Calculator program

11(a).java

package apples;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;
import javax.script.ScriptEngineManager;
import javax.script.ScriptEngine;
import javax.script.ScriptException;
class tuna
{
	public static void main(String[] args)
	{
		ScriptEngineManager mgr = new ScriptEngineManager();
	    ScriptEngine engine = mgr.getEngineByName("JavaScript");
		JFrame calc = new JFrame("Calc by Raj");
		calc.setMinimumSize(new Dimension(500,300));
		calc.setVisible(true);
		calc.setLayout(new GridLayout(2,1));
		calc.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		JTextArea tx = new JTextArea();
		Font font = tx.getFont();
		float size = font.getSize() + 20.0f;
		tx.setFont( font.deriveFont(size) );
		calc.add(tx);
		ActionListener blistener = new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				tx.append(e.getActionCommand());
			}
		};
		JPanel numberspanel = new JPanel(new GridLayout(4,3,2,1));
		JButton one = new JButton("1");
		one.addActionListener(blistener);
		JButton two = new JButton("2");
		two.addActionListener(blistener);
		JButton three = new JButton("3");
		three.addActionListener(blistener);
		JButton four = new JButton("4");
		four.addActionListener(blistener);
		JButton five = new JButton("5");
		five.addActionListener(blistener);
		JButton six = new JButton("6");
		six.addActionListener(blistener);
		JButton seven = new JButton("7");
		seven.addActionListener(blistener);
		JButton eight = new JButton("8");
		eight.addActionListener(blistener);
		JButton nine = new JButton("9");
		nine.addActionListener(blistener);
		JButton zero = new JButton("0");
		zero.addActionListener(blistener);
		JButton calculate = new JButton("=");
		calculate.addActionListener(new ActionListener() {

			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				String expr = tx.getText();
				try {
					tx.setText(null);
					tx.append(String.valueOf(engine.eval(expr)));
				} catch (ScriptException e1) {
					// TODO Auto-generated catch block
					e1.printStackTrace();
				}
			}
		});
		numberspanel.add(one);
		numberspanel.add(two);
		numberspanel.add(three);
		numberspanel.add(four);
		numberspanel.add(five);
		numberspanel.add(six);
		numberspanel.add(seven);
		numberspanel.add(eight);
		numberspanel.add(nine);
		numberspanel.add(zero);
		numberspanel.setSize(500,200);
		JButton add = new JButton("+");
		add.addActionListener(blistener);
		JButton sub = new JButton("-");
		sub.addActionListener(blistener);
		JButton mul = new JButton("*");
		mul.addActionListener(blistener);
		JButton div = new JButton("/");
		div.addActionListener(blistener);
		JButton mod = new JButton("%");
		mod.addActionListener(blistener);
		numberspanel.add(add);
		numberspanel.add(sub);
		numberspanel.add(mul);
		numberspanel.add(div);
		numberspanel.add(mod);
		numberspanel.add(calculate);
		calc.add(numberspanel);
		calc.pack();
	}
}