1 /* 2 * Copyright (C) 2024 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.multiuser.widget.data 18 19 import android.content.Context 20 import androidx.room.Database 21 import androidx.room.Room 22 import androidx.room.RoomDatabase 23 import com.android.multiuser.widget.data.model.User 24 25 @Database( 26 entities = [User::class], 27 version = 1, 28 exportSchema = false) 29 abstract class UsersDatabase : RoomDatabase() { 30 31 // This is how the database exposes DAOs. getUserDaonull32 abstract fun getUserDao(): UserDao 33 34 companion object { 35 // Singleton prevents multiple instances of database opening at the same time. 36 @Volatile 37 private var INSTANCE: UsersDatabase? = null 38 39 fun getDatabase(context: Context): UsersDatabase { 40 if(INSTANCE == null) { 41 // temporary instance that will be populated with initial data 42 val instance = Room.databaseBuilder( 43 context.applicationContext, 44 UsersDatabase::class.java, 45 "multiuser_widget_database" 46 ).build() 47 populateWithInitialData(context, instance.getUserDao()) 48 INSTANCE = instance 49 } 50 return INSTANCE as UsersDatabase 51 } 52 } 53 } 54