Easy to Learn Java: Programming Articles, Examples and Tips

Start with Java in a few days with Java Lessons or Lectures


Code Examples

Java Tools

More Java Tools!

Java Forum

All Java Tips


Submit News
Search the site here...
Search the JavaFAQ.nu
1000 Java Tips ebook

1000 Java Tips - Click here for the high resolution copy!1000 Java Tips - Click here for the high resolution copy!

Java Screensaver, take it here

Free "1000 Java Tips" eBook is here! It is huge collection of big and small Java programming articles and tips. Please take your copy here.

Take your copy of free "Java Technology Screensaver"!.

GUI Structural Patterns

JavaFAQ Home » Swing, AWT Go to all tips in Swing, AWT

Bookmark and Share

Structuring the program - Separating the Model

In all ways of structuring a GUI program, there is one vitally important issue -- separating the code which is the essence of the problem from the user interface. This logical part is variously referred to as the model, business logic, abstraction, or document. This code must not refer to the user interface directly -- it will interact with the user interface code by returning values or invoking listeners.

Motivation. There are two compelling reasons for this separation.

  1. Lower complexity -- Programs end up being less complex and therefore easier (cheaper) to modify. For the smallest programs this may not be obvious, but the benefits show up very quickly as a program grows. This is not an advantage only in large programs.
  2. Interface Flexibility -- This allows changes to the user interface, eg, moving from Swing to SWT, or to a web interface. You should be able to use your basic logic code (if applicable) with the following interfaces.
    • GUI interface. And it should be easy to change between Swing, SWT, XML based GUI, etc.
    • Command line interface - yes, some Unix sysadmins might want to run it that way.
    • Web based interface.

Well-Known Patterns

MVC - Model-View-Controller Pattern
This classic pattern is widely used, altho the Presentation-Document pattern below is a more common (because it's simpler) choice for small programs.
  • The View component presents the output and may interact with the Model to do so.
  • The Controller component accepts user input. It typically interacts with both the View and Model.
  • The Model implements the logic, and knows nothing about the interface.
Presentation-Document Pattern
This pattern is perhaps the best choice for small GUI applications.
  • The Presentation contains all user interface code (the View and Controller).
  • The Document is the logic, model, etc.
PAC - Presentation-Abstraction-Control Pattern
This is the application of stepwise refinement to GUIs. Parts of the GUI are each implemented as in MVC, and these parts are put together using MVC. This is basically a recursively applied MVC model. It would only be used for complicated GUIs.
  • The Abstraction corresponds to the Model in MVC.
  • The PAC pattern has a hierarchy of agents, each structured in the PAC model.

 Printer Friendly Page  Printer Friendly Page
 Send to a Friend  Send to a Friend

.. Bookmark and Share

Search here again if you need more info!
Custom Search

Home Code Examples Java Forum All Java Tips Books Submit News, Code... Search... Offshore Software Tech Doodling

RSS feed Java FAQ RSS feed Java FAQ News     

    RSS feed Java Forums RSS feed Java Forums

All logos and trademarks in this site are property of their respective owner. The comments are property of their posters, all the rest 1999-2006 by Java FAQs Daily Tips.

Interactive software released under GNU GPL, Code Credits, Privacy Policy