import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.text.DecimalFormat;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextArea;
public class Calculator extends JFrame {
private JLabel stuno = new JLabel("學號:29130101016");
private JLabel stuname = new JLabel("姓名：陳昕");
private JPanel inputPanel = new JPanel();
private JPanel operationPanel = new JPanel();
private JTextArea input = new JTextArea(2, 18);
private JButton backspace = new JButton("<-");
private JButton CE = new JButton("CE ");
private JButton C = new JButton("C ");
private JButton sign = new JButton("+/-");
private JButton sqrt = new JButton("SQRT");
private JButton percentage = new JButton("%");
private JButton fraction = new JButton("1/x");
private JButton add = new JButton("+");
private JButton sub = new JButton("-");
private JButton mul = new JButton("*");
private JButton div = new JButton("/");
private JButton decimal = new JButton(".");
private JButton equal = new JButton("=");
private JButton zero = new JButton("0");
private JButton one = new JButton("1");
private JButton two = new JButton("2");
private JButton three = new JButton("3");
private JButton four = new JButton("4");
private JButton five = new JButton("5");
private JButton six = new JButton("6");
private JButton seven = new JButton("7");
private JButton eight = new JButton("8");
private JButton nine = new JButton("9");
private JTextArea blank = new JTextArea(2, 18);
private String num1 = "";
private String operator = "";
public static void main(String[] args) {
new Calculator();
}
public Calculator(){
super("Calculator");
super.setBackground(Color.black);
super.setBounds(300, 300, 300, 320);
JPanel information = new JPanel();
information.setLayout(new GridLayout(1, 2));
information.add(stuno);
information.add(stuname);
super.add(information, BorderLayout.NORTH);
inputPanel.add(input);
input.setBackground(new Color(197, 215, 216));
inputPanel.add(blank);
inputPanel.setBackground(Color.gray);
inputPanel.setLayout(new GridLayout(2, 1));
blank.setEditable(false);
super.add(inputPanel, BorderLayout.CENTER);
operationPanel.add(backspace);
operationPanel.add(CE);
operationPanel.add(C);
operationPanel.add(sign);
operationPanel.add(sqrt);
operationPanel.add(seven);
operationPanel.add(eight);
operationPanel.add(nine);
operationPanel.add(div);
operationPanel.add(percentage);
operationPanel.add(four);
operationPanel.add(five);
operationPanel.add(six);
operationPanel.add(mul);
operationPanel.add(fraction);
operationPanel.add(one);
operationPanel.add(two);
operationPanel.add(three);
operationPanel.add(sub);
operationPanel.add(decimal);
JButton dummyBtn = new JButton(" ");
dummyBtn.setVisible(false);
operationPanel.add(dummyBtn);
operationPanel.add(zero);
dummyBtn = new JButton(" ");
dummyBtn.setVisible(false);
operationPanel.add(dummyBtn);
operationPanel.add(add);
operationPanel.add(equal);
operationPanel.setLayout(new GridLayout(5, 5));
operationPanel.setBackground(Color.gray);
super.add(operationPanel, BorderLayout.SOUTH);
super.setVisible(true);
super.pack();
super.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton[] operatAry = {backspace, CE, C, decimal, equal, sign, sqrt, percentage, fraction};
OperationMouseListener oepratorMouseListern = new OperationMouseListener();
for(JButton btnItem: operatAry){
btnItem.addMouseListener(oepratorMouseListern);
}
add.addMouseListener(new CalcMouseListener());
sub.addMouseListener(new CalcMouseListener());
mul.addMouseListener(new CalcMouseListener());
div.addMouseListener(new CalcMouseListener());
JButton[] numberBtnAry = {zero, one, two, three, four, five, six, seven, eight, nine};
NumberMouseListener numberMouseListener = new NumberMouseListener();
for(JButton btnItem: numberBtnAry){
btnItem.addMouseListener(numberMouseListener);
}
}
private class NumberMouseListener implements MouseListener{
public void mouseClicked(MouseEvent e) {
if(input.getText().trim().equals("0")){
input.setText(((JButton)e.getSource()).getText().trim());
}else{
input.setText(input.getText().concat(((JButton)e.getSource()).getText().trim()));
}
}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}
private class CalcMouseListener implements MouseListener{
public void mouseClicked(MouseEvent e) {
num1 = input.getText().trim();
input.setText("");
operator = ((JButton)e.getSource()).getText().trim();
}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}
private class OperationMouseListener implements MouseListener{
public void mouseClicked(MouseEvent e) {
if(e.getSource() == backspace){
String inputText = input.getText();
if(inputText.length() > 0){
input.setText(inputText.substring(0, inputText.length() - 1));
}
}else if(e.getSource() == C){
input.setText("0");
num1 = "";
}else if(e.getSource() == CE){
input.setText("0");
}else if(e.getSource() == decimal){
String text = input.getText().trim();
if(text.indexOf(".") == -1){
input.setText(text.concat("."));
}
}else if(e.getSource() == equal){
if(!operator.trim().equals("")){
if(!input.getText().trim().equals("")){
double result = 0D;
if(operator.equals("+")){
result = Double.parseDouble(num1) + Double.parseDouble(input.getText().trim());
}else if(operator.equals("-")){
result = Double.parseDouble(num1) - Double.parseDouble(input.getText().trim());
}else if(operator.equals("*")){
result = Double.parseDouble(num1) * Double.parseDouble(input.getText().trim());
}else if(operator.equals("/")){
result = Double.parseDouble(num1) / Double.parseDouble(input.getText().trim());
}
input.setText(new DecimalFormat("0.00").format(result));
}
}
}else if(e.getSource() == sign){
if(input.getText().length() > 0){
if(input.getText().charAt(0) == '-'){
input.setText(input.getText().substring(1));
}else{
input.setText("-".concat(input.getText()));
}
}
}else if(e.getSource() == sqrt){
double value = Double.parseDouble(input.getText());
if(value < 0){
JOptionPane.showMessageDialog(null, "Error! Can't calculate negative number for sqrt operation");
}else{
input.setText(String.valueOf(Math.sqrt(value)));
}
}else if(e.getSource() == percentage){
double value = Double.parseDouble(input.getText());
if(value != 0){
input.setText(String.valueOf(value / 100));
}
}else if(e.getSource() == fraction){
double value = Double.parseDouble(input.getText());
if(value != 0){
input.setText(String.valueOf(1 / value));
}
}
}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
}
}