1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of 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, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.speech; 18 19 import java.util.ArrayList; 20 21 import android.app.Activity; 22 import android.content.ActivityNotFoundException; 23 import android.content.BroadcastReceiver; 24 import android.content.ComponentName; 25 import android.content.Context; 26 import android.content.Intent; 27 import android.content.pm.PackageManager; 28 import android.content.pm.ResolveInfo; 29 import android.os.Bundle; 30 31 /** 32 * Constants for supporting speech recognition through starting an {@link Intent} 33 */ 34 public class RecognizerIntent { 35 /** 36 * The extra key used in an intent to the speech recognizer for voice search. Not 37 * generally to be used by developers. The system search dialog uses this, for example, 38 * to set a calling package for identification by a voice search API. If this extra 39 * is set by anyone but the system process, it should be overridden by the voice search 40 * implementation. 41 */ 42 public final static String EXTRA_CALLING_PACKAGE = "calling_package"; 43 44 private RecognizerIntent() { 45 // Not for instantiating. 46 } 47 48 /** 49 * Starts an activity that will prompt the user for speech and send it through a 50 * speech recognizer. The results will be returned via activity results (in 51 * {@link Activity#onActivityResult}, if you start the intent using 52 * {@link Activity#startActivityForResult(Intent, int)}), or forwarded via a PendingIntent 53 * if one is provided. 54 * 55 * <p>Starting this intent with just {@link Activity#startActivity(Intent)} is not supported. 56 * You must either use {@link Activity#startActivityForResult(Intent, int)}, or provide a 57 * PendingIntent, to receive recognition results. 58 * 59 * <p>Required extras: 60 * <ul> 61 * <li>{@link #EXTRA_LANGUAGE_MODEL} 62 * </ul> 63 * 64 * <p>Optional extras: 65 * <ul> 66 * <li>{@link #EXTRA_PROMPT} 67 * <li>{@link #EXTRA_LANGUAGE} 68 * <li>{@link #EXTRA_MAX_RESULTS} 69 * <li>{@link #EXTRA_RESULTS_PENDINGINTENT} 70 * <li>{@link #EXTRA_RESULTS_PENDINGINTENT_BUNDLE} 71 * </ul> 72 * 73 * <p> Result extras (returned in the result, not to be specified in the request): 74 * <ul> 75 * <li>{@link #EXTRA_RESULTS} 76 * </ul> 77 * 78 * <p>NOTE: There may not be any applications installed to handle this action, so you should 79 * make sure to catch {@link ActivityNotFoundException}. 80 */ 81 public static final String ACTION_RECOGNIZE_SPEECH = "android.speech.action.RECOGNIZE_SPEECH"; 82 83 /** 84 * Starts an activity that will prompt the user for speech, send it through a 85 * speech recognizer, and either display a web search result or trigger 86 * another type of action based on the user's speech. 87 * 88 * <p>If you want to avoid triggering any type of action besides web search, you can use 89 * the {@link #EXTRA_WEB_SEARCH_ONLY} extra. 90 * 91 * <p>Required extras: 92 * <ul> 93 * <li>{@link #EXTRA_LANGUAGE_MODEL} 94 * </ul> 95 * 96 * <p>Optional extras: 97 * <ul> 98 * <li>{@link #EXTRA_PROMPT} 99 * <li>{@link #EXTRA_LANGUAGE} 100 * <li>{@link #EXTRA_MAX_RESULTS} 101 * <li>{@link #EXTRA_PARTIAL_RESULTS} 102 * <li>{@link #EXTRA_WEB_SEARCH_ONLY} 103 * <li>{@link #EXTRA_ORIGIN} 104 * </ul> 105 * 106 * <p> Result extras (returned in the result, not to be specified in the request): 107 * <ul> 108 * <li>{@link #EXTRA_RESULTS} 109 * <li>{@link #EXTRA_CONFIDENCE_SCORES} (optional) 110 * </ul> 111 * 112 * <p>NOTE: There may not be any applications installed to handle this action, so you should 113 * make sure to catch {@link ActivityNotFoundException}. 114 */ 115 public static final String ACTION_WEB_SEARCH = "android.speech.action.WEB_SEARCH"; 116 117 /** 118 * The minimum length of an utterance. We will not stop recording before this amount of time. 119 * 120 * Note that it is extremely rare you'd want to specify this value in an intent. If you don't 121 * have a very good reason to change these, you should leave them as they are. Note also that 122 * certain values may cause undesired or unexpected results - use judiciously! Additionally, 123 * depending on the recognizer implementation, these values may have no effect. 