ItemsActivity.kt

class ItemsActivity : ViewActivity<ItemsControllerView>(), ItemsViewCallback {

    //--- We set up the ControllerView --- //
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.items_layout)
        setupControllerView()
        bindViews()
    }

     override fun setupControllerView() {
        val controllerView = ItemsControllerView(
                itemsViewCallback = WeakReference(this),
                store = AppStore,
                mainThread = MainThread(WeakReference(this)))
        registerControllerViewForLifecycle(controllerView)
    }  
    
    //--- Once the ControllerView is configured, we can start using it --- //
    
    override fun onResume() {
        super.onResume()
        controllerView.fetchItems()
    }
    
    private fun openEditItemScreen(item: Item) =
            controllerView.toEditItemScreen(item)

    private fun changeFavoriteStatus(item: Item) =
            controllerView.changeFavoriteStatus(item)

    // --- Implementation of the interface (ItemsViewCallback) that will make 
    // possible for the ControllerView to communicate back with the View --- //
    
     override fun updateItems(items: List<Item>) =
            itemsAdapter.updateItems(items)

    override fun goToEditItem() {
        val intent = EditItemActivity.createEditItemActivityIntent(this)
        startActivity(intent)
    }
}

interface ItemsViewCallback {
    fun updateItems(items: List<Item>)
    fun goToEditItem()
}