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 RecognizerIntent()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 displays a web search result. 86 * 87 * <p>Required extras: 88 * <ul> 89 * <li>{@link #EXTRA_LANGUAGE_MODEL} 90 * </ul> 91 * 92 * <p>Optional extras: 93 * <ul> 94 * <li>{@link #EXTRA_PROMPT} 95 * <li>{@link #EXTRA_LANGUAGE} 96 * <li>{@link #EXTRA_MAX_RESULTS} 97 * <li>{@link #EXTRA_PARTIAL_RESULTS} 98 * </ul> 99 * 100 * <p> Result extras (returned in the result, not to be specified in the request): 101 * <ul> 102 * <li>{@link #EXTRA_RESULTS} 103 * </ul> 104 * 105 * <p>NOTE: There may not be any applications installed to handle this action, so you should 106 * make sure to catch {@link ActivityNotFoundException}. 107 */ 108 public static final String ACTION_WEB_SEARCH = "android.speech.action.WEB_SEARCH"; 109 110 /** 111 * The minimum length of an utterance. We will not stop recording before this amount of time. 112 * 113 * Note that it is extremely rare you'd want to specify this value in an intent. If you don't 114 * have a very good reason to change these, you should leave them as they are. Note also that 115 * certain values may cause undesired or unexpected results - use judiciously! Additionally, 116 * depending on the recognizer implementation, these values may have no effect. 117 */ 118 public static final String EXTRA_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS = 119 "android.speech.extras.SPEECH_INPUT_MINIMUM_LENGTH_MILLIS"; 120 121 /** 122 * The amount of time that it should take after we stop hearing speech to consider the input 123 * complete. 124 * 125 * Note that it is extremely rare you'd want to specify this value in an intent. If 126 * you don't have a very good reason to change these, you should leave them as they are. Note 127 * also that certain values may cause undesired or unexpected results - use judiciously! 128 * Additionally, depending on the recognizer implementation, these values may have no effect. 129 */ 130 public static final String EXTRA_SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS = 131 "android.speech.extras.SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS"; 132 133 /** 134 * The amount of time that it should take after we stop hearing speech to consider the input 135 * possibly complete. This is used to prevent the endpointer cutting off during very short 136 * mid-speech pauses. 137 * 138 * Note that it is extremely rare you'd want to specify this value in an intent. If 139 * you don't have a very good reason to change these, you should leave them as they are. Note 140 * also that certain values may cause undesired or unexpected results - use judiciously! 141 * Additionally, depending on the recognizer implementation, these values may have no effect. 142 */ 143 public static final String EXTRA_SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS = 144 "android.speech.extras.SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS"; 145 146 /** 147 * Informs the recognizer which speech model to prefer when performing 148 * {@link #ACTION_RECOGNIZE_SPEECH}. The recognizer uses this 149 * information to fine tune the results. This extra is required. Activities implementing 150 * {@link #ACTION_RECOGNIZE_SPEECH} may interpret the values as they see fit. 151 * 152 * @see #LANGUAGE_MODEL_FREE_FORM 153 * @see #LANGUAGE_MODEL_WEB_SEARCH 154 */ 155 public static final String EXTRA_LANGUAGE_MODEL = "android.speech.extra.LANGUAGE_MODEL"; 156 157 /** 158 * Use a language model based on free-form speech recognition. This is a value to use for 159 * {@link #EXTRA_LANGUAGE_MODEL}. 160 * @see #EXTRA_LANGUAGE_MODEL 161 */ 162 public static final String LANGUAGE_MODEL_FREE_FORM = "free_form"; 163 /** 164 * Use a language model based on web search terms. 