package Utilities;
//======================================================================
//  PROJECT:            _programming.java_
//  FILE:               Keypad.java
//  PURPOSE:            Chapter 7 demo program, Keypad class
//  VERSION:            1.0
//  TARGET:             Java v1.1
//  UPDATE HISTORY:     1.0    11/2/98     
//======================================================================

//------------------------------ IMPORTS -------------------------------

import java.awt.*;
import java.awt.event.*;

//=========================== Keypad CLASS =============================

/**
 * A Keypad object contains eleven buttons, representing
 * the digits 0 through 9 and the decimal point.  When
 * another class uses a Keypad object, an appropriate
 * ActionListener must be provided to the Keypad
 * constructor, by calling addActionListener().
 * <BR>
 * We have to invent our own method for registering
 * the buttons, since the Panel class doesn't have an
 * addActionListener() method.
 */
public class Keypad extends Panel
{
    private Button  b0, b1, b2, b3, b4, b5, b6,
                    b7, b8, b9, bPoint;
    
    /**
     * Construct a Keypad object by laying out
     * the buttons.
     */
    public Keypad()
    {
        setLayout(new GridLayout(4, 1, 4, 4));
        
        // Top row
        Panel p1 = new Panel();
        p1.setLayout(new GridLayout(1, 3, 4, 4));
        b7 = new Button("7");
        p1.add(b7);
        b8 = new Button("8");
        p1.add(b8);
        b9 = new Button("9");
        p1.add(b9);
        add(p1);
        
        // Second row
        Panel p2 = new Panel();
        p2.setLayout(new GridLayout(1, 3, 4, 4));
        b4 = new Button("4");
        p2.add(b4);
        b5 = new Button("5");
        p2.add(b5);
        b6 = new Button("6");
        p2.add(b6);
        add(p2);
        
        // Third row
        Panel p3 = new Panel();
        p3.setLayout(new GridLayout(1, 3, 4, 4));
        b1 = new Button("1");
        p3.add(b1);
        b2 = new Button("2");
        p3.add(b2);
        b3 = new Button("3");
        p3.add(b3);
        add(p3);
        
        // Bottom row
        Panel p4 = new Panel();
        p4.setLayout(new BorderLayout(7, 4));
        b0 = new Button("0");
        p4.add("Center", b0);
        bPoint = new Button(".");
        p4.add("East", bPoint);
        add(p4);
    }
    
    /**
     * Register all of the buttons as sources for
     * ActionEvents to be handled by the ActionListener
     * provided in the argument.
     */
    public void addActionListener(ActionListener listener)
    {
        b0.addActionListener(listener);
        b1.addActionListener(listener);
        b2.addActionListener(listener);
        b3.addActionListener(listener);
        b4.addActionListener(listener);
        b5.addActionListener(listener);
        b6.addActionListener(listener);
        b7.addActionListener(listener);
        b8.addActionListener(listener);
        b9.addActionListener(listener);
        bPoint.addActionListener(listener);
    }
}