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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
      5  * use this file except in compliance with the License. You may obtain a copy of
      6  * the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
     12  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
     13  * License for the specific language governing permissions and limitations under
     14  * the License.
     15  */
     16 package android.speech.tts;
     17 
     18 import org.xmlpull.v1.XmlPullParserException;
     19 
     20 import android.content.Context;
     21 import android.content.Intent;
     22 import android.content.pm.ApplicationInfo;
     23 import android.content.pm.PackageManager;
     24 import android.content.pm.PackageManager.NameNotFoundException;
     25 import android.content.pm.ResolveInfo;
     26 import android.content.pm.ServiceInfo;
     27 import android.content.res.Resources;
     28 import android.content.res.TypedArray;
     29 import android.content.res.XmlResourceParser;
     30 
     31 import static android.provider.Settings.Secure.getString;
     32 
     33 import android.provider.Settings;
     34 import android.speech.tts.TextToSpeech.Engine;
     35 import android.speech.tts.TextToSpeech.EngineInfo;
     36 import android.text.TextUtils;
     37 import android.util.AttributeSet;
     38 import android.util.Log;
     39 import android.util.Xml;
     40 
     41 import java.io.IOException;
     42 import java.util.ArrayList;
     43 import java.util.Collections;
     44 import java.util.Comparator;
     45 import java.util.HashMap;
     46 import java.util.List;
     47 import java.util.Locale;
     48 import java.util.Map;
     49 import java.util.MissingResourceException;
     50 
     51 /**
     52  * Support class for querying the list of available engines
     53  * on the device and deciding which one to use etc.
     54  *
     55  * Comments in this class the use the shorthand "system engines" for engines that
     56  * are a part of the system image.
     57  *
     58  * This class is thread-safe/
     59  *
     60  * @hide
     61  */
     62 public class TtsEngines {
     63     private static final String TAG = "TtsEngines";
     64     private static final boolean DBG = false;
     65 
     66     /** Locale delimiter used by the old-style 3 char locale string format (like "eng-usa") */
     67     private static final String LOCALE_DELIMITER_OLD = "-";
     68 
     69     /** Locale delimiter used by the new-style locale string format (Locale.toString() results,
     70      * like "en_US") */
     71     private static final String LOCALE_DELIMITER_NEW = "_";
     72 
     73     private final Context mContext;
     74 
     75     /** Mapping of various language strings to the normalized Locale form */
     76     private static final Map<String, String> sNormalizeLanguage;
     77 
     78     /** Mapping of various country strings to the normalized Locale form */
     79     private static final Map<String, String> sNormalizeCountry;
     80 
     81     // Populate the sNormalize* maps
     82     static {
     83         HashMap<String, String> normalizeLanguage = new HashMap<String, String>();
     84         for (String language : Locale.getISOLanguages()) {
     85             try {
     86                 normalizeLanguage.put(new Locale(language).getISO3Language(), language);
     87             } catch (MissingResourceException e) {
     88                 continue;
     89             }
     90         }
     91         sNormalizeLanguage = Collections.unmodifiableMap(normalizeLanguage);
     92 
     93         HashMap<String, String> normalizeCountry = new HashMap<String, String>();
     94         for (String country : Locale.getISOCountries()) {
     95             try {
     96                 normalizeCountry.put(new Locale("", country).getISO3Country(), country);
     97             } catch (MissingResourceException e) {
     98                 continue;
     99             }
    100         }
    101         sNormalizeCountry = Collections.unmodifiableMap(normalizeCountry);
    102     }
    103 
    104     public TtsEngines(Context ctx) {
    105         mContext = ctx;
    106     }
    107 
    108     /**
    109      * @return the default TTS engine. If the user has set a default, and the engine
    110      *         is available on the device, the default is returned. Otherwise,
    111      *         the highest ranked engine is returned as per {@link EngineInfoComparator}.
    112      */
    113     public String getDefaultEngine() {
    114         String engine = getString(mContext.getContentResolver(),
    115                 Settings.Secure.TTS_DEFAULT_SYNTH);
    116         return isEngineInstalled(engine) ? engine : getHighestRankedEngineName();
    117     }
    118 
    119     /**
    120      * @return the package name of the highest ranked system engine, {@code null}
    121      *         if no TTS engines were present in the system image.
    122      */
    123     public String getHighestRankedEngineName() {
    124         final List<EngineInfo> engines = getEngines();
    125 
    126         if (engines.size() > 0 && engines.get(0).system) {
    127             return engines.get(0).name;
    128         }
    129 
    130         return null;
    131     }
    132 
    133     /**
    134      * Returns the engine info for a given engine name. Note that engines are
    135      * identified by their package name.