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_WEB_SEARCH = "web_search"; 169 170 /** Optional text prompt to show to the user when asking them to speak. */ 171 public static final String EXTRA_PROMPT = "android.speech.extra.PROMPT"; 172 173 /** 174 * Optional IETF language tag (as defined by BCP 47), for example "en-US". This tag informs the 175 * recognizer to perform speech recognition in a language different than the one set in the 176 * {@link java.util.Locale#getDefault()}. 177 */ 178 public static final String EXTRA_LANGUAGE = "android.speech.extra.LANGUAGE"; 179 180 /** 181 * Optional limit on the maximum number of results to return. If omitted the recognizer 182 * will choose how many results to return. Must be an integer. 183 */ 184 public static final String EXTRA_MAX_RESULTS = "android.speech.extra.MAX_RESULTS"; 185 186 /** 187 * Optional boolean to indicate whether partial results should be returned by the recognizer 188 * as the user speaks (default is false). The server may ignore a request for partial 189 * results in some or all cases. 190 */ 191 public static final String EXTRA_PARTIAL_RESULTS = "android.speech.extra.PARTIAL_RESULTS"; 192 193 /** 194 * When the intent is {@link #ACTION_RECOGNIZE_SPEECH}, the speech input activity will 195 * return results to you via the activity results mechanism. Alternatively, if you use this 196 * extra to supply a PendingIntent, the results will be added to its bundle and the 197 * PendingIntent will be sent to its target. 198 */ 199 public static final String EXTRA_RESULTS_PENDINGINTENT = 200 "android.speech.extra.RESULTS_PENDINGINTENT"; 201 202 /** 203 * If you use {@link #EXTRA_RESULTS_PENDINGINTENT} to supply a forwarding intent, you can 204 * also use this extra to supply additional extras for the final intent. The search results 205 * will be added to this bundle, and the combined bundle will be sent to the target. 206 */ 207 public static final String EXTRA_RESULTS_PENDINGINTENT_BUNDLE = 208 "android.speech.extra.RESULTS_PENDINGINTENT_BUNDLE"; 209 210 /** Result code returned when no matches are found for the given speech */ 211 public static final int RESULT_NO_MATCH = Activity.RESULT_FIRST_USER; 212 /** Result code returned when there is a generic client error */ 213 public static final int RESULT_CLIENT_ERROR = Activity.RESULT_FIRST_USER + 1; 214 /** Result code returned when the recognition server returns an error */ 215 public static final int RESULT_SERVER_ERROR = Activity.RESULT_FIRST_USER + 2; 216 /** Result code returned when a network error was encountered */ 217 public static final int RESULT_NETWORK_ERROR = Activity.RESULT_FIRST_USER + 3; 218 /** Result code returned when an audio error was encountered */ 219 public static final int RESULT_AUDIO_ERROR = Activity.RESULT_FIRST_USER + 4; 220 221 /** 222 * An ArrayList<String> of the recognition results when performing 223 * {@link #ACTION_RECOGNIZE_SPEECH}. Returned in the results; not to be specified in the 224 * recognition request. Only present when {@link Activity#RESULT_OK} is returned in 225 * an activity result. In a PendingIntent, the lack of this extra indicates failure. 226 */ 227 public static final String EXTRA_RESULTS = "android.speech.extra.RESULTS"; 228 229 /** 230 * Returns the broadcast intent to fire with 231 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, Bundle)} 232 * to receive details from the package that implements voice search. 233 * <p> 234 * This is based on the value specified by the voice search {@link Activity} in 235 * {@link #DETAILS_META_DATA}, and if this is not specified, will return null. Also if there 236 * is no chosen default to resolve for {@link #ACTION_WEB_SEARCH}, this will return null. 237 * <p> 238 * If an intent is returned and is fired, a {@link Bundle} of extras will be returned to the 239 * provided result receiver, and should ideally contain values for 240 * {@link #EXTRA_LANGUAGE_PREFERENCE} and {@link #EXTRA_SUPPORTED_LANGUAGES}. 241 * <p> 242 * (Whether these are actually provided is up to the particular implementation. It is 243 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 244 * information, but it is not required.) 