RecognizerIntent.java revision 79375f761922b208e2e50ff13a63552c9d01567b
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 private RecognizerIntent() { 36 // Not for instantiating. 37 } 38 39 /** 40 * Starts an activity that will prompt the user for speech and sends it through a 41 * speech recognizer. The results will be returned via activity results (in 42 * {@link Activity#onActivityResult}, if you start the intent using 43 * {@link Activity#startActivityForResult(Intent, int)}), or forwarded via a PendingIntent 44 * if one is provided. 45 * 46 * <p>Starting this intent with just {@link Activity#startActivity(Intent)} is not supported. 47 * You must either use {@link Activity#startActivityForResult(Intent, int)}, or provide a 48 * PendingIntent, to receive recognition results. 49 * 50 * <p>Required extras: 51 * <ul> 52 * <li>{@link #EXTRA_LANGUAGE_MODEL} 53 * </ul> 54 * 55 * <p>Optional extras: 56 * <ul> 57 * <li>{@link #EXTRA_PROMPT} 58 * <li>{@link #EXTRA_LANGUAGE} 59 * <li>{@link #EXTRA_MAX_RESULTS} 60 * <li>{@link #EXTRA_RESULTS_PENDINGINTENT} 61 * <li>{@link #EXTRA_RESULTS_PENDINGINTENT_BUNDLE} 62 * </ul> 63 * 64 * <p> Result extras (returned in the result, not to be specified in the request): 65 * <ul> 66 * <li>{@link #EXTRA_RESULTS} 67 * </ul> 68 * 69 * <p>NOTE: There may not be any applications installed to handle this action, so you should 70 * make sure to catch {@link ActivityNotFoundException}. 71 */ 72 public static final String ACTION_RECOGNIZE_SPEECH = "android.speech.action.RECOGNIZE_SPEECH"; 73 74 /** 75 * Starts an activity that will prompt the user for speech, sends it through a 76 * speech recognizer, and invokes and displays a web search result. 77 * 78 * <p>Required extras: 79 * <ul> 80 * <li>{@link #EXTRA_LANGUAGE_MODEL} 81 * </ul> 82 * 83 * <p>Optional extras: 84 * <ul> 85 * <li>{@link #EXTRA_PROMPT} 86 * <li>{@link #EXTRA_LANGUAGE} 87 * <li>{@link #EXTRA_MAX_RESULTS} 88 * <li>{@link #EXTRA_PARTIAL_RESULTS} 89 * </ul> 90 * 91 * <p> Result extras (returned in the result, not to be specified in the request): 92 * <ul> 93 * <li>{@link #EXTRA_RESULTS} 94 * </ul> 95 * 96 * <p>NOTE: There may not be any applications installed to handle this action, so you should 97 * make sure to catch {@link ActivityNotFoundException}. 98 */ 99 public static final String ACTION_WEB_SEARCH = "android.speech.action.WEB_SEARCH"; 100 101 /** 102 * The minimum length of an utterance. We will not stop recording before this amount of time. 103 * 104 * Note that it is extremely rare you'd want to specify this value in an intent. If you don't 105 * have a very good reason to change these, you should leave them as they are. Note also that 106 * certain values may cause undesired or unexpected results - use judiciously! Additionally, 107 * depending on the recognizer implementation, these values may have no effect. 108 */ 109 public static final String EXTRA_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS = 110 "android.speech.extras.SPEECH_INPUT_MINIMUM_LENGTH_MILLIS"; 111 112 /** 113 * The amount of time that it should take after we stop hearing speech to consider the input 114 * complete. 115 * 116 * Note that it is extremely rare you'd want to specify this value in an intent. If 117 * you don't have a very good reason to change these, you should leave them as they are. Note 118 * also that certain values may cause undesired or unexpected results - use judiciously! 119 * Additionally, depending on the recognizer implementation, these values may have no effect. 120 */ 121 public static final String EXTRA_SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS = 122 "android.speech.extras.SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS"; 123 124 /** 125 * The amount of time that it should take after we stop hearing speech to consider the input 126 * possibly complete. This is used to prevent the endpointer cutting off during very short 127 * mid-speech pauses. 128 * 129 * Note that it is extremely rare you'd want to specify this value in an intent. If 130 * you don't have a very good reason to change these, you should leave them as they are. Note 131 * also that certain values may cause undesired or unexpected results - use judiciously! 132 * Additionally, depending on the recognizer implementation, these values may have no effect. 