code.delx.au - gnu-emacs/blob - lisp/xwidget.el

   1 ;;; xwidget.el --- api functions for xwidgets  -*- lexical-binding: t -*-
   2 ;;
   3 ;; Copyright (C) 2011-2016 Free Software Foundation, Inc.
   4 ;;
   5 ;; Author: Joakim Verona (joakim@verona.se)
   6 ;;
   7 ;; This file is part of GNU Emacs.
   8 ;;
   9 ;; GNU Emacs is free software: you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  21 ;;
  22 ;; --------------------------------------------------------------------
  23
  24 ;;; Commentary:
  25 ;;
  26 ;; See xwidget.c for more api functions.
  27
  28 ;; This breaks compilation when we don't have xwidgets.
  29 ;; And is pointless when we do, since it's in C and so preloaded.
  30 ;;(require 'xwidget-internal)
  31
  32 ;;; Code:
  33
  34 (require 'cl-lib)
  35 (require 'bookmark)
  36
  37 (defcustom xwidget-webkit-scroll-behavior 'native
  38   "Scrolling behavior of the webkit instance.
  39 The possible values are: `native' or `image'."
  40   :version "25.1"
  41   :group 'frames   ; TODO add xwidgets group if more options are added
  42   :type '(choice (const native) (const image)))
  43
  44 (declare-function make-xwidget "xwidget.c"
  45                   (type title width height arguments &optional buffer))
  46 (declare-function xwidget-set-adjustment "xwidget.c"
  47                   (xwidget axis relative value))
  48 (declare-function xwidget-buffer "xwidget.c" (xwidget))
  49 (declare-function xwidget-webkit-get-title "xwidget.c" (xwidget))
  50 (declare-function xwidget-size-request "xwidget.c" (xwidget))
  51 (declare-function xwidget-resize "xwidget.c" (xwidget new-width new-height))
  52 (declare-function xwidget-webkit-execute-script "xwidget.c" (xwidget script))
  53 (declare-function xwidget-webkit-goto-uri "xwidget.c" (xwidget uri))
  54 (declare-function xwidget-plist "xwidget.c" (xwidget))
  55 (declare-function set-xwidget-plist "xwidget.c" (xwidget plist))
  56 (declare-function xwidget-view-window "xwidget.c" (xwidget-view))
  57 (declare-function xwidget-view-model "xwidget.c" (xwidget-view))
  58 (declare-function delete-xwidget-view "xwidget.c" (xwidget-view))
  59 (declare-function get-buffer-xwidgets "xwidget.c" (buffer))
  60 (declare-function xwidget-query-on-exit-flag "xwidget.c" (xwidget))
  61
  62 (defun xwidget-insert (pos type title width height &optional args)
  63   "Insert an xwidget at position POS.
  64 Supply the xwidget's TYPE, TITLE, WIDTH, and HEIGHT.
  65 See `make-xwidget' for the possible TYPE values.
  66 The usage of optional argument ARGS depends on the xwidget.
  67 This returns the result of `make-xwidget'."
  68   (goto-char pos)
  69   (let ((id (make-xwidget type title width height args)))
  70     (put-text-property (point) (+ 1 (point))
  71                        'display (list 'xwidget ':xwidget id))
  72     id))
  73
  74 (defun xwidget-at (pos)
  75   "Return xwidget at POS."
  76   ;; TODO this function is a bit tedious because the C layer isn't well
  77   ;; protected yet and xwidgetp apparently doesn't work yet.
  78   (let* ((disp (get-text-property pos 'display))
  79          (xw (car (cdr (cdr  disp)))))
  80     ;;(if (xwidgetp  xw) xw nil)
  81     (if (equal 'xwidget (car disp)) xw)))
  82
  83
  84
  85 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  86 ;;; webkit support
  87 (require 'browse-url)
  88 (require 'image-mode);;for some image-mode alike functionality
  89
  90 ;;;###autoload
  91 (defun xwidget-webkit-browse-url (url &optional new-session)
  92   "Ask xwidget-webkit to browse URL.
