RecognizerIntent.java revision bb7cf916b23c78dc640f8bdfb7ad5cd6b09c3636
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 17package android.speech; 18 19import java.util.ArrayList; 20 21import android.app.Activity; 22import android.content.ActivityNotFoundException; 23import android.content.BroadcastReceiver; 24import android.content.ComponentName; 25import android.content.Context; 26import android.content.Intent; 27import android.content.pm.PackageManager; 28import android.content.pm.ResolveInfo; 29import android.os.Bundle; 30 31/** 32 * Constants for supporting speech recognition through starting an {@link Intent} 33 */ 34public 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 * </ul> 104 * 105 * <p> Result extras (returned in the result, not to be specified in the request): 106 * <ul> 107 * <li>{@link #EXTRA_RESULTS} 108 * <li>{@link #EXTRA_CONFIDENCE_SCORES} (optional) 109 * </ul> 110 * 111 * <p>NOTE: There may not be any applications installed to handle this action, so you should 112 * make sure to catch {@link ActivityNotFoundException}. 113 */ 114 public static final String ACTION_WEB_SEARCH = "android.speech.action.WEB_SEARCH"; 115 116 /** 117 * The minimum length of an utterance. We will not stop recording before this amount of time. 118 * 119 * Note that it is extremely rare you'd want to specify this value in an intent. If you don't 120 * have a very good reason to change these, you should leave them as they are. Note also that 121 * certain values may cause undesired or unexpected results - use judiciously! Additionally, 122 * depending on the recognizer implementation, these values may have no effect. 123 */ 124 public static final String EXTRA_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS = 125 "android.speech.extras.SPEECH_INPUT_MINIMUM_LENGTH_MILLIS"; 126 127 /** 128 * The amount of time that it should take after we stop hearing speech to consider the input 129 * complete. 130 * 131 * Note that it is extremely rare you'd want to specify this value in an intent. If 132 * you don't have a very good reason to change these, you should leave them as they are. Note 133 * also that certain values may cause undesired or unexpected results - use judiciously! 134 * Additionally, depending on the recognizer implementation, these values may have no effect. 135 */ 136 public static final String EXTRA_SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS = 137 "android.speech.extras.SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS"; 138 139 /** 140 * The amount of time that it should take after we stop hearing speech to consider the input 141 * possibly complete. This is used to prevent the endpointer cutting off during very short 142 * mid-speech pauses. 143 * 144 * Note that it is extremely rare you'd want to specify this value in an intent. If 145 * you don't have a very good reason to change these, you should leave them as they are. Note 146 * also that certain values may cause undesired or unexpected results - use judiciously! 147 * Additionally, depending on the recognizer implementation, these values may have no effect. 148 */ 149 public static final String EXTRA_SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS = 150 "android.speech.extras.SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS"; 151 152 /** 153 * Informs the recognizer which speech model to prefer when performing 154 * {@link #ACTION_RECOGNIZE_SPEECH}. The recognizer uses this 155 * information to fine tune the results. This extra is required. Activities implementing 156 * {@link #ACTION_RECOGNIZE_SPEECH} may interpret the values as they see fit. 157 * 158 * @see #LANGUAGE_MODEL_FREE_FORM 159 * @see #LANGUAGE_MODEL_WEB_SEARCH 160 */ 161 public static final String EXTRA_LANGUAGE_MODEL = "android.speech.extra.LANGUAGE_MODEL"; 162 163 /** 164 * Use a language model based on free-form speech recognition. This is a value to use for 165 * {@link #EXTRA_LANGUAGE_MODEL}. 166 * @see #EXTRA_LANGUAGE_MODEL 167 */ 168 public static final String LANGUAGE_MODEL_FREE_FORM = "free_form"; 169 /** 170 * Use a language model based on web search terms. This is a value to use for 171 * {@link #EXTRA_LANGUAGE_MODEL}. 172 * @see #EXTRA_LANGUAGE_MODEL 173 */ 174 public static final String LANGUAGE_MODEL_WEB_SEARCH = "web_search"; 175 176 /** Optional text prompt to show to the user when asking them to speak. */ 177 public static final String EXTRA_PROMPT = "android.speech.extra.PROMPT"; 178 179 /** 180 * Optional IETF language tag (as defined by BCP 47), for example "en-US". This tag informs the 181 * recognizer to perform speech recognition in a language different than the one set in the 182 * {@link java.util.Locale#getDefault()}. 