entities)
(goto-char (point-min))
(while (re-search-forward "<\\([^ />]+\\)\\([^>]*\\)>" nil t)
(setq tag (match-string 1)
parameters (match-string 2)
start (match-beginning 0))
(when (plusp (length parameters))
(set-text-properties 0 (1- (length parameters)) nil parameters))
(delete-region start (point))
(when (search-forward (concat "") nil t)
(delete-region (match-beginning 0) (match-end 0)))
(setq end (point))
(cond
;; Fetch and insert a picture.
((equal tag "img_alt")
(when (string-match "src=\"\\([^\"]+\\)" parameters)
(setq url (match-string 1 parameters))
(if (string-match "^cid:\\(.*\\)" url)
;; URLs with cid: have their content stashed in other
;; parts of the MIME structure, so just insert them
;; immediately.
(let ((handle (mm-get-content-id
(setq url (match-string 1 url))))
image)
(when handle
(mm-with-part handle
(setq image (gnus-create-image (buffer-string)
nil t))))
(when image
(delete-region start end)
(gnus-put-image image)))
;; Normal, external URL.
(when (or (null gnus-blocked-images)
(not (string-match gnus-blocked-images url)))
(let ((file (gnus-html-image-id url)))
(if (file-exists-p file)
;; It's already cached, so just insert it.
(when (gnus-html-put-image file (point))
;; Delete the ALT text.
(delete-region start end))
;; We don't have it, so schedule it for fetching
;; asynchronously.
(push (list url
(set-marker (make-marker) start)
(point-marker))
images)))))))
;; Add a link.
((equal tag "a")
(when (string-match "href=\"\\([^\"]+\\)" parameters)
(setq url (match-string 1 parameters))
(gnus-article-add-button start end
'browse-url url
url)
(let ((overlay (gnus-make-overlay start end)))
(gnus-overlay-put overlay 'evaporate t)
(gnus-overlay-put overlay 'gnus-button-url url)
(when gnus-article-mouse-face
(gnus-overlay-put overlay 'mouse-face gnus-article-mouse-face)))))
;; Whatever. Just ignore the tag.
(t
))
(goto-char start))
(goto-char (point-min))
;; The output from -halfdump isn't totally regular, so strip
;; off any s that were left over.
(while (re-search-forward "" nil t)
(replace-match "" t t))
(when images
(gnus-html-schedule-image-fetching (current-buffer) (nreverse images)))))
(defun gnus-html-schedule-image-fetching (buffer images)
(let* ((url (caar images))
(process (start-process
"images" nil "curl"
"-s" "--create-dirs"
"--location"
"--max-time" "60"
"-o" (gnus-html-image-id url)
url)))
(process-kill-without-query process)
(set-process-sentinel process 'gnus-html-curl-sentinel)
(gnus-set-process-plist process (list 'images images
'buffer buffer))))
(defun gnus-html-image-id (url)
(expand-file-name (sha1 url) gnus-html-cache-directory))
(defun gnus-html-curl-sentinel (process event)
(when (string-match "finished" event)
(let* ((images (gnus-process-get process 'images))
(buffer (gnus-process-get process 'buffer))
(spec (pop images))
(file (gnus-html-image-id (car spec))))
(when (and (buffer-live-p buffer)
;; If the position of the marker is 1, then that
;; means that the text it was in has been deleted;
;; i.e., that the user has selected a different
;; article before the image arrived.
(not (= (marker-position (cadr spec)) (point-min))))
(with-current-buffer buffer
(let ((inhibit-read-only t))
(when (gnus-html-put-image file (cadr spec))
(delete-region (1+ (cadr spec)) (caddr spec))))))
(when images
(gnus-html-schedule-image-fetching buffer images)))))
(defun gnus-html-put-image (file point)
(when (display-graphic-p)
(let ((image (ignore-errors
(gnus-create-image file))))
(save-excursion
(goto-char point)
(if (and image
;; Kludge to avoid displaying 30x30 gif images, which
;; seems to be a signal of a broken image.
(not (and (listp image)
(eq (plist-get (cdr image) :type) 'gif)
(= (car (image-size image t)) 30)
(= (cdr (image-size image t)) 30))))
(progn
(gnus-put-image image)
t)
(when (fboundp 'find-image)
(gnus-put-image (find-image
'((:type xpm :file "lock-broken.xpm")))))
nil)))))
(defun gnus-html-prune-cache ()
(let ((total-size 0)
files)
(dolist (file (directory-files gnus-html-cache-directory t nil t))
(let ((attributes (file-attributes file)))
(unless (nth 0 attributes)
(incf total-size (nth 7 attributes))
(push (list (time-to-seconds (nth 5 attributes))
(nth 7 attributes) file)
files))))
(when (> total-size gnus-html-cache-size)
(setq files (sort files (lambda (f1 f2)
(< (car f1) (car f2)))))
(dolist (file files)
(when (> total-size gnus-html-cache-size)
(decf total-size (cadr file))
(delete-file (nth 2 file)))))))
;;;###autoload
(defun gnus-html-prefetch-images (summary)
(let (blocked-images urls)
(when (buffer-live-p summary)
(with-current-buffer summary
(setq blocked-images gnus-blocked-images))
(save-match-data
(while (re-search-forward "