Complete live region support in ChromeVox Next.

chrome/browser/resources/chromeos/chromevox/cvox2/background/chromevox_state.js

+// Copyright 2015 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 An interface for querying and modifying the global
+ *     ChromeVox state, to avoid direct dependencies on the Background
+ *     object and to facilitate mocking for tests.
+ */
+
+goog.provide('ChromeVoxMode');
+goog.provide('ChromeVoxState');
+
+goog.require('cursors.Cursor');
+
+/**
+ * All possible modes ChromeVox can run.
+ * @enum {string}
+ */
+ChromeVoxMode = {
+  CLASSIC: 'classic',
+  COMPAT: 'compat',
+  NEXT: 'next',
+  FORCE_NEXT: 'force_next'
+};
+
+/**
+ * ChromeVox2 state object.
+ * @constructor
+ */
+ChromeVoxState = function() {
+};
+
+ChromeVoxState.prototype = {
+  /** @type {ChromeVoxMode} */
+  get mode() {
+    return this.getMode();
+  },
+
+  /**
+   * @return {ChromeVoxMode} The current mode.
+   */
+  getMode: function() {
+    return ChromeVoxMode.NEXT;
+  },
+
+  /**
+   * Sets the current ChromeVox mode.
+   * @param {ChromeVoxMode} mode
+   * @param {boolean=} opt_injectClassic Injects ChromeVox classic into tabs;
+   *                                     defaults to false.
+   */
+  setMode: function(mode, opt_injectClassic) {
+  },
+
+  /** @type {cursors.Range} */
+  get currentRange() {
+    return this.getCurrentRange();
+  },
+
+  /**
+   * @return {cursors.Range} The current range.
+   */
+  getCurrentRange: function() {

[Peter Lundblad, 2015/11/24 11:04:31]

Perhaps make the get* methods private to enforce consistency.

[dmazzoni, 2015/11/30 22:00:47]

Done.

+    return null;
+  },
+
+  /**
+   * @param {cursors.Range} newRange The new range.
+   */
+  setCurrentRange: function(newRange) {

[Peter Lundblad, 2015/11/24 11:04:31]

How about making all these 'stub' methods goog.abstract so they throw?
Then create a proper stub class if needed for testing.

[dmazzoni, 2015/11/30 22:00:47]

Done.

[dmazzoni, 2015/12/01 08:19:47]

Hmmm, I tried this but got weird errors because the function signatures didn't
match. I made these throw an error instead, hope that's okay for now. We can
address in a follow-up if you thing that goog.abstractMethod() is supposed to
work here.

+  },
+};