MainActivity.kt

package com.kekyazilim.mvpblog

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.Button
import android.widget.TextView
import com.kekyazilim.mvpblog.util.DateCalculationManager

class MainActivity : AppCompatActivity(), MainActivityContract.View {

    private lateinit var tvDate: TextView
    private lateinit var btnShowDate: Button

    private lateinit var mPresenter: MainActivityPresenter

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val dateCalculationManager = DateCalculationManager()
        this.mPresenter = MainActivityPresenter(dateCalculationManager)
        this.mPresenter.setView(this)
        this.mPresenter.created()

    }

    override fun bindViews() {
        this.tvDate = findViewById(R.id.tv_date)
        this.btnShowDate = findViewById(R.id.btn_show_date)
    }

    override fun initClickListeners() {
        this.btnShowDate.setOnClickListener {
            this.mPresenter.onShowDateButtonClick()
        }
    }

    override fun showDate(date: String) {
        this.tvDate.text = date
    }
}