    136      */
    137     public EngineInfo getEngineInfo(String packageName) {
    138         PackageManager pm = mContext.getPackageManager();
    139         Intent intent = new Intent(Engine.INTENT_ACTION_TTS_SERVICE);
    140         intent.setPackage(packageName);
    141         List<ResolveInfo> resolveInfos = pm.queryIntentServices(intent,
    142                 PackageManager.MATCH_DEFAULT_ONLY);
    143         // Note that the current API allows only one engine per
    144         // package name. Since the "engine name" is the same as
    145         // the package name.
    146         if (resolveInfos != null && resolveInfos.size() == 1) {
    147             return getEngineInfo(resolveInfos.get(0), pm);
    148         }
    149 
    150         return null;
    151     }
    152 
    153     /**
    154      * Gets a list of all installed TTS engines.
    155      *
    156      * @return A list of engine info objects. The list can be empty, but never {@code null}.
    157      */
    158     public List<EngineInfo> getEngines() {
    159         PackageManager pm = mContext.getPackageManager();
    160         Intent intent = new Intent(Engine.INTENT_ACTION_TTS_SERVICE);
    161         List<ResolveInfo> resolveInfos =
    162                 pm.queryIntentServices(intent, PackageManager.MATCH_DEFAULT_ONLY);
    163         if (resolveInfos == null) return Collections.emptyList();
    164 
    165         List<EngineInfo> engines = new ArrayList<EngineInfo>(resolveInfos.size());
    166 
    167         for (ResolveInfo resolveInfo : resolveInfos) {
    168             EngineInfo engine = getEngineInfo(resolveInfo, pm);
    169             if (engine != null) {
    170                 engines.add(engine);
    171             }
    172         }
    173         Collections.sort(engines, EngineInfoComparator.INSTANCE);
    174 
    175         return engines;
    176     }
    177 
    178     private boolean isSystemEngine(ServiceInfo info) {
    179         final ApplicationInfo appInfo = info.applicationInfo;
    180         return appInfo != null && (appInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0;
    181     }
    182 
    183     /**
    184      * @return true if a given engine is installed on the system.
    185      */
    186     public boolean isEngineInstalled(String engine) {
    187         if (engine == null) {
    188             return false;
    189         }
    190 
    191         return getEngineInfo(engine) != null;
    192     }
    193 
    194     /**
    195      * @return an intent that can launch the settings activity for a given tts engine.
    196      */
    197     public Intent getSettingsIntent(String engine) {
    198         PackageManager pm = mContext.getPackageManager();
    199         Intent intent = new Intent(Engine.INTENT_ACTION_TTS_SERVICE);
    200         intent.setPackage(engine);
    201         List<ResolveInfo> resolveInfos = pm.queryIntentServices(intent,
    202                 PackageManager.MATCH_DEFAULT_ONLY | PackageManager.GET_META_DATA);
    203         // Note that the current API allows only one engine per
    204         // package name. Since the "engine name" is the same as
    205         // the package name.
    206         if (resolveInfos != null && resolveInfos.size() == 1) {
    207             ServiceInfo service = resolveInfos.get(0).serviceInfo;
    208             if (service != null) {
    209                 final String settings = settingsActivityFromServiceInfo(service, pm);
    210                 if (settings != null) {
    211                     Intent i = new Intent();
    212                     i.setClassName(engine, settings);
    213                     return i;
    214                 }
    215             }
    216         }
    217 
    218         return null;
    219     }
    220 
    221     /**
    222      * The name of the XML tag that text to speech engines must use to
    223      * declare their meta data.
