ui/accessibility/extensions/longdesc/lastRightClick.js

   1 /* Copyright (c) 2014 The Chromium Authors. All rights reserved.
   2  * Use of this source code is governed by a BSD-style license that can be
   3  * found in the LICENSE file. */
   4
   5 var borderColor;
   6 var borderStyle;
   7 var borderWidth;
   8
   9 chrome.storage.onChanged.addListener(function(changes, namespace) {
  10   if (changes.addBorder.newValue) {
  11     addBorders();
  12   } else {
  13     removeBorders();
  14   }
  15 });
  16
  17 chrome.storage.sync.get("addBorder", function(item) {
  18   if (item.addBorder) {
  19     addBorders();
  20   }
  21 });
  22
  23 document.addEventListener('contextmenu', function(element) {
  24   updateContextMenuItem(element);
  25 }, false);
  26
  27 document.addEventListener('mouseover', function(element) {
  28   updateContextMenuItem(element);
  29 }, false);
  30
  31 document.addEventListener('focus', function(element) {
  32   updateContextMenuItem(element);
  33 });
  34
  35 /**
  36  * Sends a message to the backgrond script notifying it to
  37  * enable or disable the context menu item.
  38  *
  39  * @param element
  40  */
  41 function updateContextMenuItem(element) {
  42   var longDesc = '';
  43   var ariaDescribedAt = '';
  44
  45   if (element.target.hasAttribute("longdesc")) {
  46     longDesc = element.target.getAttribute("longdesc");
  47     var link = document.createElement("a");
  48     link.href = longDesc;
  49     longDesc = link.href;
  50   }
  51
  52   if (element.target.hasAttribute("aria-describedat")) {
  53     ariaDescribedAt = element.target.getAttribute("aria-describedat");
  54   }
  55
  56   if (longDesc !== '' || ariaDescribedAt !== '') {
  57     chrome.runtime.sendMessage({
  58       ariaDescribedAt: ariaDescribedAt,
  59       longDesc: longDesc,
  60       enabled: true
  61     });
  62   } else {
  63     chrome.runtime.sendMessage({
  64       enabled: false
  65     });
  66   }
  67 }
  68
  69 /**
  70  * Modify border to make the HTML element more visible.
  71  */
  72 function addBorders() {
  73   document.body.setAttribute('showlongdescborders', '');
  74 }
  75
  76 /**
  77  * Revert back to the original border styling.
  78  */
  79 function removeBorders() {
  80   document.body.removeAttribute('showlongdescborders', '');
  81 }