RecognizerIntent.java revision b30023cabade7aebaf15b70bdbb3d17c32dfc431
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 sends 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, sends it through a 85 * speech recognizer, and invokes and either displays a web search result or triggers 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 * </ul> 109 * 110 * <p>NOTE: There may not be any applications installed to handle this action, so you should 111 * make sure to catch {@link ActivityNotFoundException}. 112 */ 113 public static final String ACTION_WEB_SEARCH = "android.speech.action.WEB_SEARCH"; 114 115 /** 116 * The minimum length of an utterance. We will not stop recording before this amount of time. 117 * 118 * Note that it is extremely rare you'd want to specify this value in an intent. If you don't 119 * have a very good reason to change these, you should leave them as they are. Note also that 120 * certain values may cause undesired or unexpected results - use judiciously! Additionally, 121 * depending on the recognizer implementation, these values may have no effect. 122 */ 123 public static final String EXTRA_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS = 124 "android.speech.extras.SPEECH_INPUT_MINIMUM_LENGTH_MILLIS"; 125 126 /** 127 * The amount of time that it should take after we stop hearing speech to consider the input 128 * complete. 129 * 130 * Note that it is extremely rare you'd want to specify this value in an intent. If 131 * you don't have a very good reason to change these, you should leave them as they are. Note 132 * also that certain values may cause undesired or unexpected results - use judiciously! 133 * Additionally, depending on the recognizer implementation, these values may have no effect. 134 */ 135 public static final String EXTRA_SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS = 136 "android.speech.extras.SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS"; 137 138 /** 139 * The amount of time that it should take after we stop hearing speech to consider the input 140 * possibly complete. This is used to prevent the endpointer cutting off during very short 141 * mid-speech pauses. 142 * 143 * Note that it is extremely rare you'd want to specify this value in an intent. If 144 * you don't have a very good reason to change these, you should leave them as they are. Note 145 * also that certain values may cause undesired or unexpected results - use judiciously! 146 * Additionally, depending on the recognizer implementation, these values may have no effect. 147 */ 148 public static final String EXTRA_SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS = 149 "android.speech.extras.SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS"; 150 151 /** 152 * Informs the recognizer which speech model to prefer when performing 153 * {@link #ACTION_RECOGNIZE_SPEECH}. The recognizer uses this 154 * information to fine tune the results. This extra is required. Activities implementing 155 * {@link #ACTION_RECOGNIZE_SPEECH} may interpret the values as they see fit. 156 * 157 * @see #LANGUAGE_MODEL_FREE_FORM 158 * @see #LANGUAGE_MODEL_WEB_SEARCH 159 */ 160 public static final String EXTRA_LANGUAGE_MODEL = "android.speech.extra.LANGUAGE_MODEL"; 161 162 /** 163 * Use a language model based on free-form speech recognition. This is a value to use for 164 * {@link #EXTRA_LANGUAGE_MODEL}. 165 * @see #EXTRA_LANGUAGE_MODEL 166 */ 167 public static final String LANGUAGE_MODEL_FREE_FORM = "free_form"; 168 /** 169 * Use a language model based on web search terms. This is a value to use for 170 * {@link #EXTRA_LANGUAGE_MODEL}. 171 * @see #EXTRA_LANGUAGE_MODEL 172 */ 173 public static final String LANGUAGE_MODEL_WEB_SEARCH = "web_search"; 174 175 /** Optional text prompt to show to the user when asking them to speak. */ 176 public static final String EXTRA_PROMPT = "android.speech.extra.PROMPT"; 177 178 /** 179 * Optional IETF language tag (as defined by BCP 47), for example "en-US". This tag informs the 180 * recognizer to perform speech recognition in a language different than the one set in the 181 * {@link java.util.Locale#getDefault()}. 