chrome/browser/resources/chromeos/chromevox/common/aural_style_util.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 A set of classes to support aural CSS.
   7  */
   8
   9
  10 goog.provide('cvox.AuralProperty');
  11 goog.provide('cvox.AuralStyleConverter');
  12 goog.provide('cvox.AuralStyleUtil');
  13
  14 // This seems the only way to lay out an enum and use it as a key.
  15 /**
  16  * @enum {string}
  17  */
  18 cvox.AuralProperty = {
  19   VOLUME: 'VOLUME',
  20   SPEAK: 'SPEAK',
  21   PAUSE_BEFORE: 'PAUSE_BEFORE',
  22   PAUSE_AFTER: 'PAUSE_AFTER',
  23   PAUSE: 'PAUSE',
  24   CUE_BEFORE: 'CUE_BEFORE',
  25   CUE_AFTER: 'CUE_AFTER',
  26   CUE: 'CUE',
  27   PLAY_DURING: 'PLAY_DURING',
  28   AZIMUTH: 'AZIMUTH',
  29   ELEVATION: 'ELEVATION',
  30   SPEECH_RATE: 'SPEECH_RATE',
  31   VOICE_FAMILY: 'VOICE_FAMILY',
  32   PITCH: 'PITCH',
  33   PITCH_RANGE: 'PITCH_RANGE',
  34   STRESS: 'STRESS',
  35   RICHNESS: 'RICHNESS',
  36   SPEAK_PUNCTUATION: 'SPEAK_PUNCTUATION',
  37   SPEAK_NUMERIAL: 'SPEAK_NUMERIAL',
  38   SPEAK_HEADER: 'SPEAK_HEADER',
  39   NONE: 'NONE'
  40 };
  41
  42
  43 /* A series of conversion functions. */
  44 /**
  45  * An identity conversion.
  46  * @param {number} value The aural CSS value to convert.
  47  * @return {number} The resulting tts property value.
  48  */
  49 cvox.AuralStyleConverter.identity = function(value) {
  50   return value;
  51 };
  52
  53
  54 /**
  55  * Conversion from an aural style property to Chrome TTS property.
  56  * TODO(dtseng): no-op's below need to be supported by the extension API itself
  57  * or by ChromeVox.
  58  * @type {Object<cvox.AuralProperty, string>}
  59  */
  60 cvox.AuralStyleConverter.propertyTable = {
  61   VOLUME: 'volume',
  62   SPEAK: 'no-op',
  63   PAUSE_BEFORE: 'no-op',
  64   PAUSE_AFTER: 'no-op',
  65   PAUSE: 'no-op',
  66   CUE_BEFORE: 'no-op',
  67   CUE_AFTER: 'no-op',
  68   CUE: 'no-op',
  69   PLAY_DURING: 'no-op',
  70   AZIMUTH: 'no-op',
  71   ELEVATION: 'no-op',
  72   SPEECH_RATE: 'relativeRate',
  73   VOICE_FAMILY: 'no-op',
  74   PITCH: 'relativePitch',
  75   PITCH_RANGE: 'no-op',
  76   STRESS: 'no-op',
  77   RICHNESS: 'no-op',
  78   SPEAK_PUNCTUATION: 'no-op',
  79   SPEAK_NUMERIAL: 'no-op',
  80   SPEAK_HEADER: 'no-op',
  81   NONE: 'no-op'
  82 };
  83
  84
  85 /**
  86  * Conversion from an aural style value to Chrome TTS value.
  87  * TODO(dtseng): Conversion of aural CSS values is incomplete; everything is an
  88  * identity conversion at the moment.