  93 NEW-SESSION specifies whether to create a new xwidget-webkit session.
  94 Interactively, URL defaults to the string looking like a url around point."
  95   (interactive (progn
  96                  (require 'browse-url)
  97                  (browse-url-interactive-arg "xwidget-webkit URL: "
  98                                              ;;(xwidget-webkit-current-url)
  99                                              )))
 100   (or (featurep 'xwidget-internal)
 101       (user-error "Your Emacs was not compiled with xwidgets support"))
 102   (when (stringp url)
 103     (if new-session
 104         (xwidget-webkit-new-session url)
 105       (xwidget-webkit-goto-url url))))
 106
 107 ;;todo.
 108 ;; - check that the webkit support is compiled in
 109 (defvar xwidget-webkit-mode-map
 110   (let ((map (make-sparse-keymap)))
 111     (define-key map "g" 'xwidget-webkit-browse-url)
 112     (define-key map "a" 'xwidget-webkit-adjust-size-dispatch)
 113     (define-key map "b" 'xwidget-webkit-back)
 114     (define-key map "r" 'xwidget-webkit-reload)
 115     (define-key map "t" (lambda () (interactive) (message "o"))) ;FIXME: ?!?
 116     (define-key map "\C-m" 'xwidget-webkit-insert-string)
 117     (define-key map "w" 'xwidget-webkit-current-url)
 118
 119     ;;similar to image mode bindings
 120     (define-key map (kbd "SPC")                 'xwidget-webkit-scroll-up)
 121     (define-key map (kbd "DEL")                 'xwidget-webkit-scroll-down)
 122
 123     (define-key map [remap scroll-up]           'xwidget-webkit-scroll-up)
 124     (define-key map [remap scroll-up-command]   'xwidget-webkit-scroll-up)
 125
 126     (define-key map [remap scroll-down]         'xwidget-webkit-scroll-down)
 127     (define-key map [remap scroll-down-command] 'xwidget-webkit-scroll-down)
 128
 129     (define-key map [remap forward-char]        'xwidget-webkit-scroll-forward)
 130     (define-key map [remap backward-char]       'xwidget-webkit-scroll-backward)
 131     (define-key map [remap right-char]          'xwidget-webkit-scroll-forward)
 132     (define-key map [remap left-char]           'xwidget-webkit-scroll-backward)
 133     ;; (define-key map [remap previous-line]          'image-previous-line)
 134     ;; (define-key map [remap next-line]              'image-next-line)
 135
 136     ;; (define-key map [remap move-beginning-of-line] 'image-bol)
 137     ;; (define-key map [remap move-end-of-line]       'image-eol)
 138     ;; (define-key map [remap beginning-of-buffer]    'image-bob)
 139     ;; (define-key map [remap end-of-buffer]          'image-eob)
 140     map)
 141   "Keymap for `xwidget-webkit-mode'.")
 142
 143 (defun xwidget-webkit-scroll-up ()
 144   "Scroll webkit up.
 145 Depending on the value of `xwidget-webkit-scroll-behavior',
 146 this scrolls in `native' fashion, or like `image-mode' would."
 147   (interactive)
 148   (if (eq xwidget-webkit-scroll-behavior 'native)
 149       (xwidget-set-adjustment (xwidget-webkit-last-session) 'vertical t 50)
 150     (image-scroll-up)))
 151
 152 (defun xwidget-webkit-scroll-down ()
 153   "Scroll webkit down.
 154 Depending on the value of `xwidget-webkit-scroll-behavior',
 155 this scrolls in `native' fashion, or like `image-mode' would."
 156   (interactive)
 157   (if (eq xwidget-webkit-scroll-behavior 'native)
 158       (xwidget-set-adjustment (xwidget-webkit-last-session) 'vertical t -50)
 159     (image-scroll-down)))
 160
 161 (defun xwidget-webkit-scroll-forward ()
 162   "Scroll webkit forwards.
