path: root/lisp/xwidget.el

;;; xwidget.el --- api functions for xwidgets
;;  see xwidget.c for more api functions


;;; Commentary:
;;

;;TODO this breaks compilation when we dont have xwidgets
;;(require 'xwidget-internal)

;;TODO model after make-text-button instead!
;;; Code:

(eval-when-compile (require 'cl))
(require 'reporter)

(defcustom xwidget-webkit-scroll-behaviour 'native
  "Scroll behaviour of the webkit instance.
'native or 'image."
  :group 'xwidgets)

(defun xwidget-insert (pos type title width height)
  "Insert an xwidget at POS.
given ID, TYPE, TITLE WIDTH and
HEIGHT in the current buffer.

Return ID

see `make-xwidget' for types suitable for TYPE."
  (goto-char pos)
  (let ((id (make-xwidget (point) (point)
                          type title width height nil)))
    (put-text-property (point) (+ 1 (point))
                       'display (list 'xwidget ':xwidget id))
    id))

(defun xwidget-at (pos)
  "Return xwidget at POS."
  ;;TODO this function is a bit tedious because the C layer isnt well protected yet and
  ;;xwidgetp aparently doesnt work yet
  (let* ((disp (get-text-property pos 'display))
         (xw (car (cdr (cdr  disp)))))
    ;;(if ( xwidgetp  xw) xw nil)
    (if (equal 'xwidget (car disp)) xw)))


;; (defun xwidget-socket-handler ()
;;   "Create plug for socket.  TODO."
;;   (interactive)
;;   (message "socket handler xwidget %S" last-input-event)
;;   (let*
;;       ((xwidget-event-type (nth 2 last-input-event))
;;        (xwidget-id (nth 1 last-input-event)))
;;     (cond ( (eq xwidget-event-type 'xembed-ready)
;;             (let*
;;                 ((xembed-id (nth 3 last-input-event)))
;;               (message "xembed ready  event: %S xw-id:%s" xembed-id xwidget-id)
;;               ;;TODO fetch process data from the xwidget. create it, store process info
;;               ;;will start emacs/uzbl in a xembed socket when its ready
;;               ;; (cond
;;               ;;  ((eq 3 xwidget-id)
;;               ;;   (start-process "xembed" "*xembed*" (format "%ssrc/emacs" default-directory) "-q" "--parent-id" (number-to-string xembed-id) ) )
;;               ;;  ((eq 5 xwidget-id)
;;               ;;   (start-process "xembed2" "*xembed2*" "uzbl-core"  "-s" (number-to-string xembed-id)  "http://www.fsf.org" )  )
;;               )))))

(defun xwidget-display (xwidget)
  "Force XWIDGET to be displayed to create a xwidget_view.
Return the window displaying XWIDGET."
  (let* ((buffer (xwidget-buffer xwidget))
         (window (display-buffer buffer))
         (frame (window-frame window)))
    (set-frame-visible frame t)
    (redisplay t)
    window))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; webkit support
(require 'browse-url)
(require 'image-mode);;for some image-mode alike functionality
(require 'cl-macs);;for flet

;;;###autoload
(defun xwidget-webkit-browse-url (url &optional new-session)
  "Ask xwidget-webkit to browse URL.
NEW-SESSION specifies whether to create a new xwidget-webkit session.  URL
defaults to the string looking like a url around the cursor position."
  (interactive (progn
                 (require 'browse-url)
                 (browse-url-interactive-arg "xwidget-webkit URL: "
                                             ;;( xwidget-webkit-current-url)
                                             )))
  (when (stringp url)
    (setq url (url-tidy url))
    (if new-session
        (xwidget-webkit-new-session url)
      (xwidget-webkit-goto-url url))))


;;shims for adapting image mode code to the webkit browser window
(defun xwidget-image-display-size  (spec &optional pixels frame)
  "Image code adaptor.  SPEC PIXELS FRAME like the corresponding `image-mode' fn."
  (let ((xwi (xwidget-info  (xwidget-at 1))))
    (cons (aref xwi 2)
          (aref xwi 3))))

