Hi everyone! This is GUI coding to create a simple calculator. It looks like the following!
It does simple mathematical calculation for multiplication, division, summation and subtraction. It works for integers and real numbers.
The coding of this simple calculator is as follows. Go ahead and try by typing it or copy paste into your NetBeans Source window. I named my file as SimpleCalculator.java.
My coding looks like following in NetBeans Source window. I will provide you coding so that you can directly copy and paste.
Coding to copy into NetBeans;
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import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class Calculator implements ActionListener {
int operator = 0;
double a = 0, b = 0, result = 0;
Operation obj = new Operation();
JLabel Name, SLab;
JButton n1, n2, n3, n4, n5, n6, n7, n8, n9, n0, clear, plus, negative, divide, multi, equal, decimal;
JTextField Result;
JFrame frame;
JPanel panel;
Font text, text1, text2;
// Buttons
Calculator() {
Result = new JTextField();
n1 = new JButton(“1”);
n2 = new JButton(“2”);
n3 = new JButton(“3”);
n4 = new JButton(“4”);
n5 = new JButton(“5”);
n6 = new JButton(“6”);
n7 = new JButton(“7”);
n8 = new JButton(“8”);
n9 = new JButton(“9”);
n0 = new JButton(“0”);
clear = new JButton(“Clear”);
plus = new JButton(“+”);
divide = new JButton(“÷”);
multi = new JButton(“*”);
negative = new JButton(“-“);
equal = new JButton(“=”);
decimal = new JButton(“.”);
SLab = new JLabel(“”);
//Setting fonts
text = new Font(“Sansserif”, Font.BOLD, 30);
text1 = new Font(“Sansserif”, Font.BOLD, 18);
text2 = new Font(“Sansserif”, Font.BOLD, 30);
n1.setFont(text1);
n2.setFont(text1);
n3.setFont(text1);
n4.setFont(text1);
n5.setFont(text1);
n6.setFont(text1);
n7.setFont(text1);
n8.setFont(text1);
n9.setFont(text1);
n0.setFont(text1);
clear.setFont(text1);
plus.setFont(text2);
divide.setFont(text2);
negative.setFont(text2);
multi.setFont(text2);
equal.setFont(text2);
decimal.setFont(text1);
Result.setFont(text);
//Setting colors
Result.setBackground(Color.white);
Result.setToolTipText(“Enter The Value”);
Result.setForeground(Color.black);
n1.setBackground(Color.yellow);
n2.setBackground(Color.yellow);
n3.setBackground(Color.yellow);
n4.setBackground(Color.yellow);
n5.setBackground(Color.yellow);
n6.setBackground(Color.yellow);
n7.setBackground(Color.yellow);
n8.setBackground(Color.yellow);
n9.setBackground(Color.yellow);
n0.setBackground(Color.yellow);
decimal.setBackground(Color.yellow);
clear.setBackground(Color.gray);
plus.setBackground(Color.gray);
divide.setBackground(Color.gray);
multi.setBackground(Color.gray);
negative.setBackground(Color.gray);
equal.setBackground(Color.gray);
equal.setToolTipText(“Click for Equal”);
//Setting boundaries
SLab.setBounds(0, 10, 100, 10);
Result.setBounds(30, 20, 405, 120);
n1.setBounds(30, 160, 50, 40);
n2.setBounds(90, 160, 50, 40);
n3.setBounds(150, 160, 50, 40);
n4.setBounds(30, 210, 50, 40);
n5.setBounds(90, 210, 50, 40);
n6.setBounds(150, 210, 50, 40);
n7.setBounds(30, 260, 50, 40);
n8.setBounds(90, 260, 50, 40);
n9.setBounds(150, 260, 50, 40);
n0.setBounds(30, 310, 50, 40);
decimal.setBounds(90, 310, 50, 40);
clear.setBounds(30, 360, 170, 40);
multi.setBounds(240, 160, 60, 65);
divide.setBounds(305, 160, 60, 65);
plus.setBounds(240, 260, 60, 65);
negative.setBounds(305, 260, 60, 65);
equal.setBounds(370, 160, 60, 165);
//action
n1.addActionListener(this);
n2.addActionListener(this);
n3.addActionListener(this);
n4.addActionListener(this);