 163 Depending on the value of `xwidget-webkit-scroll-behavior',
 164 this scrolls in `native' fashion, or like `image-mode' would."
 165   (interactive)
 166   (if (eq xwidget-webkit-scroll-behavior 'native)
 167       (xwidget-set-adjustment (xwidget-webkit-last-session) 'horizontal t 50)
 168     (xwidget-webkit-scroll-forward)))   ; FIXME infloop!
 169
 170 (defun xwidget-webkit-scroll-backward ()
 171   "Scroll webkit backwards.
 172 Depending on the value of `xwidget-webkit-scroll-behavior',
 173 this scrolls in `native' fashion, or like `image-mode' would."
 174   (interactive)
 175   (if (eq xwidget-webkit-scroll-behavior 'native)
 176       (xwidget-set-adjustment (xwidget-webkit-last-session) 'horizontal t -50)
 177     (xwidget-webkit-scroll-backward))) ; FIXME infloop!
 178
 179
 180 ;; The xwidget event needs to go into a higher level handler
 181 ;; since the xwidget can generate an event even if it's offscreen.
 182 ;; TODO this needs to use callbacks and consider different xwidget event types.
 183 (define-key (current-global-map) [xwidget-event] #'xwidget-event-handler)
 184 (defun xwidget-log (&rest msg)
 185   "Log MSG to a buffer."
 186   (let ((buf (get-buffer-create " *xwidget-log*")))
 187     (with-current-buffer buf
 188       (insert (apply #'format msg))
 189       (insert "\n"))))
 190
 191 (defun xwidget-event-handler ()
 192   "Receive xwidget event."
 193   (interactive)
 194   (xwidget-log "stuff happened to xwidget %S" last-input-event)
 195   (let*
 196       ((xwidget-event-type (nth 1 last-input-event))
 197        (xwidget (nth 2 last-input-event))
 198        ;;(xwidget-callback (xwidget-get xwidget 'callback))
 199        ;;TODO stopped working for some reason
 200        )
 201     ;;(funcall  xwidget-callback xwidget xwidget-event-type)
 202     (message "xw callback %s" xwidget)
 203     (funcall  'xwidget-webkit-callback xwidget xwidget-event-type)))
 204
 205 (defun xwidget-webkit-callback (xwidget xwidget-event-type)
 206   "Callback for xwidgets.
 207 XWIDGET instance, XWIDGET-EVENT-TYPE depends on the originating xwidget."
 208   (if (not (buffer-live-p (xwidget-buffer xwidget)))
 209       (xwidget-log
 210        "error: callback called for xwidget with dead buffer")
 211     (with-current-buffer (xwidget-buffer xwidget)
 212       (let* ((strarg  (nth 3 last-input-event)))
 213         (cond ((eq xwidget-event-type 'document-load-finished)
 214                (xwidget-log "webkit finished loading: '%s'"
 215                             (xwidget-webkit-get-title xwidget))
 216                ;;TODO - check the native/internal scroll
 217                ;;(xwidget-adjust-size-to-content xwidget)
 218                (xwidget-webkit-adjust-size-dispatch) ;;TODO xwidget arg
 219                (rename-buffer (format "*xwidget webkit: %s *"
 220                                       (xwidget-webkit-get-title xwidget)))
 221                (pop-to-buffer (current-buffer)))
 222               ((eq xwidget-event-type
 223                    'navigation-policy-decision-requested)
 224                (if (string-match ".*#\\(.*\\)" strarg)
 225                    (xwidget-webkit-show-id-or-named-element
 226                     xwidget
 227                     (match-string 1 strarg))))
 228               (t (xwidget-log "unhandled event:%s" xwidget-event-type)))))))
 229
 230 (defvar bookmark-make-record-function)
 231 (define-derived-mode xwidget-webkit-mode
 232     special-mode "xwidget-webkit" "Xwidget webkit view mode."
