Calculator

/**
 * Calculator 2.0 (Java Swing)
 * Date : 13.08.19
 */
package Swing;
import javax.swing.*;
import java.awt.event.*;
import java.awt.font.*;
import java.awt.Font;

public class Calculator implements ActionListener {
    JTextField tf;
    JButton b0, b1, b2, b3, b4, b5, b6, b7, b8, b9;
    JButton plus, minus, mult, div, equal, point, sqrt, power, reset;
    String display = "0", temporary = "0";
    double dis = 0, temp = 0;
    int operation = 0;
    boolean pointonof = false;
    boolean poweronof = false;
    Font f1 = new Font("Consolas", Font.BOLD, 40);
    Calculator(){
        JFrame f = new JFrame("Calculator");
        tf = new JTextField("0");
        tf.setBounds(50, 50, 300, 50);
        tf.setHorizontalAlignment(JTextField.RIGHT);
        tf.setFont(f1);
        f.add(tf);

        b7 = new JButton("7");
        b7.setBounds(50, 110, 50, 50);
        b7.addActionListener(this);
        f.add(b7);

        b8 = new JButton("8");
        b8.setBounds(110, 110, 50, 50);
        b8.addActionListener(this);
        f.add(b8);

        b9 = new JButton("9");
        b9.setBounds(170, 110, 50, 50);
        b9.addActionListener(this);
        f.add(b9);

        div = new JButton("/");
        div.setBounds(230, 110, 50, 50);
        div.addActionListener(this);
        f.add(div);

        sqrt = new JButton("Sqrt");
        sqrt.setBounds(290, 110, 60, 50);
        sqrt.addActionListener(this);
        f.add(sqrt);

        b4 = new JButton("4");
        b4.setBounds(50, 170, 50, 50);
        b4.addActionListener(this);
        f.add(b4);

        b5 = new JButton("5");
        b5.setBounds(110, 170, 50, 50);
        b5.addActionListener(this);
        f.add(b5);

        b6 = new JButton("6");
        b6.setBounds(170, 170, 50, 50);
        b6.addActionListener(this);
        f.add(b6);

        mult = new JButton("X");
        mult.setBounds(230, 170, 50, 50);
        mult.addActionListener(this);
        f.add(mult);

        power = new JButton("X^Y");
        power.setBounds(290, 170, 60, 50);
        power.addActionListener(this);
        f.add(power);

        b1 = new JButton("1");
        b1.setBounds(50, 230, 50, 50);
        b1.addActionListener(this);
        f.add(b1);

        b2 = new JButton("2");
        b2.setBounds(110, 230, 50, 50);
        b2.addActionListener(this);
        f.add(b2);

        b3 = new JButton("3");
        b3.setBounds(170, 230, 50, 50);
        b3.addActionListener(this);
        f.add(b3);

        minus = new JButton("-");
        minus.setBounds(230, 230, 50, 50);
        minus.addActionListener(this);
        f.add(minus);

        reset = new JButton("RC");
        reset.setBounds(290, 230, 60, 50);
        reset.addActionListener(this);
        f.add(reset);

        b0 = new JButton("0");
        b0.setBounds(50, 290, 50, 50);
        b0.addActionListener(this);
        f.add(b0);

        point = new JButton(".");
        point.setBounds(110, 290, 50, 50);
        point.addActionListener(this);
        f.add(point);

        equal = new JButton("=");
        equal.setBounds(170, 290, 50, 50);
        equal.addActionListener(this);
        f.add(equal);

        plus = new JButton("+");
        plus.setBounds(230, 290, 50, 50);
        plus.addActionListener(this);
        f.add(plus);

        f.setSize(420,400);
        f.setLayout(null);
        f.setVisible(true);
    }
    public void actionPerformed(ActionEvent e){
        if(e.getSource() == reset){
            display = "0"; temporary = "0";
            dis = 0; temp = 0;
            operation = 0;
            pointonof = false;
            poweronof = false;
            tf.setText(display);
        }
        else if(e.getSource() == point){
            if(!pointonof){
                pointonof = true;
                display = display + '.';
                tf.setText(display);
            }
        }
        else if(e.getSource() == b0){
            if(display != "0"){
                display = display + '0';
            }
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == b1){
            if(display == "0"){ display = "1"; }
            else display = display + '1';
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == b2){
            if(display == "0"){ display = "2"; }
            else display = display + '2';
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == b3){
            if(display == "0"){ display = "3"; }
            else display = display + '3';
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == b4){
            if(display == "0"){ display = "4"; }
            else display = display + '4';
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == b5){
            if(display == "0"){ display = "5"; }
            else display = display + '5';
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == b6){
            if(display == "0"){ display = "6"; }
            else display = display + '6';
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == b7){
            if(display == "0"){ display = "7"; }
            else display = display + '7';
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == b8){
            if(display == "0"){ display = "8"; }
            else display = display + '8';
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == b9){
            if(display == "0"){ display = "9"; }
            else display = display + '9';
            dis = Double.parseDouble(display);
            tf.setText(display);
        }
        else if(e.getSource() == equal){
            if(operation == 1){
                temp += dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 2){
                temp -= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 3){
                temp *= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 4){
                temp /= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            tf.setText(display);
            display = "0";
            operation = 0;
            pointonof = false;
        }
        else if(e.getSource() == plus){
            if(operation == 1){
                temp += dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 2){
                temp -= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 3){
                temp *= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 4){
                temp /= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else{
                temp = Double.parseDouble(display);
            }
            operation = 1;
            tf.setText(display);
            display = "0";
            pointonof = false;
        }
        else if(e.getSource() == minus){
            if(operation == 1){
                temp += dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 2){
                temp -= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 3){
                temp *= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 4){
                temp /= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else{
                temp = Double.parseDouble(display);
            }
            operation = 2;
            tf.setText(display);
            display = "0";
            pointonof = false;
        }
        else if(e.getSource() == mult){
            if(operation == 1){
                temp += dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 2){
                temp -= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 3){
                temp *= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 4){
                temp /= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else{
                temp = Double.parseDouble(display);
            }
            operation = 3;
            tf.setText(display);
            display = "0";
            pointonof = false;
        }
        else if(e.getSource() == div){
            if(operation == 1){
                temp += dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 2){
                temp -= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 3){
                temp *= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else if(operation == 4){
                temp /= dis;
                dis = 0;
                display = String.valueOf(temp);
            }
            else{
                temp = Double.parseDouble(display);
            }
            operation = 4;
            tf.setText(display);
            display = "0";
            pointonof = false;
        }
        else if(e.getSource() == sqrt){
            if(operation == 0){
                dis = Math.sqrt(dis);
                display = String.valueOf(dis);
                tf.setText(display);
            }
            else{
                display = "ERROR";
                tf.setText(display);
            }
            display = "0";
            //dis = 0;
            pointonof = false;
            operation = 0;
        }
        else if(e.getSource() == power){
            if(operation == 0){
                if(poweronof){
                    dis = Math.pow(temp, dis);
                    display = String.valueOf(dis);
                    tf.setText(display);
                    dis = 0;
                    display = "0";
                     //dis = 0;
                    pointonof = false;
                    operation = 0;
                    pointonof = false;
                }
                else{
                    poweronof = true;
                    temp = dis;
                    dis = 0;
                    display = "0";
                }
            }
            else{
                display = "ERROR";
                tf.setText(display);
                display = "0";
                //dis = 0;
                pointonof = false;
                operation = 0;

            }
        }
    }
    public static void main(String[] args){
        new Calculator();
    }
}