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Understanding User Interface in Android - Part 1: Layouts. So far in my previous few articles on Android I have focused on showing you how to get things done in Android without really spending too much time discussing the visual aspect of Android application development - User Interface design.

Understanding User Interface in Android - Part 1: Layouts

In this article, and the next, I will walk you through the various elements that make up the UI of an Android application. In this first part of the article, I will discuss the various layouts available in Android to position the various widgets on your screen. Android Screen UI Components Up to this point, you have seen that the basic unit of an Android application is an Activity. An Activity displays the user interface of your application, which may contain widgets like buttons, labels, text boxes, etc.

During runtime, you load the XML UI in the onCreate() event handler in your Activity class, using the setContentView() method of the Activity class: Views and ViewGroups An Activity contains Views and ViewGroups. Android Preferences. For almost any application we need to provide some settings in order to enable users have some level of control over how the application works.

Android Preferences

Android has provided a standard mechanism to show, save and manipulate user's preferences. PreferenceActivity class is the standard Android Activity to show Preferences page, it contains a bunch of Preference class instances which use SharedPreferenceclass to save and manipulate corresponding data.There are different types of Preferences Available in Preference package, and if you need something more you can extend Preference class and create your own Preference type. in this article we will go through predefined Preference types in Android and I'm also going to implement a custom Preference type to see how that works.Our Preferences page is gonna look like this : public class MyPreferenceActivity extends PreferenceActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); return layout; } if(!

The Developer's Guide. Android provides a rich application framework that allows you to build innovative apps and games for mobile devices in a Java language environment.

The Developer's Guide

The documents listed in the left navigation provide details about how to build apps using Android's various APIs. If you're new to Android development, it's important that you understand the following fundamental concepts about the Android app framework: Apps provide multiple entry points Android apps are built as a combination of distinct components that can be invoked individually. For instance, an individual activity provides a single screen for a user interface, and a service independently performs work in the background.

From one component you can start another component using an intent. Learn more: Apps adapt to different devices Android provides an adaptive app framework that allows you to provide unique resources for different device configurations. Android Development Tutorial - Gingerbread. 1.1.

Android Development Tutorial - Gingerbread

The Android operating system Android is an operating system based on the Linux kernel. The project responsible for developing the Android system is called the Android Open Source Project (AOSP) and is primarily lead by Google. The Android system supports background processing, provides a rich user interface library, supports 2-D and 3-D graphics using the OpenGL-ES (short OpenGL) standard and grants access to the file system as well as an embedded SQLite database. An Android application typically consists of different visual and non visual components and can reuse components of other applications.

In Android the reuse of other application components is a concept known as task. Such a flow of events is depicted in the following graphic. 1.3. The Android system is a full software stack, which is typically divided into the four areas as depicted in the following graphic. The levels can be described as: Google Play also offers an update service. 2.