[lb8] MainActivity.kt

package com.example.lb8

import android.annotation.SuppressLint
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.ArrayAdapter
import android.widget.ListView
import android.widget.TextView
import android.widget.Toast
import androidx.core.os.bundleOf
import androidx.fragment.app.FragmentTransaction

interface OnDataListener {
    fun onData(Data: Int)
    fun onAnswer(right: Int?, summary: Int?, difficulty: Int?)
}

class MainActivity : AppCompatActivity(), OnDataListener {
    private var rightAnswers: Int= 0
    private var countAnswers: Int = 0
    private var taskDifficulty: Int = 10

    private var isTwoPane = false
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        isTwoPane = findViewById<View>(R.id.frame_left) != null
        val bundle = bundleOf("Data" to 0, "right" to rightAnswers, "all" to countAnswers, "diff" to taskDifficulty)
        val frag2 = RightFragment()
        frag2.arguments = bundle
        if (isTwoPane) {
            supportFragmentManager.beginTransaction()
                .add(R.id.frame_left, LeftFragment())
                .add(R.id.frame_right, frag2)
                .commit()
        }
        else {
            supportFragmentManager.beginTransaction()
                .add(R.id.container, LeftFragment())
                .commit()
        }
    }


    override fun onData(Data: Int) {
        val bundle = bundleOf("Data" to 0, "right" to rightAnswers, "all" to countAnswers, "diff" to taskDifficulty)
        val frag2 = RightFragment()
        frag2.arguments = bundle

        supportFragmentManager.beginTransaction()
            .replace(
                if (isTwoPane)
                    R.id.frame_right
                else
                    R.id.container,
                frag2)
            .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE)
            .addToBackStack(null)
            .commit()

    }

    override fun onAnswer(right: Int?, summary: Int?, diff: Int?) {
        if (right != null) {
            rightAnswers = right
        }
        if (summary != null) {
            countAnswers = summary
        }
        if (diff != null) {
            taskDifficulty = diff
        }
    }

}