Fix up the w3m/curl dependencies.
[gnus] / lisp / gnus-html.el
index 7bef46c..ffa5ff1 100644 (file)
@@ -1,4 +1,4 @@
-;;; gnus-html.el --- Quoted-Printable functions
+;;; gnus-html.el --- Render HTML in a buffer.
 
 ;; Copyright (C) 2010  Free Software Foundation, Inc.
 
 
 ;;; 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)
+
+(defcustom gnus-max-image-proportion 0.7
+  "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 'gnus-art
+  :type 'float)
+
+(defvar gnus-html-image-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map "u" 'gnus-article-copy-string)
+    (define-key map "i" 'gnus-html-insert-image)
+    map))
+
+(defvar gnus-html-displayed-image-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map "a" 'gnus-html-show-alt-text)
+    (define-key map "i" 'gnus-html-browse-image)
+    (define-key map "\r" 'gnus-html-browse-url)
+    (define-key map "u" 'gnus-article-copy-string)
+    (define-key map [tab] 'widget-forward)
+    map))
+
 ;;;###autoload
-(defun gnus-article-html (handle)
+(defun gnus-article-html (&optional handle)
   (let ((article-buffer (current-buffer)))
+    (unless handle
+      (setq handle (mm-dissect-buffer t)))
     (save-restriction
-      (narrow-to-region (1- (point)) (point))
+      (narrow-to-region (point) (point))
       (save-excursion
-       (set-buffer (car handle))
-       (call-process-region (point-min) (point-max)
-                            "w3m" 
-                            nil article-buffer nil
-                            "-halfdump"
-                            "-T" "text/html"))
+       (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))
+                (charset (mail-content-type-get (mm-handle-type handle)
+                                                'charset)))
+           (when (and charset
+                      (setq charset (mm-charset-to-coding-system charset))
+                      (not (eq charset 'ascii)))
+             (insert (prog1
+                         (mm-decode-coding-string (buffer-string) charset)
+                       (erase-buffer)
+                       (mm-enable-multibyte))))
+           (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=on"
+                                "-T" "text/html"))))
       (gnus-html-wash-tags))))
 
+(defvar gnus-article-mouse-face)
+
+(defun gnus-html-pre-wash ()
+  (goto-char (point-min))
+  (while (re-search-forward " *<pre_int> *</pre_int> *\n" nil t)
+    (replace-match "" t t))
+  (goto-char (point-min))
+  (while (re-search-forward "<a name[^\n>]+>" nil t)
+    (replace-match "" t t)))
+
+(defun gnus-html-wash-images ()
+  (let (tag parameters string start end images url)
+    (goto-char (point-min))
+    ;; Search for all the images first.
+    (while (re-search-forward "<img_alt \\([^>]*\\)>" nil t)
+      (setq parameters (match-string 1)
+           start (match-beginning 0))
+      (delete-region start (point))
+      (when (search-forward "</img_alt>" (line-end-position) t)
+       (delete-region (match-beginning 0) (match-end 0)))
+      (setq end (point))
+      (when (string-match "src=\"\\([^\"]+\\)" parameters)
+       (setq url (match-string 1 parameters))
+       (gnus-message 8 "gnus-html-wash-tags: fetching image URL %s" url)
+       (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
+               (let ((string (buffer-substring start end)))
+                 (delete-region start end)
+                 (gnus-put-image image (gnus-string-or string "*") 'cid)
+                 (gnus-add-image 'cid image))))
+         ;; Normal, external URL.
+         (if (gnus-html-image-url-blocked-p
+              url
+              (if (buffer-live-p gnus-summary-buffer)
+                  (with-current-buffer gnus-summary-buffer
+                    gnus-blocked-images)
+                gnus-blocked-images))
+             (progn
+               (widget-convert-button
+                'link start end
+                :action 'gnus-html-insert-image
+                :help-echo url
+                :keymap gnus-html-image-map
+                :button-keymap gnus-html-image-map)
+               (let ((overlay (gnus-make-overlay start end))
+                     (spec (list url
+                                 (set-marker (make-marker) start)
+                                 (set-marker (make-marker) end))))
+                 (gnus-overlay-put overlay 'local-map gnus-html-image-map)
+                 (gnus-overlay-put overlay 'gnus-image spec)
+                 (gnus-put-text-property
+                  start end
+                  'gnus-image spec)))
+           (let ((file (gnus-html-image-id url))
+                 width height alt-text)
+             (when (string-match "height=\"?\\([0-9]+\\)" parameters)
+               (setq height (string-to-number (match-string 1 parameters))))
+             (when (string-match "width=\"?\\([0-9]+\\)" parameters)
+               (setq width (string-to-number (match-string 1 parameters))))
+             (when (string-match "\\(alt\\|title\\)=\"\\([^\"]+\\)"
+                                 parameters)
+               (setq alt-text (match-string 2 parameters)))
+             ;; Don't fetch images that are really small.  They're
+             ;; probably tracking pictures.