    224      *
    225      * {@link com.android.internal.R.styleable#TextToSpeechEngine}
    226      */
    227     private static final String XML_TAG_NAME = "tts-engine";
    228 
    229     private String settingsActivityFromServiceInfo(ServiceInfo si, PackageManager pm) {
    230         XmlResourceParser parser = null;
    231         try {
    232             parser = si.loadXmlMetaData(pm, TextToSpeech.Engine.SERVICE_META_DATA);
    233             if (parser == null) {
    234                 Log.w(TAG, "No meta-data found for :" + si);
    235                 return null;
    236             }
    237 
    238             final Resources res = pm.getResourcesForApplication(si.applicationInfo);
    239 
    240             int type;
    241             while ((type = parser.next()) != XmlResourceParser.END_DOCUMENT) {
    242                 if (type == XmlResourceParser.START_TAG) {
    243                     if (!XML_TAG_NAME.equals(parser.getName())) {
    244                         Log.w(TAG, "Package " + si + " uses unknown tag :"
    245                                 + parser.getName());
    246                         return null;
    247                     }
    248 
    249                     final AttributeSet attrs = Xml.asAttributeSet(parser);
    250                     final TypedArray array = res.obtainAttributes(attrs,
    251                             com.android.internal.R.styleable.TextToSpeechEngine);
    252                     final String settings = array.getString(
    253                             com.android.internal.R.styleable.TextToSpeechEngine_settingsActivity);
    254                     array.recycle();
    255 
    256                     return settings;
    257                 }
    258             }
    259 
    260             return null;
    261         } catch (NameNotFoundException e) {
    262             Log.w(TAG, "Could not load resources for : " + si);
    263             return null;
    264         } catch (XmlPullParserException e) {
    265             Log.w(TAG, "Error parsing metadata for " + si + ":" + e);
    266             return null;
    267         } catch (IOException e) {
    268             Log.w(TAG, "Error parsing metadata for " + si + ":" + e);
    269             return null;
    270         } finally {
    271             if (parser != null) {
    272                 parser.close();
    273             }
    274         }
    275     }
    276 
    277     private EngineInfo getEngineInfo(ResolveInfo resolve, PackageManager pm) {
    278         ServiceInfo service = resolve.serviceInfo;
    279         if (service != null) {
    280             EngineInfo engine = new EngineInfo();
    281             // Using just the package name isn't great, since it disallows having
    282             // multiple engines in the same package, but that's what the existing API does.
    283             engine.name = service.packageName;
    284             CharSequence label = service.loadLabel(pm);
    285             engine.label = TextUtils.isEmpty(label) ? engine.name : label.toString();
    286             engine.icon = service.getIconResource();
    287             engine.priority = resolve.priority;
    288             engine.system = isSystemEngine(service);
    289             return engine;
    290         }
    291 
    292         return null;
    293     }
    294 
    295     private static class EngineInfoComparator implements Comparator<EngineInfo> {
    296         private EngineInfoComparator() { }
    297 
    298         static EngineInfoComparator INSTANCE = new EngineInfoComparator();
    299 
    300         /**
    301          * Engines that are a part of the system image are always lesser
    302          * than those that are not. Within system engines / non system engines
    303          * the engines are sorted in order of their declared priority.
    304          */
    305         @Override
    306         public int compare(EngineInfo lhs, EngineInfo rhs) {
    307             if (lhs.system && !rhs.system) {
    308                 return -1;
    309             } else if (rhs.system && !lhs.system) {
    310                 return 1;
    311             } else {
    312                 // Either both system engines, or both non system
    313                 // engines.
    314                 //
    315                 // Note, this isn't a typo. Higher priority numbers imply
    316                 // higher priority, but are "lower" in the sort order.
    317                 return rhs.priority - lhs.priority;
    318             }
    319         }
    320     }
    321 
    322     /**
    323      * Returns the default locale for a given TTS engine. Attempts to read the
    324      * value from {@link Settings.Secure#TTS_DEFAULT_LOCALE}, failing which the
    325      * default phone locale is returned.
    326      *
    327      * @param engineName the engine to return the locale for.
    328      * @return the locale preference for this engine. Will be non null.
    329      */
    330     public Locale getLocalePrefForEngine(String engineName) {
    331         return getLocalePrefForEngine(engineName,
    332                 getString(mContext.getContentResolver(), Settings.Secure.TTS_DEFAULT_LOCALE));
    333     }
    334 
    335     /**
    336      * Returns the default locale for a given TTS engine from given settings string. */
    337     public Locale getLocalePrefForEngine(String engineName, String prefValue) {
    338         String localeString = parseEnginePrefFromList(
    339                 prefValue,
    340                 engineName);
    341 
    342         if (TextUtils.isEmpty(localeString)) {
    343             // The new style setting is unset, attempt to return the old style setting.
    344             return Locale.getDefault();
    345         }
    346 
    347         Locale result = parseLocaleString(localeString);
    348         if (result == null) {
    349             Log.w(TAG, "Failed to parse locale " + localeString + ", returning en_US instead");
    350             result = Locale.US;
    351         }
    352 
    353         if (DBG) Log.d(TAG, "getLocalePrefForEngine(" + engineName + ")= " + result);
    354 
    355         return result;
    356     }
    357 
    358 
    359     /**
    360      * True if a given TTS engine uses the default phone locale as a default locale. Attempts to
    361      * read the value from {@link Settings.Secure#TTS_DEFAULT_LOCALE}. If
    362      * its  value is empty, this methods returns true.
    363      *
    364      * @param engineName the engine to return the locale for.
