1 /* 2 * Copyright 2020 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 17 package com.android.settings.tts; 18 19 import android.app.Application; 20 import android.speech.tts.TextToSpeech; 21 import android.util.Pair; 22 23 import androidx.lifecycle.AndroidViewModel; 24 25 /** 26 * A helper view model to protect the TTS object from being destroyed and 27 * recreated on orientation change. 28 */ 29 public class TextToSpeechViewModel extends AndroidViewModel { 30 private TextToSpeech mTts; 31 32 // Save the application so we can use it as the TTS context 33 private final Application mApplication; 34 TextToSpeechViewModel(Application application)35 public TextToSpeechViewModel(Application application) { 36 super(application); 37 38 mApplication = application; 39 } 40 41 /* 42 * Since the view model now controls the TTS object, we need to handle shutting it down 43 * ourselves. 44 */ 45 @Override onCleared()46 protected void onCleared() { 47 shutdownTts(); 48 } 49 shutdownTts()50 protected void shutdownTts() { 51 mTts.shutdown(); 52 mTts = null; 53 } 54 55 /* 56 * An accessor method to get the TTS object. Returns a pair of the TTS object and a boolean 57 * indicating whether the TTS object was newly created or not. 58 */ getTtsAndWhetherNew( TextToSpeech.OnInitListener listener)59 protected Pair<TextToSpeech, Boolean> getTtsAndWhetherNew( 60 TextToSpeech.OnInitListener listener) { 61 boolean ttsCreated = false; 62 if (mTts == null) { 63 mTts = new TextToSpeech(this.mApplication, listener); 64 ttsCreated = true; 65 } 66 67 return Pair.create(mTts, ttsCreated); 68 } 69 70 } 71