133 */ 134 public static final String EXTRA_SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS = 135 "android.speech.extras.SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS"; 136 137 /** 138 * Informs the recognizer which speech model to prefer when performing 139 * {@link #ACTION_RECOGNIZE_SPEECH}. The recognizer uses this 140 * information to fine tune the results. This extra is required. Activities implementing 141 * {@link #ACTION_RECOGNIZE_SPEECH} may interpret the values as they see fit. 142 * 143 * @see #LANGUAGE_MODEL_FREE_FORM 144 * @see #LANGUAGE_MODEL_WEB_SEARCH 145 */ 146 public static final String EXTRA_LANGUAGE_MODEL = "android.speech.extra.LANGUAGE_MODEL"; 147 148 /** 149 * Use a language model based on free-form speech recognition. This is a value to use for 150 * {@link #EXTRA_LANGUAGE_MODEL}. 151 * @see #EXTRA_LANGUAGE_MODEL 152 */ 153 public static final String LANGUAGE_MODEL_FREE_FORM = "free_form"; 154 /** 155 * Use a language model based on web search terms. This is a value to use for 156 * {@link #EXTRA_LANGUAGE_MODEL}. 157 * @see #EXTRA_LANGUAGE_MODEL 158 */ 159 public static final String LANGUAGE_MODEL_WEB_SEARCH = "web_search"; 160 161 /** Optional text prompt to show to the user when asking them to speak. */ 162 public static final String EXTRA_PROMPT = "android.speech.extra.PROMPT"; 163 164 /** 165 * Optional IETF language tag (as defined by BCP 47), for example "en-US". This tag informs the 166 * recognizer to perform speech recognition in a language different than the one set in the 167 * {@link java.util.Locale#getDefault()}. 168 */ 169 public static final String EXTRA_LANGUAGE = "android.speech.extra.LANGUAGE"; 170 171 /** 172 * Optional limit on the maximum number of results to return. If omitted the recognizer 173 * will choose how many results to return. Must be an integer. 174 */ 175 public static final String EXTRA_MAX_RESULTS = "android.speech.extra.MAX_RESULTS"; 176 177 /** 178 * Optional boolean to indicate whether partial results should be returned by the recognizer 179 * as the user speaks (default is false). The server may ignore a request for partial 180 * results in some or all cases. 181 */ 182 public static final String EXTRA_PARTIAL_RESULTS = "android.speech.extra.PARTIAL_RESULTS"; 183 184 /** 185 * When the intent is {@link #ACTION_RECOGNIZE_SPEECH}, the speech input activity will 186 * return results to you via the activity results mechanism. Alternatively, if you use this 187 * extra to supply a PendingIntent, the results will be added to its bundle and the 188 * PendingIntent will be sent to its target. 189 */ 190 public static final String EXTRA_RESULTS_PENDINGINTENT = 191 "android.speech.extra.RESULTS_PENDINGINTENT"; 192 193 /** 194 * If you use {@link #EXTRA_RESULTS_PENDINGINTENT} to supply a forwarding intent, you can 195 * also use this extra to supply additional extras for the final intent. The search results 196 * will be added to this bundle, and the combined bundle will be sent to the target. 197 */ 198 public static final String EXTRA_RESULTS_PENDINGINTENT_BUNDLE = 199 "android.speech.extra.RESULTS_PENDINGINTENT_BUNDLE"; 200 201 /** Result code returned when no matches are found for the given speech */ 202 public static final int RESULT_NO_MATCH = Activity.RESULT_FIRST_USER; 203 /** Result code returned when there is a generic client error */ 204 public static final int RESULT_CLIENT_ERROR = Activity.RESULT_FIRST_USER + 1; 205 /** Result code returned when the recognition server returns an error */ 206 public static final int RESULT_SERVER_ERROR = Activity.RESULT_FIRST_USER + 2; 207 /** Result code returned when a network error was encountered */ 208 public static final int RESULT_NETWORK_ERROR = Activity.RESULT_FIRST_USER + 3; 209 /** Result code returned when an audio error was encountered */ 210 public static final int RESULT_AUDIO_ERROR = Activity.RESULT_FIRST_USER + 4; 211 212 /** 213 * An ArrayList<String> of the recognition results when performing 214 * {@link #ACTION_RECOGNIZE_SPEECH}. Returned in the results; not to be specified in the 215 * recognition request. Only present when {@link Activity#RESULT_OK} is returned in 216 * an activity result. In a PendingIntent, the lack of this extra indicates failure. 217 */ 218 public static final String EXTRA_RESULTS = "android.speech.extra.RESULTS"; 219 220 /** 221 * Returns the broadcast intent to fire with 222 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, Bundle)} 223 * to receive details from the package that implements voice search. 