ChromeOS: Implement Language Selection screen of material design OOBE.

chrome/browser/resources/chromeos/login/oobe_welcome.js

 // Copyright 2016 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 Polymer element for displaying material design OOBE.
  */
 
 Polymer({
   is: 'oobe-welcome-md',
 
   properties: {
     /**
-     * Currently selected system language.
+     * Currently selected system language (display name).
      */
     currentLanguage: {
       type: String,
-      value: 'English (US)',
+      value: '',
     },
 
     /**
-     * Flag that switches Welcome screen to Network Selection screen.
+     * List of languages for language selector dropdown.
+     * @type {!Array<OobeTypes.LanguageDsc>}
+     */
+    languages: {
+      type: Array,
+    },
+
+    /**
+     * List of keyboards for keyboard selector dropdown.
+     * @type {!Array<OobeTypes.IMEDsc>}
+     */
+    keyboards: {
+      type: Array,
+    },
+
+    /**
+     * Flag that shows Welcome screen.
+     */
+    welcomeScreenShown: {
+      type: Boolean,
+      value: true,
+    },
+
+    /**
+     * Flag that shows Language Selection screen.
+     */
+    languageSelectionScreenShown: {
+      type: Boolean,
+      value: false,
+    },
+
+    /**
+     * Flag that shows Network Selection screen.
      */
     networkSelectionScreenShown: {
       type: Boolean,
       value: false,
     },
+
+    /**
+     * Flag that enables MD-OOBE.

[michaelpg, 2016/08/04 07:56:45]

Can you explain more what this does? If this is the flag you added to hide the
language selection from tests, it needs a better name and comment.

+     */
+    enabled: {
+      type: Boolean,
+      value: false,
+    },
   },
 
   /**
+   * Hides all screens to help switching from one screen to another.
+   */
+  hideAllScreens_: function() {
+    this.welcomeScreenShown = false;
+    this.networkSelectionScreenShown = false;
+    this.languageSelectionScreenShown = false;
+  },
+
+  /**
    * GUID of the user-selected network. It is remembered after user taps on
    * network entry. After we receive event "connected" on this network,
    * OOBE will proceed.
    */
   networkLastSelectedGuid_: '',
 
   /**
    * Sets proper focus.
    */
   focus: function() {
@@ skipping 37 matching lines @@
       },
     ];
   },
 
   /**
    * Handle "Next" button for "Welcome" screen.
    *
    * @private
    */
   onWelcomeNextButtonClicked_: function() {
+    this.hideAllScreens_();
     this.networkSelectionScreenShown = true;
   },
 
   /**
+   * Handle "Language" button for "Welcome" screen.
+   *
+   * @private
+   */
+  onWelcomeSelectLanguageButtonClicked_: function() {
+    this.hideAllScreens_();
+    this.languageSelectionScreenShown = true;
+  },
+
+  /**
    * Handle Networwork Setup screen "Proxy settings" button.
    *
    * @private
    */
   OpenProxySettingsDialog_: function(item) {
     chrome.send('launchProxySettingsDialog');
   },
 
   /**
    * Handle Networwork Setup screen "Add WiFi network" button.
@@ skipping 71 matching lines @@
         return;
       }
 
       if (lastError.message != 'connecting')
         console.error('networkingPrivate.startConnect error: ' + lastError);
     });
   },
 
   /**
    * @param {!Event} event
+   * @private
    */
   onNetworkListCustomItemSelected_: function(e) {
     var itemState = e.detail;
     itemState.customData.onTap();
   },
+
+  /**
+   * Handle language selection.
+   *
+   * @param {!{detail: {!OobeTypes.LanguageDsc}}} event
+   * @private
+   */
+  onLanguageSelected_: function(event) {
+    var item = event.detail;
+    var languageId = item.value;
+    this.screen.onLanguageSelected_(languageId);
+  },
+
+  /**
+   * Handle keyboard layout selection.
+   *
+   * @param {!{detail: {!OobeTypes.IMEDsc}}} event
+   * @private
+   */
+  onKeyboardSelected_: function(event) {
+    var item = event.detail;
+    var inputMethodId = item.value;
+    this.screen.onKeyboardSelected_(inputMethodId);
+  },
+
+  /**
+   * Handle "OK" button for "LanguageSelection" screen.
+   *
+   * @private
+   */
+  closeLanguageSection_: function() {
+    this.hideAllScreens_();
+    this.welcomeScreenShown = true;
+  },
 });