    365      */
    366     public boolean isLocaleSetToDefaultForEngine(String engineName) {
    367         return TextUtils.isEmpty(parseEnginePrefFromList(
    368                     getString(mContext.getContentResolver(), Settings.Secure.TTS_DEFAULT_LOCALE),
    369                     engineName));
    370     }
    371 
    372     /**
    373      * Parses a locale encoded as a string, and tries its best to return a valid {@link Locale}
    374      * object, even if the input string is encoded using the old-style 3 character format e.g.
    375      * "deu-deu". At the end, we test if the resulting locale can return ISO3 language and
    376      * country codes ({@link Locale#getISO3Language()} and {@link Locale#getISO3Country()}),
    377      * if it fails to do so, we return null.
    378      */
    379     public Locale parseLocaleString(String localeString) {
    380         String language = "", country = "", variant = "";
    381         if (!TextUtils.isEmpty(localeString)) {
    382             String[] split = localeString.split(
    383                     "[" + LOCALE_DELIMITER_OLD + LOCALE_DELIMITER_NEW + "]");
    384             language = split[0].toLowerCase();
    385             if (split.length == 0) {
    386                 Log.w(TAG, "Failed to convert " + localeString + " to a valid Locale object. Only" +
    387                             " separators");
    388                 return null;
    389             }
    390             if (split.length > 3) {
    391                 Log.w(TAG, "Failed to convert " + localeString + " to a valid Locale object. Too" +
    392                         " many separators");
    393                 return null;
    394             }
    395             if (split.length >= 2) {
    396                 country = split[1].toUpperCase();
    397             }
    398             if (split.length >= 3) {
    399                 variant = split[2];
    400             }
    401 
    402         }
    403 
    404         String normalizedLanguage = sNormalizeLanguage.get(language);
    405         if (normalizedLanguage != null) {
    406             language = normalizedLanguage;
    407         }
    408 
    409         String normalizedCountry= sNormalizeCountry.get(country);
    410         if (normalizedCountry != null) {
    411             country = normalizedCountry;
    412         }
    413 
    414         if (DBG) Log.d(TAG, "parseLocalePref(" + language + "," + country +
    415                 "," + variant +")");
    416 
    417         Locale result = new Locale(language, country, variant);
    418         try {
    419             result.getISO3Language();
    420             result.getISO3Country();
    421             return result;
    422         } catch(MissingResourceException e) {
    423             Log.w(TAG, "Failed to convert " + localeString + " to a valid Locale object.");
    424             return null;
    425         }
    426     }
    427 
    428     /**
    429      * This method tries its best to return a valid {@link Locale} object from the TTS-specific
    430      * Locale input (returned by {@link TextToSpeech#getLanguage}
    431      * and {@link TextToSpeech#getDefaultLanguage}). A TTS Locale language field contains
    432      * a three-letter ISO 639-2/T code (where a proper Locale would use a two-letter ISO 639-1
    433      * code), and the country field contains a three-letter ISO 3166 country code (where a proper
    434      * Locale would use a two-letter ISO 3166-1 code).
    435      *
    436      * This method tries to convert three-letter language and country codes into their two-letter
    437      * equivalents. If it fails to do so, it keeps the value from the TTS locale.
    438      */
    439     public static Locale normalizeTTSLocale(Locale ttsLocale) {
    440         String language = ttsLocale.getLanguage();
    441         if (!TextUtils.isEmpty(language)) {
    442             String normalizedLanguage = sNormalizeLanguage.get(language);
    443             if (normalizedLanguage != null) {
    444                 language = normalizedLanguage;
    445             }
    446         }
    447 
    448         String country = ttsLocale.getCountry();
    449         if (!TextUtils.isEmpty(country)) {
    450             String normalizedCountry= sNormalizeCountry.get(country);
    451             if (normalizedCountry != null) {
    452                 country = normalizedCountry;
    453             }
    454         }
    455         return new Locale(language, country, ttsLocale.getVariant());
    456     }
    457 
    458     /**
    459      * Return the old-style string form of the locale. It consists of 3 letter codes:
    460      * <ul>
    461      *   <li>"ISO 639-2/T language code" if the locale has no country entry</li>
    462      *   <li> "ISO 639-2/T language code{@link #LOCALE_DELIMITER}ISO 3166 country code"
    463      *     if the locale has no variant entry</li>
    464      *   <li> "ISO 639-2/T language code{@link #LOCALE_DELIMITER}ISO 3166 country
    465      *     code{@link #LOCALE_DELIMITER}variant" if the locale has a variant entry</li>
    466      * </ul>
    467      * If we fail to generate those codes using {@link Locale#getISO3Country()} and
    468      * {@link Locale#getISO3Language()}, then we return new String[]{"eng","USA",""};
    469      */
    470     static public String[] toOldLocaleStringFormat(Locale locale) {
    471         String[] ret = new String[]{"","",""};
    472         try {
    473             // Note that the default locale might have an empty variant
    474             // or language.