182 */ 183 public static final String EXTRA_LANGUAGE = "android.speech.extra.LANGUAGE"; 184 185 /** 186 * Optional limit on the maximum number of results to return. If omitted the recognizer 187 * will choose how many results to return. Must be an integer. 188 */ 189 public static final String EXTRA_MAX_RESULTS = "android.speech.extra.MAX_RESULTS"; 190 191 /** 192 * Optional boolean, to be used with {@link #ACTION_WEB_SEARCH}, to indicate whether to 193 * only fire web searches in response to a user's speech. The default is false, meaning 194 * that other types of actions can be taken based on the user's speech. 195 */ 196 public static final String EXTRA_WEB_SEARCH_ONLY = "android.speech.extra.WEB_SEARCH_ONLY"; 197 198 /** 199 * Optional boolean to indicate whether partial results should be returned by the recognizer 200 * as the user speaks (default is false). The server may ignore a request for partial 201 * results in some or all cases. 202 */ 203 public static final String EXTRA_PARTIAL_RESULTS = "android.speech.extra.PARTIAL_RESULTS"; 204 205 /** 206 * When the intent is {@link #ACTION_RECOGNIZE_SPEECH}, the speech input activity will 207 * return results to you via the activity results mechanism. Alternatively, if you use this 208 * extra to supply a PendingIntent, the results will be added to its bundle and the 209 * PendingIntent will be sent to its target. 210 */ 211 public static final String EXTRA_RESULTS_PENDINGINTENT = 212 "android.speech.extra.RESULTS_PENDINGINTENT"; 213 214 /** 215 * If you use {@link #EXTRA_RESULTS_PENDINGINTENT} to supply a forwarding intent, you can 216 * also use this extra to supply additional extras for the final intent. The search results 217 * will be added to this bundle, and the combined bundle will be sent to the target. 218 */ 219 public static final String EXTRA_RESULTS_PENDINGINTENT_BUNDLE = 220 "android.speech.extra.RESULTS_PENDINGINTENT_BUNDLE"; 221 222 /** Result code returned when no matches are found for the given speech */ 223 public static final int RESULT_NO_MATCH = Activity.RESULT_FIRST_USER; 224 /** Result code returned when there is a generic client error */ 225 public static final int RESULT_CLIENT_ERROR = Activity.RESULT_FIRST_USER + 1; 226 /** Result code returned when the recognition server returns an error */ 227 public static final int RESULT_SERVER_ERROR = Activity.RESULT_FIRST_USER + 2; 228 /** Result code returned when a network error was encountered */ 229 public static final int RESULT_NETWORK_ERROR = Activity.RESULT_FIRST_USER + 3; 230 /** Result code returned when an audio error was encountered */ 231 public static final int RESULT_AUDIO_ERROR = Activity.RESULT_FIRST_USER + 4; 232 233 /** 234 * An ArrayList<String> of the recognition results when performing 235 * {@link #ACTION_RECOGNIZE_SPEECH}. Returned in the results; not to be specified in the 236 * recognition request. Only present when {@link Activity#RESULT_OK} is returned in 237 * an activity result. In a PendingIntent, the lack of this extra indicates failure. 238 */ 239 public static final String EXTRA_RESULTS = "android.speech.extra.RESULTS"; 240 241 /** 242 * Returns the broadcast intent to fire with 243 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, Bundle)} 244 * to receive details from the package that implements voice search. 245 * <p> 246 * This is based on the value specified by the voice search {@link Activity} in 247 * {@link #DETAILS_META_DATA}, and if this is not specified, will return null. Also if there 248 * is no chosen default to resolve for {@link #ACTION_WEB_SEARCH}, this will return null. 249 * <p> 250 * If an intent is returned and is fired, a {@link Bundle} of extras will be returned to the 251 * provided result receiver, and should ideally contain values for 252 * {@link #EXTRA_LANGUAGE_PREFERENCE} and {@link #EXTRA_SUPPORTED_LANGUAGES}. 