chrome/browser/resources/chromeos/chromevox/braille/braille_table.js

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 /**
   6  * @fileoverview Holds information about a braille table.
   7  */
   8
   9 goog.provide('cvox.BrailleTable');
  10
  11
  12 /**
  13  * @typedef {{
  14  *   locale:string,
  15  *   dots:string,
  16  *   id:string,
  17  *   grade:(string|undefined),
  18  *   variant:(string|undefined),
  19  *   fileNames:string
  20  * }}
  21  */
  22 cvox.BrailleTable.Table;
  23
  24
  25 /**
  26  * @const {string}
  27  */
  28 cvox.BrailleTable.TABLE_PATH = 'braille/tables.json';
  29
  30
  31 /**
  32  * @const {string}
  33  * @private
  34  */
  35 cvox.BrailleTable.COMMON_DEFS_FILENAME_ = 'cvox-common.cti';
  36
  37
  38 /**
  39  * Retrieves a list of all available braille tables.
  40  * @param {function(!Array<cvox.BrailleTable.Table>)} callback
  41  *     Called asynchronously with an array of tables.
  42  */
  43 cvox.BrailleTable.getAll = function(callback) {
  44   function appendCommonFilename(tables) {
  45     // Append the common definitions to all table filenames.
  46     tables.forEach(function(table) {
  47       table.fileNames += (',' + cvox.BrailleTable.COMMON_DEFS_FILENAME_);
  48     });
  49     return tables;
  50   }
  51   var url = chrome.extension.getURL(cvox.BrailleTable.TABLE_PATH);
  52   if (!url) {
  53     throw 'Invalid path: ' + cvox.BrailleTable.TABLE_PATH;
  54   }
  55
  56   var xhr = new XMLHttpRequest();
  57   xhr.open('GET', url, true);
  58   xhr.onreadystatechange = function() {
  59     if (xhr.readyState == 4) {
  60       if (xhr.status == 200) {
  61         callback(
  62             appendCommonFilename(
  63                 /** @type {!Array<cvox.BrailleTable.Table>} */ (
  64                     JSON.parse(xhr.responseText))));
  65       }
  66     }
  67   };
  68   xhr.send();
  69 };
  70
  71
  72 /**
  73  * Finds a table in a list of tables by id.
  74  * @param {!Array<cvox.BrailleTable.Table>} tables tables to search in.
  75  * @param {string} id id of table to find.
  76  * @return {cvox.BrailleTable.Table} The found table, or null if not found.
  77  */
  78 cvox.BrailleTable.forId = function(tables, id) {
  79   return tables.filter(function(table) { return table.id === id })[0] || null;
  80 };
  81
  82
  83 /**
  84  * Returns an uncontracted braille table corresponding to another, possibly
  85  * contracted, table.  If {@code table} is the lowest-grade table for its
  86  * locale and dot count, {@code table} itself is returned.
  87  * @param {!Array<cvox.BrailleTable.Table>} tables tables to search in.
  88  * @param {!cvox.BrailleTable.Table} table Table to match.
  89  * @return {!cvox.BrailleTable.Table} Corresponding uncontracted table,
  90  *     or {@code table} if it is uncontracted.
  91  */
  92 cvox.BrailleTable.getUncontracted = function(tables, table) {
  93   function mostUncontractedOf(current, candidate) {
  94     // An 8 dot table for the same language is prefered over a 6 dot table
  95     // even if the locales differ by region.
  96     if (current.dots === '6' &&
  97         candidate.dots === '8' &&
  98         current.locale.lastIndexOf(candidate.locale, 0) == 0) {
  99       return candidate;
 100     }
 101     if (current.locale === candidate.locale &&
 102         current.dots === candidate.dots &&
 103         goog.isDef(current.grade) &&
 104         goog.isDef(candidate.grade) &&
 105         candidate.grade < current.grade) {
 106       return candidate;
 107     }
 108     return current;
 109   }
 110   return tables.reduce(mostUncontractedOf, table);
 111 };
 112
 113
 114 /**
 115  * @param {!cvox.BrailleTable.Table} table Table to get name for.
 116  * @return {string} Localized display name.
 117  */
 118 cvox.BrailleTable.getDisplayName = function(table) {
 119   var msgs = cvox.ChromeVox.msgs;
 120   var localeName = msgs.getLocaleDisplayName(table.locale);
 121   if (!table.grade && !table.variant) {
 122     return localeName;
 123   } else if (table.grade && !table.variant) {
 124     return msgs.getMsg('braille_table_name_with_grade',
 125                        [localeName, table.grade]);
 126   } else if (!table.grade && table.variant) {
 127     return msgs.getMsg('braille_table_name_with_variant',
 128                        [localeName, table.variant]);
 129   } else {
 130     return msgs.getMsg('braille_table_name_with_variant_and_grade',
 131                        [localeName, table.variant, table.grade]);
 132   }
 133 };