(defadvice image-display-size (around image-display-size-for-xwidget
                                      (spec &optional pixels frame)
                                      activate)
  "Advice for re-using image mode for xwidget."
  (if (eq (car spec) 'xwidget)
      (setq ad-return-value (xwidget-image-display-size spec pixels frame))
    ad-do-it))

;;todo.
;; - check that the webkit support is compiled in
(defvar xwidget-webkit-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map "g" 'xwidget-webkit-browse-url)
    (define-key map "a" 'xwidget-webkit-adjust-size-dispatch)
    (define-key map "b" 'xwidget-webkit-back )
    (define-key map "r" 'xwidget-webkit-reload )
    (define-key map "t" (lambda () (interactive) (message "o")) )
    (define-key map "\C-m" 'xwidget-webkit-insert-string)
    (define-key map "w" 'xwidget-webkit-current-url)

    ;;similar to image mode bindings
    (define-key map (kbd "SPC")                    'xwidget-webkit-scroll-up)
    (define-key map (kbd "DEL")                    'xwidget-webkit-scroll-down)

    (define-key map [remap scroll-up]              'xwidget-webkit-scroll-up)
    (define-key map [remap scroll-up-command]      'xwidget-webkit-scroll-up)

    (define-key map [remap scroll-down]            'xwidget-webkit-scroll-down)
    (define-key map [remap scroll-down-command]    'xwidget-webkit-scroll-down)

    (define-key map [remap forward-char]           'xwidget-webkit-scroll-forward)
    (define-key map [remap backward-char]          'xwidget-webkit-scroll-backward)
    (define-key map [remap right-char]             'xwidget-webkit-scroll-forward)
    (define-key map [remap left-char]              'xwidget-webkit-scroll-backward)
    ;; (define-key map [remap previous-line]          'image-previous-line)
    ;; (define-key map [remap next-line]              'image-next-line)

    ;; (define-key map [remap move-beginning-of-line] 'image-bol)
    ;; (define-key map [remap move-end-of-line]       'image-eol)
    ;; (define-key map [remap beginning-of-buffer]    'image-bob)
    ;; (define-key map [remap end-of-buffer]          'image-eob)
    map)
  "Keymap for `xwidget-webkit-mode'.")

(defun xwidget-webkit-scroll-up ()
  "Scroll webkit up,either native or like image mode."
  (interactive)
  (if (eq xwidget-webkit-scroll-behaviour 'native)
      (xwidget-set-adjustment (xwidget-webkit-last-session) 'vertical t 50) )
      (image-scroll-up))

(defun xwidget-webkit-scroll-down ()
  "Scroll webkit down,either native or like image mode."
  (interactive)
  (if (eq xwidget-webkit-scroll-behaviour 'native)
      (xwidget-set-adjustment (xwidget-webkit-last-session) 'vertical t -50) )
      (image-scroll-down))

(defun xwidget-webkit-scroll-forward ()
  (interactive)
  (if (eq xwidget-webkit-scroll-behaviour 'native)
      (xwidget-set-adjustment (xwidget-webkit-last-session) 'horizontal t 50) )
      (xwidget-webkit-scroll-forward))

(defun xwidget-webkit-scroll-backward ()
  (interactive)
  (if (eq xwidget-webkit-scroll-behaviour 'native)
      (xwidget-set-adjustment (xwidget-webkit-last-session) 'horizontal t -50) )
      (xwidget-webkit-scroll-backward))


;;the xwidget event needs to go into a higher level handler
;;since the xwidget can generate an event even if its offscreen
;;TODO this needs to use callbacks and consider different xw ev types
(define-key (current-global-map) [xwidget-event] 'xwidget-event-handler)
(defun xwidget-log ( &rest msg)
  "Log MSG to a buffer."
  (let ( (buf  (get-buffer-create "*xwidget-log*")))
    (save-excursion
      (buffer-disable-undo buf)
      (set-buffer buf)
      (insert (apply  'format msg))
      (insert "\n"))))

