My Code [Refactor]

class McPatternsPresenter { //This is the class that will handle the model <-> UI communication. private MenuModel model; private ArrayList<ChangeListener> listeners; private Formatter formatter; public McPatternsPresenter() { //code to read a file and load the menu items. MenuReader menuReader = FileReaderStrategy.getFromDefaultFile('|'); model = new MenuModel(menuReader); listeners = new ArrayList<ChangeListener>(); formatter = new Formatter(); } /* *Method adds "menuItem" to MenuModel, then updates the view's screen *Obserser Design Pattern */ public void add(MenuItem menuItem){ model.add(menuItem); ChangeEvent event = new ChangeEvent(this); for(ChangeListener lister : listeners) lister.stateChanged(event); } // clears the screen & model's data public void clear(){ model.clear(); ChangeEvent event = new ChangeEvent(this); for(ChangeListener lister : listeners) lister.stateChanged(event); } public void addChangeListener(ChangeListener listener){ listeners.add(listener); } // Instruction to display text public String getOrder(){ StringBuilder sb = new StringBuilder(); sb.append(formatter.formatHeader()); for(MenuItem item : model.getOrderList()) sb.append(formatter.formatOrder(item)); sb.append(formatter.formatFooter()); return sb.toString(); } /* *Factory Design Pattern */ public String getCreditCardNumber(String number){ CreditCard cc = CreditCardFactory.createCard(number); if(cc == null) return "Please Re-Enter"; return cc.display(); } /* Contains the menu. The GUI will ask for the List then makes JButtons array from it. */ public ArrayList<MenuItem> getMenuItem(){ return model.getMenuItem(); } } //////////////////// HERE IS THE MAIN MODIFICATION //////////////////////////////////// //If and only if you can modify the MenuReader and transform it in a interface/////// public interface MenuReader{ public void read(); public List<MenuItem> getMenu(); } public class FileReaderStrategy implements MenuReader{ private List<MenuItem> items; private String fileName; private String sep; private FileReaderStrategy(String fileName, String sep){ this.fileName = fileName; this.sep = sep; } @Override public void read(){ //do your reading XD } @Override public List<MenuItem> getMenu(){ //never return the reference :) return new ArrayList<>(this.items); } public static FileReaderStrategy getFromDefaultFile(String sep){ return new FileReaderStrategy(fileName, sep); } public static FileReaderStrategy getFromFile(String file, String sep){ return new FileReaderStrategy(file, sep); } } ////////////////////////////////////////////////////////////////////////////// class MenuModel { // ArrayList hold MenuItem private ArrayList<MenuItem> menuItems; private ArrayList<MenuItem> order; public MenuModel(MenuReader menuReader){ order = new ArrayList<MenuItem>(); menuReader.read(); menuItems = reader.getMenu(); } // update the menu & price public void add(MenuItem menuItem){ order.add(menuItem); } /** * @return Menu Order Size */ public int size(){ return order.size(); } // clear price and menu public void clear(){ order.clear(); } // Possible order available public List<MenuItem> getMenuItem(){ return new ArrayList<>(menuItems); } // Get what was ordered //Interfaces over implementation public List<MenuItem> getOrderList(){ return new ArrayList<>(order); } } class McPatternsGUI{ private McPatternsPresenter presenter; public McPatternsGUI(McPatternsPresenter presenter) { this.presenter = presenter; presenter.attachView(this); showGUI(); } // Update JTextArea screen private void showGUI() { final JTextArea screen = new JTextArea(3, 20); JScrollPane qScroller = new JScrollPane(screen); qScroller.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS); qScroller.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER); JFrame theFrame = new JFrame(); theFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); theFrame.setLayout(new BorderLayout()); screen.setEditable(false); JPanel title = new JPanel(new BorderLayout()); title.setSize(500,500); title.add(new JLabel("Welcome to McPatterns"), BorderLayout.NORTH); screen.setText("Input..."); // Observer Design Pattern ChangeListener listener = new ChangeListener(){ @Override public void stateChanged(ChangeEvent e) { screen.setText(presenter.getOrder()); } }; presenter.addChangeListener(listener); JPanel orderPane = new JPanel(); orderPane.setLayout(new BoxLayout(orderPane, BoxLayout.PAGE_AXIS)); final JLabel orderDetails = new JLabel("Your order"); orderPane.setBorder(BorderFactory.createRaisedBevelBorder()); //orderPane.add(qScroller); orderPane.add(orderDetails); final JTextField ccEntry = new JTextField("Enter CC #"); JButton confirm = new JButton("Place Order"); confirm.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { //Add the function to handle confirmed order //Talks to presenter to get credit caard String display = presenter.getCreditCardNumber(ccEntry.getText()); orderDetails.setText("Order confrimed for " + display); } }); JButton cancel = new JButton("Cancel Order"); cancel.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { // Add the function to handle cancel order // Presenter will create Screen & Model presenter.clear(); orderDetails.setText("Order cancelled"); } }); orderPane.add(ccEntry); orderPane.add(confirm); orderPane.add(cancel); JPanel buttonPanel = new JPanel(); //buttonPanel.setLayout(new GridLayout(4,4,1,1));//new BoxLayout(buttonPanel, BoxLayout.LINE_AXIS)); // Ask the presenter for the buttons to create // Iterate over the buttons and create them ArrayList<MenuItem> menuList = presenter.getMenuItem(); buttonPanel.setLayout(new GridLayout(menuList.size()/2,menuList.size()/2)); for(final MenuItem menuItem : menuList){ JButton button = new JButton(menuItem.getName()); buttonPanel.add(button); button.addActionListener(new ActionListener(){ @Override public void actionPerformed(ActionEvent e) { presenter.add(menuItem); } }); } buttonPanel.setLayout(new FlowLayout()); theFrame.add(title,BorderLayout.NORTH); theFrame.add(buttonPanel, BorderLayout.CENTER); theFrame.add(qScroller, BorderLayout.EAST); theFrame.add(orderPane, BorderLayout.SOUTH); theFrame.setSize(800, 600); theFrame.setLocationRelativeTo(null); theFrame.setVisible(true); } }