Add ChromeVox panel and implement caption display functionality.

chrome/browser/resources/chromeos/chromevox/cvox2/background/panel.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 ChromeVox panel.
+ *
+ */
+
+goog.provide('Panel');
+
+goog.require('Msgs');
+goog.require('PanelCommand');
+
+function $(id) {
+  return document.getElementById(id);
+}
+
+/**
+ * Class to manage the panel.
+ * @constructor
+ */
+Panel = function() {
+};
+
+/**
+ * Initialize the panel.
+ */
+Panel.init = function() {
+  /** @type {Element} @private */
+  this.speechContainer_ = $('speech-container');
+
+  /** @type {Element} @private */
+  this.speechElement_ = $('speech');
+
+  /** @type {Element} @private */
+  this.brailleContainer_ = $('braille-container');
+
+  /** @type {Element} @private */
+  this.brailleTextElement_ = $('braille-text');
+
+  /** @type {Element} @private */
+  this.brailleCellsElement_ = $('braille-cells');
+
+  Panel.updateFromPrefs();
+  window.addEventListener('storage', function(event) {
+    if (event.key == 'brailleCaptions') {
+      Panel.updateFromPrefs();
+    }
+  }, false);
+
+  window.addEventListener('message', function(message) {
+    var command = JSON.parse(message.data);
+    Panel.exec(/** @type {PanelCommand} */(command));
+  }, false);
+
+  $('menu').addEventListener('click', Panel.onMenu, false);
+  $('options').addEventListener('click', Panel.onOptions, false);
+  $('close').addEventListener('click', Panel.onClose, false);
+
+  Msgs.addTranslatedMessagesToDom(document);
+};
+
+/**
+ * Update the display based on prefs.
+ */
+Panel.updateFromPrefs = function() {
+  if (localStorage['brailleCaptions'] === String(true)) {
+    this.speechContainer_.style.visibility = 'hidden';
+    this.brailleContainer_.style.visibility = 'visible';
+  } else {
+    this.speechContainer_.style.visibility = 'visible';
+    this.brailleContainer_.style.visibility = 'hidden';
+  }
+};
+
+/**
+ * Execute a command to update the panel.
+ *
+ * @param {PanelCommand} command The command to execute.
+ */
+Panel.exec = function(command) {
+  /**
+   * Escape text so it can be safely added to HTML.
+   * @param {*} str Text to be added to HTML, will be cast to string.
+   * @return {string} The escaped string.
+   */
+  function escapeForHtml(str) {
+    return String(str)
+        .replace(/&/g, '&')
+        .replace(/</g, '&lt;')
+        .replace(/\>/g, '&gt;')
+        .replace(/"/g, '&quot;')
+        .replace(/'/g, '&#039;')
+        .replace(/\//g, '&#x2F;');
+  }
+
+  switch (command.type) {
+    case PanelCommandType.CLEAR_SPEECH:
+      this.speechElement_.innerHTML = '';
+      break;
+    case PanelCommandType.ADD_NORMAL_SPEECH:
+      if (this.speechElement_.innerHTML != '') {
+        this.speechElement_.innerHTML += '&nbsp;&nbsp;';
+      }
+      this.speechElement_.innerHTML += '<span class="usertext">' +
+                                       escapeForHtml(command.data) +
+                                       '</span>';
+      break;
+    case PanelCommandType.ADD_ANNOTATION_SPEECH:
+      if (this.speechElement_.innerHTML != '') {
+        this.speechElement_.innerHTML += '&nbsp;&nbsp;';
+      }
+      this.speechElement_.innerHTML += escapeForHtml(command.data);
+      break;
+    case PanelCommandType.UPDATE_BRAILLE:
+      this.brailleTextElement_.textContent = command.data.text;
+      this.brailleCellsElement_.textContent = command.data.braille;
+      break;
+  }
+};
+
+/**
+ * Open the ChromeVox Menu.
+ */
+Panel.onMenu = function() {
+  window.location = '#fullscreen';
+  // TODO(dmazzoni): implement the menu UI here.
+};
+
+/**
+ * Open the ChromeVox Options.
+ */
+Panel.onOptions = function() {
+  var bkgnd =
+      chrome.extension.getBackgroundPage()['global']['backgroundObj'];
+  bkgnd['showOptionsPage']();
+  window.location = '#';
+};
+
+/**
+ * Exit ChromeVox.
+ */
+Panel.onClose = function() {
+  window.location = '#close';
+};
+
+window.addEventListener('load', function() {
+  Panel.init();
+}, false);