 233     (setq buffer-read-only t)
 234     (setq-local bookmark-make-record-function
 235                 #'xwidget-webkit-bookmark-make-record)
 236     ;; Keep track of [vh]scroll when switching buffers
 237     (image-mode-setup-winprops))
 238
 239 (defun xwidget-webkit-bookmark-make-record ()
 240   "Integrate Emacs bookmarks with the webkit xwidget."
 241   (nconc (bookmark-make-record-default t t)
 242          `((page     . ,(xwidget-webkit-current-url))
 243            (handler  . (lambda (bmk) (browse-url
 244                                  (bookmark-prop-get bmk 'page)))))))
 245
 246
 247 (defvar xwidget-webkit-last-session-buffer nil)
 248
 249 (defun xwidget-webkit-last-session ()
 250   "Last active webkit, or nil."
 251   (if (buffer-live-p xwidget-webkit-last-session-buffer)
 252       (with-current-buffer xwidget-webkit-last-session-buffer
 253         (xwidget-at (point-min)))
 254     nil))
 255
 256 (defun xwidget-webkit-current-session ()
 257   "Either the webkit in the current buffer, or the last one used.
 258 The latter might be nil."
 259   (or (xwidget-at (point-min)) (xwidget-webkit-last-session)))
 260
 261 (defun xwidget-adjust-size-to-content (xw)
 262   "Resize XW to content."
 263   ;; xwidgets doesn't support widgets that have their own opinions about
 264   ;; size well, yet this reads the desired size and resizes the Emacs
 265   ;; allocated area accordingly.
 266   (let ((size (xwidget-size-request xw)))
 267     (xwidget-resize xw (car size) (cadr size))))
 268
 269
 270 (defvar xwidget-webkit-activeelement-js"
 271 function findactiveelement(doc){
 272 //alert(doc.activeElement.value);
 273    if(doc.activeElement.value != undefined){
 274       return doc.activeElement;
 275    }else{
 276         // recurse over the child documents:
 277         var frames = doc.getElementsByTagName('frame');
 278         for (var i = 0; i < frames.length; i++)
 279         {
 280                 var d = frames[i].contentDocument;
 281                  var rv = findactiveelement(d);
 282                  if(rv != undefined){
 283                     return rv;
 284                  }
 285         }
 286     }
 287     return undefined;
 288 };
 289
 290
 291 "
 292
 293   "javascript that finds the active element."
 294   ;; Yes it's ugly, because:
 295   ;; - there is apparently no way to find the active frame other than recursion
 296   ;; - the js "for each" construct misbehaved on the "frames" collection
 297   ;; - a window with no frameset still has frames.length == 1, but
 298   ;; frames[0].document.activeElement != document.activeElement
 299   ;;TODO the activeelement type needs to be examined, for iframe, etc.
 300   )
 301
 302 (defun xwidget-webkit-insert-string (xw str)
 303   "Insert string STR in the active field in the webkit XW."
 304   ;; Read out the string in the field first and provide for edit.
 305   (interactive
 306    (let* ((xww (xwidget-webkit-current-session))
 307
 308           (field-value
 309            (progn
 310              (xwidget-webkit-execute-script xww xwidget-webkit-activeelement-js)
 311              (xwidget-webkit-execute-script-rv
 312               xww
 313               "findactiveelement(document).value;")))
 314           (field-type (xwidget-webkit-execute-script-rv
 315                        xww
 316                        "findactiveelement(document).type;")))
 317      (list xww
 318            (cond ((equal "text" field-type)
 319                   (read-string "Text: " field-value))
 320                  ((equal "password" field-type)
 321                   (read-passwd "Password: " nil field-value))
 322                  ((equal "textarea" field-type)
 323                   (xwidget-webkit-begin-edit-textarea xww field-value))))))
 324   (xwidget-webkit-execute-script
 325    xw
 326    (format "findactiveelement(document).value='%s'" str)))
 327
 328 (defvar xwidget-xwbl)
 329 (defun xwidget-webkit-begin-edit-textarea (xw text)
 330   "Start editing of a webkit text area.
