Initial checkin of accessibility extensions.

ui/accessibility/extensions/longdesc/lastRightClick.js

+/* Copyright (c) 2014 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file. */
+
+var borderColor;
+var borderStyle;
+var borderWidth;
+
+chrome.storage.onChanged.addListener(function(changes, namespace) {
+  if (changes.addBorder.newValue) {
+    addBorders();
+  } else {
+    removeBorders();
+  }
+});
+
+chrome.storage.sync.get("addBorder", function(item) {
+  if (item.addBorder) {
+    addBorders();
+  }
+});
+
+document.addEventListener('contextmenu', function(element) {
+  updateContextMenuItem(element);
+}, false);
+
+document.addEventListener('mouseover', function(element) {
+  updateContextMenuItem(element);
+}, false);
+
+document.addEventListener('focus', function(element) {
+  updateContextMenuItem(element);
+});
+
+/**
+ * Sends a message to the backgrond script notifying it to
+ * enable or disable the context menu item.
+ *
+ * @param element
+ */
+function updateContextMenuItem(element) {
+  var longDesc = '';
+  var ariaDescribedAt = '';
+
+  if (element.target.hasAttribute("longdesc")) {
+    longDesc = element.target.getAttribute("longdesc");
+  }
+
+  if (element.target.hasAttribute("aria-describedat")) {
+    ariaDescribedAt = element.target.getAttribute("aria-describedat");
+  }
+
+  if (longDesc !== '' || ariaDescribedAt !== '') {
+    chrome.runtime.sendMessage({
+      ariaDescribedAt: ariaDescribedAt,
+      longDesc: longDesc,
+      enabled: true
+    });
+  } else {
+    chrome.runtime.sendMessage({
+      enabled: false
+    });
+  }
+}
+
+/**
+ * Modify border to make the HTML element more visible.
+ */
+function addBorders() {
+  var elementArray = new Array(document.querySelectorAll('[longdesc]'));
+  elementArray.concat(new Array(document.querySelectorAll('[aria-describedat]')));
+
+  for (var i = 0; i < elementArray.length; i++) {
+    borderColor = elementArray[0][i].style.borderColor;
+    borderStyle = elementArray[0][i].style.borderStyle;
+    borderWidth = elementArray[0][i].style.borderWidth;
+
+    elementArray[0][i].style.borderColor = 'blue';
+    elementArray[0][i].style.borderStyle = 'groove';
+    elementArray[0][i].style.borderWidth = '15px';
+  }
+}
+
+/**
+ * Revert back to the original border styling.
+ */
+function removeBorders() {
+  var elementArray = new Array(document.querySelectorAll('[longdesc]'));
+  elementArray.concat(new Array(document.querySelectorAll('[aria-describedat]')));
+
+  for (var i = 0; i < elementArray.length; i++) {
+    elementArray[0][i].style.borderColor = borderColor;
+    elementArray[0][i].style.borderStyle = borderStyle;
+    elementArray[0][i].style.borderWidth = borderWidth;
+  }
+}