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/* * Copyright (C) 2008 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.speech; import java.util.ArrayList; import android.app.Activity; import android.content.ActivityNotFoundException; import android.content.BroadcastReceiver; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.pm.PackageManager; import android.content.pm.ResolveInfo; import android.os.Bundle; /** * Constants for supporting speech recognition through starting an {@link Intent} */ public class RecognizerIntent { /** * The extra key used in an intent to the speech recognizer for voice search. Not * generally to be used by developers. The system search dialog uses this, for example, * to set a calling package for identification by a voice search API. If this extra * is set by anyone but the system process, it should be overridden by the voice search * implementation. */ public final static String EXTRA_CALLING_PACKAGE = "calling_package"; private RecognizerIntent() { // Not for instantiating. } /** * Starts an activity that will prompt the user for speech and send it through a * speech recognizer. The results will be returned via activity results (in * {@link Activity#onActivityResult}, if you start the intent using * {@link Activity#startActivityForResult(Intent, int)}), or forwarded via a PendingIntent * if one is provided. * * <p>Starting this intent with just {@link Activity#startActivity(Intent)} is not supported. * You must either use {@link Activity#startActivityForResult(Intent, int)}, or provide a * PendingIntent, to receive recognition results. * * <p>The implementation of this API is likely to stream audio to remote servers to perform * speech recognition which can use a substantial amount of bandwidth. * * <p>Required extras: * <ul> * <li>{@link #EXTRA_LANGUAGE_MODEL} * </ul> * * <p>Optional extras: * <ul> * <li>{@link #EXTRA_PROMPT} * <li>{@link #EXTRA_LANGUAGE} * <li>{@link #EXTRA_MAX_RESULTS} * <li>{@link #EXTRA_RESULTS_PENDINGINTENT} * <li>{@link #EXTRA_RESULTS_PENDINGINTENT_BUNDLE} * </ul> * * <p> Result extras (returned in the result, not to be specified in the request): * <ul> * <li>{@link #EXTRA_RESULTS} * </ul> * * <p>NOTE: There may not be any applications installed to handle this action, so you should * make sure to catch {@link ActivityNotFoundException}. */ public static final String ACTION_RECOGNIZE_SPEECH = "android.speech.action.RECOGNIZE_SPEECH"; /** * Starts an activity that will prompt the user for speech, send it through a * speech recognizer, and either display a web search result or trigger * another type of action based on the user's speech. * * <p>If you want to avoid triggering any type of action besides web search, you can use * the {@link #EXTRA_WEB_SEARCH_ONLY} extra. * * <p>Required extras: * <ul> * <li>{@link #EXTRA_LANGUAGE_MODEL} * </ul> * * <p>Optional extras: * <ul> * <li>{@link #EXTRA_PROMPT} * <li>{@link #EXTRA_LANGUAGE} * <li>{@link #EXTRA_MAX_RESULTS} * <li>{@link #EXTRA_PARTIAL_RESULTS} * <li>{@link #EXTRA_WEB_SEARCH_ONLY} * <li>{@link #EXTRA_ORIGIN} * </ul> * * <p> Result extras (returned in the result, not to be specified in the request): * <ul> * <li>{@link #EXTRA_RESULTS} * <li>{@link #EXTRA_CONFIDENCE_SCORES} (optional) * </ul> * * <p>NOTE: There may not be any applications installed to handle this action, so you should * make sure to catch {@link ActivityNotFoundException}. */ public static final String ACTION_WEB_SEARCH = "android.speech.action.WEB_SEARCH"; /** * Starts an activity that will prompt the user for speech without requiring the user's * visual attention or touch input. It will send it through a speech recognizer, * and either synthesize speech for a web search result or trigger * another type of action based on the user's speech. * * This activity may be launched while device is locked in a secure mode. * Special care must be taken to ensure that the voice actions that are performed while * hands free cannot compromise the device's security. * The activity should check the value of the {@link #EXTRA_SECURE} extra to determine * whether the device has been securely locked. If so, the activity should either restrict * the set of voice actions that are permitted or require some form of secure * authentication before proceeding. * * To ensure that the activity's user interface is visible while the lock screen is showing, * the activity should set the * {@link android.view.WindowManager.LayoutParams#FLAG_SHOW_WHEN_LOCKED} window