1. GUIs for Applets N.A.Shulver@staffs.ac.uk Introduction Applets and Swing/JFC Alternatives to Swing Look-and-Feel issues Example applet graphical user interfaces How do I build a GUI? Conclusion

2. GUIs for Applets N.A.Shulver@staffs.ac.uk Applets and Swing/JFC Swing is a kit of GUI “widgets” - it provides a simple way to create, position and interact with standard interface components It is a major part of the Java Foundation Classes (c.f. MFC, Microsoft Foundation Classes)‏ It is a “lightweight” component library, uses the MVC (model-view-controller) architecture design pattern Applets may use most Swing components For security reasons some are restricted (which ones?)‏

3. GUIs for Applets N.A.Shulver@staffs.ac.uk Alternatives to Swing The original GUI system for Java was called the “Abstract Windowing Toolkit” or AWT NB Swing is based on many of the AWT components, either through compatible methods or through inheritance AWT is a “heavyweight” component library, uses the widgets built into the underlying OS architecture It has some OS-specific behaviour and thus some portability problems

4. GUIs for Applets N.A.Shulver@staffs.ac.uk Alternatives to Swing SWT is the Standard Widget Toolkit originally developed by IBM as part of the Eclipse project (see http://www.developer.com/java/other/article.php/2179061)‏ http://www.developer.com/java/other/article.php/2179061 It is seen a “thin wrapper” over the native GUI of the host OS – it is a “heavyweight” library It is not OS-specific but was originally designed to run in MS Windows SWT attempts to use the strengths of the Swing and AWT approaches while staying simple and quick

5. GUIs for Applets N.A.Shulver@staffs.ac.uk Examples Simple visual applet with mouse- sensitive image- based components Note that the title bar is not settable This is a Swing- based Japplet running in Win XP

6. GUIs for Applets N.A.Shulver@staffs.ac.uk Swing Example Quite a lot of components in this simple applet JLabel, JCheckBox, JTextArea, JComboBox, JButton, JRadioButton This applet will look very similar in any graphical OS

7. GUIs for Applets N.A.Shulver@staffs.ac.uk Swing Example This example shows most of the simple Swing components The GUI is X- Windows http://commons.wikimedia.org/ wiki/Image:Gui-widgets.png

8. GUIs for Applets N.A.Shulver@staffs.ac.uk SWT platform-specific examples The Standard Widget Toolkit (SWT) library uses heavyweight components Tied to the look-and-feel of the host OS

9. GUIs for Applets N.A.Shulver@staffs.ac.uk SWT – a familiar example Eclipse has one of the best-known examples of SWT in action Looks good and works well

10. GUIs for Applets N.A.Shulver@staffs.ac.uk Building a GUI Choose AWT, Swing (recommended) or SWT Learn about component types, event handlers and layout options – documentation and examples Design a user interface and critically evaluate it Revise and repeat! For background on development in AWT, with reference to Swing, see “Graphical User Interface (GUI) Fundamentals” (old article) [http://www.wirelessdevnet.com/channels/java/training/javagui.html]http://www.wirelessdevnet.com/channels/java/training/javagui.html

11. GUIs for Applets N.A.Shulver@staffs.ac.uk Conclusion There are varied ways to build GUI applications in Java Applets Different approaches have different strengths and weaknesses Swing is often a good choice (widely supported, flexible, elegant but quite complex)‏ Predefined widgets/components are available for most tasks Designing a good interface is hard

12. GUIs for Applets N.A.Shulver@staffs.ac.uk Optional Further Reading Swing article on Wikipedia [http://en.wikipedia.org/wiki/Java_Swing]http://en.wikipedia.org/wiki/Java_Swing Applet article on Wikipedia [http://en.wikipedia.org/wiki/Java_applet]http://en.wikipedia.org/wiki/Java_applet Standard Widget Toolkit article on Wikipedia [http://en.wikipedia.org/wiki/Standard_Widget_Toolkit]http://en.wikipedia.org/wiki/Standard_Widget_Toolkit Swing documentation (Sun) [http://java.sun.com/javase/6/docs/api/index.html]http://java.sun.com/javase/6/docs/api/index.html How to make Applets (Sun) [http://java.sun.com/docs/books/tutorial/uiswing/components/applet.html]http://java.sun.com/docs/books/tutorial/uiswing/components/applet.html