+             (when (and (or (null height)
+                            (> height 4))
+                        (or (null width)
+                            (> width 4)))
+               (if (file-exists-p file)
+                   ;; It's already cached, so just insert it.
+                   (let ((string (buffer-substring start end)))
+                     ;; Delete the IMG text.
+                     (delete-region start end)
+                     (gnus-html-put-image file (point) string url alt-text))
+                 ;; We don't have it, so schedule it for fetching
+                 ;; asynchronously.
+                 (push (list url
+                             (set-marker (make-marker) start)
+                             (point-marker))
+                       images))))))))
+    (when images
+      (gnus-html-schedule-image-fetching (current-buffer) (nreverse images)))))
+
 (defun gnus-html-wash-tags ()
-  (let (tag parameters string start end)
-    ;;(subst-char-in-region (point-min) (point-max) ?_ ? )
+  (let (tag parameters string start end images url)
+    (gnus-html-pre-wash)
+    (gnus-html-wash-images)
+
     (goto-char (point-min))
+    ;; Then do the other tags.
     (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 "</" tag ">"))
+      (when (search-forward (concat "</" tag ">") nil t)
        (delete-region (match-beginning 0) (match-end 0)))
       (setq end (point))
       (cond
        ;; Fetch and insert a picture.
-       ((equal tag "img_alt")
-       ;;
-       )
+       ((equal tag "img_alt"))
        ;; Add a link.
-       ((equal tag "a")
+       ((or (equal tag "a")
+           (equal tag "A"))
        (when (string-match "href=\"\\([^\"]+\\)" parameters)
-         (setq parameters (match-string 1 parameters))
+         (setq url (match-string 1 parameters))
+          (gnus-message 8 "gnus-html-wash-tags: fetching link URL %s" url)
          (gnus-article-add-button start end
-                                  'browse-url parameters)
+                                  'browse-url url
+                                  url)
          (let ((overlay (gnus-make-overlay start end)))
            (gnus-overlay-put overlay 'evaporate t)
-           (gnus-overlay-put overlay 'gnus-button-url parameters)
+           (gnus-overlay-put overlay 'gnus-button-url url)
+           (gnus-put-text-property start end 'gnus-string url)
            (when gnus-article-mouse-face
              (gnus-overlay-put overlay 'mouse-face gnus-article-mouse-face)))))
+       ;; The upper-case IMG_ALT is apparently just an artifact that
+       ;; should be deleted.
+       ((equal tag "IMG_ALT")
+       (delete-region start end))
        ;; Whatever.  Just ignore the tag.
        (t
        ))
-      (goto-char start))))
+      (goto-char start))
+    (goto-char (point-min))
+    ;; The output from -halfdump isn't totally regular, so strip
+    ;; off any </pre_int>s that were left over.
+    (while (re-search-forward "</pre_int>\\|</internal>" nil t)
+      (replace-match "" t t))
+    (mm-url-decode-entities)))
+
+(defun gnus-html-insert-image ()
+  "Fetch and insert the image under point."
+  (interactive)
+  (gnus-html-schedule-image-fetching
+   (current-buffer) (list (get-text-property (point) 'gnus-image))))
+
+(defun gnus-html-show-alt-text ()
+  "Show the ALT text of the image under point."
+  (interactive)
+  (message "%s" (get-text-property (point) 'gnus-alt-text)))
+
+(defun gnus-html-browse-image ()
+  "Browse the image under point."
+  (interactive)
+  (browse-url (get-text-property (point) 'gnus-image)))
+
+(defun gnus-html-browse-url ()
+  "Browse the image under point."