flag. * Otherwise the activity's user interface may be hidden by the lock screen. The activity * should take care not to leak private information when the device is securely locked. * * <p>Optional extras: * <ul> * <li>{@link #EXTRA_SECURE} * </ul> * * <p class="note"> * In some cases, a matching Activity may not exist, so ensure you * safeguard against this. */ public static final String ACTION_VOICE_SEARCH_HANDS_FREE = "android.speech.action.VOICE_SEARCH_HANDS_FREE"; /** * Optional boolean to indicate that a "hands free" voice search was performed while the device * was in a secure mode. An example of secure mode is when the device's screen lock is active, * and it requires some form of authentication to be unlocked. * * When the device is securely locked, the voice search activity should either restrict * the set of voice actions that are permitted, or require some form of secure authentication * before proceeding. */ public static final String EXTRA_SECURE = "android.speech.extras.EXTRA_SECURE"; /** * The minimum length of an utterance. We will not stop recording before this amount of time. * * Note that it is extremely rare you'd want to specify this value in an intent. If you don't * have a very good reason to change these, you should leave them as they are. Note also that * certain values may cause undesired or unexpected results - use judiciously! Additionally, * depending on the recognizer implementation, these values may have no effect. */ public static final String EXTRA_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS = "android.speech.extras.SPEECH_INPUT_MINIMUM_LENGTH_MILLIS"; /** * The amount of time that it should take after we stop hearing speech to consider the input * complete. * * Note that it is extremely rare you'd want to specify this value in an intent. If * you don't have a very good reason to change these, you should leave them as they are. Note * also that certain values may cause undesired or unexpected results - use judiciously! * Additionally, depending on the recognizer implementation, these values may have no effect. */ public static final String EXTRA_SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS = "android.speech.extras.SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS"; /** * The amount of time that it should take after we stop hearing speech to consider the input * possibly complete. This is used to prevent the endpointer cutting off during very short * mid-speech pauses. * * Note that it is extremely rare you'd want to specify this value in an intent. If * you don't have a very good reason to change these, you should leave them as they are. Note * also that certain values may cause undesired or unexpected results - use judiciously! * Additionally, depending on the recognizer implementation, these values may have no effect. */ public static final String EXTRA_SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS = "android.speech.extras.SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS"; /** * Informs the recognizer which speech model to prefer when performing * {@link #ACTION_RECOGNIZE_SPEECH}. The recognizer uses this * information to fine tune the results. This extra is required. Activities implementing * {@link #ACTION_RECOGNIZE_SPEECH} may interpret the values as they see fit. * * @see #LANGUAGE_MODEL_FREE_FORM * @see #LANGUAGE_MODEL_WEB_SEARCH */ public static final String EXTRA_LANGUAGE_MODEL = "android.speech.extra.LANGUAGE_MODEL"; /** * Use a language model based on free-form speech recognition. This is a value to use for * {@link #EXTRA_LANGUAGE_MODEL}. * @see #EXTRA_LANGUAGE_MODEL */ public static final String LANGUAGE_MODEL_FREE_FORM = "free_form"; /** * Use a language model based on web search terms. This is a value to use for * {@link #EXTRA_LANGUAGE_MODEL}. * @see #EXTRA_LANGUAGE_MODEL */ public static final String LANGUAGE_MODEL_WEB_SEARCH = "web_search"; /** Optional text prompt to show to the user when asking them to speak. */ public static final String EXTRA_PROMPT = "android.speech.extra.PROMPT"; /** * Optional IETF language tag (as defined by BCP 47), for example "en-US". This tag informs the * recognizer to perform speech recognition in a language different than the one set in the * {@link java.util.Locale#getDefault()}. */ public static final String EXTRA_LANGUAGE = "android.speech.extra.LANGUAGE"; /** * Optional value which can be used to indicate the referer url of a page in which * speech was requested. For