org.jetbrains.kotlin.gradle.utils.Delegates.kt Maven / Gradle / Ivy

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Kotlin Gradle Plugin

There is a newer version: 2.1.0-Beta1

/*
 * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
 * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
 */

package org.jetbrains.kotlin.gradle.utils

import kotlin.reflect.KProperty

open class ProviderDelegate(
    private val defaultValueProvider: () -> T
) {
    operator fun getValue(thisRef: Any?, property: KProperty<*>): T {
        return defaultValueProvider()
    }
}

class PropertyDelegate(
    private val defaultValueProvider: () -> T
) {
    private var backing: T? = null

    operator fun getValue(thisRef: Any?, property: KProperty<*>): T {
        return backing ?: defaultValueProvider()
    }

    operator fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
        backing = value
    }
}

fun  provider(
    defaultValueProvider: () -> T
): ProviderDelegate = ProviderDelegate(defaultValueProvider)

fun  property(
    defaultValueProvider: () -> T
): PropertyDelegate = PropertyDelegate(defaultValueProvider)