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.tools.metalava.model.item 18 19 import com.android.tools.metalava.model.Codebase 20 import com.android.tools.metalava.model.ParameterItem 21 22 /** 23 * A lamda that given a [ParameterItem] will create a [ParameterDefaultValue] for it. 24 * 25 * This is called from within the constructor of the [ParameterItem] and should not access any 26 * properties of [ParameterItem] as they may not have been initialized. This should just store a 27 * reference for later use. 28 */ 29 typealias ParameterDefaultValueFactory = (ParameterItem) -> ParameterDefaultValue 30 31 /** Indicates whether a parameter has a default value. */ 32 interface ParameterDefaultValue { 33 34 /** A [ParameterDefaultValue] to use for a parameter that has no default value. */ 35 data object NONE : ParameterDefaultValue { hasDefaultValuenull36 override fun hasDefaultValue() = false 37 38 /** This is suitable for use by [parameter] as it has no model or codebase dependencies. */ 39 override fun duplicate(parameter: ParameterItem) = this 40 41 /** This is suitable for use in the snapshot as it has no model or codebase dependencies. */ 42 override fun snapshot(parameter: ParameterItem) = this 43 } 44 45 /** 46 * A [ParameterDefaultValue] to use for a parameter that has a default value but its actual 47 * value is not known. 48 */ 49 data object UNKNOWN : ParameterDefaultValue { 50 override fun hasDefaultValue() = true 51 52 /** This is suitable for use by [parameter] as it has no model or codebase dependencies. */ 53 override fun duplicate(parameter: ParameterItem) = this 54 55 /** This is suitable for use in the snapshot as it has no model or codebase dependencies. */ 56 override fun snapshot(parameter: ParameterItem) = this 57 } 58 59 /** 60 * Returns whether this parameter has a default value. 61 * 62 * This is only supported in Kotlin. 63 */ hasDefaultValuenull64 fun hasDefaultValue(): Boolean 65 66 /** 67 * Return a duplicate of this instance to use by [parameter] which will be in the same type of 68 * [Codebase] as this. 69 */ 70 fun duplicate(parameter: ParameterItem): ParameterDefaultValue 71 72 /** 73 * Creates a snapshot of this. 74 * 75 * The default implementation assumes that this is either dependent on a model or the codebase 76 * and so creates a new [ParameterDefaultValue] based on the functions above. 77 */ 78 fun snapshot(parameter: ParameterItem) = 79 when { 80 !hasDefaultValue() -> NONE 81 else -> UNKNOWN 82 } 83 } 84