    475             ret[0] = locale.getISO3Language();
    476             ret[1] = locale.getISO3Country();
    477             ret[2] = locale.getVariant();
    478 
    479             return ret;
    480         } catch (MissingResourceException e) {
    481             // Default locale does not have a ISO 3166 and/or ISO 639-2/T codes. Return the
    482             // default "eng-usa" (that would be the result of Locale.getDefault() == Locale.US).
    483             return new String[]{"eng","USA",""};
    484         }
    485     }
    486 
    487     /**
    488      * Parses a comma separated list of engine locale preferences. The list is of the
    489      * form {@code "engine_name_1:locale_1,engine_name_2:locale2"} and so on and
    490      * so forth. Returns null if the list is empty, malformed or if there is no engine
    491      * specific preference in the list.
    492      */
    493     private static String parseEnginePrefFromList(String prefValue, String engineName) {
    494         if (TextUtils.isEmpty(prefValue)) {
    495             return null;
    496         }
    497 
    498         String[] prefValues = prefValue.split(",");
    499 
    500         for (String value : prefValues) {
    501             final int delimiter = value.indexOf(':');
    502             if (delimiter > 0) {
    503                 if (engineName.equals(value.substring(0, delimiter))) {
    504                     return value.substring(delimiter + 1);
    505                 }
    506             }
    507         }
    508 
    509         return null;
    510     }
    511 
    512     /**
    513      * Serialize the locale to a string and store it as a default locale for the given engine. If
    514      * the passed locale is null, an empty string will be serialized; that empty string, when
    515      * read back, will evaluate to {@link Locale#getDefault()}.
    516      */
    517     public synchronized void updateLocalePrefForEngine(String engineName, Locale newLocale) {
    518         final String prefList = Settings.Secure.getString(mContext.getContentResolver(),
    519                 Settings.Secure.TTS_DEFAULT_LOCALE);
    520         if (DBG) {
    521             Log.d(TAG, "updateLocalePrefForEngine(" + engineName + ", " + newLocale +
    522                     "), originally: " + prefList);
    523         }
    524 
    525         final String newPrefList = updateValueInCommaSeparatedList(prefList,
    526                 engineName, (newLocale != null) ? newLocale.toString() : "");
    527 
    528         if (DBG) Log.d(TAG, "updateLocalePrefForEngine(), writing: " + newPrefList.toString());
    529 
    530         Settings.Secure.putString(mContext.getContentResolver(),
    531                 Settings.Secure.TTS_DEFAULT_LOCALE, newPrefList.toString());
    532     }
    533 
    534     /**
    535      * Updates the value for a given key in a comma separated list of key value pairs,
    536      * each of which are delimited by a colon. If no value exists for the given key,
    537      * the kay value pair are appended to the end of the list.
    538      */
    539     private String updateValueInCommaSeparatedList(String list, String key,
    540             String newValue) {
    541         StringBuilder newPrefList = new StringBuilder();
    542         if (TextUtils.isEmpty(list)) {
    543             // If empty, create a new list with a single entry.
    544             newPrefList.append(key).append(':').append(newValue);
    545         } else {
    546             String[] prefValues = list.split(",");
    547             // Whether this is the first iteration in the loop.
    548             boolean first = true;
    549             // Whether we found the given key.
    550             boolean found = false;
    551             for (String value : prefValues) {
    552                 final int delimiter = value.indexOf(':');
    553                 if (delimiter > 0) {
    554                     if (key.equals(value.substring(0, delimiter))) {
    555                         if (first) {
    556                             first = false;
    557                         } else {
    558                             newPrefList.append(',');
    559                         }
    560                         found = true;
    561                         newPrefList.append(key).append(':').append(newValue);
    562                     } else {
    563                         if (first) {
    564                             first = false;
    565                         } else {
    566                             newPrefList.append(',');
    567                         }
    568                         // Copy across the entire key + value as is.
    569                         newPrefList.append(value);
    570                     }
    571                 }
    572             }
    573 
    574             if (!found) {
    575                 // Not found, but the rest of the keys would have been copied
    576                 // over already, so just append it to the end.
    577                 newPrefList.append(',');
    578                 newPrefList.append(key).append(':').append(newValue);
    579             }
    580         }
    581 
    582         return newPrefList.toString();
    583     }
    584 }
    585