This document discusses user interface layout basics in Android application development. It explains that layouts are defined as XML resources that template a user interface screen or portion of a screen. It also describes layout classes like LinearLayout and RelativeLayout that organize child controls on the screen. The document notes that user interfaces can be defined via XML layout resources or programmatically, and that using XML is the most convenient way to separate view and logic.

1. Android Application Development
User Interface: Layout Basics

2. User Interface: Layouts
● In the Android developer community the term layout is
used to mean one of the following two things:
○ A type of resource that defines what is drawn on the
screen. Layout resources are stored as XML files in the
/res/layout resource directory for the application. A
layout resource is simply a template for a user
interface screen or portion of a screen.
○ A type of view class whose primary purpose is to
organize other controls. These layout classes
(LinearLayout, RelativeLayout, TableLayout etc.)
are used to display child controls, such as text
controls or buttons or images on the screen.
● Android user interfaces can be defined as layout
resources in XML or created programmatically.

3. User Interface: Layout in Eclipse

4. Defining an XML Layout Resource
● The most convenient and maintainable way to design UI
● Simplifies the UI design process
● This way, we can separate view and logic easily

5. Defining a Layout Programmatically