 331 XW is the xwidget identifier, TEXT is retrieved from the webkit."
 332   (switch-to-buffer
 333    (generate-new-buffer "textarea"))
 334   (set (make-local-variable 'xwidget-xwbl) xw)
 335   (insert text))
 336
 337 (defun xwidget-webkit-end-edit-textarea ()
 338   "End editing of a webkit text area."
 339   (interactive)
 340   (goto-char (point-min))
 341   (while (search-forward "\n" nil t)
 342     (replace-match "\\n" nil t))
 343   (xwidget-webkit-execute-script
 344    xwidget-xwbl
 345    (format "findactiveelement(document).value='%s'"
 346            (buffer-substring (point-min) (point-max))))
 347   ;;TODO convert linefeed to \n
 348   )
 349
 350 (defun xwidget-webkit-show-named-element (xw element-name)
 351   "Make webkit xwidget XW show a named element ELEMENT-NAME.
 352 For example, use this to display an anchor."
 353   (interactive (list (xwidget-webkit-current-session)
 354                      (read-string "Element name: ")))
 355   ;;TODO since an xwidget is an Emacs object, it is not trivial to do
 356   ;; some things that are taken for granted in a normal browser.
 357   ;; scrolling an anchor/named-element into view is one such thing.
 358   ;; This function implements a proof-of-concept for this.  Problems
 359   ;; remaining: - The selected window is scrolled but this is not
 360   ;; always correct - This needs to be interfaced into browse-url
 361   ;; somehow.  The tricky part is that we need to do this in two steps:
 362   ;; A: load the base url, wait for load signal to arrive B: navigate
 363   ;; to the anchor when the base url is finished rendering
 364
 365   ;; This part figures out the Y coordinate of the element
 366   (let ((y (string-to-number
 367             (xwidget-webkit-execute-script-rv
 368              xw
 369              (format
 370               "document.getElementsByName('%s')[0].getBoundingClientRect().top"
 371               element-name)
 372              0))))
 373     ;; Now we need to tell Emacs to scroll the element into view.
 374     (xwidget-log "scroll: %d" y)
 375     (set-window-vscroll (selected-window) y t)))
 376
 377 (defun xwidget-webkit-show-id-element (xw element-id)
 378   "Make webkit xwidget XW show an id-element ELEMENT-ID.
 379 For example, use this to display an anchor."
 380   (interactive (list (xwidget-webkit-current-session)
 381                      (read-string "Element id: ")))
 382   (let ((y (string-to-number
 383             (xwidget-webkit-execute-script-rv
 384              xw
 385              (format "document.getElementById('%s').getBoundingClientRect().top"
 386                      element-id)
 387              0))))
 388     ;; Now we need to tell Emacs to scroll the element into view.
 389     (xwidget-log "scroll: %d" y)
 390     (set-window-vscroll (selected-window) y t)))
 391
 392 (defun xwidget-webkit-show-id-or-named-element (xw element-id)
 393    "Make webkit xwidget XW show a name or element id ELEMENT-ID.
 394 For example, use this to display an anchor."
 395   (interactive (list (xwidget-webkit-current-session)
 396                      (read-string "Name or element id: ")))
 397   (let* ((y1 (string-to-number
 398               (xwidget-webkit-execute-script-rv
 399                xw
 400                (format "document.getElementsByName('%s')[0].getBoundingClientRect().top" element-id)
 401                "0")))
 402          (y2 (string-to-number
 403               (xwidget-webkit-execute-script-rv
 404                xw
 405                (format "document.getElementById('%s').getBoundingClientRect().top" element-id)
 406                "0")))
 407          (y3 (max y1 y2)))
 408     ;; Now we need to tell Emacs to scroll the element into view.
