// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/**
* @fileoverview Keeps track of the current braille translators.
*/
import {TestImportManager} from '/common/testing/test_import_manager.js';
import {BrailleTable} from '../../common/braille/braille_table.js';
import {SettingsManager} from '../../common/settings_manager.js';
import {Output} from '../output/output.js';
import {ExpandingBrailleTranslator} from './expanding_braille_translator.js';
import {LibLouis} from './liblouis.js';
export class BrailleTranslatorManager {
/**
* @param {LibLouis=} opt_liblouisForTest Liblouis instance to use
* for testing.
*/
constructor(opt_liblouisForTest) {
/** @private {!LibLouis} */
this.liblouis_ =
opt_liblouisForTest ||
new LibLouis(
chrome.extension.getURL(
'chromevox/third_party/liblouis/liblouis_wrapper.js'),
chrome.extension.getURL('chromevox/background/braille/tables'),
() => this.loadLiblouis_());
/** @private {!Array<function()>} */
this.changeListeners_ = [];
/** @private {!Array<BrailleTable.Table>} */
this.tables_ = [];
/** @private {?ExpandingBrailleTranslator} */
this.expandingTranslator_ = null;
/** @private {?LibLouis.Translator} */
this.defaultTranslator_ = null;
/** @private {?string} */
this.defaultTableId_ = null;
/** @private {?LibLouis.Translator} */
this.uncontractedTranslator_ = null;
/** @private {?string} */
this.uncontractedTableId_ = null;
}
static init() {
if (BrailleTranslatorManager.instance) {
throw new Error('\nCannot create two BrailleTranslatorManagers');
}
BrailleTranslatorManager.instance = new BrailleTranslatorManager();
SettingsManager.addListenerForKey(
'brailleTable',
brailleTable =>
BrailleTranslatorManager.instance.refresh(brailleTable));
}
/**
* @param {!ArrayBuffer} cells
* @return {!Promise<?string>}
*/
static backTranslate(cells) {
return new Promise(resolve => {
BrailleTranslatorManager.instance.getDefaultTranslator().backTranslate(
cells, resolve);
});
}
/**
* Adds a listener to be called whenever there is a change in the
* translator(s) returned by other methods of this instance.
* @param {function()} listener The listener.
*/
addChangeListener(listener) {
this.changeListeners_.push(listener);
}
/**
* Refreshes the braille translator(s) used for input and output. This
* should be called when something has changed (such as a preference) to
* make sure that the correct translator is used.
* @param {string} brailleTable The table for this translator to use.
* @param {string=} opt_brailleTable8 Optionally specify an uncontracted
* table.
* @param {function()=} opt_finishCallback Called when the refresh finishes.
*/
async refresh(brailleTable, opt_brailleTable8, opt_finishCallback) {
const finishCallback = opt_finishCallback || (() => {});
if (brailleTable && brailleTable === this.defaultTableId_) {
finishCallback();
return;
}
const tables = this.tables_;
if (tables.length === 0) {
finishCallback();
return;
}
// Look for the table requested.
let table = BrailleTable.forId(tables, brailleTable);
if (!table) {
// Match table against current locale.
const currentLocale = chrome.i18n.getMessage('@@ui_locale').split(/[_-]/);
const major = currentLocale[0];
const minor = currentLocale[1];
const firstPass =
tables.filter(table => table.locale.split(/[_-]/)[0] === major);
if (firstPass.length > 0) {
table = firstPass[0];
if (minor) {
const secondPass = firstPass.filter(
table => table.locale.split(/[_-]/)[1] === minor);
if (secondPass.length > 0) {
table = secondPass[0];
}
}
}
}
if (!table) {
table = BrailleTable.forId(tables, 'en-nabcc');
}
// If the user explicitly set an 8 dot table, use that when looking
// for an uncontracted table. Otherwise, use the current table and let
// getUncontracted find an appropriate corresponding table.
const table8Dot = opt_brailleTable8 ?
