Qfyilyi

I'm new to Kotlin and I started a new Android project using this language. From the beginning I faced some issues when a tried to make a schema of a MVP pattern in Kotlin using generic types. This is what I'm trying to accomplish:

AbstractBasePresenter.kt

abstract class AbstractBasePresenter<T: Any> internal constructor(

    private val compositeDisposable: CompositeDisposable = CompositeDisposable()

) {



    constructor() : this(CompositeDisposable())



    private var view: T? = null



    fun bind(view: T) {

        if (this.view != null) throw IllegalStateException("view already bound")

        this.view = view

        afterBind()

    }



    fun unbind() {

        if (this.view == null) throw IllegalStateException("view already unbound")

        this.view = null

        compositeDisposable.clear()

    }



    abstract fun afterBind()



    protected fun addDisposable(disposable: Disposable): Disposable =

        disposable.also {

            compositeDisposable.add(it)

        }



    protected fun view(): T = view ?: throw IllegalStateException("view not bound")

}

BaseView.kt

interface BaseView<T : AbstractBasePresenter<*>> {



    fun getPresenter(): T

}

AbstractBaseActivity

abstract class AbstractBaseActivity<T : AbstractBasePresenter<*>> : AppCompatActivity(), BaseView<T> {



    override fun onStart() {

        super.onStart()

        getPresenter().bind(this)

    }



    override fun onStop() {

        getPresenter().unbind()

        super.onStop()

    }



    override fun startActivity(intent: Intent?) {

        super.startActivity(intent)

        slideInRight(this)

    }



    override fun onBackPressed() {

        super.onBackPressed()

        slideOutRight(this)

    }

}

When I'm trying to use the base class I want something like bellow:

SplashActivity

class SplashActivity : AbstractBaseActivity<SplashPresenter>(), SplashActivityView {



    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)

        setContentView(R.layout.splash_activity)

    }



    override fun getPresenter(): SplashPresenter {

        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.

    }

}

SplashPresenter

class SplashPresenter : AbstractBasePresenter<SplashActivityView>() {



    override fun afterBind() {

        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.

    }

}

SplashActivityView

interface SplashActivityView {



}

The idea is that this type of implementation is working fine in Java, but after the conversion it seems that with generic types from Kotlin I'm missing something and I got the following error in AbstractBaseActivity at binding the view:

    **getPresenter().bind(this)** ------> "this" is underlined and I have the error: **"Type mismatch. Required nothing AbstractBaseActivity<T> found"**

Please tell me where I am doing things wrong or give me another type of solution to accomplish the actual BaseActivity scope (bind and unbing from a single place).
Thank you!