253 * <p> 254 * (Whether these are actually provided is up to the particular implementation. It is 255 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 256 * information, but it is not required.) 257 * 258 * @param context a context object 259 * @return the broadcast intent to fire or null if not available 260 */ 261 public static final Intent getVoiceDetailsIntent(Context context) { 262 Intent voiceSearchIntent = new Intent(ACTION_WEB_SEARCH); 263 ResolveInfo ri = context.getPackageManager().resolveActivity( 264 voiceSearchIntent, PackageManager.GET_META_DATA); 265 if (ri == null || ri.activityInfo == null || ri.activityInfo.metaData == null) return null; 266 267 String className = ri.activityInfo.metaData.getString(DETAILS_META_DATA); 268 if (className == null) return null; 269 270 Intent detailsIntent = new Intent(ACTION_GET_LANGUAGE_DETAILS); 271 detailsIntent.setComponent(new ComponentName(ri.activityInfo.packageName, className)); 272 return detailsIntent; 273 } 274 275 /** 276 * Meta-data name under which an {@link Activity} implementing {@link #ACTION_WEB_SEARCH} can 277 * use to expose the class name of a {@link BroadcastReceiver} which can respond to request for 278 * more information, from any of the broadcast intents specified in this class. 279 * <p> 280 * Broadcast intents can be directed to the class name specified in the meta-data by creating 281 * an {@link Intent}, setting the component with 282 * {@link Intent#setComponent(android.content.ComponentName)}, and using 283 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)} 284 * with another {@link BroadcastReceiver} which can receive the results. 285 * <p> 286 * The {@link #getVoiceDetailsIntent(Context)} method is provided as a convenience to create 287 * a broadcast intent based on the value of this meta-data, if available. 288 * <p> 289 * This is optional and not all {@link Activity}s which implement {@link #ACTION_WEB_SEARCH} 290 * are required to implement this. Thus retrieving this meta-data may be null. 291 */ 292 public static final String DETAILS_META_DATA = "android.speech.DETAILS"; 293 294 /** 295 * A broadcast intent which can be fired to the {@link BroadcastReceiver} component specified 296 * in the meta-data defined in the {@link #DETAILS_META_DATA} meta-data of an 297 * {@link Activity} satisfying {@link #ACTION_WEB_SEARCH}. 298 * <p> 299 * When fired with 300 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)}, 301 * a {@link Bundle} of extras will be returned to the provided result receiver, and should 302 * ideally contain values for {@link #EXTRA_LANGUAGE_PREFERENCE} and 303 * {@link #EXTRA_SUPPORTED_LANGUAGES}. 304 * <p> 305 * (Whether these are actually provided is up to the particular implementation. It is 306 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 307 * information, but it is not required.) 308 */ 309 public static final String ACTION_GET_LANGUAGE_DETAILS = 310 "android.speech.action.GET_LANGUAGE_DETAILS"; 311 312 /** 313 * Specify this boolean extra in a broadcast of {@link #ACTION_GET_LANGUAGE_DETAILS} to 314 * indicate that only the current language preference is needed in the response. This 315 * avoids any additional computation if all you need is {@link #EXTRA_LANGUAGE_PREFERENCE} 316 * in the response. 317 */ 318 public static final String EXTRA_ONLY_RETURN_LANGUAGE_PREFERENCE = 319 "android.speech.extra.ONLY_RETURN_LANGUAGE_PREFERENCE"; 320 321 /** 322 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 323 * which is a {@link String} that represents the current language preference this user has 324 * specified - a locale string like "en-US". 325 */ 326 public static final String EXTRA_LANGUAGE_PREFERENCE = 327 "android.speech.extra.LANGUAGE_PREFERENCE"; 328 329 /** 330 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 331 * which is an {@link ArrayList} of {@link String}s that represents the languages supported by 332 * this implementation of voice recognition - a list of strings like "en-US", "cmn-Hans-CN", 333 * etc. 334 */ 335 public static final String EXTRA_SUPPORTED_LANGUAGES = 336 "android.speech.extra.SUPPORTED_LANGUAGES"; 337} 338