Extract language settings methods into a LanguageHelper interface

chrome/browser/resources/settings/languages_page/languages_types.js

Index: chrome/browser/resources/settings/languages_page/languages_types.js
diff --git a/chrome/browser/resources/settings/languages_page/languages_types.js b/chrome/browser/resources/settings/languages_page/languages_types.js
new file mode 100644
index 0000000000000000000000000000000000000000..6f76c4e1b67a024b3113026ee4c902a0bc9dbcb3
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+++ b/chrome/browser/resources/settings/languages_page/languages_types.js
@@ -0,0 +1,127 @@
+// 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 Closure typedefs for dictionaries and interfaces used by
+ * language settings.
+ */
+
+/**
+ * Current properties of a language.
+ * @typedef {{spellCheckEnabled: boolean, translateEnabled: boolean,
+ *            removable: boolean}} */
+var LanguageState;
+
+/**
+ * Information about a language including intrinsic information (|language|)
+ * and the |state| of the language.
+ * @typedef {{language: !chrome.languageSettingsPrivate.Language,
+ *            state: !LanguageState}}
+ */
+var LanguageInfo;
+
+/**
+ * Languages data to expose to consumers.
+ * supportedLanguages: an array of languages, ordered alphabetically.
+ * enabledLanguages: an array of enabled language info, ordered by preference.
+ * translateTarget: the default language to translate into.
+ * @typedef {{
+ *   supportedLanguages: !Array<!chrome.languageSettingsPrivate.Language>,
+ *   enabledLanguages: !Array<!LanguageInfo>,
+ *   translateTarget: string
+ * }}
+ */
+var LanguagesModel;
+
+/**
+ * Helper methods implemented by settings-languages-singleton. The nature of
+ * the interaction between the singleton Polymer element and the |languages|
+ * properties kept in sync is hidden from the consumer, which can just treat
+ * these methods as a handy interface.
+ * @interface
+ */
+var LanguageSettingsHelper = function() {};

[Dan Beam, 2015/11/25 00:29:38]

typically you see less-specific names for interfaces in Chrome, i.e. Thinger and
ThingerImpl where Thinger is the interface and ThingerImpl is it's
implementation.  Polymer does something similar, I think, by just adding "Impl"
when you have to do the dirty work.

i understand you needed 2 different names here, but I'm wondering why "Settings"
is more appropriate here?  could we do LanguageHelper (interface) +
LanguageHelperImpl (concrete)?  LanguageHelper (interface) +
LanguageHelperSingleton (concrete)?

[michaelpg, 2015/11/25 06:20:51]

good ideas, thanks

+
+LanguageSettingsHelper.prototype = {
+
+<if expr="chromeos or is_win">
+  /**
+   * Sets the prospective UI language to the chosen language. This won't affect
+   * the actual UI language until a restart.
+   * @param {string} languageCode
+   */
+  setUILanguage: assertNotReached,
+
+  /** Resets the prospective UI language back to the actual UI language. */
+  resetUILanguage: assertNotReached,
+
+  /**
+   * Returns the "prospective" UI language, i.e. the one to be used on next
+   * restart. If the pref is not set, the current UI language is also the
+   * "prospective" language.
+   * @return {string} Language code of the prospective UI language.
+   */
+  getProspectiveUILanguage: assertNotReached,
+</if>
+
+  /**
+   * @param {string} languageCode
+   * @return {boolean}
+   */
+  isLanguageEnabled: assertNotReached,
+
+  /**
+   * Enables the language, making it available for spell check and input.
+   * @param {string} languageCode
+   */
+  enableLanguage: assertNotReached,
+
+  /**
+   * Disables the language.
+   * @param {string} languageCode
+   */
+  disableLanguage: assertNotReached,
+
+  /**
+   * @param {string} languageCode Language code for an enabled language.
+   * @return {boolean}
+   */
+  canDisableLanguage: assertNotReached,
+
+  /**
+   * Enables translate for the given language by removing the translate
+   * language from the blocked languages preference.
+   * @param {string} languageCode
+   */
+  enableTranslateLanguage: assertNotReached,
+
+  /**
+   * Disables translate for the given language by adding the translate
+   * language to the blocked languages preference.
+   * @param {string} languageCode
+   */
+  disableTranslateLanguage: assertNotReached,
+
+  /**
+   * Enables or disables spell check for the given language.
+   * @param {string} languageCode
+   * @param {boolean} enable
+   */
+  toggleSpellCheck: assertNotReached,
+
+  /**
+   * Converts the language code for translate. There are some differences
+   * between the language set the Translate server uses and that for
+   * Accept-Language.
+   * @param {string} languageCode
+   * @return {string} The converted language code.
+   */
+  convertLanguageCodeForTranslate: assertNotReached,
+
+  /**
+   * @param {string} languageCode
+   * @return {!chrome.languageSettingsPrivate.Language|undefined}
+   */
+  getLanguage: assertNotReached,
+};