183 */ 184 public static final String EXTRA_LANGUAGE = "android.speech.extra.LANGUAGE"; 185 186 /** 187 * Optional limit on the maximum number of results to return. If omitted the recognizer 188 * will choose how many results to return. Must be an integer. 189 */ 190 public static final String EXTRA_MAX_RESULTS = "android.speech.extra.MAX_RESULTS"; 191 192 /** 193 * Optional boolean, to be used with {@link #ACTION_WEB_SEARCH}, to indicate whether to 194 * only fire web searches in response to a user's speech. The default is false, meaning 195 * that other types of actions can be taken based on the user's speech. 196 */ 197 public static final String EXTRA_WEB_SEARCH_ONLY = "android.speech.extra.WEB_SEARCH_ONLY"; 198 199 /** 200 * Optional boolean to indicate whether partial results should be returned by the recognizer 201 * as the user speaks (default is false). The server may ignore a request for partial 202 * results in some or all cases. 203 */ 204 public static final String EXTRA_PARTIAL_RESULTS = "android.speech.extra.PARTIAL_RESULTS"; 205 206 /** 207 * When the intent is {@link #ACTION_RECOGNIZE_SPEECH}, the speech input activity will 208 * return results to you via the activity results mechanism. Alternatively, if you use this 209 * extra to supply a PendingIntent, the results will be added to its bundle and the 210 * PendingIntent will be sent to its target. 211 */ 212 public static final String EXTRA_RESULTS_PENDINGINTENT = 213 "android.speech.extra.RESULTS_PENDINGINTENT"; 214 215 /** 216 * If you use {@link #EXTRA_RESULTS_PENDINGINTENT} to supply a forwarding intent, you can 217 * also use this extra to supply additional extras for the final intent. The search results 218 * will be added to this bundle, and the combined bundle will be sent to the target. 219 */ 220 public static final String EXTRA_RESULTS_PENDINGINTENT_BUNDLE = 221 "android.speech.extra.RESULTS_PENDINGINTENT_BUNDLE"; 222 223 /** Result code returned when no matches are found for the given speech */ 224 public static final int RESULT_NO_MATCH = Activity.RESULT_FIRST_USER; 225 /** Result code returned when there is a generic client error */ 226 public static final int RESULT_CLIENT_ERROR = Activity.RESULT_FIRST_USER + 1; 227 /** Result code returned when the recognition server returns an error */ 228 public static final int RESULT_SERVER_ERROR = Activity.RESULT_FIRST_USER + 2; 229 /** Result code returned when a network error was encountered */ 230 public static final int RESULT_NETWORK_ERROR = Activity.RESULT_FIRST_USER + 3; 231 /** Result code returned when an audio error was encountered */ 232 public static final int RESULT_AUDIO_ERROR = Activity.RESULT_FIRST_USER + 4; 233 234 /** 235 * An ArrayList<String> of the recognition results when performing 236 * {@link #ACTION_RECOGNIZE_SPEECH}. Generally this list should be ordered in 237 * descending order of speech recognizer confidence. (See {@link #EXTRA_CONFIDENCE_SCORES}). 238 * Returned in the results; not to be specified in the recognition request. Only present 239 * when {@link Activity#RESULT_OK} is returned in an activity result. In a PendingIntent, 240 * the lack of this extra indicates failure. 241 */ 242 public static final String EXTRA_RESULTS = "android.speech.extra.RESULTS"; 243 244 /** 245 * A float array of confidence scores of the recognition results when performing 246 * {@link #ACTION_RECOGNIZE_SPEECH}. The array should be the same size as the ArrayList 247 * returned in {@link #EXTRA_RESULTS}, and should contain values ranging from 0.0 to 1.0, 248 * or -1 to represent an unavailable confidence score. 249 * <p> 250 * Confidence values close to 1.0 indicate high confidence (the speech recognizer is 251 * confident that the recognition result is correct), while values close to 0.0 indicate 252 * low confidence. 253 * <p> 254 * Returned in the results; not to be specified in the recognition request. This extra is 255 * optional and might not be provided. Only present when {@link Activity#RESULT_OK} is 256 * returned in an activity result. 257 */ 258 public static final String EXTRA_CONFIDENCE_SCORES = "android.speech.extra.CONFIDENCE_SCORES"; 259 260 /** 261 * Returns the broadcast intent to fire with 262 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, Bundle)} 263 * to receive details from the package that implements voice search. 