(defun xwidget-event-handler ()
  "Receive xwidget event."
  (interactive)
  (xwidget-log "stuff happened to xwidget %S" last-input-event)
  (let*
      ((xwidget-event-type (nth 1 last-input-event))
       (xwidget (nth 2 last-input-event))
                                        ;(xwidget-callback (xwidget-get xwidget 'callback));;TODO stopped working for some reason
       )
                                        ;(funcall  xwidget-callback xwidget xwidget-event-type)
    (message "xw callback %s" xwidget)
    (funcall  'xwidget-webkit-callback xwidget xwidget-event-type)))

(defun xwidget-webkit-callback (xwidget xwidget-event-type)
  "Callback for xwidgets.
XWIDGET instance, XWIDGET-EVENT-TYPE depends on the originating xwidget."
  (save-excursion
    (cond ((buffer-live-p (xwidget-buffer xwidget))
           (set-buffer (xwidget-buffer xwidget))
           (let* ((strarg  (nth 3 last-input-event)))
             (cond ((eq xwidget-event-type 'document-load-finished)
                    (xwidget-log "webkit finished loading: '%s'" (xwidget-webkit-get-title xwidget))
                    ;;TODO - check the native/internal scroll
                    ;;(xwidget-adjust-size-to-content xwidget)
                    (xwidget-webkit-adjust-size-dispatch) ;;TODO send xwidget here
                    (rename-buffer (format "*xwidget webkit: %s *" (xwidget-webkit-get-title xwidget)))
                    (pop-to-buffer (current-buffer)))
                   ((eq xwidget-event-type 'navigation-policy-decision-requested)
                    (if (string-match ".*#\\(.*\\)" strarg)
                        (xwidget-webkit-show-id-or-named-element xwidget (match-string 1 strarg))))
                   (t (xwidget-log "unhandled event:%s" xwidget-event-type)))))
          (t (xwidget-log "error: callback called for xwidget with dead buffer")))))

(define-derived-mode xwidget-webkit-mode
  special-mode "xwidget-webkit" "xwidget webkit view mode"
  (setq buffer-read-only t)
  ;; Keep track of [vh]scroll when switching buffers
  (image-mode-setup-winprops))

(defvar xwidget-webkit-last-session-buffer nil)

(defun  xwidget-webkit-last-session ()
  "Last active webkit, or nil."
  (if (buffer-live-p xwidget-webkit-last-session-buffer)
      (with-current-buffer xwidget-webkit-last-session-buffer
        (xwidget-at 1))
    nil))

(defun xwidget-webkit-current-session ()
  "Either the webkit in the current buffer, or the last one used, which might be nil."
  (if (xwidget-at 1)
      (xwidget-at 1)
    (xwidget-webkit-last-session)))

(defun xwidget-adjust-size-to-content (xw)
  "Resize XW to content."
  ;;xwidgets doesnt support widgets that have their own opinions about size well yet
  ;;this reads the desired size and resizes the emacs allocated area accordingly
  (let ((size (xwidget-size-request xw)))
    (xwidget-resize xw (car size) (cadr size))))


(defvar xwidget-webkit-activeelement-js"
function findactiveelement(doc){
//alert(doc.activeElement.value);
   if(doc.activeElement.value != undefined){
      return doc.activeElement;
   }else{
        // recurse over the child documents:
        var frames = doc.getElementsByTagName('frame');
        for (var i = 0; i < frames.length; i++)
        {
                var d = frames[i].contentDocument;
                 var rv = findactiveelement(d);
                 if(rv != undefined){
                    return rv;
                 }
        }
    }
    return undefined;
};


"

  "javascript that finds the active element."
  ;;yes its ugly. because:
  ;; - there is aparently no way to find the active frame other than recursion
  ;; - the js "for each" construct missbehaved on the "frames" collection
  ;; - a window with no frameset still has frames.length == 1, but frames[0].document.activeElement != document.activeElement
  ;;TODO the activeelement type needs to be examined, for iframe, etc. sucks.
  )

