6 magic sugars that can make your Kotlin codebase happier #15

Sugar.kt

abstract class Item

class MediaItem : Item() {
    val media = ...
}

class IconItem : Item() {
    val icon = ...
}

interface Renderer {
    fun render(view: View, item: Item)
}

class MediaItemRenderer : Renderer {

    override fun render(view: View, item: Item) {
        if (item !is MediaItem) {
            throw AssertionError("Item is not an instance of MediaItem")
        }

        view.showMedia(item.media)
        view.reset()
    }
}

class IconItemRenderer : Renderer {

    override fun render(view: View, item: Item) {
        if (item !is IconItem) {
            throw AssertionError("Item is not an instance of IconItem")
        }

        view.showIcon(item.icon)
        view.reset()
    }
}