1. JLabel, JTextField, JButton and JOptionPane
GUI Applications
JLabel, JTextField, JButton and JOptionPane

2. Contents Problem: The Hello Application Converting Kilometers to Miles
Problem Description
New Requirement: Using an Option Pane
New Requirement: Allowing the User to Press Enter
Converting Kilometers to Miles
The Number Guessing Game

3. 1. Problem: The Hello Application
Develop a GUI application that asks the user to input a name and then displays a welcome message to that name

4. Solution 1.1. Creating the Project 1.2. Developing the View
Creating the GUI Container
Putting GUI Components into the GUI Container
1.3. Implementing an Event Handler for the Button
1.4. Running the project
1.5. Summary: The Design

5. 1.1. Creating the Project File > New Project… New Project
Categories: Java
Projects: Java Application
Next
New Java Application
Project Name: HelloDesktop
Turn off Create Main Class
Finish

6. 1.2.1. Creating the GUI Container
Right-click the project name > New > JFrame Form…
New JFrame Form
Class Name: HelloView
Package: hello
Finish
Naming the Form
Properties > title: Hello

7. 1.2.2. Putting GUI Components into the Container

8. Label Text Field Button text: Name: text: Enter your name
Variable Name: nameTextField
Button
text: Say Hello
Variable Name: sayHelloButton
text: empty
Variable Name: messageLabel

9. 1.3.3. Implementing an Event Handler for the Button
Double-click the Say Hello button (or right-click > Events > Action > actionPerformed)

10. 1.4. Running Application
Click the Run Main Project (F6) button

11. 1.5. Summary: The Design

12. 2. New Requirement: Using an Option Pane
Modify the application so that after the user enters a name, the welcome message will be shown in a different window

13. Solution
Delete the messageLabel
Modify the event handler:

14. 3. New Requirement: Allowing the User to Press Enter
Modify the application so that after the user enters a name and press the Enter key, the welcome message will also be shown in a different window

15. Solution Develop an Event Handler for the nameTextField
Double-click the text field

16. B. Converting Kilometers to Miles
A kilometer is equal to miles. Develop a GUI in which the user will enter a distance in kilometers, and then click a button to see the distance converted to miles

17. Solution Project name: KmToMiles The Design Developing the View
Developing the Model
Developing the Event Handler

18. 1. The Design

19. 2. Developing the View Frame tile: Kilometers to Miles Conversion
GUI components
Label: Enter a distance in kilometers
Km text field
Convert To Miles button

20. 3. Developing the Model

21. 4. Developing the Event Handler

22. C. The Number Guessing Game
Develop an application that asks the user to input a guess number (See the next slide for an example). After the user enters a number and clicks the Submit button, the application displays one among the following messages
Sorry, try something higher
Too bad, go lower
Sweet, you got it right!

24. Solution Project name: Number Guessing Game The Design
Developing the View
Developing the Model
Developing the Event Handler

25. 1. The Design

26. 2. Developing the View Frame title: Number Guessing Game
GUI components
Prompt label
Guess text field
Submit button

27. 3. Developing the Model

28. 4. Developing the Event Handler
4.1. Declaring the Model Inside the View
4.2. Validating the input
4.3. Matching the guess number to the target

29. 4.1. Declaring the Model Inside the View

30. 4.2. Validating the Input

31. 4.3. Matching the Guess to the Target

32. References
GUI Building in NetBeans IDE
Developing a Web Application.
Adding Functionality to Buttons: A Beginner Guide.
Starting Out With Java 5 from control structures to objects. Tony Gaddis
Introduction to Facelets.

33. Revision History