What is a View in Android

1. What is a View?
Confused About A View in Android?

2. View Class
● View Class is just a UI component
● Just treat the sub-package name in the Android
SDK as being labeled UI components

3. ViewGroup
● ViewGroup also an UI component but not a
view

4. Layout Classes
● Yes, again not a view but UI components
● Tiring of this game yet?

5. Widget Classes
● Its a specialized UI control but again its not a
view

6. The XML Layout file
● Its a configuration file for some UI components
but again is NOT A VIEW

7. What IS A VIEW?!!!
● A View in the Application Architecture Patterns
is a Contextual Meaning Entity
● You form the contextual meaning from how the
UI components are used in the Controllers

8. Activity ViewController
● If you have a plain old Activity than that
viewController indicates two possible contextual
meanings of View
● The Whole Screen as View
● The PopUp dialogs as other Views

9. FragmentActivity ViewController
● In its contextual meaning contains no VIEWs
● The fragments its loading point to the
contextual
meaning of Views for the application

10. Fragment Mini-ViewController
● Indicates that the contextual meaning of View
for the application is the section of screen it
controls in the form of the UI components its
loading

11. Conclusion
● A sign of a quality software engineer is the proper use of
OOP terminology.
● Referring to Views as concrete classes shows a lack of
understanding of the power of OOP.
● Part of the power of OOP is that the patterns have
the View as a contextual meaning rather than something
just concrete.
● Saying a XML layout configuration file is a View is like
stating that a XML java Bean configuration file is a Java
Bean. Wise Up People