import javax.swing.*;
import java.awt.*;
import java.awt.Graphics;
import java.awt.event.*;

public class phonepad extends JFrame implements ActionListener
{
    // declare constants and variables for the entire window
    private int gap = 30;
    private int W = 60;   // width of textfield

    // declare gui elements
    private JButton convertbutton;
    private JTextField[] A; 

    // constructor:
    public phonepad(int size)
    {  int i = 0;  // loop counter
    //   create gui elements
	convertbutton = new JButton("convert");
        A = new JTextField[size];
	while (i<A.length)
	    {
		A[i] = new JTextField("-");
		i++;
	    }
    //   set position of elements
        i = 0;
	while (i<A.length)
	    {
		A[i].setBounds(gap+(i*(W+gap)),2*W,W,W);
		i++;
	    }
	convertbutton.setBounds(gap+2*(W+gap),4*W,4*(gap+W),2*gap);


    //   set additional properties (font, color, etc...)
	convertbutton.setHorizontalAlignment(JTextField.CENTER);
	for(i=0;i<size;i++) 
	    {A[i].setFont(new Font("Serif",Font.BOLD,W-2));
	     A[i].setHorizontalAlignment(JTextField.CENTER);
	    }
	convertbutton.setBackground(Color.green);
	A[3].setEditable(false);

    //   associate relevant parts with an "ActionListener"
	convertbutton.addActionListener(this);

    //   add them to window's content pane.
	Container pane = this.getContentPane();
	pane.setLayout(null);  
	pane.add(convertbutton);
	for(i=0;i<size;i++) pane.add(A[i]);

    //   set attributes of the entire window
	pane.setBackground(Color.white);
	this.setBounds(100,100,2*gap+(size*(gap+W)),6*W);
    } // constructor

    // "actionPerformed" function
    public void actionPerformed(ActionEvent e)
    {
	if (e.getSource()==convertbutton) convert();
    }

    // write event handler functions
    public void convert()
    {
	String input;
	char c;  // char to convert
	int i = 0;
	while (i<A.length)
	    {
		input=A[i].getText();
		c = input.charAt(0);
		c = convert1(c);
		A[i].setText(""+c);
		i++;
	    }
    } // convert;

    // write other functions as required by our application
    public char convert1(char c)
    {
       int a = (int)c;
       if (a>=97 && a<=122) a=a-32;
       if (a<65 || a>90) return c;
       if (a<=(int)'C') return '2';
       if (a<=(int)'F') return '3';
       if (a<=(int)'I') return '4';
       if (a<=(int)'L') return '5';
       if (a<=(int)'O') return '6';
       if (a<=(int)'S') return '7';
       if (a<=(int)'V') return '8';
         else return '9';
    }  // convert1

    public static void main(String[] args)
    {
	phonepad app = new phonepad(8);
	app.setVisible(true);
	app.addWindowListener(new WindowAdapter() {
	  public void windowClosing(WindowEvent e) {System.exit(0);} });
    }  // main

} // phonepad