264 * <p> 265 * This is based on the value specified by the voice search {@link Activity} in 266 * {@link #DETAILS_META_DATA}, and if this is not specified, will return null. Also if there 267 * is no chosen default to resolve for {@link #ACTION_WEB_SEARCH}, this will return null. 268 * <p> 269 * If an intent is returned and is fired, a {@link Bundle} of extras will be returned to the 270 * provided result receiver, and should ideally contain values for 271 * {@link #EXTRA_LANGUAGE_PREFERENCE} and {@link #EXTRA_SUPPORTED_LANGUAGES}. 272 * <p> 273 * (Whether these are actually provided is up to the particular implementation. It is 274 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 275 * information, but it is not required.) 276 * 277 * @param context a context object 278 * @return the broadcast intent to fire or null if not available 279 */ 280 public static final Intent getVoiceDetailsIntent(Context context) { 281 Intent voiceSearchIntent = new Intent(ACTION_WEB_SEARCH); 282 ResolveInfo ri = context.getPackageManager().resolveActivity( 283 voiceSearchIntent, PackageManager.GET_META_DATA); 284 if (ri == null || ri.activityInfo == null || ri.activityInfo.metaData == null) return null; 285 286 String className = ri.activityInfo.metaData.getString(DETAILS_META_DATA); 287 if (className == null) return null; 288 289 Intent detailsIntent = new Intent(ACTION_GET_LANGUAGE_DETAILS); 290 detailsIntent.setComponent(new ComponentName(ri.activityInfo.packageName, className)); 291 return detailsIntent; 292 } 293 294 /** 295 * Meta-data name under which an {@link Activity} implementing {@link #ACTION_WEB_SEARCH} can 296 * use to expose the class name of a {@link BroadcastReceiver} which can respond to request for 297 * more information, from any of the broadcast intents specified in this class. 298 * <p> 299 * Broadcast intents can be directed to the class name specified in the meta-data by creating 300 * an {@link Intent}, setting the component with 301 * {@link Intent#setComponent(android.content.ComponentName)}, and using 302 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)} 303 * with another {@link BroadcastReceiver} which can receive the results. 304 * <p> 305 * The {@link #getVoiceDetailsIntent(Context)} method is provided as a convenience to create 306 * a broadcast intent based on the value of this meta-data, if available. 307 * <p> 308 * This is optional and not all {@link Activity}s which implement {@link #ACTION_WEB_SEARCH} 309 * are required to implement this. Thus retrieving this meta-data may be null. 310 */ 311 public static final String DETAILS_META_DATA = "android.speech.DETAILS"; 312 313 /** 314 * A broadcast intent which can be fired to the {@link BroadcastReceiver} component specified 315 * in the meta-data defined in the {@link #DETAILS_META_DATA} meta-data of an 316 * {@link Activity} satisfying {@link #ACTION_WEB_SEARCH}. 317 * <p> 318 * When fired with 319 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)}, 320 * a {@link Bundle} of extras will be returned to the provided result receiver, and should 321 * ideally contain values for {@link #EXTRA_LANGUAGE_PREFERENCE} and 322 * {@link #EXTRA_SUPPORTED_LANGUAGES}. 323 * <p> 324 * (Whether these are actually provided is up to the particular implementation. It is 325 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 326 * information, but it is not required.) 327 */ 328 public static final String ACTION_GET_LANGUAGE_DETAILS = 329 "android.speech.action.GET_LANGUAGE_DETAILS"; 330 331 /** 332 * Specify this boolean extra in a broadcast of {@link #ACTION_GET_LANGUAGE_DETAILS} to 333 * indicate that only the current language preference is needed in the response. This 334 * avoids any additional computation if all you need is {@link #EXTRA_LANGUAGE_PREFERENCE} 335 * in the response. 336 */ 337 public static final String EXTRA_ONLY_RETURN_LANGUAGE_PREFERENCE = 338 "android.speech.extra.ONLY_RETURN_LANGUAGE_PREFERENCE"; 339 340 /** 341 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 342 * which is a {@link String} that represents the current language preference this user has 343 * specified - a locale string like "en-US". 344 */ 345 public static final String EXTRA_LANGUAGE_PREFERENCE = 346 "android.speech.extra.LANGUAGE_PREFERENCE"; 347 348 /** 349 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 350 * which is an {@link ArrayList} of {@link String}s that represents the languages supported by 351 * this implementation of voice recognition - a list of strings like "en-US", "cmn-Hans-CN", 352 * etc. 353 */ 354 public static final String EXTRA_SUPPORTED_LANGUAGES = 355 "android.speech.extra.SUPPORTED_LANGUAGES"; 356} 357