(defun xwidget-webkit-insert-string (xw str)
  "Insert string in the active field in the webkit.
Argument XW webkit.
Argument STR string."
  ;;read out the string in the field first and provide for edit
  (interactive
   (let* ((xww (xwidget-webkit-current-session))

          (field-value
           (progn
             (xwidget-webkit-execute-script xww xwidget-webkit-activeelement-js)
             (xwidget-webkit-execute-script-rv xww "findactiveelement(document).value;" )))
          (field-type (xwidget-webkit-execute-script-rv xww "findactiveelement(document).type;" )))
     (list xww
           (cond ((equal "text" field-type)
                  (read-string "text:" field-value))
                 ((equal "password" field-type)
                  (read-passwd "password:" nil field-value))
                 ((equal "textarea" field-type)
                  (xwidget-webkit-begin-edit-textarea xww field-value))))))
  (xwidget-webkit-execute-script xw (format "findactiveelement(document).value='%s'" str)))


(defun xwidget-webkit-begin-edit-textarea (xw text)
  (switch-to-buffer
   (generate-new-buffer "textarea"))

  (set (make-local-variable 'xwbl) xw)
  (insert text))

(defun xwidget-webkit-end-edit-textarea ()
  (interactive)
  (goto-char (point-min))
  (while (search-forward "\n" nil t)
    (replace-match "\\n" nil t))
  (xwidget-webkit-execute-script xwbl (format "findactiveelement(document).value='%s'"
                                              (buffer-substring (point-min) (point-max))))
  ;;TODO convert linefeed to \n
  )

(defun xwidget-webkit-show-named-element (xw element-name)
  "make named-element show. for instance an anchor."
  (interactive (list (xwidget-webkit-current-session) (read-string "element name:")))
  ;;TODO
  ;; since an xwidget is an Emacs object, it is not trivial to do some things that are taken for granted in a normal browser.
  ;; scrolling an anchor/named-element into view is one such thing.
  ;; this function implements a proof-of-concept for this.
  ;; problems remaining:
  ;; - the selected window is scrolled but this is not always correct
  ;; - this needs to be interfaced into browse-url somehow. the tricky part is that we need to do this in two steps:
  ;;   A: load the base url, wait for load signal to arrive B: navigate to the anchor when the base url is finished rendering

  ;;this part figures out the Y coordinate of the element
  (let ((y (string-to-number
            (xwidget-webkit-execute-script-rv xw
                                              (format "document.getElementsByName('%s')[0].getBoundingClientRect().top" element-name)
                                              0))))
    ;;now we need to tell emacs to scroll the element into view.
    (xwidget-log "scroll: %d" y)
    (set-window-vscroll (selected-window) y t)))

(defun xwidget-webkit-show-id-element (xw element-id)
  "make id-element show. for instance an anchor."
  (interactive (list (xwidget-webkit-current-session)
                     (read-string "element id:")))
  (let ((y (string-to-number
            (xwidget-webkit-execute-script-rv xw
                                              (format "document.getElementById('%s').getBoundingClientRect().top" element-id)
                                              0))))
    ;;now we need to tell emacs to scroll the element into view.
    (xwidget-log "scroll: %d" y)
    (set-window-vscroll (selected-window) y t)))

(defun xwidget-webkit-show-id-or-named-element (xw element-id)
  "make id-element show. for instance an anchor."
  (interactive (list (xwidget-webkit-current-session)
                     (read-string "element id:")))
  (let* ((y1 (string-to-number
              (xwidget-webkit-execute-script-rv xw
                                                (format "document.getElementsByName('%s')[0].getBoundingClientRect().top" element-id)
                                                "0")))
         (y2 (string-to-number
              (xwidget-webkit-execute-script-rv xw
                                                (format "document.getElementById('%s').getBoundingClientRect().top" element-id)
                                                "0")))
         (y3 (max y1 y2)))
    ;;now we need to tell emacs to scroll the element into view.
    (xwidget-log "scroll: %d" y3)
    (set-window-vscroll (selected-window) y3 t)))

