Using Java Swing, Implement a simple integer calculator JCalculator program with
ID: 3879859 • Letter: U
Question
Using Java Swing, Implement a simple integer calculator JCalculator program with the following features: .
1. Center the calculator on the screen at startup.
2. All the operations are in the form: (operand1 operator1 operand2 =) operator2 operand3 =
3. The [C] button will clear the calculator, eg. initial state. Ctrl+Shift+[C] button combination will display “(c) 2018 your-name” Only the [C] button will restore the current display.
4. The [=] button is the default button.
5. Only allow up to 10 digits.
6. Display errors such as “Overflow”, “Div by 0”, …, and the [C] button will clear the error and reset the calculator.
7. Use JCalculator.png as the program icon.
Explanation / Answer
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class JCalculator extends JFrame implements ActionListener {
JPanel[] row = new JPanel[5];
JButton[] button = new JButton[19];
String[] buttonString = {"7", "8", "9", "+",
"4", "5", "6", "-",
"1", "2", "3", "*",
".", "/", "C", "",
"+/-", "=", "0"};
int[] dimW = {300,45,100,90};
int[] dimH = {35, 40};
Dimension displayDimension = new Dimension(dimW[0], dimH[0]);
Dimension regularDimension = new Dimension(dimW[1], dimH[1]);
Dimension rColumnDimension = new Dimension(dimW[2], dimH[1]);
Dimension zeroButDimension = new Dimension(dimW[3], dimH[1]);
boolean[] function = new boolean[4];
double[] temporary = {0, 0};
JTextArea display = new JTextArea(1,20);
Font font = new Font("Times new Roman", Font.BOLD, 14);
JCalculator() {
super("JCalculator");
setDesign();
setSize(380, 250);
setResizable(false);
setDefaultCloseOperation(EXIT_ON_CLOSE);
GridLayout grid = new GridLayout(5,5);
setLayout(grid);
for(int i = 0; i < 4; i++)
function[i] = false;
FlowLayout f1 = new FlowLayout(FlowLayout.CENTER);
FlowLayout f2 = new FlowLayout(FlowLayout.CENTER,1,1);
for(int i = 0; i < 5; i++)
row[i] = new JPanel();
row[0].setLayout(f1);
for(int i = 1; i < 5; i++)
row[i].setLayout(f2);
for(int i = 0; i < 19; i++) {
button[i] = new JButton();
button[i].setText(buttonString[i]);
button[i].setFont(font);
button[i].addActionListener(this);
}
display.setFont(font);
display.setEditable(false);
display.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
display.setPreferredSize(displayDimension);
for(int i = 0; i < 14; i++)
button[i].setPreferredSize(regularDimension);
for(int i = 14; i < 18; i++)
button[i].setPreferredSize(rColumnDimension);
button[18].setPreferredSize(zeroButDimension);
row[0].add(display);
add(row[0]);
for(int i = 0; i < 4; i++)
row[1].add(button[i]);
row[1].add(button[14]);
add(row[1]);
for(int i = 4; i < 8; i++)
row[2].add(button[i]);
row[2].add(button[15]);
add(row[2]);
for(int i = 8; i < 12; i++)
row[3].add(button[i]);
row[3].add(button[16]);
add(row[3]);
row[4].add(button[18]);
for(int i = 12; i < 14; i++)
row[4].add(button[i]);
row[4].add(button[17]);
add(row[4]);
setVisible(true);
}
public void clear() {
try {
display.setText("");
for(int i = 0; i < 4; i++)
function[i] = false;
for(int i = 0; i < 2; i++)
temporary[i] = 0;
} catch(NullPointerException e) {
}
}
public void getSqrt() {
try {
double value = Math.sqrt(Double.parseDouble(display.getText()));
display.setText(Double.toString(value));
} catch(NumberFormatException e) {
}
}
public void getPosNeg() {
try {
double value = Double.parseDouble(display.getText());
if(value != 0) {
value = value * (-1);
display.setText(Double.toString(value));
}
else {
}
} catch(NumberFormatException e) {
}
}
public void getResult() {
double result = 0;
temporary[1] = Double.parseDouble(display.getText());
String temp0 = Double.toString(temporary[0]);
String temp1 = Double.toString(temporary[1]);
try {
if(temp0.contains("-")) {
String[] temp00 = temp0.split("-", 2);
temporary[0] = (Double.parseDouble(temp00[1]) * -1);
}
if(temp1.contains("-")) {
String[] temp11 = temp1.split("-", 2);
temporary[1] = (Double.parseDouble(temp11[1]) * -1);
}
} catch(ArrayIndexOutOfBoundsException e) {
}
try {
if(function[2] == true)
result = temporary[0] * temporary[1];
else if(function[3] == true)
result = temporary[0] / temporary[1];
else if(function[0] == true)
result = temporary[0] + temporary[1];
else if(function[1] == true)
result = temporary[0] - temporary[1];
display.setText(Double.toString(result));
for(int i = 0; i < 4; i++)
function[i] = false;
} catch(NumberFormatException e) {
}
}
public final void setDesign() {
try {
UIManager.setLookAndFeel(
"com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
} catch(Exception e) {
}
}
@Override
public void actionPerformed(ActionEvent ae) {
if(ae.getSource() == button[0])
display.append("7");
if(ae.getSource() == button[1])
display.append("8");
if(ae.getSource() == button[2])
display.append("9");
if(ae.getSource() == button[3]) {
//add function[0]
temporary[0] = Double.parseDouble(display.getText());
function[0] = true;
display.setText("");
}
if(ae.getSource() == button[4])
display.append("4");
if(ae.getSource() == button[5])
display.append("5");
if(ae.getSource() == button[6])
display.append("6");
if(ae.getSource() == button[7]) {
//subtract function[1]
temporary[0] = Double.parseDouble(display.getText());
function[1] = true;
display.setText("");
}
if(ae.getSource() == button[8])
display.append("1");
if(ae.getSource() == button[9])
display.append("2");
if(ae.getSource() == button[10])
display.append("3");
if(ae.getSource() == button[11]) {
//multiply function[2]
temporary[0] = Double.parseDouble(display.getText());
function[2] = true;
display.setText("");
}
if(ae.getSource() == button[12])
display.append(".");
if(ae.getSource() == button[13]) {
//divide function[3]
temporary[0] = Double.parseDouble(display.getText());
function[3] = true;
display.setText("");
}
if(ae.getSource() == button[14])
clear();
if(ae.getSource() == button[15])
getSqrt();
if(ae.getSource() == button[16])
getPosNeg();
if(ae.getSource() == button[17])
getResult();
if(ae.getSource() == button[18])
display.append("0");
}
public static void main(String[] arguments) {
JCalculator c = new JCalculator();
}
}
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