224 * <p> 225 * This is based on the value specified by the voice search {@link Activity} in 226 * {@link #DETAILS_META_DATA}, and if this is not specified, will return null. Also if there 227 * is no chosen default to resolve for {@link #ACTION_WEB_SEARCH}, this will return null. 228 * <p> 229 * If an intent is returned and is fired, a {@link Bundle} of extras will be returned to the 230 * provided result receiver, and should ideally contain values for 231 * {@link #EXTRA_LANGUAGE_PREFERENCE} and {@link #EXTRA_SUPPORTED_LANGUAGES}. 232 * <p> 233 * (Whether these are actually provided is up to the particular implementation. It is 234 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 235 * information, but it is not required.) 236 * 237 * @param context a context object 238 * @return the broadcast intent to fire or null if not available 239 */ 240 public static final Intent getVoiceDetailsIntent(Context context) { 241 Intent voiceSearchIntent = new Intent(ACTION_WEB_SEARCH); 242 ResolveInfo ri = context.getPackageManager().resolveActivity( 243 voiceSearchIntent, PackageManager.GET_META_DATA); 244 if (ri == null || ri.activityInfo == null || ri.activityInfo.metaData == null) return null; 245 246 String className = ri.activityInfo.metaData.getString(DETAILS_META_DATA); 247 if (className == null) return null; 248 249 Intent detailsIntent = new Intent(ACTION_GET_LANGUAGE_DETAILS); 250 detailsIntent.setComponent(new ComponentName(ri.activityInfo.packageName, className)); 251 return detailsIntent; 252 } 253 254 /** 255 * Meta-data name under which an {@link Activity} implementing {@link #ACTION_WEB_SEARCH} can 256 * use to expose the class name of a {@link BroadcastReceiver} which can respond to request for 257 * more information, from any of the broadcast intents specified in this class. 258 * <p> 259 * Broadcast intents can be directed to the class name specified in the meta-data by creating 260 * an {@link Intent}, setting the component with 261 * {@link Intent#setComponent(android.content.ComponentName)}, and using 262 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)} 263 * with another {@link BroadcastReceiver} which can receive the results. 264 * <p> 265 * The {@link #getVoiceDetailsIntent(Context)} method is provided as a convenience to create 266 * a broadcast intent based on the value of this meta-data, if available. 267 * <p> 268 * This is optional and not all {@link Activity}s which implement {@link #ACTION_WEB_SEARCH} 269 * are required to implement this. Thus retrieving this meta-data may be null. 270 */ 271 public static final String DETAILS_META_DATA = "android.speech.DETAILS"; 272 273 /** 274 * A broadcast intent which can be fired to the {@link BroadcastReceiver} component specified 275 * in the meta-data defined in the {@link #DETAILS_META_DATA} meta-data of an 276 * {@link Activity} satisfying {@link #ACTION_WEB_SEARCH}. 277 * <p> 278 * When fired with 279 * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)}, 280 * a {@link Bundle} of extras will be returned to the provided result receiver, and should 281 * ideally contain values for {@link #EXTRA_LANGUAGE_PREFERENCE} and 282 * {@link #EXTRA_SUPPORTED_LANGUAGES}. 283 * <p> 284 * (Whether these are actually provided is up to the particular implementation. It is 285 * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this 286 * information, but it is not required.) 287 */ 288 public static final String ACTION_GET_LANGUAGE_DETAILS = 289 "android.speech.action.GET_LANGUAGE_DETAILS"; 290 291 /** 292 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 293 * which is a {@link String} that represents the current language preference this user has 294 * specified - a locale string like "en-US". 295 */ 296 public static final String EXTRA_LANGUAGE_PREFERENCE = 297 "android.speech.extra.LANGUAGE_PREFERENCE"; 298 299 /** 300 * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} 301 * which is an {@link ArrayList} of {@link String}s that represents the languages supported by 302 * this implementation of voice recognition - a list of strings like "en-US", "cmn-Hans-CN", 303 * etc. 304 */ 305 public static final String EXTRA_SUPPORTED_LANGUAGES = 306 "android.speech.extra.SUPPORTED_LANGUAGES"; 307} 308