124 */ 125 public static final String EXTRA_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS = 126 "android.speech.extras.SPEECH_INPUT_MINIMUM_LENGTH_MILLIS"; 127 128 /** 129 * The amount of time that it should take after we stop hearing speech to consider the input 130 * complete. 131 * 132 * Note that it is extremely rare you'd want to specify this value in an intent. If 133 * you don't have a very good reason to change these, you should leave them as they are. Note 134 * also that certain values may cause undesired or unexpected results - use judiciously! 135 * Additionally, depending on the recognizer implementation, these values may have no effect. 136 */ 137 public static final String EXTRA_SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS = 138 "android.speech.extras.SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS"; 139 140 /** 141 * The amount of time that it should take after we stop hearing speech to consider the input 142 * possibly complete. This is used to prevent the endpointer cutting off during very short 143 * mid-speech pauses. 144 * 145 * Note that it is extremely rare you'd want to specify this value in an intent. If 146 * you don't have a very good reason to change these, you should leave them as they are. Note 147 * also that certain values may cause undesired or unexpected results - use judiciously! 148 * Additionally, depending on the recognizer implementation, these values may have no effect. 149 */ 150 public static final String EXTRA_SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS = 151 "android.speech.extras.SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS"; 152 153 /** 154 * Informs the recognizer which speech model to prefer when performing 155 * {@link #ACTION_RECOGNIZE_SPEECH}. The recognizer uses this 156 * information to fine tune the results. This extra is required. Activities implementing 157 * {@link #ACTION_RECOGNIZE_SPEECH} may interpret the values as they see fit. 158 * 159 * @see #LANGUAGE_MODEL_FREE_FORM 160 * @see #LANGUAGE_MODEL_WEB_SEARCH 161 */ 162 public static final String EXTRA_LANGUAGE_MODEL = "android.speech.extra.LANGUAGE_MODEL"; 163 164 /** 165 * Use a language model based on free-form speech recognition. This is a value to use for 166 * {@link #EXTRA_LANGUAGE_MODEL}. 167 * @see #EXTRA_LANGUAGE_MODEL 168 */ 169 public static final String LANGUAGE_MODEL_FREE_FORM = "free_form"; 170 /** 171 * Use a language model based on web search terms. This is a value to use for 172 * {@link #EXTRA_LANGUAGE_MODEL}. 173 * @see #EXTRA_LANGUAGE_MODEL 174 */ 175 public static final String LANGUAGE_MODEL_WEB_SEARCH = "web_search"; 176 177 /** Optional text prompt to show to the user when asking them to speak. */ 178 public static final String EXTRA_PROMPT = "android.speech.extra.PROMPT"; 179 180 /** 181 * Optional IETF language tag (as defined by BCP 47), for example "en-US". This tag informs the 182 * recognizer to perform speech recognition in a language different than the one set in the 183 * {@link java.util.Locale#getDefault()}. 184 */ 185 public static final String EXTRA_LANGUAGE = "android.speech.extra.LANGUAGE"; 186 187 /** 188 * Optional value which can be used to indicate the referer url of a page in which 189 * speech was requested. For example, a web browser may choose to provide this for 190 * uses of speech on a given page. 191 */ 192 public static final String EXTRA_ORIGIN = "android.speech.extra.ORIGIN"; 193 194 /** 195 * Optional limit on the maximum number of results to return. If omitted the recognizer 196 * will choose how many results to return. Must be an integer. 197 */ 198 public static final String EXTRA_MAX_RESULTS = "android.speech.extra.MAX_RESULTS"; 199 200 /** 201 * Optional boolean, to be used with {@link #ACTION_WEB_SEARCH}, to indicate whether to 202 * only fire web searches in response to a user's speech. The default is false, meaning 203 * that other types of actions can be taken based on the user's speech. 