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RecognizerIntent.javaAPI DocAndroid 5.1 API20084Thu Mar 12 22:22:10 GMT 2015android.speech

RecognizerIntent

public class RecognizerIntent extends Object
Constants for supporting speech recognition through starting an {@link Intent}

Fields Summary
public static final String
EXTRA_CALLING_PACKAGE
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 static final String
ACTION_RECOGNIZE_SPEECH
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.

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.

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.

Required extras:

  • {@link #EXTRA_LANGUAGE_MODEL}

Optional extras:

  • {@link #EXTRA_PROMPT}
  • {@link #EXTRA_LANGUAGE}
  • {@link #EXTRA_MAX_RESULTS}
  • {@link #EXTRA_RESULTS_PENDINGINTENT}
  • {@link #EXTRA_RESULTS_PENDINGINTENT_BUNDLE}

Result extras (returned in the result, not to be specified in the request):

  • {@link #EXTRA_RESULTS}

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
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.

If you want to avoid triggering any type of action besides web search, you can use the {@link #EXTRA_WEB_SEARCH_ONLY} extra.

Required extras:

  • {@link #EXTRA_LANGUAGE_MODEL}

Optional extras:

  • {@link #EXTRA_PROMPT}
  • {@link #EXTRA_LANGUAGE}
  • {@link #EXTRA_MAX_RESULTS}
  • {@link #EXTRA_PARTIAL_RESULTS}
  • {@link #EXTRA_WEB_SEARCH_ONLY}
  • {@link #EXTRA_ORIGIN}

Result extras (returned in the result, not to be specified in the request):

  • {@link #EXTRA_RESULTS}
  • {@link #EXTRA_CONFIDENCE_SCORES} (optional)

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_VOICE_SEARCH_HANDS_FREE
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.

Optional extras:

  • {@link #EXTRA_SECURE}
public static final String
EXTRA_SECURE
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_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS
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_COMPLETE_SILENCE_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_POSSIBLY_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_LANGUAGE_MODEL
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.
public static final String
LANGUAGE_MODEL_FREE_FORM
Use a language model based on free-form speech recognition. This is a value to use for {@link #EXTRA_LANGUAGE_MODEL}.
public static final String
LANGUAGE_MODEL_WEB_SEARCH
Use a language model based on web search terms. This is a value to use for {@link #EXTRA_LANGUAGE_MODEL}.
public static final String
EXTRA_PROMPT
Optional text prompt to show to the user when asking them to speak.
public static final String
EXTRA_LANGUAGE
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_ORIGIN
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_MAX_RESULTS
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_WEB_SEARCH_ONLY
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_PARTIAL_RESULTS
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_RESULTS_PENDINGINTENT
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_BUNDLE
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 int
RESULT_NO_MATCH
Result code returned when no matches are found for the given speech
public static final int
RESULT_CLIENT_ERROR
Result code returned when there is a generic client error
public static final int
RESULT_SERVER_ERROR
Result code returned when the recognition server returns an error
public static final int
RESULT_NETWORK_ERROR
Result code returned when a network error was encountered
public static final int
RESULT_AUDIO_ERROR
Result code returned when an audio error was encountered
public static final String
EXTRA_RESULTS
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_CONFIDENCE_SCORES
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.

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.

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
DETAILS_META_DATA
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.

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.

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.

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
ACTION_GET_LANGUAGE_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}.

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}.

(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
EXTRA_ONLY_RETURN_LANGUAGE_PREFERENCE
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_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_SUPPORTED_LANGUAGES
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.
Constructors Summary
private RecognizerIntent()


      
        // Not for instantiating.
Methods Summary
public static final android.content.IntentgetVoiceDetailsIntent(android.content.Context context)
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.

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.

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}.

(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

    
                                                                                                                                                           
          
        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;