Introduction
JavaFX is a popular Java-based framework for building user interfaces for desktop, mobile, and web applications. With JavaFX, developers can create visually rich and interactive interfaces that are easy to use and navigate.
The NameFormatter
JavaFX application is a simple program that allows the user to enter their first name, middle name, last name, and title (if applicable), and then format it in one of six different ways using various button options. The formatted name is then displayed in a label below the input fields.
Let’s break down the code step by step:
public class NameFormatter extends Application {
private Label resultLabel;
// ...
}
This code defines a class NameFormatter
that extends Application
. The class contains a Label
object named resultLabel
, which will be used to display the formatted name.
@Override
public void start(Stage primaryStage) {
resultLabel = new Label();
// ...
}
This code defines the start()
method, which is called when the application is launched. In this method, the resultLabel
object is instantiated.
Label fnameLabel = new Label("First Name: ");
TextField fname = new TextField();
HBox fnameHbox = new HBox(10, fnameLabel, fname);
These lines of code create the input fields for the user’s first name. A Label
object is created with the text “First Name:”, and a TextField
object is created for the user to input their first name. These two objects are then added to an HBox
object named fnameHbox
, which will display the label and text field side by side.
VBox inputVbox = new VBox(5, fnameHbox, mnameHbox, lnameHbox, titleHbox);
inputVbox.setAlignment(Pos.CENTER_LEFT);
These lines of code create a VBox
object named inputVbox
, which will contain all of the input fields. The fnameHbox
, mnameHbox
, lnameHbox
, and titleHbox
objects (which contain the input fields for the user’s first name, middle name, last name, and title, respectively) are added to inputVbox
. The setAlignment()
method is used to align the input fields to the left side of the window.
Button format1 = new Button("Format 1");
format1.setOnAction(event -> {
resultLabel.setText(String.format("%s %s %s %s", title.getText(), fname.getText(), mname.getText(), lname.getText()));
});
These lines of code create a Button
object named format1
, which will be used to format the user’s name in a specific way. When the button is clicked, an event handler is triggered that formats the name using String.format()
. The formatted name is then displayed in the resultLabel
object.
HBox buttonsHbox = new HBox(5, format1, format2, format3, format4, format5, format6);
buttonsHbox.setAlignment(Pos.CENTER);
These lines of code create an HBox
object named buttonsHbox
, which will contain all of the formatting buttons. The format1
, format2
, format3
, format4
, format5
, and format6
objects (which are Button
objects that will be used to format the user’s name in different ways) are added to buttonsHbox
. The setAlignment()
method is used to center the buttons within the HBox
.
VBox resultsVbox = new VBox(10, buttonsHbox, resultLabel);
Next, we create a VBox to contain the results label and the formatting buttons HBox. We set the spacing between the children to 10 pixels and add the HBox and the results label to it using its constructor.
VBox allVbox = new VBox(10, inputVbox, resultsVbox);
allVbox.setPadding(new Insets(30));
Scene scene = new Scene(allVbox);
primaryStage.setScene(scene);
primaryStage.show();
Finally, we create another VBox that contains both the input VBox and the results VBox, which we named allVbox. We set the spacing between its children to 10 pixels and set its padding to 30 pixels using the setPadding method. We then create a new Scene using this VBox and set the Scene to be displayed on the Stage.
Finally, we show the Stage using the show method.
See My Code:
See the App in Action:
Challenges
There are several possible challenges that developers may encounter when creating an application like NameFormatter using JavaFX. Here are a few examples:
- User input validation: Since the user input will determine the output of the application, it is important to validate the input to ensure that it meets the expected format. For example, the first name, middle name, and last name fields should not be empty, and the title field should contain only letters and spaces. The developer needs to account for possible user input errors and provide helpful error messages to the user.
- Cross-platform compatibility: JavaFX applications should work on different operating systems and devices. However, there might be differences in rendering and behavior across platforms, which can result in inconsistent user experiences. The developer needs to test the application on various devices and operating systems to ensure that it works correctly.
- Responsiveness and performance: If the user types in a long name or a title with many words, the application may take longer to process and display the results. This can lead to a sluggish user experience. The developer should optimize the application’s code to ensure it is as responsive as possible, even with large amounts of user input.
- Localization and internationalization: If the application is intended to be used by people from different countries and cultures, it needs to support localization and internationalization. This means that the application needs to be able to handle different languages, date and time formats, and other cultural differences. The developer needs to take care to use appropriate APIs and libraries to support localization and internationalization.
- Accessibility: The application should be accessible to users with disabilities, such as vision impairments. This means that the user interface should be designed to work with assistive technologies, such as screen readers, and should conform to accessibility standards such as Web Content Accessibility Guidelines (WCAG). The developer needs to take care to design the application’s user interface with accessibility in mind.
Conclusion
Overall, this program demonstrates how to use JavaFX to create a simple user interface that allows the user to format a person’s name in multiple ways. It showcases the use of various layout managers, such as VBox and HBox, and how to use event handlers to respond to user input. With a little bit of creativity, this program could be extended to do other tasks such as formatting phone numbers or addresses.
Reference
T. Gaddis and G. Muganda, Starting Out with Java – From Control Structures through Data Structures, 4th Edition, 330 Hudson Street, NY NY 10013: Pearson, 2019.