 409     (xwidget-log "scroll: %d" y3)
 410     (set-window-vscroll (selected-window) y3 t)))
 411
 412 (defun xwidget-webkit-adjust-size-to-content ()
 413   "Adjust webkit to content size."
 414   (interactive)
 415   (xwidget-adjust-size-to-content (xwidget-webkit-current-session)))
 416
 417 (defun xwidget-webkit-adjust-size-dispatch ()
 418   "Adjust size according to mode."
 419   (interactive)
 420   (if (eq xwidget-webkit-scroll-behavior 'native)
 421       (xwidget-webkit-adjust-size-to-window)
 422     (xwidget-webkit-adjust-size-to-content))
 423   ;; The recenter is intended to correct a visual glitch.
 424   ;; It errors out if the buffer isn't visible, but then we don't get
 425   ;; the glitch, so silence errors.
 426   (ignore-errors
 427     (recenter-top-bottom)))
 428
 429 (defun xwidget-webkit-adjust-size-to-window ()
 430   "Adjust webkit to window."
 431   (interactive)
 432   (xwidget-resize (xwidget-webkit-current-session) (window-pixel-width)
 433                   (window-pixel-height)))
 434
 435 (defun xwidget-webkit-adjust-size (w h)
 436   "Manually set webkit size to width W, height H."
 437   ;; TODO shouldn't be tied to the webkit xwidget
 438   (interactive "nWidth:\nnHeight:\n")
 439   (xwidget-resize (xwidget-webkit-current-session) w h))
 440
 441 (defun xwidget-webkit-fit-width ()
 442   "Adjust width of webkit to window width."
 443   (interactive)
 444   (xwidget-webkit-adjust-size (- (nth 2 (window-inside-pixel-edges))
 445                                  (car (window-inside-pixel-edges)))
 446                               1000))
 447
 448 (defun xwidget-webkit-new-session (url)
 449   "Create a new webkit session buffer with URL."
 450   (let*
 451       ((bufname (generate-new-buffer-name "*xwidget-webkit*"))
 452        xw)
 453     (setq xwidget-webkit-last-session-buffer (switch-to-buffer
 454                                               (get-buffer-create bufname)))
 455     (insert " 'a' adjusts the xwidget size.")
 456     (setq xw (xwidget-insert 1 'webkit  bufname 1000 1000))
 457     (xwidget-put xw 'callback 'xwidget-webkit-callback)
 458     (xwidget-webkit-mode)
 459     (xwidget-webkit-goto-uri (xwidget-webkit-last-session) url)))
 460
 461
 462 (defun xwidget-webkit-goto-url (url)
 463   "Goto URL."
 464   (if (xwidget-webkit-current-session)
 465       (progn
 466         (xwidget-webkit-goto-uri (xwidget-webkit-current-session) url))
 467     (xwidget-webkit-new-session url)))
 468
 469 (defun xwidget-webkit-back ()
 470   "Go back in history."
 471   (interactive)
 472   (xwidget-webkit-execute-script (xwidget-webkit-current-session)
 473                                  "history.go(-1);"))
 474
 475 (defun xwidget-webkit-reload ()
 476   "Reload current url."
 477   (interactive)
 478   (xwidget-webkit-execute-script (xwidget-webkit-current-session)
 479                                  "history.go(0);"))
 480
 481 (defun xwidget-webkit-current-url ()
 482   "Get the webkit url and place it on the kill-ring."
 483   (interactive)
 484   (let* ((rv (xwidget-webkit-execute-script-rv (xwidget-webkit-current-session)
 485                                                "document.URL"))
 486          (url (kill-new (or rv ""))))
 487     (message "url: %s" url)
 488     url))
 489
 490 (defun xwidget-webkit-execute-script-rv (xw script &optional default)
 491   "Same as `xwidget-webkit-execute-script' but with return value.
