Can I use a if statement to create a currency converter app?

Im trying to make an app that has a simple currency system that uses copper, silver, and gold, which are worth different values. I want the app to be able to convert one currency to another. The user first enters an amount that they wish to convert. They then select the currency this amount represents and the currency they wish to convert it to. Once they have selected both options, clicking ‘Calculate’ will show the converted cost. Ive started my code but as I am a beginner is the best way to go about this using a if statement for which buttons are selected to convert the currency?

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<Button
    android:id="@+id/copperBt1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/copperBt1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.151"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.314" />

<Button
    android:id="@+id/silverBt1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/silverBt1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.313" />

<Button
    android:id="@+id/goldBt1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/goldBt1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.848"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.313" />

<Button
    android:id="@+id/copperBt2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/copperBt2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.151"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.515" />

<Button
    android:id="@+id/silverBt2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/silverBt2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.515" />

<Button
    android:id="@+id/goldBt2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/goldBt2"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.848"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.515" />

<Button
    android:id="@+id/calculateBt"
    android:layout_width="250dp"
    android:layout_height="wrap_content"
    android:text="@string/calculateBt"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.496"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.651" />

<TextView
    android:id="@+id/textViewFrom"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/fromTxt"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.498"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.257" />

<TextView
    android:id="@+id/textViewTo"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/toTxt"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.446" />

<TextView
    android:id="@+id/textViewCost"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/convertedCostTxt"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.742" />

<TextView
    android:id="@+id/textViewAmount"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/amountTxt"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.045"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.061" />

<EditText
    android:id="@+id/editTxt"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:ems="10"
    android:hint="@string/editTxt"
    android:inputType="textPersonName"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.582"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.04"
    android:autofillHints="" />
</androidx.constraintlayout.widget.ConstraintLayout>

Here is my main activity code:

package com.currencyconverter;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.EditText;
import android.text.InputType;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final Button btCopper1 = findViewById(R.id.copperBt1);
    final Button btCopper2 = findViewById(R.id.copperBt2);
    final Button btSilver1 = findViewById(R.id.silverBt1);
    final Button btSilver2 = findViewById(R.id.silverBt2);
    final Button btGold1 = findViewById(R.id.goldBt1);
    final Button btGold2 = findViewById(R.id.goldBt2);
    final Button btCalculate = findViewById(R.id.calculateBt);
    final EditText editText = findViewById(R.id.editTxt);
    final TextView costTextView = findViewById(R.id.textViewCost);

    btCopper1.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v) {

            btCopper1.setTextColor(Color.parseColor("#a0522d"));

        }
    });

    btCopper2.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v) {

            btCopper2.setTextColor(Color.parseColor("#a0522d"));
        }
    });

    btSilver1.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v) {

            btSilver1.setTextColor(Color.parseColor("#8b8989"));

        }
    });

    btSilver2.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v) {

            btSilver2.setTextColor(Color.parseColor("#8b8989"));

        }
    });

    btGold1.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v) {

            btGold1.setTextColor(Color.parseColor("#daa520"));

        }
    });

    btGold2.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v) {

            btGold2.setTextColor(Color.parseColor("#daa520"));

        }
    });

    btCalculate.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v) {

            int num = Integer.parseInt(editText.getText().toString());




            costTextView.setText(editText.getText());


        }
    });


}

}