VoiceInteractionService.java revision 07b4a6f42d75909785f4362181619983e21894eb
1/** 2 * Copyright (C) 2014 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.service.voice; 18 19import android.annotation.SdkConstant; 20import android.app.Service; 21import android.content.ComponentName; 22import android.content.Context; 23import android.content.Intent; 24import android.hardware.soundtrigger.KeyphraseEnrollmentInfo; 25import android.os.Bundle; 26import android.os.Handler; 27import android.os.IBinder; 28import android.os.Message; 29import android.os.RemoteException; 30import android.os.ServiceManager; 31import android.provider.Settings; 32 33import com.android.internal.annotations.VisibleForTesting; 34import com.android.internal.app.IVoiceInteractionManagerService; 35 36import java.io.FileDescriptor; 37import java.io.PrintWriter; 38import java.util.Locale; 39 40 41/** 42 * Top-level service of the current global voice interactor, which is providing 43 * support for hotwording, the back-end of a {@link android.app.VoiceInteractor}, etc. 44 * The current VoiceInteractionService that has been selected by the user is kept 45 * always running by the system, to allow it to do things like listen for hotwords 46 * in the background to instigate voice interactions. 47 * 48 * <p>Because this service is always running, it should be kept as lightweight as 49 * possible. Heavy-weight operations (including showing UI) should be implemented 50 * in the associated {@link android.service.voice.VoiceInteractionSessionService} when 51 * an actual voice interaction is taking place, and that service should run in a 52 * separate process from this one. 53 */ 54public class VoiceInteractionService extends Service { 55 /** 56 * The {@link Intent} that must be declared as handled by the service. 57 * To be supported, the service must also require the 58 * {@link android.Manifest.permission#BIND_VOICE_INTERACTION} permission so 59 * that other applications can not abuse it. 60 */ 61 @SdkConstant(SdkConstant.SdkConstantType.SERVICE_ACTION) 62 public static final String SERVICE_INTERFACE = 63 "android.service.voice.VoiceInteractionService"; 64 65 /** 66 * Name under which a VoiceInteractionService component publishes information about itself. 67 * This meta-data should reference an XML resource containing a 68 * <code><{@link 69 * android.R.styleable#VoiceInteractionService voice-interaction-service}></code> tag. 70 */ 71 public static final String SERVICE_META_DATA = "android.voice_interaction"; 72 73 IVoiceInteractionService mInterface = new IVoiceInteractionService.Stub() { 74 @Override public void ready() { 75 mHandler.sendEmptyMessage(MSG_READY); 76 } 77 @Override public void shutdown() { 78 mHandler.sendEmptyMessage(MSG_SHUTDOWN); 79 } 80 @Override public void soundModelsChanged() { 81 mHandler.sendEmptyMessage(MSG_SOUND_MODELS_CHANGED); 82 } 83 }; 84 85 MyHandler mHandler; 86 87 IVoiceInteractionManagerService mSystemService; 88 89 private final Object mLock = new Object(); 90 91 private KeyphraseEnrollmentInfo mKeyphraseEnrollmentInfo; 92 93 private AlwaysOnHotwordDetector mHotwordDetector; 94 95 static final int MSG_READY = 1; 96 static final int MSG_SHUTDOWN = 2; 97 static final int MSG_SOUND_MODELS_CHANGED = 3; 98 99 class MyHandler extends Handler { 100 @Override 101 public void handleMessage(Message msg) { 102 switch (msg.what) { 103 case MSG_READY: 104 onReady(); 105 break; 106 case MSG_SHUTDOWN: 107 onShutdownInternal(); 108 break; 109 case MSG_SOUND_MODELS_CHANGED: 110 onSoundModelsChangedInternal(); 111 break; 112 default: 113 super.handleMessage(msg); 114 } 115 } 116 } 117 118 /** 119 * Check whether the given service component is the currently active 120 * VoiceInteractionService. 121 */ 122 public static boolean isActiveService(Context context, ComponentName service) { 123 String cur = Settings.Secure.getString(context.getContentResolver(), 124 Settings.Secure.VOICE_INTERACTION_SERVICE); 125 if (cur == null || cur.isEmpty()) { 126 return false; 127 } 128 ComponentName curComp = ComponentName.unflattenFromString(cur); 129 if (curComp == null) { 130 return false; 131 } 132 return curComp.equals(service); 133 } 134 135 /** 136 * Initiate the execution of a new {@link android.service.voice.VoiceInteractionSession}. 