ATM Simulation Implementation

// ATM Simulation Implementation - the Card Reader

ATM Simulation Implementation - the Card Reader


/*
 * Example ATM simulation - file CardReader.java
 *
 * This file implements the class that manages the ATM's Card Reader
 *
 * Copyright (c) 1997 - Russell C. Bjork
 *
 */

package atm.atmparts;
import java.awt.*;

//

Class CardReader


public class CardReader extends Button
  {

    //


    public CardReader()
      { super("Click to insert Card");
        _status = NO_CARD;
        _originalBounds = null;  // Must get this after GUI is all laid out
      }
      
    //


    public void ejectCard()
      { // Animate card coming out of machine
      
        setLabel("Ejecting card");
        Rectangle currentBounds = 
           new Rectangle(_originalBounds.x + _originalBounds.width / 2,
                         _originalBounds.y + _originalBounds.height / 2,
                         _originalBounds.width / _originalBounds.height, 1);
        show();
        
        while (currentBounds.height <= _originalBounds.height &&
               currentBounds.width <= _originalBounds.width)
          { reshape(currentBounds.x, currentBounds.y,
                    currentBounds.width, currentBounds.height);
            repaint();
            try 
              { Thread.sleep(100); } 
            catch (InterruptedException e) 
              { }
            currentBounds.height += 1;
            currentBounds.width = 
              (_originalBounds.width * currentBounds.height) / _originalBounds.height;
            currentBounds.x =
              _originalBounds.x + (_originalBounds.width - currentBounds.width) / 2;
            currentBounds.y =
              _originalBounds.y + (_originalBounds.height - currentBounds.height) / 2;
          }
          
        hide();
                  
        _status = NO_CARD; 
      }
    
    //


    public void retainCard()
      { _status = NO_CARD;
        try
          { Thread.sleep(10 * 1000); }
        catch (InterruptedException e)
          { } 
      }
                
    //


    // These are the values that can be returned by checkForCardInserted()
    
    public static final int NO_CARD = 0;
    public static final int UNREADABLE_CARD = 1;
    public static final int CARD_HAS_BEEN_READ = 2;
    
    //


    public synchronized int checkForCardInserted()
      { 
        // Wait until user clicks the "Click To Insert Card" button, or operator
        // Turns the machine off.  (The timeout in the wait ensures that we will
        // return periodically so that ATM can recheck the switch status.)
      
        if (_originalBounds == null)
            _originalBounds = bounds();
        else
            reshape(_originalBounds.x, _originalBounds.y,
                    _originalBounds.width, _originalBounds.height);

        setLabel("Click to insert card");
        show();
        repaint();
        requestFocus();
                                
        try
          { wait(1000); }
        catch (InterruptedException e)
          { }
        if (_status == NO_CARD)   // This happens if we timeout
          { hide();
            return NO_CARD;
          }
             
        // Animate card going into the machine

        Rectangle currentBounds =
           new Rectangle(_originalBounds.x, _originalBounds.y,
                         _originalBounds.width, _originalBounds.height);
                         
        while (currentBounds.width > 0 && currentBounds.height > 0)
          { reshape(currentBounds.x, currentBounds.y,
                    currentBounds.width, currentBounds.height);
            repaint();
            try 
              { Thread.sleep(100); } 
            catch (InterruptedException e) 
              { }
            currentBounds.height -= 1;
            currentBounds.width = 
              (_originalBounds.width * currentBounds.height) / _originalBounds.height;
            currentBounds.x =
              _originalBounds.x + (_originalBounds.width - currentBounds.width) / 2;
            currentBounds.y =
              _originalBounds.y + (_originalBounds.height - currentBounds.height) / 2;
          }
          
        hide();  

        // Since we don't have a magnetic stripe reader (or a literal card!),
        // pop up a dialog and ask user to enter the card number.  
        
        QuestionDialog cardNumberDialog = 
            new QuestionDialog("Enter card number:", this);

        String answer = cardNumberDialog.answer();
        
        // Extract the number typed.  Typing a non-number simulates an unreadable
        // card.
        
        if (answer == null)
             _status = UNREADABLE_CARD;
        else
          { try
              { _cardNumberRead = Integer.parseInt(answer); 
                _status = CARD_HAS_BEEN_READ;
              }
            catch (NumberFormatException e)
              { _status = UNREADABLE_CARD;
              }
           }
        return _status;
      }

    //


    public int cardNumber()
      { return _cardNumberRead;
      }
    
    //


    // Instance variables
    
    private int _status;
    private int _cardNumberRead;    

    //


    /* The following method and field are needed for the GUI */
    
    public synchronized boolean action(Event e, Object arg)
      { if (e.target == this)
          { _status = CARD_HAS_BEEN_READ;
            notify();
            return true;
          }
        else
            return false;
      }
      
    private Rectangle _originalBounds;
  }

//