/*
* 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>
*/
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";
}
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