View, ViewGroup, Layout, and Widget

This section describes UI class and object terminologies used in Android SDK documentation. View and ViewGroup are base classes serving as UI building blocks. Widget and Layout are classes extended from View or ViewGroup class providing specific UI functions.

In the Android SDK documentation, there are 4 terms used to refer to different parts of the user interface (UI) class hierarchy:

Examples of UI classes:

When building your own UI, you can search and find a Widget class provided in the Android SDK that matches your UI structure. Then you extend a new class from that Widget class to add your own customizations.

If you want build your UI from scratch, you can just start with a ViewGroup object, add child ViewGroup or View objects repeatedly to build a View object tree, then customize each View or ViewGroup object to complete the UI structure.

Table of Contents

 About This Book

 Installing JDK 1.8 on Windows System

 Installation of Android SDK R24 and Emulator

 Installing Apache Ant 1.9 on Windows System

 Developing First Android Application - HelloAndroid

 Android Application Package (APK) Files

 Android Debug Bridge (adb) Tool

 Android File Systems

 AboutAndroid - Application to Retrieve System Information

 android.app.Activity Class and Activity Lifecycle

View Objects and Layout Resource Files

 android.view.View Class - Base of User Interface Components

View, ViewGroup, Layout, and Widget

 What Is Layout Resource File?

 AndroidView v1.0 - Creating a Layout in Java Class

 AndroidView v2.0 - Creating a Layout in Resource File

 AndroidView v3.0 - Referencing Views in Resource Files

 AndroidView v3.1 - Layouts with Vertical Orientation

 AndroidView v3.2 - Layouts with Horizontal Orientation

 AndroidView v4.0 - Inserting Views to Parent Layout

 Using "adb logcat" Command for Debugging

 Build Process and Package File Content

 Building Your Own Web Browser

 Android Command Line Shell

 Samsung Galaxy Tab 3 Mini Tablet

 USB Debugging Applications on Samsung Tablet

 Android Tablet - LG-V905R

 USB Debugging Applications on LG-V905R Tablet

 Android Phone - LG-P925g

 USB Debugging Applications on LG-P925g Phone

 Archived Tutorials

 References

 Full Version in PDF/EPUB