1 /*
2  * Copyright (C) 2023 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.source.utils
18 
19 import com.android.tools.metalava.model.Item
20 import kotlin.properties.ReadWriteProperty
21 import kotlin.reflect.KProperty
22 
23 // a property with a lazily calculated default value
24 class LazyDelegate<T>(val defaultValueProvider: () -> T) : ReadWriteProperty<Item, T> {
25     private var currentValue: T? = null
26 
setValuenull27     override operator fun setValue(thisRef: Item, property: KProperty<*>, value: T) {
28         currentValue = value
29     }
30 
getValuenull31     override operator fun getValue(thisRef: Item, property: KProperty<*>): T {
32         if (currentValue == null) {
33             currentValue = defaultValueProvider()
34         }
35 
36         return currentValue!!
37     }
38 }
39