245 * 246 * @param context a context object 247 * @return the broadcast intent to fire or null if not available 248 */ getVoiceDetailsIntent(Context context)249 public static final Intent getVoiceDetailsIntent(Context context) { 250 Intent voiceSearchIntent = new Intent(ACTION_WEB_SEARCH); 251 ResolveInfo ri = context.getPackageManager().resolveActivity( 252 voiceSearchIntent, PackageManager.GET_META_DATA); 253 if (ri == null || ri.activityInfo == null || ri.activityInfo.metaData == null) return null; 254 255 String className = ri.activityInfo.metaData.getString(DETAILS_META_DATA); 256 if (className == null) return null; 257 258 Intent detailsIntent = new Intent(ACTION_GET_LANGUAGE_DETAILS); 259 detailsIntent.setComponent(new ComponentName(ri.activityInfo.packageName, className)); 260 return detailsIntent; 261 } 262 263 /** 264 * Meta-data name under which an {@link Activity} implementing {@link #ACTION_WEB_SEARCH} can 265 * use to expose the class name of a {@link BroadcastReceiver} which can respond to request for 266 * more information, from any of the broadcast intents specified in this class. 267 * <p> 268 * Broadcast intents can be directed to the class name specified in the meta-data by creating 269 * an {@link Intent}, setting the component with 270 * {@link Intent#setComponent(android.content.ComponentName)}, and using 271 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)} 272 * with another {@link BroadcastReceiver} which can receive the results. 273 * <p> 274 * The {@link #getVoiceDetailsIntent(Context)} method is provided as a convenience to create 275 * a broadcast intent based on the value of this meta-data, if available. 276 * <p> 277 * This is optional and not all {@link Activity}s which implement {@link #ACTION_WEB_SEARCH} 278 * are required to implement this. Thus retrieving this meta-data may be null. 279 */ 280 public static final String DETAILS_META_DATA = "android.speech.DETAILS"; 281 282 /** 283 * A broadcast intent which can be fired to the {@link BroadcastReceiver} component specified 284 * in the meta-data defined in the {@link #DETAILS_META_DATA} meta-data of an 285 * {@link Activity} satisfying {@link #ACTION_WEB_SEARCH}. 286 * <p> 287 * When fired with 288 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)}, 289 * a {@link Bundle} of extras will be returned to the provided result receiver, and should 290 * ideally contain values for {@link #EXTRA_LANGUAGE_PREFERENCE} and 291 * {@link #EXTRA_SUPPORTED_LANGUAGES}. 292 * <p> 293 * (Whether these are actually provided is up to the particular implementation. It is 294 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 295 * information, but it is not required.) 296 */ 297 public static final String ACTION_GET_LANGUAGE_DETAILS = 298 "android.speech.action.GET_LANGUAGE_DETAILS"; 299 300 /** 301 * Specify this boolean extra in a broadcast of {@link #ACTION_GET_LANGUAGE_DETAILS} to 302 * indicate that only the current language preference is needed in the response. This 303 * avoids any additional computation if all you need is {@link #EXTRA_LANGUAGE_PREFERENCE} 304 * in the response. 305 */ 306 public static final String EXTRA_ONLY_RETURN_LANGUAGE_PREFERENCE = 307 "android.speech.extra.ONLY_RETURN_LANGUAGE_PREFERENCE"; 308 309 /** 310 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 311 * which is a {@link String} that represents the current language preference this user has 312 * specified - a locale string like "en-US". 313 */ 314 public static final String EXTRA_LANGUAGE_PREFERENCE = 315 "android.speech.extra.LANGUAGE_PREFERENCE"; 316 317 /** 318 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 319 * which is an {@link ArrayList} of {@link String}s that represents the languages supported by 320 * this implementation of voice recognition - a list of strings like "en-US", "cmn-Hans-CN", 321 * etc. 322 */ 323 public static final String EXTRA_SUPPORTED_LANGUAGES = 324 "android.speech.extra.SUPPORTED_LANGUAGES"; 325 } 326