hi guys, i have a simple question, i’ve overrided ...

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[Roberto Fernandez]

hi guys, i have a simple question, i’ve overrided a class that exposes a method

protected Class getPrototypeClass(T content) {

With this code

override fun getPrototypeClass(content: AlfredElement): Class<*> {
        return when (content) {
            is Category -> AlfredCategoryRenderer::class.java
            is Suggestion -> AlfredSuggestionElement::class.java
        }
    }

And AlfredCategoryRenderer is a class with this type

: Renderer<AlfredElement>()

So, how can i tell kotlin compiler something like i can do i java which is tell the method getPrototypeClass will return a class that is Something like extends AlfredElement?

[voddan]

do you mean variance http://kotlinlang.org/docs/reference/generics.html#variance ?

[marcinmoskala]

I am not sure it this is what you mean, but I would return covariant type:

sealed class AlfredElement
class Category : AlfredElement()
class Suggestion : AlfredElement()

abstract class Renderer
class AlfredSuggestionElement : Renderer()
class AlfredCategoryRenderer : Renderer()

fun getPrototypeClass(content: AlfredElement): Class<out Renderer> = when (content) {
    is Category -> AlfredCategoryRenderer::class.java
    is Suggestion -> AlfredSuggestionElement::class.java
}

[marcinmoskala]

It means that getPrototypeClass returns Class of something that is subtype of Renderer