 492 XW is the webkit instance.  SCRIPT is the script to execute.
 493 DEFAULT is the default return value."
 494   ;; Notice the ugly "title" hack.  It is needed because the Webkit
 495   ;; API at the time of writing didn't support returning values.  This
 496   ;; is a wrapper for the title hack so it's easy to remove should
 497   ;; Webkit someday support JS return values or we find some other way
 498   ;; to access the DOM.
 499
 500   ;; Reset webkit title.  Not very nice.
 501   (let* ((emptytag "titlecantbewhitespaceohthehorror")
 502          title)
 503     (xwidget-webkit-execute-script xw (format "document.title=\"%s\";"
 504                                               (or default emptytag)))
 505     (xwidget-webkit-execute-script xw (format "document.title=%s;" script))
 506     (setq title (xwidget-webkit-get-title xw))
 507     (if (equal emptytag title)
 508         (setq title ""))
 509     (unless title
 510       (setq title default))
 511     title))
 512
 513 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 514 (defun xwidget-webkit-get-selection ()
 515   "Get the webkit selection."
 516   (xwidget-webkit-execute-script-rv (xwidget-webkit-current-session)
 517                                     "window.getSelection().toString();"))
 518
 519 (defun xwidget-webkit-copy-selection-as-kill ()
 520   "Get the webkit selection and put it on the kill-ring."
 521   (interactive)
 522   (kill-new (xwidget-webkit-get-selection)))
 523
 524
 525 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 526 ;; Xwidget plist management (similar to the process plist functions)
 527
 528 (defun xwidget-get (xwidget propname)
 529   "Get an xwidget's property value.
 530 XWIDGET is an xwidget, PROPNAME a property.
 531 Returns the last value stored with `xwidget-put'."
 532   (plist-get (xwidget-plist xwidget) propname))
 533
 534 (defun xwidget-put (xwidget propname value)
 535   "Set an xwidget's property value.
 536 XWIDGET is an xwidget, PROPNAME a property to be set to specified VALUE.
 537 You can retrieve the value with `xwidget-get'."
 538   (set-xwidget-plist xwidget
 539                      (plist-put (xwidget-plist xwidget) propname value)))
 540
 541
 542 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 543
 544 (defvar xwidget-view-list)              ; xwidget.c
 545 (defvar xwidget-list)                   ; xwidget.c
 546
 547 (defun xwidget-delete-zombies ()
 548   "Helper for `xwidget-cleanup'."
 549   (dolist (xwidget-view xwidget-view-list)
 550     (when (or (not (window-live-p (xwidget-view-window xwidget-view)))
 551               (not (memq (xwidget-view-model xwidget-view)
 552                          xwidget-list)))
 553       (delete-xwidget-view xwidget-view))))
 554
 555 (defun xwidget-cleanup ()
 556   "Delete zombie xwidgets."
 557   ;; During development it was sometimes easy to wind up with zombie
 558   ;; xwidget instances.
 559   ;; This function tries to implement a workaround should it occur again.
 560   (interactive)
 561   ;; Kill xviews that should have been deleted but still linger.
 562   (xwidget-delete-zombies)
 563   ;; Redraw display otherwise ghost of zombies will remain to haunt the screen
 564   (redraw-display))
 565
 566 (defun xwidget-kill-buffer-query-function ()
 567   "Ask before killing a buffer that has xwidgets."
 568   (let ((xwidgets (get-buffer-xwidgets (current-buffer))))
 569     (or (not xwidgets)
 570         (not (memq t (mapcar #'xwidget-query-on-exit-flag xwidgets)))
 571         (yes-or-no-p
 572          (format "Buffer %S has xwidgets; kill it? " (buffer-name))))))
 573
 574 (when (featurep 'xwidget-internal)
 575   (add-hook 'kill-buffer-query-functions #'xwidget-kill-buffer-query-function)
 576   ;; This would have felt better in C, but this seems to work well in
 577   ;; practice though.
 578   (add-hook 'window-configuration-change-hook #'xwidget-delete-zombies))
 579
 580 (provide 'xwidget)
 581 ;;; xwidget.el ends here