137 * @param args Arbitrary arguments that will be propagated to the session. 138 */ 139 public void startSession(Bundle args) { 140 if (mSystemService == null) { 141 throw new IllegalStateException("Not available until onReady() is called"); 142 } 143 try { 144 mSystemService.startSession(mInterface, args); 145 } catch (RemoteException e) { 146 } 147 } 148 149 @Override 150 public void onCreate() { 151 super.onCreate(); 152 mHandler = new MyHandler(); 153 } 154 155 @Override 156 public IBinder onBind(Intent intent) { 157 if (SERVICE_INTERFACE.equals(intent.getAction())) { 158 return mInterface.asBinder(); 159 } 160 return null; 161 } 162 163 /** 164 * Called during service initialization to tell you when the system is ready 165 * to receive interaction from it. You should generally do initialization here 166 * rather than in {@link #onCreate()}. Methods such as {@link #startSession(Bundle)} and 167 * {@link #createAlwaysOnHotwordDetector(String, Locale, android.service.voice.AlwaysOnHotwordDetector.Callback)} 168 * will not be operational until this point. 169 */ 170 public void onReady() { 171 mSystemService = IVoiceInteractionManagerService.Stub.asInterface( 172 ServiceManager.getService(Context.VOICE_INTERACTION_MANAGER_SERVICE)); 173 mKeyphraseEnrollmentInfo = new KeyphraseEnrollmentInfo(getPackageManager()); 174 } 175 176 private void onShutdownInternal() { 177 onShutdown(); 178 // Stop any active recognitions when shutting down. 179 // This ensures that if implementations forget to stop any active recognition, 180 // It's still guaranteed to have been stopped. 181 // This helps with cases where the voice interaction implementation is changed 182 // by the user. 183 safelyShutdownHotwordDetector(); 184 } 185 186 /** 187 * Called during service de-initialization to tell you when the system is shutting the 188 * service down. 189 * At this point this service may no longer be the active {@link VoiceInteractionService}. 190 */ 191 public void onShutdown() { 192 } 193 194 private void onSoundModelsChangedInternal() { 195 synchronized (this) { 196 if (mHotwordDetector != null) { 197 // TODO: Stop recognition if a sound model that was being recognized gets deleted. 198 mHotwordDetector.onSoundModelsChanged(); 199 } 200 } 201 } 202 203 /** 204 * Creates an {@link AlwaysOnHotwordDetector} for the given keyphrase and locale. 205 * This instance must be retained and used by the client. 206 * Calling this a second time invalidates the previously created hotword detector 207 * which can no longer be used to manage recognition. 208 * 209 * @param keyphrase The keyphrase that's being used, for example "Hello Android". 210 * @param locale The locale for which the enrollment needs to be performed. 211 * @param callback The callback to notify of detection events. 212 * @return An always-on hotword detector for the given keyphrase and locale. 213 */ 214 public final AlwaysOnHotwordDetector createAlwaysOnHotwordDetector( 215 String keyphrase, Locale locale, AlwaysOnHotwordDetector.Callback callback) { 216 if (mSystemService == null) { 217 throw new IllegalStateException("Not available until onReady() is called"); 218 } 219 synchronized (mLock) { 220 // Allow only one concurrent recognition via the APIs. 221 safelyShutdownHotwordDetector(); 222 mHotwordDetector = new AlwaysOnHotwordDetector(keyphrase, locale, callback, 223 mKeyphraseEnrollmentInfo, mInterface, mSystemService); 224 } 225 return mHotwordDetector; 226 } 227 228 /** 229 * @return Details of keyphrases available for enrollment. 230 * @hide 231 */ 232 @VisibleForTesting 233 protected final KeyphraseEnrollmentInfo getKeyphraseEnrollmentInfo() { 234 return mKeyphraseEnrollmentInfo; 235 } 236 237 private void safelyShutdownHotwordDetector() { 238 try { 239 synchronized (mLock) { 240 if (mHotwordDetector != null) { 241 mHotwordDetector.stopRecognition(); 242 mHotwordDetector.invalidate(); 243 mHotwordDetector = null; 244 } 245 } 246 } catch (Exception ex) { 247 // Ignore. 248 } 249 } 250 251 @Override 252 protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) { 253 pw.println("VOICE INTERACTION"); 254 synchronized (mLock) { 255 pw.println(" AlwaysOnHotwordDetector"); 256 if (mHotwordDetector == null) { 257 pw.println(" NULL"); 258 } else { 259 mHotwordDetector.dump(" ", pw); 260 } 261 } 262 } 263} 264