+  (interactive)
+  (let ((url (get-text-property (point) 'gnus-string)))
+    (if (not url)
+       (message "No URL at point")
+      (browse-url url))))
+
+(defun gnus-html-schedule-image-fetching (buffer images)
+  (gnus-message 8 "gnus-html-schedule-image-fetching: buffer %s, images %s"
+                buffer images)
+  (when (executable-find "curl")
+    (let* ((url (caar images))
+          (process (start-process
+                    "images" nil "curl"
+                    "-s" "--create-dirs"
+                    "--location"
+                    "--max-time" "60"
+                    "-o" (gnus-html-image-id url)
+                    (mm-url-decode-entities-string 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)
+               (string (buffer-substring (cadr spec) (caddr spec))))
+           (delete-region (cadr spec) (caddr spec))
+           (gnus-html-put-image file (cadr spec) string))))
+      (when images
+       (gnus-html-schedule-image-fetching buffer images)))))
+
+(defun gnus-html-put-image (file point string &optional url alt-text)
+  (when (gnus-graphic-display-p)
+    (let* ((image (ignore-errors
+                  (gnus-create-image file)))
+         (size (and image
+                    (if (featurep 'xemacs)
+                        (cons (glyph-width image) (glyph-height image))
+                      (image-size image t)))))
+      (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 (if (featurep 'xemacs)
+                              (glyphp image)
+                            (listp image))
+                          (eq (if (featurep 'xemacs)
+                                  (let ((data (cdadar (specifier-spec-list
+                                                       (glyph-image image)))))
+                                    (and (vectorp data)
+                                         (aref data 0)))
+                                (plist-get (cdr image) :type))
+                              'gif)
+                          (= (car size) 30)
+                          (= (cdr size) 30))))
+           (let ((start (point)))
+             (setq image (gnus-html-rescale-image image file size))
+             (gnus-put-image image
+                             (gnus-string-or string "*")
+                             'external)
+             (let ((overlay (gnus-make-overlay start (point))))
+               (gnus-overlay-put overlay 'local-map
+                                 gnus-html-displayed-image-map)
+               (gnus-put-text-property start (point) 'gnus-alt-text alt-text)
+               (when url
+                 (gnus-put-text-property start (point) 'gnus-image url)))
+             (gnus-add-image 'external image)
+             t)
+         (insert string)
+         (when (fboundp 'find-image)
+           (setq image (find-image '((:type xpm :file "lock-broken.xpm"))))
+           (gnus-put-image image
+                           (gnus-string-or string "*")
+                           'internal)
+           (gnus-add-image 'internal image))
+         nil)))))
+
+(defun gnus-html-rescale-image (image file size)
+  (if (or (not (fboundp 'imagemagick-types))
+         (not (get-buffer-window (current-buffer))))
+      image
+    (let* ((width (car size))
+          (height (cdr size))
+          (edges (window-pixel-edges (get-buffer-window (current-buffer))))
+          (window-width (truncate (* gnus-max-image-proportion
+                                     (- (nth 2 edges) (nth 0 edges)))))
+          (window-height (truncate (* gnus-max-image-proportion
+                                      (- (nth 3 edges) (nth 1 edges)))))
+          scaled-image)
+      (when (> height window-height)
+       (setq image (or (create-image file 'imagemagick nil
+                                     :height window-height)
+                       image))
+       (setq size (image-size image t)))
+      (when (> (car size) window-width)
+       (setq image (or
+                    (create-image file 'imagemagick nil
+                                  :width window-width)
+                    image)))
+      image)))
+
+(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)))))))
+
+(defun gnus-html-image-url-blocked-p (url blocked-images)
+  "Find out if URL is blocked by BLOCKED-IMAGES."
+  (let ((ret (and blocked-images
+                  (string-match blocked-images url))))
+    (if ret
+        (gnus-message 8 "gnus-html-image-url-blocked-p: %s blocked by regex %s"
+                      url blocked-images)
+      (gnus-message 9 "gnus-html-image-url-blocked-p: %s passes regex %s"
+                    url blocked-images))
+    ret))
+
+(defun gnus-html-show-images ()
+  "Show any images that are in the HTML-rendered article buffer.
+This only works if the article in question is HTML."
+  (interactive)
+  (gnus-with-article-buffer
+    (let ((overlays (overlays-in (point-min) (point-max)))
+         overlay images)
+      (while (setq overlay (pop overlays))
+       (when (overlay-get overlay 'gnus-image)
+         (push (overlay-get overlay 'gnus-image) images)))
+      (if (not images)
+         (message "No images to show")
+       (gnus-html-schedule-image-fetching (current-buffer) images)))))
+
+;;;###autoload
+(defun gnus-html-prefetch-images (summary)
+  (let (blocked-images urls)
+    (when (and (buffer-live-p summary)
+              (executable-find "curl"))
+      (with-current-buffer summary
+       (setq blocked-images gnus-blocked-images))
+      (save-match-data
+       (while (re-search-forward "<img.*src=[\"']\\([^\"']+\\)" nil t)
+         (let ((url (match-string 1)))
+           (unless (gnus-html-image-url-blocked-p url blocked-images)
+              (unless (file-exists-p (gnus-html-image-id url))
+                (push (mm-url-decode-entities-string url) urls)
+                (push (gnus-html-image-id url) urls)
+                (push "-o" urls)))))
+       (let ((process
+              (apply 'start-process
+                     "images" nil "curl"
+                     "-s" "--create-dirs"
+                     "--location"
+                     "--max-time" "60"
+                     urls)))
+         (process-kill-without-query process))))))
+
+(provide 'gnus-html)
 
 ;;; gnus-html.el ends here