204 */ 205 public static final String EXTRA_WEB_SEARCH_ONLY = "android.speech.extra.WEB_SEARCH_ONLY"; 206 207 /** 208 * Optional boolean to indicate whether partial results should be returned by the recognizer 209 * as the user speaks (default is false). The server may ignore a request for partial 210 * results in some or all cases. 211 */ 212 public static final String EXTRA_PARTIAL_RESULTS = "android.speech.extra.PARTIAL_RESULTS"; 213 214 /** 215 * When the intent is {@link #ACTION_RECOGNIZE_SPEECH}, the speech input activity will 216 * return results to you via the activity results mechanism. Alternatively, if you use this 217 * extra to supply a PendingIntent, the results will be added to its bundle and the 218 * PendingIntent will be sent to its target. 219 */ 220 public static final String EXTRA_RESULTS_PENDINGINTENT = 221 "android.speech.extra.RESULTS_PENDINGINTENT"; 222 223 /** 224 * If you use {@link #EXTRA_RESULTS_PENDINGINTENT} to supply a forwarding intent, you can 225 * also use this extra to supply additional extras for the final intent. The search results 226 * will be added to this bundle, and the combined bundle will be sent to the target. 227 */ 228 public static final String EXTRA_RESULTS_PENDINGINTENT_BUNDLE = 229 "android.speech.extra.RESULTS_PENDINGINTENT_BUNDLE"; 230 231 /** Result code returned when no matches are found for the given speech */ 232 public static final int RESULT_NO_MATCH = Activity.RESULT_FIRST_USER; 233 /** Result code returned when there is a generic client error */ 234 public static final int RESULT_CLIENT_ERROR = Activity.RESULT_FIRST_USER + 1; 235 /** Result code returned when the recognition server returns an error */ 236 public static final int RESULT_SERVER_ERROR = Activity.RESULT_FIRST_USER + 2; 237 /** Result code returned when a network error was encountered */ 238 public static final int RESULT_NETWORK_ERROR = Activity.RESULT_FIRST_USER + 3; 239 /** Result code returned when an audio error was encountered */ 240 public static final int RESULT_AUDIO_ERROR = Activity.RESULT_FIRST_USER + 4; 241 242 /** 243 * An ArrayList<String> of the recognition results when performing 244 * {@link #ACTION_RECOGNIZE_SPEECH}. Generally this list should be ordered in 245 * descending order of speech recognizer confidence. (See {@link #EXTRA_CONFIDENCE_SCORES}). 246 * Returned in the results; not to be specified in the recognition request. Only present 247 * when {@link Activity#RESULT_OK} is returned in an activity result. In a PendingIntent, 248 * the lack of this extra indicates failure. 249 */ 250 public static final String EXTRA_RESULTS = "android.speech.extra.RESULTS"; 251 252 /** 253 * A float array of confidence scores of the recognition results when performing 254 * {@link #ACTION_RECOGNIZE_SPEECH}. The array should be the same size as the ArrayList 255 * returned in {@link #EXTRA_RESULTS}, and should contain values ranging from 0.0 to 1.0, 256 * or -1 to represent an unavailable confidence score. 257 * <p> 258 * Confidence values close to 1.0 indicate high confidence (the speech recognizer is 259 * confident that the recognition result is correct), while values close to 0.0 indicate 260 * low confidence. 261 * <p> 262 * Returned in the results; not to be specified in the recognition request. This extra is 263 * optional and might not be provided. Only present when {@link Activity#RESULT_OK} is 264 * returned in an activity result. 265 */ 266 public static final String EXTRA_CONFIDENCE_SCORES = "android.speech.extra.CONFIDENCE_SCORES"; 267 268 /** 269 * Returns the broadcast intent to fire with 270 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, Bundle)} 271 * to receive details from the package that implements voice search. 272 * <p> 273 * This is based on the value specified by the voice search {@link Activity} in 274 * {@link #DETAILS_META_DATA}, and if this is not specified, will return null. Also if there 275 * is no chosen default to resolve for {@link #ACTION_WEB_SEARCH}, this will return null. 276 * <p> 277 * If an intent is returned and is fired, a {@link Bundle} of extras will be returned to the 278 * provided result receiver, and should ideally contain values for 279 * {@link #EXTRA_LANGUAGE_PREFERENCE} and {@link #EXTRA_SUPPORTED_LANGUAGES}. 