n5.addActionListener(this);
n6.addActionListener(this);
n7.addActionListener(this);
n8.addActionListener(this);
n9.addActionListener(this);
n0.addActionListener(this);
decimal.addActionListener(this);
clear.addActionListener(this);
plus.addActionListener(this);
divide.addActionListener(this);
multi.addActionListener(this);
negative.addActionListener(this);
equal.addActionListener(this);
//Panel
panel = new JPanel();
panel.setLayout(null);
panel.setVisible(true);
panel.setBackground(Color.LIGHT_GRAY);
panel.add(Result);
panel.add(n1);
panel.add(n2);
panel.add(n3);
panel.add(n4);
panel.add(n5);
panel.add(n6);
panel.add(n7);
panel.add(n8);
panel.add(n9);
panel.add(n0);
panel.add(decimal);
panel.add(clear);
panel.add(plus);
panel.add(divide);
panel.add(multi);
panel.add(negative);
panel.add(equal);
panel.add(SLab);
//Frame
frame = new JFrame(“Calculator”);
frame.setBounds(600, 300, 460, 470);
frame.setVisible(true);
frame.getContentPane().add(panel);
frame.setResizable(false);
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
}
public void actionPerformed(ActionEvent ae) {
if (ae.getSource() == n1) {
Result.setText(Result.getText().concat(“1”));
} else if (ae.getSource() == n2) {
Result.setText(Result.getText().concat(“2”));
} else if (ae.getSource() == n3) {
Result.setText(Result.getText().concat(“3”));
} else if (ae.getSource() == n4) {
Result.setText(Result.getText().concat(“4”));
} else if (ae.getSource() == n5) {
Result.setText(Result.getText().concat(“5”));
} else if (ae.getSource() == n6) {
Result.setText(Result.getText().concat(“6”));
} else if (ae.getSource() == n7) {
Result.setText(Result.getText().concat(“7”));
} else if (ae.getSource() == n8) {
Result.setText(Result.getText().concat(“8”));
} else if (ae.getSource() == n9) {
Result.setText(Result.getText().concat(“9”));
} else if (ae.getSource() == n0) {
Result.setText(Result.getText().concat(“0”));
} else if (ae.getSource() == decimal) {
Result.setText(Result.getText().concat(“.”));
//
} else if (ae.getSource() == plus) {
a = Double.parseDouble(Result.getText());
operator = 1;
Result.setText(“”);
} else if (ae.getSource() == divide) {
a = Double.parseDouble(Result.getText());
operator = 2;
Result.setText(“”);
} else if (ae.getSource() == multi) {
a = Double.parseDouble(Result.getText());
operator = 3;
Result.setText(“”);
} else if (ae.getSource() == negative) {
a = Double.parseDouble(Result.getText());
operator = 4;
Result.setText(“”);
} else if (ae.getSource() == equal) {
b = Double.parseDouble(Result.getText());
switch (operator) {
case 1:
result = obj.Add(a, b);
break;
case 2:
result = obj.Divide(a, b);
break;
case 3:
result = obj.Multi(a, b);
break;
case 4:
result = obj.Sub(a, b);
break;
}
Result.setText(“” + result);
} else if (ae.getSource() == clear) {
Result.setText(“”);
}
}
}
class Operation {
public double Add(double input1, double input2) {
double c = input1 + input2;
return (c);
}
public double Sub(double input1, double input2) {
double c = input1 – input2;
return (c);
}
public double Multi(double input1, double input2) {
double c = input1 * input2;
return (c);
}
public double Divide(double input1, double input2) {
double c = input1 / input2;
return (c);
}
}
public class SimpleCalculator {
public static void main(String[] arg) {
Calculator b = new Calculator();
}
}
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In the next post, we will learn how to convert GUI codings into desktop applications.
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