ResultActivity.kt

package com.example.uniformcivilnumber

import android.content.Intent
import android.os.Bundle
import android.view.View
import androidx.appcompat.app.AppCompatActivity
import com.example.uniformcivilnumber.databinding.ActivityResultBinding

class ResultActivity : AppCompatActivity() {
    private lateinit var binding: ActivityResultBinding
    private var mode: ResultActivityMode = ResultActivityMode.DEFAULT

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityResultBinding.inflate(layoutInflater)
        setContentView(binding.root)
        mode = when (intent.extras?.getString("mode")) {
            ResultActivityMode.GENERATE.mode -> ResultActivityMode.GENERATE
            ResultActivityMode.PARSE.mode -> ResultActivityMode.PARSE
            else -> ResultActivityMode.DEFAULT
        }
        binding.backButtonResult.setOnClickListener {
            backButtonTap(it)
        }
    }

    fun backButtonTap(view: View) {
        if (mode == ResultActivityMode.PARSE) {
            val intent = Intent(this, ParseActivity::class.java)
            startActivity(intent)
        } else if (mode == ResultActivityMode.GENERATE) {
            val intent = Intent(this, GenerateActivity::class.java)
            startActivity(intent)
        }
    }
}

Oh. When clause looks super sexy. Haha.