Adding ChromeVox as a component extensions (enabled only for ChromeOS, for no...

chrome/browser/resources/access_chromevox/common/focus_util.js

+// Copyright (c) 2011 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.
+
+/**
+ * @fileoverview A collection of JavaScript utilities used to manage focus
+ * within a document.
+ */
+
+
+goog.provide('cvox.FocusUtil');
+
+
+/**
+ * Utilities for managing focus.
+ * @constructor
+ */
+cvox.FocusUtil = function() {
+};
+
+/**
+ * Maps whether an input element of specified type accepts text selection or
+ * not. True if the element does accept text selection, false if it does not.
+ * This can be used to determine whether a visitor to that element should
+ * provide interactive text editing to the user.
+ * From the W3C table of possible type keywords:
+ * http://www.w3.org/TR/html5/the-input-element.html#attr-input-type
+ * @type {Object}
+ */
+cvox.FocusUtil.INPUT_TYPE_ACCEPTS_SELECTION_TABLE = {
+  'hidden' : false,
+  'text' : true,
+  'search' : true,
+  'tel' : true,
+  'url' : true,
+  'email' : true,
+  'password' : true,
+  'datetime' : false,
+  'date' : false,
+  'month' : false,
+  'week' : false,
+  'time' : false,
+  'datetime-local' : false,
+  'number' : false,
+  'range' : false,
+  'color' : false,
+  'checkbox' : false,
+  'radio' : false,
+  'file' : false,
+  'submit' : false,
+  'image' : false,
+  'reset' : false,
+  'button' : false
+};
+
+/**
+ * Checks if the currently focused element is a field that accepts text input
+ * (This can include text fields and selectors)
+ *
+ * @return {boolean} True if the currently focused element accepts text input.
+ */
+cvox.FocusUtil.isFocusInTextInputField = function() {
+  // TODO(rshearer): Check all editable text fields here, including
+  // aria role=textbox.
+
+  var activeElement = document.activeElement;
+
+  if (activeElement.isContentEditable) {
+    return true;
+  }
+
+  if ((activeElement.tagName === 'INPUT') ||
+      (activeElement.tagName === 'TEXTAREA') ||
+      (activeElement.tagName === 'SELECT')) {
+
+    if (activeElement.getAttribute('readOnly') == 'true') {
+      return false;
+    } else if (! activeElement.hasAttribute('type')) {
+      return true;
+    } else {
+      var activeType = activeElement.getAttribute('type').toLowerCase();
+
+      return cvox.FocusUtil.INPUT_TYPE_ACCEPTS_SELECTION_TABLE[activeType];
+    }
+  }
+  return false;
+};