How to do delegation in Kotlin

5 minute talk about delegation in Kotlin programming language.

Transcript

1. designing & developing for mobile Demoday, 05/02/2018 Harri Kirik, engineer Kotlin: Delegation
2. Kotlin KOTLIN: DELEGATION #kotlin
3. Delegation pattern KOTLIN: DELEGATION #delegation
4. Java example KOTLIN: DELEGATION #java
5. KOTLIN: DELEGATION class CarBody { int getDoorCount() { return 4; } } class Car { CarBody body; public Car(CarBody body) { this.body = body; } public int getDoorCount() { return body.getDoorCount(); } } #demoday
6. Kotlin example KOTLIN: DELEGATION #kotlin
7. The by-clause KOTLIN: DELEGATION #by-clause
8. KOTLIN: DELEGATION interface CarBody { fun getDoorCount(): Int } class CarBodyImpl() : CarBody { override fun getDoorCount() = 4 } class Car(c: CarBody) : CarBody by c #demoday
9. KOTLIN: DELEGATION interface CarBody { fun getDoorCount(): Int } class CarBodyImpl() : CarBody { override fun getDoorCount() = 4 } class Car(c: CarBody) : CarBody by c #demoday
10. KOTLIN: DELEGATION interface CarBody { fun getDoorCount(): Int } class CarBodyImpl() : CarBody { override fun getDoorCount() = 4 } class Car(c: CarBody) : CarBody by c #demoday
11. KOTLIN: DELEGATION interface CarBody { fun getDoorCount(): Int } class CarBodyImpl() : CarBody { override fun getDoorCount() = 4 } class Car(c: CarBody) : CarBody by c fun main(args: Array<String>) { val car = Car(CarBodyImpl()).getDoorCount() println(car) } #demoday
12. Delegated properties KOTLIN: DELEGATION #properties
13. KOTLIN: DELEGATION class Car { val bodyWeight: Int by CarBodyWight() } #demoday
14. http:// lab.mobi designing & developing for mobile thanks Questions?