280 * <p> 281 * (Whether these are actually provided is up to the particular implementation. It is 282 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 283 * information, but it is not required.) 284 * 285 * @param context a context object 286 * @return the broadcast intent to fire or null if not available 287 */ 288 public static final Intent getVoiceDetailsIntent(Context context) { 289 Intent voiceSearchIntent = new Intent(ACTION_WEB_SEARCH); 290 ResolveInfo ri = context.getPackageManager().resolveActivity( 291 voiceSearchIntent, PackageManager.GET_META_DATA); 292 if (ri == null || ri.activityInfo == null || ri.activityInfo.metaData == null) return null; 293 294 String className = ri.activityInfo.metaData.getString(DETAILS_META_DATA); 295 if (className == null) return null; 296 297 Intent detailsIntent = new Intent(ACTION_GET_LANGUAGE_DETAILS); 298 detailsIntent.setComponent(new ComponentName(ri.activityInfo.packageName, className)); 299 return detailsIntent; 300 } 301 302 /** 303 * Meta-data name under which an {@link Activity} implementing {@link #ACTION_WEB_SEARCH} can 304 * use to expose the class name of a {@link BroadcastReceiver} which can respond to request for 305 * more information, from any of the broadcast intents specified in this class. 306 * <p> 307 * Broadcast intents can be directed to the class name specified in the meta-data by creating 308 * an {@link Intent}, setting the component with 309 * {@link Intent#setComponent(android.content.ComponentName)}, and using 310 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)} 311 * with another {@link BroadcastReceiver} which can receive the results. 312 * <p> 313 * The {@link #getVoiceDetailsIntent(Context)} method is provided as a convenience to create 314 * a broadcast intent based on the value of this meta-data, if available. 315 * <p> 316 * This is optional and not all {@link Activity}s which implement {@link #ACTION_WEB_SEARCH} 317 * are required to implement this. Thus retrieving this meta-data may be null. 318 */ 319 public static final String DETAILS_META_DATA = "android.speech.DETAILS"; 320 321 /** 322 * A broadcast intent which can be fired to the {@link BroadcastReceiver} component specified 323 * in the meta-data defined in the {@link #DETAILS_META_DATA} meta-data of an 324 * {@link Activity} satisfying {@link #ACTION_WEB_SEARCH}. 325 * <p> 326 * When fired with 327 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)}, 328 * a {@link Bundle} of extras will be returned to the provided result receiver, and should 329 * ideally contain values for {@link #EXTRA_LANGUAGE_PREFERENCE} and 330 * {@link #EXTRA_SUPPORTED_LANGUAGES}. 331 * <p> 332 * (Whether these are actually provided is up to the particular implementation. It is 333 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 334 * information, but it is not required.) 335 */ 336 public static final String ACTION_GET_LANGUAGE_DETAILS = 337 "android.speech.action.GET_LANGUAGE_DETAILS"; 338 339 /** 340 * Specify this boolean extra in a broadcast of {@link #ACTION_GET_LANGUAGE_DETAILS} to 341 * indicate that only the current language preference is needed in the response. This 342 * avoids any additional computation if all you need is {@link #EXTRA_LANGUAGE_PREFERENCE} 343 * in the response. 344 */ 345 public static final String EXTRA_ONLY_RETURN_LANGUAGE_PREFERENCE = 346 "android.speech.extra.ONLY_RETURN_LANGUAGE_PREFERENCE"; 347 348 /** 349 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 350 * which is a {@link String} that represents the current language preference this user has 351 * specified - a locale string like "en-US". 352 */ 353 public static final String EXTRA_LANGUAGE_PREFERENCE = 354 "android.speech.extra.LANGUAGE_PREFERENCE"; 355 356 /** 357 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 358 * which is an {@link ArrayList} of {@link String}s that represents the languages supported by 359 * this implementation of voice recognition - a list of strings like "en-US", "cmn-Hans-CN", 360 * etc. 361 */ 362 public static final String EXTRA_SUPPORTED_LANGUAGES = 363 "android.speech.extra.SUPPORTED_LANGUAGES"; 364 } 365