BrailleTable.forId(tables, opt_brailleTable8) :
null;
const uncontractedTable =
BrailleTable.getUncontracted(tables, table8Dot || table);
const newDefaultTableId = table.id;
const newUncontractedTableId =
table.id === uncontractedTable.id ? null : uncontractedTable.id;
if (newDefaultTableId === this.defaultTableId_ &&
newUncontractedTableId === this.uncontractedTableId_) {
finishCallback();
return;
}
const finishRefresh = (defaultTranslator, uncontractedTranslator) => {
this.defaultTableId_ = newDefaultTableId;
this.uncontractedTableId_ = newUncontractedTableId;
this.expandingTranslator_ = new ExpandingBrailleTranslator(
defaultTranslator, uncontractedTranslator);
this.defaultTranslator_ = defaultTranslator;
this.uncontractedTranslator_ = uncontractedTranslator;
this.changeListeners_.forEach(listener => listener());
finishCallback();
};
const translator = await this.liblouis_.getTranslator(table.fileNames);
if (!newUncontractedTableId) {
finishRefresh(translator, null);
} else {
const uncontractedTranslator =
await this.liblouis_.getTranslator(uncontractedTable.fileNames);
finishRefresh(translator, uncontractedTranslator);
}
}
/**
* @return {ExpandingBrailleTranslator} The current expanding braille
* translator, or {@code null} if none is available.
*/
getExpandingTranslator() {
return this.expandingTranslator_;
}
/**
* @return {LibLouis.Translator} The current braille translator to use
* by default, or {@code null} if none is available.
*/
getDefaultTranslator() {
return this.defaultTranslator_;
}
/**
* @return {LibLouis.Translator} The current uncontracted braille
* translator, or {@code null} if it is the same as the default
* translator.
*/
getUncontractedTranslator() {
return this.uncontractedTranslator_;
}
/** Toggles the braille table type. */
toggleBrailleTable() {
let brailleTableType = SettingsManager.getString('brailleTableType');
let output = '';
if (brailleTableType === 'brailleTable6') {
brailleTableType = 'brailleTable8';
// This label reads "switch to 8 dot braille".
output = '@OPTIONS_BRAILLE_TABLE_TYPE_6';
} else {
brailleTableType = 'brailleTable6';
// This label reads "switch to 6 dot braille".
output = '@OPTIONS_BRAILLE_TABLE_TYPE_8';
}
const brailleTable = SettingsManager.getString(brailleTableType);
SettingsManager.set('brailleTable', brailleTable);
SettingsManager.set('brailleTableType', brailleTableType);
this.refresh(brailleTable);
new Output().format(output).go();
}
/**
* Asynchronously fetches the list of braille tables and refreshes the
* translators when done.
* @return {!Promise} Resolves when tables are loaded.
* @private
*/
async fetchTables_() {
return new Promise(r => {
BrailleTable.getAll(tables => {
this.tables_ = tables;
// Initial refresh; set options from user preferences.
this.refresh(SettingsManager.getString('brailleTable'), undefined, r);
});
});
}
/**
* Loads the liblouis instance by attaching it to the document.
* @private
*/
loadLiblouis_() {
this.fetchTables_();
}
/**
* @return {!LibLouis} The liblouis instance used by this object.
*/
getLibLouisForTest() {
return this.liblouis_;
}
/**
* @return {!Array<BrailleTable.Table>} The currently loaded braille
* tables, or an empty array if they are not yet loaded.
*/
getTablesForTest() {
return this.tables_;
}
/**
* Loads liblouis tables and returns a promise resolved when loaded.
* @return {!Promise}
*/
async loadTablesForTest() {
await this.fetchTables_();
}
}
/** @type {BrailleTranslatorManager} */
BrailleTranslatorManager.instance;
TestImportManager.exportForTesting(BrailleTranslatorManager);
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