package com.example.myapplication

import android.os.Bundle
import android.view.View
import android.widget.Button
import android.widget.EditText
import androidx.appcompat.app.AppCompatActivity
import com.example.test1.R

class MainActivity : AppCompatActivity() {

    private lateinit var per1: EditText
    private lateinit var sl: Button
    private lateinit var vc: Button
    private lateinit var mn: Button
    private lateinit var del: Button
    private lateinit var rav: Button
    private lateinit var clr: Button
    private lateinit var drb: Button
    private lateinit var nol: Button
    private lateinit var odin: Button
    private lateinit var dva: Button
    private lateinit var tri: Button
    private lateinit var chet: Button
    private lateinit var pyat: Button
    private lateinit var shes: Button
    private lateinit var sem: Button
    private lateinit var vos: Button
    private lateinit var dev: Button

    private var save: Float = 0f
    private var result: Float = 0f
    private var flag: Int = 0

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

        per1 = findViewById(R.id.per1)
        sl = findViewById(R.id.sl)
        vc = findViewById(R.id.vc)
        mn = findViewById(R.id.mn)
        del = findViewById(R.id.del)
        rav = findViewById(R.id.rav)
        clr = findViewById(R.id.clr)
        drb = findViewById(R.id.drb)
        nol = findViewById(R.id.nol)
        odin = findViewById(R.id.odin)
        dva = findViewById(R.id.dva)
        tri = findViewById(R.id.tri)
        chet = findViewById(R.id.chet)
        pyat = findViewById(R.id.pyat)
        shes = findViewById(R.id.shes)
        sem = findViewById(R.id.sem)
        vos = findViewById(R.id.vos)
        dev = findViewById(R.id.dev)

        sl.setOnClickListener {
            val num1 = per1.text.toString().toFloatOrNull() ?: return@setOnClickListener
            if (flag == 5) {
                per1.setText("")
                flag = 1
            } else {
                per1.setText("")
                if (save == 0f) {
                    save = num1
                    flag = 1
                    return@setOnClickListener
                }
                save += num1
                flag = 1
            }
        }

        vc.setOnClickListener {
            val num1 = per1.text.toString().toFloatOrNull() ?: return@setOnClickListener
            if (flag == 5) {
                per1.setText("")
                flag = 2
            } else {
                per1.setText("")
                if (save == 0f) {
                    save = num1
                    flag = 2
                    return@setOnClickListener
                }
                save -= num1
                flag = 2
            }
        }

        mn.setOnClickListener {
            val num1 = per1.text.toString().toFloatOrNull() ?: return@setOnClickListener
            if (flag == 5) {
                per1.setText("")
                flag = 3
            } else {
                per1.setText("")
                if (save == 0f) {
                    save = num1
                    flag = 3
                    return@setOnClickListener
                }
                save *= num1
                flag = 3
            }
        }

        del.setOnClickListener {
            val num1 = per1.text.toString().toFloatOrNull() ?: return@setOnClickListener
            if (flag == 5) {
                per1.setText("")
                flag = 4
            } else {
                per1.setText("")
                if (save == 0f) {
                    save = num1
                    flag = 4
                    return@setOnClickListener
                }
                save /= num1
                flag = 4
            }
        }

        rav.setOnClickListener {
            val num1 = per1.text.toString().toFloatOrNull() ?: return@setOnClickListener
            when (flag) {
                1 -> save += num1
                2 -> save -= num1
                3 -> save *= num1
                4 -> save /= num1
            }
            if (Math.abs(save - save.toInt()) < 0.00001) {
                per1.setText(save.toInt().toString())
            } else {
                per1.setText(save.toString())
            }
            flag = 5
        }

        clr.setOnClickListener {
            save = 0f
            flag = 0
            per1.setText("")
        }

        nol.setOnClickListener {
            save = 0f
            flag = 0
            per1.setText("")
        }
    }
}

enter image description here
enter image description here

Хотел реализовать калькулятор, как на айфоне, сделал много кнопочек, прописал логику, изначально все работало хорошо, но постепенно с добавлением кнопок и логики приложение перестало запускаться, я подозреваю, что здесь проблема с использованием ресурсов, но не знаю, как это решить, читать LogCat пока не умею