MD Settings: simplify language model and data binding

chrome/browser/resources/settings/languages_page/languages_page.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 'settings-languages-page' is the settings page
  * for language and input method settings.
  */
 (function() {
 'use strict';
@@ skipping 14 matching lines @@
      * Preferences state.
      */
     prefs: {
       type: Object,
       notify: true,
     },
 
     /**
      * Read-only reference to the languages model provided by the
      * 'settings-languages' instance.
-     * @type {LanguagesModel|undefined}
+     * @type {!LanguagesModel|undefined}
      */
     languages: {
       type: Object,
       notify: true,
     },
 
     /** @private */
     inputMethodsSecondary_: {
       type: String,
       value: 'Placeholder, e.g. US keyboard',
     },
 
     /** @private */
     spellCheckSecondary_: {
       type: String,
       value: 'Placeholder, e.g. English (United States)',
     },
 
     /**
      * The language to display the details for.
-     * @type {!LanguageInfo|undefined}
+     * @type {!LanguageState|undefined}
      * @private
      */
     detailLanguage_: Object,
 
     /** @private {!LanguageHelper} */
     languageHelper_: Object,
   },
 
   /** @override */
   created: function() {
-     this.languageHelper_ = LanguageHelperImpl.getInstance();
+    this.languageHelper_ = LanguageHelperImpl.getInstance();
   },
 
   /**
    * Handler for clicking a language on the main page, which selects the
    * language as the prospective UI language on Chrome OS and Windows.
-   * @param {!{model: !{item: !LanguageInfo}}} e
+   * @param {!{model: !{item: !LanguageState}}} e
    */
   onLanguageTap_: function(e) {
     // Only change the UI language on platforms that allow it.
     if (!cr.isChromeOS && !cr.isWindows)
       return;
 
     // Taps on the paper-icon-button are handled in onShowLanguageDetailTap_.
     if (e.target.tagName == 'PAPER-ICON-BUTTON')
       return;
 
     // Set the prospective UI language. This won't take effect until a restart.
     if (e.model.item.language.supportsUI)
       this.languageHelper_.setUILanguage(e.model.item.language.code);
   },
 
   /**
    * Handler for enabling or disabling spell check.
-   * @param {!{target: Element, model: !{item: !LanguageInfo}}} e
+   * @param {!{target: Element, model: !{item: !LanguageState}}} e
    */
   onSpellCheckChange_: function(e) {
     this.languageHelper_.toggleSpellCheck(e.model.item.language.code,
                                           e.target.checked);
   },
 
   /** @private */
   onBackTap_: function() {
     this.$.pages.back();
   },
 
   /**
    * Opens the Manage Languages page.
    * @private
    */
   onManageLanguagesTap_: function() {
     this.$.pages.setSubpageChain(['manage-languages']);
     this.forceRenderList_('settings-manage-languages-page');
   },
 
   /**
    * Opens the Language Detail page for the language.
-   * @param {!{model: !{item: !LanguageInfo}}} e
+   * @param {!{model: !{item: !LanguageState}}} e
    * @private
    */
   onShowLanguageDetailTap_: function(e) {
     this.detailLanguage_ = e.model.item;
     this.$.pages.setSubpageChain(['language-detail']);
   },
 
-<if expr="not is_macosx">
   /**
    * Returns the enabled languages which support spell check.
+   * @return {!Array<!LanguageState>}
    * @private
    */
   spellCheckLanguages_: function() {
-    return this.languages.enabledLanguages.filter(function(languageInfo) {
-      return languageInfo.language.supportsSpellcheck;
+    assert(!cr.isMac);
+    return this.languages.enabled.filter(function(languageState) {
+      return languageState.language.supportsSpellcheck;
     });
   },
 
   /**
    * Opens the Custom Dictionary page.
    * @private
    */
   onEditDictionaryTap_: function() {
+    assert(!cr.isMac);
     this.$.pages.setSubpageChain(['edit-dictionary']);
     this.forceRenderList_('settings-edit-dictionary-page');
   },
-</if>
 
-<if expr="chromeos or is_win">
   /**
    * Checks whether the prospective UI language (the pref that indicates what
    * language to use in Chrome) matches the current language. This pref is only
    * on Chrome OS and Windows; we don't control the UI language elsewhere.
    * @param {string} languageCode The language code identifying a language.
    * @param {string} prospectiveUILanguage The prospective UI language.
    * @return {boolean} True if the given language matches the prospective UI
    *     pref (which may be different from the actual UI language).
    * @private
    */
   isProspectiveUILanguage_: function(languageCode, prospectiveUILanguage) {
+    assert(cr.isChromeOS || cr.isWindows);
     return languageCode == this.languageHelper_.getProspectiveUILanguage();
   },
-</if>
 
    /**
     * @return {string}
     * @private
     */
   getProspectiveUILanguageName_: function() {
     return this.languageHelper_.getLanguage(
         this.languageHelper_.getProspectiveUILanguage()).displayName;
   },
 
   /**
    * Returns either the "selected" class, if the language matches the
    * prospective UI language, or an empty string. Languages can only be
    * selected on Chrome OS and Windows.
    * @param {string} languageCode The language code identifying a language.
    * @param {string} prospectiveUILanguage The prospective UI language.
    * @return {string} The class name for the language item.
    * @private
    */
   getLanguageItemClass_: function(languageCode, prospectiveUILanguage) {
-<if expr="chromeos or is_win">
-    if (this.isProspectiveUILanguage_(languageCode, prospectiveUILanguage))
+    if ((cr.isChromeOS || cr.isWindows) &&
+        this.isProspectiveUILanguage_(languageCode, prospectiveUILanguage)) {
       return 'selected';
-</if>
+    }
     return '';
   },
 
-<if expr="chromeos">
   /**
    * @param {string} id The input method ID.
    * @param {string} currentId The ID of the currently enabled input method.
    * @return {boolean} True if the IDs match.
    * @private
    */
   isCurrentInputMethod_: function(id, currentId) {
     assert(cr.isChromeOS);
     return id == currentId;
   },
 
   /**
    * @param {string} id The input method ID.
    * @param {string} currentId The ID of the currently enabled input method.
    * @return {string} The class for the input method item.
    * @private
    */
   getInputMethodItemClass_: function(id, currentId) {
+    assert(cr.isChromeOS);
     return this.isCurrentInputMethod_(id, currentId) ? 'selected' : '';
   },
-</if>
 
   /**
    * HACK(michaelpg): This is necessary to show the list when navigating to
    * the sub-page. Remove this function when PolymerElements/neon-animation#60
    * is fixed.
    * @param {string} tagName Name of the element containing the <iron-list>.
    */
   forceRenderList_: function(tagName) {
     this.$$(tagName).$$('iron-list').fire('iron-resize');
   },
 });
 })();