1 /* 2 * Copyright 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.photopicker.core.configuration 18 19 import android.provider.DeviceConfig 20 import java.util.concurrent.Executor 21 22 /** 23 * A supplier interface for [DeviceConfig]. This allows for isolating the device state during tests 24 * by providing an alternate implementation to the [ConfigurationManager]. 25 * 26 * For production / runtime usage that wraps the real [DeviceConfig], see [DeviceConfigProxyImpl] 27 */ 28 interface DeviceConfigProxy { 29 30 /** 31 * Register a listener to receive callbacks when flags in the backing [DeviceConfig] supplier 32 * change. 33 * 34 * @param namespace The namespace to attach this listener to. 35 * @param executor An executor for the listener to be run on. If being called from kotlin, 36 * consider providing a `[CoroutineDispatcher].asExecutor` 37 * @param listener the implementation of [DeviceConfig.OnPropertiesChangedListener] to register. 38 */ addOnPropertiesChangedListenernull39 fun addOnPropertiesChangedListener( 40 namespace: String, 41 executor: Executor, 42 listener: DeviceConfig.OnPropertiesChangedListener, 43 ) 44 45 /** Remove the provided listener from receiving future device config flag updates. */ 46 fun removeOnPropertiesChangedListener(listener: DeviceConfig.OnPropertiesChangedListener) 47 48 /** 49 * Fetch a flag from the backing [DeviceConfig] supplier. 50 * 51 * This method assumes the caller knows the correct type of the flag they are fetching, and will 52 * expect a flag type that matches the same type as the defaultValue. 53 * 54 * This wraps the various "getFlagOfType" methods that exist in device config into one method. 55 * 56 * In the event the flag is unset, the provided defaultValue will be returned. If the flag type 57 * is incorrect, the provided defaultValue will be returned. 58 */ 59 fun <T> getFlag(namespace: String, key: String, defaultValue: T): T 60 } 61