example, a web browser may choose to provide this for * uses of speech on a given page. */ public static final String EXTRA_ORIGIN = "android.speech.extra.ORIGIN"; /** * Optional limit on the maximum number of results to return. If omitted the recognizer * will choose how many results to return. Must be an integer. */ public static final String EXTRA_MAX_RESULTS = "android.speech.extra.MAX_RESULTS"; /** * Optional boolean, to be used with {@link #ACTION_WEB_SEARCH}, to indicate whether to * only fire web searches in response to a user's speech. The default is false, meaning * that other types of actions can be taken based on the user's speech. */ public static final String EXTRA_WEB_SEARCH_ONLY = "android.speech.extra.WEB_SEARCH_ONLY"; /** * Optional boolean to indicate whether partial results should be returned by the recognizer * as the user speaks (default is false). The server may ignore a request for partial * results in some or all cases. */ public static final String EXTRA_PARTIAL_RESULTS = "android.speech.extra.PARTIAL_RESULTS"; /** * When the intent is {@link #ACTION_RECOGNIZE_SPEECH}, the speech input activity will * return results to you via the activity results mechanism. Alternatively, if you use this * extra to supply a PendingIntent, the results will be added to its bundle and the * PendingIntent will be sent to its target. */ public static final String EXTRA_RESULTS_PENDINGINTENT = "android.speech.extra.RESULTS_PENDINGINTENT"; /** * If you use {@link #EXTRA_RESULTS_PENDINGINTENT} to supply a forwarding intent, you can * also use this extra to supply additional extras for the final intent. The search results * will be added to this bundle, and the combined bundle will be sent to the target. */ public static final String EXTRA_RESULTS_PENDINGINTENT_BUNDLE = "android.speech.extra.RESULTS_PENDINGINTENT_BUNDLE"; /** Result code returned when no matches are found for the given speech */ public static final int RESULT_NO_MATCH = Activity.RESULT_FIRST_USER; /** Result code returned when there is a generic client error */ public static final int RESULT_CLIENT_ERROR = Activity.RESULT_FIRST_USER + 1; /** Result code returned when the recognition server returns an error */ public static final int RESULT_SERVER_ERROR = Activity.RESULT_FIRST_USER + 2; /** Result code returned when a network error was encountered */ public static final int RESULT_NETWORK_ERROR = Activity.RESULT_FIRST_USER + 3; /** Result code returned when an audio error was encountered */ public static final int RESULT_AUDIO_ERROR = Activity.RESULT_FIRST_USER + 4; /** * An ArrayList<String> of the recognition results when performing * {@link #ACTION_RECOGNIZE_SPEECH}. Generally this list should be ordered in * descending order of speech recognizer confidence. (See {@link #EXTRA_CONFIDENCE_SCORES}). * Returned in the results; not to be specified in the recognition request. Only present * when {@link Activity#RESULT_OK} is returned in an activity result. In a PendingIntent, * the lack of this extra indicates failure. */ public static final String EXTRA_RESULTS = "android.speech.extra.RESULTS"; /** * A float array of confidence scores of the recognition results when performing * {@link #ACTION_RECOGNIZE_SPEECH}. The array should be the same size as the ArrayList * returned in {@link #EXTRA_RESULTS}, and should contain values ranging from 0.0 to 1.0, * or -1 to represent an unavailable confidence score. * <p> * Confidence values close to 1.0 indicate high confidence (the speech recognizer is * confident that the recognition result is correct), while values close to 0.0 indicate * low confidence. * <p> * Returned in the results; not to be specified in the recognition request. This extra is * optional and might not be provided. Only present when {@link Activity#RESULT_OK} is * returned in an activity result. */ public static final String EXTRA_CONFIDENCE_SCORES = "android.speech.extra.CONFIDENCE_SCORES"; /** * Returns the broadcast intent to fire with * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, Bundle)} * to receive details from the package that implements voice search. * <p> * This is based on the value specified by the voice search {@link Activity} in * {@link #DETAILS_META_DATA}, and if this is not specified, will return null. Also if there * is no chosen default to resolve for {@link #ACTION_WEB_SEARCH}, this will return null. * <p> * If an intent is returned and is fired, a {@link Bundle} of extras will be returned to the * provided