I have this GUI application. If there is not already, can you add class hierarchy, polymorphism, use of abstract class, and 2 classes?

Thank you.

Java code:

import javafx.application.Application; import javafx.event.ActionEvent; import javafx.event.EventHandler; import javafx.geometry.HPos; import javafx.geometry.Insets; import javafx.geometry.Pos; import javafx.scene.Scene; import javafx.scene.control.*; import javafx.scene.layout.*; import javafx.scene.text.Font; import javafx.scene.text.FontWeight; import javafx.stage.Stage; import javafx.stage.Window;

public class RegistrationFormApplication extends Application {

@Override public void start(Stage primaryStage) throws Exception { primaryStage.setTitle("Registration Form JavaFX Application");

// Create the registration form grid pane GridPane gridPane = createRegistrationFormPane(); // Add UI controls to the registration form grid pane addUIControls(gridPane); // Create a scene with registration form grid pane as the root node Scene scene = new Scene(gridPane, 800, 500); // Set the scene in primary stage primaryStage.setScene(scene);

primaryStage.show(); }

private GridPane createRegistrationFormPane() { // Instantiate a new Grid Pane GridPane gridPane = new GridPane();

// Position the pane at the center of the screen, both vertically and horizontally gridPane.setAlignment(Pos.CENTER);

// Set a padding of 20px on each side gridPane.setPadding(new Insets(40, 40, 40, 40));

// Set the horizontal gap between columns gridPane.setHgap(10);

// Set the vertical gap between rows gridPane.setVgap(10);

// Add Column Constraints

// columnOneConstraints will be applied to all the nodes placed in column one. ColumnConstraints columnOneConstraints = new ColumnConstraints(100, 100, Double.MAX_VALUE); columnOneConstraints.setHalignment(HPos.RIGHT);

// columnTwoConstraints will be applied to all the nodes placed in column two. ColumnConstraints columnTwoConstrains = new ColumnConstraints(200,200, Double.MAX_VALUE); columnTwoConstrains.setHgrow(Priority.ALWAYS);

gridPane.getColumnConstraints().addAll(columnOneConstraints, columnTwoConstrains);

return gridPane; }

private void addUIControls(GridPane gridPane) { // Add Header Label headerLabel = new Label("Registration Form"); headerLabel.setFont(Font.font("Arial", FontWeight.BOLD, 24)); gridPane.add(headerLabel, 0,0,2,1); GridPane.setHalignment(headerLabel, HPos.CENTER); GridPane.setMargin(headerLabel, new Insets(20, 0,20,0));

// Add Name Label Label nameLabel = new Label("Full Name : "); gridPane.add(nameLabel, 0,1);

// Add Name Text Field TextField nameField = new TextField(); nameField.setPrefHeight(40); gridPane.add(nameField, 1,1);

// Add Email Label Label emailLabel = new Label("Email ID : "); gridPane.add(emailLabel, 0, 2);

// Add Email Text Field TextField emailField = new TextField(); emailField.setPrefHeight(40); gridPane.add(emailField, 1, 2);

// Add Password Label Label passwordLabel = new Label("Password : "); gridPane.add(passwordLabel, 0, 3);

// Add Password Field PasswordField passwordField = new PasswordField(); passwordField.setPrefHeight(40); gridPane.add(passwordField, 1, 3);

// Add Submit Button Button submitButton = new Button("Submit"); submitButton.setPrefHeight(40); submitButton.setDefaultButton(true); submitButton.setPrefWidth(100); gridPane.add(submitButton, 0, 4, 2, 1); GridPane.setHalignment(submitButton, HPos.CENTER); GridPane.setMargin(submitButton, new Insets(20, 0,20,0));

submitButton.setOnAction(new EventHandler() { @Override public void handle(ActionEvent event) { if(nameField.getText().isEmpty()) { showAlert(Alert.AlertType.ERROR, gridPane.getScene().getWindow(), "Form Error!", "Please enter your name"); return; } if(emailField.getText().isEmpty()) { showAlert(Alert.AlertType.ERROR, gridPane.getScene().getWindow(), "Form Error!", "Please enter your email id"); return; } if(passwordField.getText().isEmpty()) { showAlert(Alert.AlertType.ERROR, gridPane.getScene().getWindow(), "Form Error!", "Please enter a password"); return; }

showAlert(Alert.AlertType.CONFIRMATION, gridPane.getScene().getWindow(), "Registration Successful!", "Welcome " + nameField.getText()); } }); }

private void showAlert(Alert.AlertType alertType, Window owner, String title, String message) { Alert alert = new Alert(alertType); alert.setTitle(title); alert.setHeaderText(null); alert.setContentText(message); alert.initOwner(owner); alert.show(); }

public static void main(String[] args) { launch(args); } }