  89  * @type {Object<cvox.AuralProperty, function(*)>}
  90  */
  91 cvox.AuralStyleConverter.valueTable = {
  92   VOLUME: cvox.AuralStyleConverter.identity,
  93   SPEAK: cvox.AuralStyleConverter.identity,
  94   PAUSE_BEFORE: cvox.AuralStyleConverter.identity,
  95   PAUSE_AFTER: cvox.AuralStyleConverter.identity,
  96   PAUSE: cvox.AuralStyleConverter.identity,
  97   CUE_BEFORE: cvox.AuralStyleConverter.identity,
  98   CUE_AFTER: cvox.AuralStyleConverter.identity,
  99   CUE: cvox.AuralStyleConverter.identity,
 100   PLAY_DURING: cvox.AuralStyleConverter.identity,
 101   AZIMUTH: cvox.AuralStyleConverter.identity,
 102   ELEVATION: cvox.AuralStyleConverter.identity,
 103   SPEECH_RATE: cvox.AuralStyleConverter.identity,
 104   VOICE_FAMILY: cvox.AuralStyleConverter.identity,
 105   PITCH: cvox.AuralStyleConverter.identity,
 106   PITCH_RANGE: cvox.AuralStyleConverter.identity,
 107   STRESS: cvox.AuralStyleConverter.identity,
 108   RICHNESS: cvox.AuralStyleConverter.identity,
 109   SPEAK_PUNCTUATION: cvox.AuralStyleConverter.identity,
 110   SPEAK_NUMERIAL: cvox.AuralStyleConverter.identity,
 111   SPEAK_HEADER: cvox.AuralStyleConverter.identity,
 112   NONE: cvox.AuralStyleConverter.identity
 113 };
 114
 115
 116 /**
 117  * Converts a given aural property/value rule to a tts property/value.
 118  * @param {cvox.AuralProperty} property The property.
 119  * @param {*} value The CSS-based value.
 120  * @return {Object} An object holding tts property and value.
 121  */
 122 cvox.AuralStyleConverter.convertRule = function(property, value) {
 123   return {
 124     property: cvox.AuralStyleConverter.propertyTable[property],
 125     value: cvox.AuralStyleConverter.valueTable[property](value)
 126   };
 127 };
 128
 129
 130 /**
 131  * Converts an aural CSS style block to a TTS property object.
 132  * @param {Object<cvox.AuralProperty, *>} style The style.
 133  * @return {Object} The tts property object.
 134  */
 135 cvox.AuralStyleConverter.convertStyle = function(style) {
 136   var ttsProperties = {};
 137   for (var property in style) {
 138     var ttsProperty =
 139         cvox.AuralStyleConverter.convertRule(property, style[property]);
 140     ttsProperties[ttsProperty.property] = ttsProperty.value;
 141   }
 142   return ttsProperties;
 143 };
 144
 145
 146 /**
 147  * Gets the aural style for a node.
 148  * @param {Node} node The node.
 149  * @return {Object} The aural style, converted to tts properties.
 150 */
 151 cvox.AuralStyleUtil.getStyleForNode = function(node) {
 152   var style = cvox.AuralStyleUtil.defaultStyles[node.tagName];
 153   if (!style) {
 154     return null;
 155   }
 156   return cvox.AuralStyleConverter.convertStyle(style);
 157 };
 158
 159
 160 /**
 161  * A list of default aural styles.
 162  */
 163 cvox.AuralStyleUtil.defaultStyles = {
 164   'ARTICLE': {
 165     PITCH: -0.1
 166   },
 167   'ASIDE': {
 168     PITCH: -0.1
 169   },
 170   'FOOTER': {
 171     PITCH: -0.1
 172   },
 173   'H1': {
 174     PITCH: -0.3
 175   },
 176   'H2': {
 177     PITCH: -0.25
 178   },
 179   'H3': {
 180     PITCH: -0.2
 181   },
 182   'H4': {
 183     PITCH: -0.15
 184   },
 185   'H5': {
 186     PITCH: -0.1
 187   },
 188   'H6': {
 189     PITCH: -0.05
 190   },
 191   'HEADER': {
 192     PITCH: -0.1
 193   },
 194   'HGROUP': {
 195     PITCH: -0.1
 196   },
 197   'MARK': {
 198     PITCH: -0.1
 199   },
 200   'NAV': {
 201     PITCH: -0.1
 202   },
 203   'SECTION': {
 204     PITCH: -0.1
 205   },
 206   'TIME': {
 207     PITCH: -0.1
 208   }
 209 };