result receiver, and should ideally contain values for * {@link #EXTRA_LANGUAGE_PREFERENCE} and {@link #EXTRA_SUPPORTED_LANGUAGES}. * <p> * (Whether these are actually provided is up to the particular implementation. It is * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this * information, but it is not required.) * * @param context a context object * @return the broadcast intent to fire or null if not available */ public static final Intent getVoiceDetailsIntent(Context context) { Intent voiceSearchIntent = new Intent(ACTION_WEB_SEARCH); ResolveInfo ri = context.getPackageManager().resolveActivity(voiceSearchIntent, PackageManager.GET_META_DATA); if (ri == null || ri.activityInfo == null || ri.activityInfo.metaData == null) return null; String className = ri.activityInfo.metaData.getString(DETAILS_META_DATA); if (className == null) return null; Intent detailsIntent = new Intent(ACTION_GET_LANGUAGE_DETAILS); detailsIntent.setComponent(new ComponentName(ri.activityInfo.packageName, className)); return detailsIntent; } /** * Meta-data name under which an {@link Activity} implementing {@link #ACTION_WEB_SEARCH} can * use to expose the class name of a {@link BroadcastReceiver} which can respond to request for * more information, from any of the broadcast intents specified in this class. * <p> * Broadcast intents can be directed to the class name specified in the meta-data by creating * an {@link Intent}, setting the component with * {@link Intent#setComponent(android.content.ComponentName)}, and using * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)} * with another {@link BroadcastReceiver} which can receive the results. * <p> * The {@link #getVoiceDetailsIntent(Context)} method is provided as a convenience to create * a broadcast intent based on the value of this meta-data, if available. * <p> * This is optional and not all {@link Activity}s which implement {@link #ACTION_WEB_SEARCH} * are required to implement this. Thus retrieving this meta-data may be null. */ public static final String DETAILS_META_DATA = "android.speech.DETAILS"; /** * A broadcast intent which can be fired to the {@link BroadcastReceiver} component specified * in the meta-data defined in the {@link #DETAILS_META_DATA} meta-data of an * {@link Activity} satisfying {@link #ACTION_WEB_SEARCH}. * <p> * When fired with * {@link Context#sendOrderedBroadcast(Intent, String, BroadcastReceiver, android.os.Handler, int, String, android.os.Bundle)}, * a {@link Bundle} of extras will be returned to the provided result receiver, and should * ideally contain values for {@link #EXTRA_LANGUAGE_PREFERENCE} and * {@link #EXTRA_SUPPORTED_LANGUAGES}. * <p> * (Whether these are actually provided is up to the particular implementation. It is * recommended that {@link Activity}s implementing {@link #ACTION_WEB_SEARCH} provide this * information, but it is not required.) */ public static final String ACTION_GET_LANGUAGE_DETAILS = "android.speech.action.GET_LANGUAGE_DETAILS"; /** * Specify this boolean extra in a broadcast of {@link #ACTION_GET_LANGUAGE_DETAILS} to * indicate that only the current language preference is needed in the response. This * avoids any additional computation if all you need is {@link #EXTRA_LANGUAGE_PREFERENCE} * in the response. */ public static final String EXTRA_ONLY_RETURN_LANGUAGE_PREFERENCE = "android.speech.extra.ONLY_RETURN_LANGUAGE_PREFERENCE"; /** * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} * which is a {@link String} that represents the current language preference this user has * specified - a locale string like "en-US". */ public static final String EXTRA_LANGUAGE_PREFERENCE = "android.speech.extra.LANGUAGE_PREFERENCE"; /** * The key to the extra in the {@link Bundle} returned by {@link #ACTION_GET_LANGUAGE_DETAILS} * which is an {@link ArrayList} of {@link String}s that represents the languages supported by * this implementation of voice recognition - a list of strings like "en-US", "cmn-Hans-CN", * etc. */ public static final String EXTRA_SUPPORTED_LANGUAGES = "android.speech.extra.SUPPORTED_LANGUAGES"; /** * Optional boolean, to be used with {@link #ACTION_RECOGNIZE_SPEECH}, * {@link #ACTION_VOICE_SEARCH_HANDS_FREE}, {@link #ACTION_WEB_SEARCH} to indicate whether to * only use an offline speech recognition engine. The default is false, meaning that either * network or offline recognition engines may be used. */ public static final String EXTRA_PREFER_OFFLINE = "android.speech.extra.PREFER_OFFLINE"; }