calc.java

java calculator that calculate what you want we have +/-/*/// and much more

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Vector;
public class Calc extends JFrame implements ActionListener
{
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private Vector <Double> numbers = null;
	private Vector <Integer> actions = null;
	private Container c;
	private int dottedHez = 1;
	private JButton plus;
	private JButton minus;
	private JButton mult;
	private JButton div;
	private JButton point;
	private JButton sign;
	private JButton calc;
	private Double sum =0.0;

	
	int [] flags = new int [9];
	/*
	 * this are the array indexes:
	 * plus
	 * minus
	 * mult
	 * div
	 * sign
	 * dot
	 * calc
	 * number
 */
	
	private Double temp = 0.0;

	JButton[] numArray = new JButton [10];
	
	private JTextArea output = new JTextArea(1,100);
	
	public Calc()
	{
		
		super("calculator");
		setSize (300,200);
		zeroes();
		numbers = new Vector<Double>(1);
		actions = new Vector<Integer>(1);
		c= getContentPane();
		c.setLayout(new FlowLayout(FlowLayout.LEFT, 20, 20));
		createButtons();
		c.add(output,0);
		setVisible(true);
		
	}
	public static void main(String[] args)
	{
		Calc myCalc = new Calc();
		
	}
	
	@Override
	public void actionPerformed(ActionEvent e )
	{
		// TODO Auto-generated method stub
		/*
		 * this are the array indexes:
		 * plus -0
		 * minus -1
		 * mult -2
		 * div -3
		 * sign -4
		 * dot -5 
		 * calc -6
		 * number -7
	 */
		
		if (flags[7]==0)
			output.setText("");
		flags[7] =0;
		Integer i =0;
		for (i=0; i<10; i++)
		{
			if (e.getSource() == numArray[i])
			{	
				
				output.append (i.toString());
				if (flags[5] == 1)//it is with dot
				{
					dottedHez *=10;
					if (temp>=0)
						temp+=(i.doubleValue()/dottedHez);
					else
						temp-=(i.doubleValue()/dottedHez);
						
				}
				else
				{
					temp *= 10;
					if (temp>= 0)
					{
						temp += i;
					}
					else
						temp -= i;
				
				}
				flags[7] =1 ;
				
			}
		}
		if ( e.getSource() == sign)
		{
			temp = 0 - temp;
			output.setText(temp+"");
			
			flags[7] = 1;
		}
			
		if ( e.getSource() == point)
		{
			output.append(".");
			flags[5] =1;
			flags[7] = 1;
		}
		if ( e.getSource() != point && flags [7]== 0)
		{
			
			dottedHez=1;
			flags[5] = 0;
		}
		
		if (flags[7]==0 && flags [5] == 0)
		{
			numbers.addElement(temp);
			temp =0.0;
			calculate();
			output.setText(sum+"");
		
		}
				
		if ( e.getSource() == plus)
		{
		
			flags[0] =1;
			actions.add(1);
					
		}
		
		if ( e.getSource() == minus)
		{
			flags[1] =1;
			actions.add(2);
		
		}
	
		if ( e.getSource() == div)
		{
			flags[3] = 1;
			actions.add(4);
		}
		
		
		if ( e.getSource() == mult)
		{
			flags[2] =1;
			actions.add(3);
		}
		if ( e.getSource() == calc)
		{
			calculate();
			output.setText(sum+"");
		}
		
	
	}

	private void createButtons()
	{
		Integer i =1;
		for (i=0 ; i<10; i++)
			numArray[i] = new JButton (i.toString());
		for (i=0 ; i<10; i++)
			c.add(numArray[i]);
		for (i=0; i<10; i++)
		{
			numArray[i].addActionListener(this);
		}
		plus = new JButton ("+");
		minus= new JButton ("-");
		mult= new JButton ("*");;
		div = new JButton ("/");
		point= new JButton (".");
		sign=  new JButton ("+/-");
		calc= new JButton ("=");
		plus.addActionListener(this);
		minus.addActionListener(this);
		mult.addActionListener(this);
		div.addActionListener(this);
		point.addActionListener(this);
		sign.addActionListener(this);
		calc.addActionListener(this);
		c.add(plus);
		c.add(minus);
		c.add(div);
		c.add (mult);
		c.add(point);
		c.add (sign);
		c.add (calc);
		
	}
	
	private void zeroes ()
	{
		for (int i =0 ; i <flags.length; i++)
		{
			flags[i] = 0;
		}
	}
private void calculate ()
{
	int i=0;
	int j=0;
	sum = numbers.elementAt(i);
	output.setText(numbers.size()+"");
	for (i = 0; i< numbers.size()-1; i++)
	{
		switch (actions.elementAt(j))
		{
			case 1:
			{
				sum+=numbers.elementAt(i+1);
				break;
			}
			case 2:
			{
				sum-=numbers.elementAt(i+1);
				break;
			}
			case 3:
			{
				sum*=numbers.elementAt(i+1);
				break;
			}
			case 4:
			{
				sum/=numbers.elementAt(i+1);
				break;
			}
			
		}
		j++;
	}

}

}