//======================================================================
//  PROJECT:            programming.java, Chapter 9
//  FILE:               OrderPlease.java
//  VERSION:            2.0
//  TARGET:             Java 1.1
//  UPDATE HISTORY:     version 2.0        10/9/98     1.1 event model
//                      version 1.1        7/9/97      the version in _p.j_
//                      version 1.0        8/22/96     original: no Labels class
//======================================================================

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

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

//========================== OrderPlease CLASS =========================

/**
 * This applet implements a simple order form, using exceptions
 * to catch some of the possible input errors the user might make.
 */
public class OrderPlease extends    Applet
                         implements ActionListener
{
    private final String EMPTY = new String(), 
                         CRLF = new String("\n");
   	
    private Label        title = new Label("Monty's Musical Madness");	
    
    private TextField    custName = new TextField(20),
                         custStreet = new TextField(20),
                         custCityState = new TextField(20),
                         custZip = new TextField(20),
                         custPhone = new TextField(20),
                         custCC = new TextField(15),
                         custExp = new TextField("  /  ",5),
                         custQuantity = new TextField(4);
	
    private Labels       label = new Labels();
						
    private Choice       ccChoice = new Choice(),
                         productChoice = new Choice();
   
    private Button       bAddItem = new Button("Add Item"),
                         bReset = new Button("Reset"),
                         bSubmit = new Button("Submit");
                         
    private TextArea     order = new TextArea(6,40);
   	
    /**
     * Lay out the (many!) widgets and register the
     * three buttons as sources of action events
     */
    public void init()
    {
    	title.setForeground(Color.red);
    	title.setFont(new Font("TimesRoman", Font.BOLD, 24));
        add(title);
		
        //----- p1 is the panel that holds the basic customer information.
        
        Panel p1 = new Panel();
        p1.setBackground(Color.cyan);
        p1.setLayout(new GridLayout(5,2, 6, 2));
      	
        p1.add(label.name);
        custName.setBackground(Color.white);
        p1.add(custName);
      	
        p1.add(label.street);
        custStreet.setBackground(Color.white);
        p1.add(custStreet);
      	
        p1.add(label.cityState);
        custCityState.setBackground(Color.white);
        p1.add(custCityState);
      	
        p1.add(label.zip);
        custZip.setBackground(Color.white);
        p1.add(custZip);
      	
        p1.add(label.phone);
        custPhone.setBackground(Color.white);
        p1.add(custPhone);
      	
        add(p1);
            
        //----- p2 is the credit card information panel.
        
        Panel p2 = new Panel();
        p2.setBackground(Color.cyan);
		
        ccChoice.addItem("Visa");
        ccChoice.addItem("AMEX");
        ccChoice.addItem("MasterCard");
        ccChoice.addItem("Discover");
      	
        p2.add(label.ccName);
        ccChoice.setBackground(Color.white);
        p2.add(ccChoice);
      	
        p2.add(label.ccNum);
        custCC.setBackground(Color.white);
        p2.add(custCC);
      	
        p2.add(label.ccExp);
        custExp.setBackground(Color.white);
        p2.add(custExp);
      	
        add(p2);
      
        //----- p3 is the product panel.
        
        Panel p3 = new Panel();
        p3.setBackground(Color.cyan);
		
        productChoice.addItem("Amazing Accordian");
        productChoice.addItem("Harmonious Harmonica");
        productChoice.addItem("Dapper Drum Set");
        productChoice.addItem("Going Going Gong!");
        productChoice.addItem("Trump No Trumpet");
        productChoice.addItem("Kabloowie Kazooie!");
        productChoice.addItem("Power Panflute");
        productChoice.addItem("Supersizer Synthesizer");
        productChoice.addItem("Zany Zither");
      	
        p3.add(label.product);
        productChoice.setBackground(Color.white);
        p3.add(productChoice);
      	
        p3.add(label.quantity);
        custQuantity.setBackground(Color.white);
        p3.add(custQuantity);
      	
        add(p3);
      
        //----- Panel p4a is the button panel.
        
        Panel p4a = new Panel();
        p4a.add(bAddItem);
        p4a.add(bReset);
        p4a.add(bSubmit);
        
        // Register the three buttons
        bAddItem.addActionListener(this);
        bReset.addActionListener(this);
        bSubmit.addActionListener(this);
  	
        //----- p4b holds the information about the current order.
        
