{

// the attributes

private int noOfRooms;

private TenantList list;

// WIDTH and HEIGHT of GUI stored as constants

private final int WIDTH = 800;

private final int HEIGHT = 500;

// visual components

private Label headingLabel = new Label("Hostel Application");

private Label roomLabel1 = new Label("Room");

private TextField roomField1 = new TextField();

private Label nameLabel = new Label("Name");

private TextField nameField = new TextField();

private Button addButton = new Button("Add Tenant");

private Button displayButton = new Button("Display Tenants");

private Button removeButton = new Button("Remove Tenant");

private Button saveAndQuitButton = new Button("Save and Quit");

private TextArea displayArea1 = new TextArea();

private Label roomLabel2 = new Label("Room");

private TextField roomField2 = new TextField();

private Label monthLabel = new Label("Month");

private TextField monthField = new TextField();

private Label amountLabel = new Label("Amount");

private TextField amountField = new TextField();

private Button paymentButton = new Button("Make Payment");

private Button listButton = new Button("List Payments");

private TextArea displayArea2 = new TextArea();

@Override

/** Initialises the screen

public void start(Stage stage)

{

noOfRooms = getNumberOfRooms(); // call private method

// initialise tenant list

list = new TenantList(noOfRooms);

TenantFileHandler.readRecords(list);

// create four HBoxes

HBox roomDetails = new HBox (10);

HBox tenantButtons = new HBox(10);

HBox paymentDetails = new HBox(10);

HBox paymentButtons = new HBox(10);

// add components to HBoxes

roomDetails.getChildren().addAll(roomLabel1, roomField1, nameLabel, nameField);

tenantButtons.getChildren().addAll( addButton, displayButton, removeButton,

saveAndQuitButton);

paymentDetails.getChildren().addAll( roomLabel2, roomField2, monthLabel, monthField,

amountLabel, amountField);

paymentButtons.getChildren().addAll(paymentButton, listButton);

// create VBox

VBox root = new VBox(10);

// add all components to VBox

root.getChildren().addAll( headingLabel, roomDetails, tenantButtons, displayArea1,

paymentDetails, paymentButtons, displayArea2);

// create the scene

Scene scene = new Scene(root, Color.LIGHTBLUE);

// set font of heading

Font font = new Font("Calibri", 40);

headingLabel.setFont(font);

// set alignment of HBoxes

roomDetails.setAlignment(Pos.CENTER);

tenantButtons.setAlignment(Pos.CENTER);

paymentDetails.setAlignment(Pos.CENTER);

paymentButtons.setAlignment(Pos.CENTER);

// set alignment of VBox

root.setAlignment(Pos.CENTER);

// set minimum and maximum width of components

roomField1.setMaxWidth(50);

roomField2.setMaxWidth(50);

roomDetails.setMinWidth(WIDTH);

roomDetails.setMaxWidth(WIDTH);

tenantButtons.setMinWidth(WIDTH);

tenantButtons.setMaxWidth(WIDTH);

paymentDetails.setMinWidth(WIDTH);

paymentDetails.setMaxWidth(WIDTH);

paymentButtons.setMinWidth(WIDTH);

paymentButtons.setMaxWidth(WIDTH);

root.setMinSize(WIDTH, HEIGHT);

root.setMaxSize(WIDTH, HEIGHT);

displayArea1.setMaxSize(WIDTH - 80, HEIGHT/5);

displayArea2.setMaxSize(WIDTH - 80, HEIGHT/5);

stage.setWidth(WIDTH);

stage.setHeight(HEIGHT);

// customise the visual components

// customise the VBox border and background

BorderStroke style = new BorderStroke(Color.BLACK, BorderStrokeStyle.SOLID,

new CornerRadii(0), new BorderWidths(2) );

root.setBorder(new Border (style));

root.setBackground(Background.EMPTY);

// customise buttons

addButton.setBackground(new Background(new BackgroundFill(Color.LIGHTYELLOW,

new CornerRadii(10), Insets.EMPTY)));

displayButton.setBackground( new Background(new BackgroundFill(Color.LIGHTYELLOW,

new CornerRadii(10), Insets.EMPTY)));

removeButton.setBackground( new Background(new BackgroundFill(Color.LIGHTYELLOW,

new CornerRadii(10), Insets.EMPTY)));

saveAndQuitButton.setBackground( new Background(new BackgroundFill(Color.LIGHTYELLOW,

new CornerRadii(10), Insets.EMPTY)));

paymentButton.setBackground( new Background(new BackgroundFill(Color.LIGHTYELLOW,

new CornerRadii(10), Insets.EMPTY)));

listButton.setBackground( new Background(new BackgroundFill(Color.LIGHTYELLOW,

new CornerRadii(10), Insets.EMPTY)));

// call private methods for button event handlers

addButton.setOnAction(e -> addHandler());

displayButton.setOnAction(e -> displayHandler() );

removeButton.setOnAction( e -> removeHandler());

paymentButton.setOnAction( e -> paymentHandler());

listButton.setOnAction( e -> listHandler());

saveAndQuitButton.setOnAction( e -> saveAndQuitHandler());