(defun xwidget-webkit-adjust-size-to-content ()
  "Adjust webkit to content size."
  (interactive)
  (xwidget-adjust-size-to-content (xwidget-webkit-current-session)))

(defun xwidget-webkit-adjust-size-dispatch ()
  "Adjust size according to mode."
  (interactive)
  (if (eq xwidget-webkit-scroll-behaviour 'native)
      (xwidget-webkit-adjust-size-to-window)
    (xwidget-webkit-adjust-size-to-content)))

(defun xwidget-webkit-adjust-size-to-window ()
  "Adjust webkit to window."
  (interactive)
    (xwidget-resize ( xwidget-webkit-current-session) (window-pixel-width) (window-pixel-height)))

(defun xwidget-webkit-adjust-size (w h)
  "Manualy set webkit size.
Argument W width.
Argument H height."
  ;;TODO shouldnt be tied to the webkit xwidget
  (interactive "nWidth:\nnHeight:\n")
  (xwidget-resize ( xwidget-webkit-current-session) w h))

(defun xwidget-webkit-fit-width ()
  "Adjust width of webkit to window width."
  (interactive)
  (xwidget-webkit-adjust-size (- (caddr (window-inside-pixel-edges))
                                 (car (window-inside-pixel-edges)))
                              1000))

(defun xwidget-webkit-new-session (url)
  "Create a new webkit session buffer with URL."
  (let*
      ((bufname (generate-new-buffer-name "*xwidget-webkit*"))
       xw)
    (setq xwidget-webkit-last-session-buffer (switch-to-buffer (get-buffer-create bufname)))
    (insert " ")
    (setq xw (xwidget-insert 1 'webkit-osr  bufname 1000 1000))
    (xwidget-put xw 'callback 'xwidget-webkit-callback)
    (xwidget-webkit-mode)
    (xwidget-webkit-goto-uri (xwidget-webkit-last-session) url )))


(defun xwidget-webkit-goto-url (url)
  "Goto URL."
  (if (xwidget-webkit-current-session)
      (progn
        (xwidget-webkit-goto-uri (xwidget-webkit-current-session) url))
    (xwidget-webkit-new-session url)))

(defun xwidget-webkit-back ()
  "Back in history."
  (interactive)
  (xwidget-webkit-execute-script (xwidget-webkit-current-session)  "history.go(-1);"))

(defun xwidget-webkit-reload ()
  "Reload current url."
  (interactive)
  (xwidget-webkit-execute-script (xwidget-webkit-current-session)  "history.go(0);"))

(defun xwidget-webkit-current-url ()
  "Get the webkit url.  place it on kill ring."
  (interactive)
  (let* ((rv (xwidget-webkit-execute-script-rv (xwidget-webkit-current-session)
                                               "document.URL"))
         (url (kill-new (or rv ""))))
    (message "url: %s" url )
    url))

(defun xwidget-webkit-execute-script-rv (xw script &optional default)
  "Same as 'xwidget-webkit-execute-script' but but with return value.
XW is the webkit instance.  SCRIPT is the script to execut.
DEFAULT is the defaultreturn value."
  ;;notice the fugly "title" hack. it is needed because the webkit api
  ;;doesnt support returning values.  this is a wrapper for the title
  ;;hack so its easy to remove should webkit someday support JS return
  ;;values or we find some other way to access the DOM

  ;;reset webkit title. fugly.
  (let* ((emptytag "titlecantbewhitespaceohthehorror")
         title)
    (xwidget-webkit-execute-script xw (format "document.title=\"%s\";" (or default emptytag)))
    (xwidget-webkit-execute-script xw (format "document.title=%s;" script))
    (setq title (xwidget-webkit-get-title xw))
    (if (equal emptytag title)
        (setq title ""))
    (unless title
      (setq title default))
    title))


;; use declare here?
;; (declare-function xwidget-resize-internal "xwidget.c" )
;; check-declare-function?