        Panel p4b = new Panel();
        p4b.add(label.order);
        p4b.add(order);
        
        //----- p4 holds the button panel and the info panel
        
        Panel p4 = new Panel();
        p4.setLayout(new BorderLayout());
        p4.add("North", p4a);
        p4.add("Center", p4b);
        
        add(p4);
    }
    
    /**
     * This action routine not only responds to the button clicks 
     * for processing the order information, but also catches the possible
     * MissingData exception thrown by method processSubmitButton().
     */
    public void actionPerformed(ActionEvent e) 
    {
    	Object source = e.getSource();
        if (source == bAddItem)
        {
            processAddItemButton();
        }
        else if (source == bReset)
        {
            processResetButton();
        }
        else if (source == bSubmit)
        {
            try
            {
                processSubmitButton();
            }
            catch (MissingData ex)	// Some data was missing
            {
                order.appendText("*** " + ex.getMessage() + CRLF);
            }
        }
    }

    //----------------------- PRIVATE UTILITIES ------------------------
	
    /**
     * Before adding a new item to the order, this method first checks that
     * the quantity entered in the custQuantity Textfield is
     * (1) an integer and (2) greater than zero.
     * CALLED BY: actionPerformed()
     */
    private void processAddItemButton()
    {
        try
        {
            // This might throw a NumberFormatException
            int quantity = Integer.parseInt(custQuantity.getText());
            // This might throw our own IllegalQuantity exception
            doAddItem(quantity);
        }
        catch (NumberFormatException ex) 	// The quantity is not an integer.
        {
            order.appendText("*** Must provide an integer value" + CRLF);
            order.appendText("*** in the quantity field" + CRLF);
        }
        catch (IllegalQuantity ex) 		// The quantity is not positive.
        {
            order.appendText("*** " + ex.getMessage() + CRLF);
            order.appendText("*** in the quantity field" + CRLF);
        }
    }

    /**
     * Try to add the current item to the order, checking that the
     * number entered was positive.
     * CALLED BY: processAddItemButton()
     * THROWS: IllegalQuantity
     */
    private void doAddItem(int quant) throws IllegalQuantity
    {
        if (quant < 1) // Scream if it isn't!
        {
            throw new IllegalQuantity("Must have a positive amount");
        }
        else // Quantity is OK, so go ahead and add the item to our order.
        {
            order.appendText("" + productChoice.getSelectedItem() + 
                            "   (" + custQuantity.getText() + ")" + CRLF);
        }
    }
	
    /**
     * Clear all the data fields.
     * CALLED BY: actionPerformed()
     */
    private void processResetButton()
    {
        custName.setText(EMPTY);
        custStreet.setText(EMPTY);
        custCityState.setText(EMPTY);
        custZip.setText(EMPTY);
        custPhone.setText(EMPTY);
        custCC.setText(EMPTY);
        custQuantity.setText(EMPTY);
        custExp.setText("  /  ");
        order.setText(EMPTY);
    }
		
    /**
     * Make sure all data is filled in before submitting the order.
     * CALLED BY: actionPerformed()
     * THROWS: MissingData
     */
    private void processSubmitButton() throws MissingData
    {
        if ((custName.getText().equals(EMPTY))        || 
            (custStreet.getText().equals(EMPTY))      ||
            (custCityState.getText().equals(EMPTY))   ||
            (custZip.getText().equals(EMPTY))         ||
            (custPhone.getText().equals(EMPTY))       ||
            (custCC.getText().equals(EMPTY))          ||
            (custQuantity.getText().equals(EMPTY))    ||
            (custExp.getText().equals("  /  "))       ||
            (order.getText().equals(EMPTY))	) 
        {
            throw new MissingData("Must enter data in all fields");
        }
        else // Data is all there, so submit the order.
        {
            order.appendText(CRLF + "	***  ORDER PLACED  ***");
        }
    }	
}

//============================ Labels CLASS ============================

/**
 * The sole purpose of this class is to encapsulate the labels used
 * in the OrderPlease applet.
 */
class Labels
{
    // Since this class is private within the applet, we can get
    // away with giving these variables package access.
    Label   name,
            street,
            cityState,
            zip,
            phone,
            ccName,
            ccNum,
            ccExp,
            product,
            quantity,
            order;
						
    /**
     * All the constructor has to do is initialize the labels.
     */
    public Labels()
    {
        name =      new Label("Name:", Label.RIGHT);
        street =    new Label("Street:", Label.RIGHT);
        cityState = new Label("City/State:", Label.RIGHT);
        zip =       new Label("Zip Code:", Label.RIGHT);
        phone =	    new Label("Phone #:", Label.RIGHT);
        ccName =    new Label("Use:", Label.RIGHT);
        ccNum =	    new Label("Card #:", Label.RIGHT);
        ccExp =     new Label("Exp. date:", Label.RIGHT);
        product =   new Label("Product:", Label.RIGHT);
        quantity =  new Label("Qty:", Label.RIGHT);
        order =     new Label("Order:", Label.RIGHT);
    }
}

//========================== EXCEPTION CLASSES =========================

/**
 * This is thrown by the doAddItem() method when the number 
 * of items isn't positive.
 */
class IllegalQuantity extends Exception 
{
    public IllegalQuantity()
    {
        super();
    }
    
    public IllegalQuantity(String s)
    {
        super(s);
    }
}

/**
 * Thrown by the processSubmitButton() method when one or more
 * of the data fields are empty.
 */
class MissingData extends Exception 
{
    public MissingData()
    {
        super();
    }
    
    public MissingData(String s)
    {
        super(s);
    }
}