// configure the stage and make the stage visible

stage.setScene(scene);

stage.setTitle("Hostel Applicaton");

stage.setResizable(false); // see discussion below

stage.show();

}

/**

private int getNumberOfRooms()

{

TextInputDialog dialog = new TextInputDialog();

dialog.setHeaderText("How many rooms?");

dialog.setTitle("Room Information Request");

String response = dialog.showAndWait().get();

return Integer.parseInt(response); }

// event handler methods

private void addHandler()

{

String roomEntered = roomField1.getText();

String nameEntered = nameField.getText();

// check for errors

if(roomEntered.length()== 0 || nameEntered.length()== 0)

{

displayArea1.setText ("Room number and name must be entered");

}

else if(Integer.parseInt(roomEntered)< 1 || Integer.parseInt(roomEntered)>noOfRooms)

{

displayArea1.setText ("There are only " + noOfRooms + " rooms");

}

else if(list.search(Integer.parseInt(roomEntered)) != null)

{

displayArea1.setText("Room number " + Integer.parseInt(roomEntered) + " is occupied");

}

else // ok to add a Tenant

{

Tenant t = new Tenant(nameEntered,Integer.parseInt(roomEntered));

list.addTenant(t);

roomField1.setText("");

nameField.setText("");

displayArea1.setText("New tenant in room " + roomEntered + " successfully added");

}

}

public void displayHandler()

{

int i;

if(list.isEmpty()) // no rooms to display

{

displayArea1.setText("All rooms are empty");

}

else // display rooms

{

displayArea1.setText("Room" + "\t" + "Name" + "\n");

for(i = 1; i <= list.getTotal(); i++ )

{

displayArea1.appendText(list.getTenant(i).getRoom()

+ "\t\t"

+ list.getTenant(i).getName() + "\n");

}

}

}

private void removeHandler()

{

String roomEntered = roomField1.getText();

// check for errors

if(roomEntered.length()== 0)

{

displayArea1.setText("Room number must be entered");

}

else if(Integer.parseInt(roomEntered) < 1 || Integer.parseInt(roomEntered)>noOfRooms)

{

displayArea1.setText("Invalid room number");

}

else if(list.search(Integer.parseInt(roomEntered))== null)

{

displayArea1.setText("Room number " + roomEntered + " is empty");

}

else // ok to remove Tenant

{

list.removeTenant(Integer.parseInt(roomEntered));

displayArea1.setText("Tenant removed from room " + Integer.parseInt(roomEntered));

}

}

private void paymentHandler()

{

String roomEntered = roomField2.getText();

String monthEntered = monthField.getText();

String amountEntered = amountField.getText();

// check for errors

if(roomEntered.length()== 0 || monthEntered.length()== 0 || amountEntered.length()== 0)

{

displayArea2.setText("Room number, month and amount must all be entered");

}

else if(Integer.parseInt(roomEntered) < 1 || Integer.parseInt(roomEntered)>noOfRooms)

{

displayArea2.setText("Invalid room number");

}

else if(list.search(Integer.parseInt(roomEntered)) == null)

{

displayArea2.setText("Room number " + roomEntered + " is empty");

}

else // ok to process payment

{

Payment p = new Payment(monthEntered,Double.parseDouble(amountEntered));

list.search(Integer.parseInt(roomEntered)).makePayment(p);

displayArea2.setText("Payment recorded");

}

}

private void listHandler()

{

int i;

String roomEntered = roomField2.getText();

// check for errors

if(roomEntered.length()== 0)

{

displayArea2.setText("Room number must be entered");

}

else if(Integer.parseInt(roomEntered) < 1 || Integer.parseInt(roomEntered) > noOfRooms)

{

displayArea2.setText("Invalid room number");

}

else if(list.search(Integer.parseInt(roomEntered)) == null)

{

displayArea2.setText("Room number " + Integer.parseInt(roomEntered) + " is empty");

}

else // ok to list payments

{

Tenant t = list.search(Integer.parseInt(roomEntered));

PaymentList p = t.getPayments();

if(t.getPayments().getTotal() == 0)

{

displayArea2.setText("No payments made for this tenant");

}

else

{

/* The NumberFormat class is similar to the DecimalFormat class that we used

NumberFormat nf = NumberFormat.getCurrencyInstance();

String s;

displayArea2.setText("Month" + "\t\t" + "Amount" + "\n");

for(i = 1; i <= p.getTotal(); i++ )

{

s = nf.format(p.getPayment(i).getAmount());

displayArea2.appendText("" + p.getPayment(i).getMonth() + "\t\t\t" + s + "\n");

}

displayArea2.appendText("\n" + "Total paid so far : " +

nf.format(p.calculateTotalPaid()));

monthField.setText("");

amountField.setText("");

}

}

}

private void saveAndQuitHandler()

{

TenantFileHandler.saveRecords(noOfRooms,list);

Platform.exit();

}

public static void main(String[] args)

{

launch(args);

}