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defun xwidget-webkit-get-selection ()
  "Get the webkit selection."
  (xwidget-webkit-execute-script-rv (xwidget-webkit-current-session)
                                    "window.getSelection().toString();"))

(defun xwidget-webkit-copy-selection-as-kill ()
  "Get the webkit selection and put it on the kill ring."
  (interactive)
  (kill-new (xwidget-webkit-get-selection)))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; xwidget plist management(similar to the process plist functions)

(defun xwidget-get (xwidget propname)
  "Return the value of XWIDGET' PROPNAME property.
This is the last value stored with `(xwidget-put XWIDGET PROPNAME VALUE)'."
  (plist-get (xwidget-plist xwidget) propname))

(defun xwidget-put (xwidget propname value)
  "Change XWIDGET' PROPNAME property to VALUE.
It can be retrieved with `(xwidget-get XWIDGET PROPNAME)'."
  (set-xwidget-plist xwidget
                     (plist-put (xwidget-plist xwidget) propname value)))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun xwidget-delete-zombies ()
  "Helper for xwidget-cleanup."
  (dolist (xwidget-view xwidget-view-list)
    (when (or (not (window-live-p (xwidget-view-window xwidget-view)))
              (not (memq (xwidget-view-model xwidget-view)
                         xwidget-list)))
      (delete-xwidget-view xwidget-view))))

(defun xwidget-cleanup ()
  "Delete zombie xwidgets."
  ;;its still pretty easy to trigger bugs with xwidgets.
  ;;this function tries to implement a workaround
  (interactive)
  ;; kill xviews who should have been deleted but stull linger
  (xwidget-delete-zombies)
  ;; redraw display otherwise ghost of zombies  will remain to haunt the screen
  (redraw-display))

;;this is a workaround because I cant find the right place to put it in C
;;seems to work well in practice though
;;(add-hook 'window-configuration-change-hook 'xwidget-cleanup)
(add-hook 'window-configuration-change-hook 'xwidget-delete-zombies)

(defun xwidget-kill-buffer-query-function ()
  "Ask beforek illing a buffer that has xwidgets."
  (let ((xwidgets (get-buffer-xwidgets (current-buffer))))
    (or (not xwidgets)
        (not (memq t (mapcar 'xwidget-query-on-exit-flag xwidgets)))
        (yes-or-no-p
         (format "Buffer %S has xwidgets; kill it? "
                 (buffer-name (current-buffer)))))))

(add-hook 'kill-buffer-query-functions 'xwidget-kill-buffer-query-function)

;;killflash is sadly not reliable yet.
(defvar xwidget-webkit-kill-flash-oneshot t)
(defun xwidget-webkit-kill-flash ()
  "Disable the flash plugin in webkit.
This is needed because Flash is non-free and doesnt work reliably
on 64 bit systems and offscreen rendering.  Sadly not reliable
yet, so deinstall Flash instead for now."
  ;;you can only call this once or webkit crashes and takes emacs with it. odd.
  (unless xwidget-webkit-kill-flash-oneshot
    (xwidget-disable-plugin-for-mime "application/x-shockwave-flash")
    (setq xwidget-webkit-kill-flash-oneshot t)))

(xwidget-webkit-kill-flash)

(defun report-xwidget-bug ()
  "Report a bug in GNU Emacs about the XWidget branch.
Prompts for bug subject.  Leaves you in a mail buffer."
  (interactive)
  (let ((reporter-prompt-for-summary-p t))
    (reporter-submit-bug-report "submit@debbugs.gnu.org" nil nil nil nil
                                (format "Package: emacs-xwidgets

Please describee xactly whata ctions triggered the bug, and the
precise symptoms of the bug.  If you can, give a recipe starting
from `emacs -Q'.

If Emacs crashed, and you have the Emacs process in the gdb
deubbger, please include the output from the following gdb
commands:
    `bt full' and `xbacktrace'.

For information about debugging Emacs, please read the file
%s" (expand-file-name "DEBUG" data-directory)))))

(provide 'xwidget)

;;; xwidget.el ends here