Kotlin Standard Library Cookbook

How to do it...

1. Let's start by defining an initial value for the temperature variable:

val initialValue = 1

2. Define the update condition for the observed variable:

val initialTemperature = 1val updateCondition: (KProperty<*>, Int, Int) -> Boolean =        { _, oldValue: Int, newValue: Int -> Math.abs(oldValue - newValue) >= 10 }

3. Declare the temperature: Int variable and delegate it to the result of the Delegates.vetoable() function:

val initialTemperature = 1val updateCondition: (KProperty<*>, Int, Int) -> Boolean =        { _, oldValue: Int, newValue: Int -> Math.abs(oldValue - newValue) >= 10 }var temperature: Int by Delegates.vetoable(initialTemperature, updateCondition)