MY Calculator app

 

activity_main.xml:

<?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"
    android:background="@color/background"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/num_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="60dp"
        android:layout_marginTop="60dp"
        android:layout_marginEnd="60dp"
        android:ems="10"
        android:hint="Num 1"
        android:textStyle="bold"
        android:textSize="25sp"
        android:textColor="#FFFFFF"
        android:backgroundTint="#FFFFFF"
        android:textAlignment="center"
        android:inputType="number"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/num_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="60dp"
        android:layout_marginTop="50dp"
        android:layout_marginEnd="60dp"
        android:ems="10"
        android:hint="Num 2"
        android:textStyle="bold"
        android:textSize="25sp"
        android:textColor="#FFFFFF"
        android:backgroundTint="#FFFFFF"
        android:textAlignment="center"
        android:inputType="number"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/num_1" />

    <androidx.gridlayout.widget.GridLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="1dp"
        android:layout_marginTop="24dp"
        android:layout_marginEnd="1dp"
        app:columnCount="2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/num_2">

        <ImageButton
            android:id="@+id/plus_btn"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:src="@drawable/add" />


        <ImageButton
            android:id="@+id/multiply_btn"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:src="@drawable/multiply" />

        <ImageButton
            android:id="@+id/divide_btn"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:src="@drawable/divide" />

        <ImageButton
            android:id="@+id/minus_btn"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:src="@drawable/subtract" />


    </androidx.gridlayout.widget.GridLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        android:orientation="horizontal"
        android:padding="8dp"

        android:background="@drawable/round_corner_background"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.51"
        app:layout_constraintStart_toStartOf="parent">

        <TextView
            android:id="@+id/textView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#000000"
            android:textSize="34sp"
            android:text="@string/ans"/>

        <TextView
            android:id="@+id/ans"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:layout_weight="1"
            android:textColor="#000000"
            android:textSize="34sp"
            android:text="@string/no_input_found" />
    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity.java:

package com.example.mycalculator;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private EditText number1;
    private EditText number2;
    private ImageButton plusBtn,multiplyBtn,divideBtn,minusBtn;
    private TextView tvAns;

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

        number1 = findViewById(R.id.num_1);
        number2 = findViewById(R.id.num_2);

        plusBtn = findViewById(R.id.plus_btn);
        multiplyBtn = findViewById(R.id.multiply_btn);
        divideBtn = findViewById(R.id.divide_btn);
        minusBtn = findViewById(R.id.minus_btn);
        tvAns = findViewById(R.id.ans);

        plusBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int ansValue = plus_numbers();
                tvAns.setText(String.valueOf(ansValue));
            }
        } );

        multiplyBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int ansValue =multiply_numbers();
                tvAns.setText(String.valueOf(ansValue));
            }
        } );

        divideBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int ansValue = divide_numbers();
                tvAns.setText(String.valueOf(ansValue));
            }
        } );

        minusBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int ansValue = minus_numbers();
                tvAns.setText(String.valueOf(ansValue));
            }
        } );

    }
    private int plus_numbers(){

        int x = Integer.parseInt(number1.getText().toString());
        int y = Integer.parseInt(number2.getText().toString());

        return x + y;
    }

    private int multiply_numbers(){

        int x = Integer.parseInt(number1.getText().toString());
        int y = Integer.parseInt(number2.getText().toString());

        return x * y;
    }

    private int divide_numbers(){

        int x = Integer.parseInt(number1.getText().toString());
        int y = Integer.parseInt(number2.getText().toString());

        return x / y;
    }

    private int minus_numbers(){

        int x = Integer.parseInt(number1.getText().toString());
        int y = Integer.parseInt(number2.getText().toString());

        return x - y;
    }
}