Android is a software stack that includes an operating system and applications for mobile devices. It is based on the Linux kernel and was developed by the Open Handset Alliance, including Google. Android supports a variety of hardware platforms and provides features like storage, messaging, a web browser, media support, Bluetooth, and more. Developers can create Android applications using the Android SDK and Eclipse IDE, targeting the Dalvik virtual machine. The SDK includes tools, libraries, and sample code needed to build Android apps.

1. ANDROID

2. History
 Android is a software stack for mobile devices that includes an operating
system and applications.
 Android's mobile operating system is based on a modified version of the
Linux kernel.
 Google and other members of the Open Handset Alliance collaborated
on Android's development and release.

3. Features
 Storage
 Messaging
 Web browser
 Java support
 Media support
 Market
 Bluetooth
 Video calling

4. Android phones do better than the
iPhone
 Market
 Google integration
 Open Source

5. Introduction
 What is Android?
• A software platform and operating system for mobile devices
• Based on the Linux kernel
• Developed by Open Handset Alliance (OHA) and later google
• Allows writing managed code in the Java language
• The Open Handset Alliance (OHA) is a collection of more than
50 technology companies, including hardware manufacturers,
mobile carriers, and software developers

6. What is the Open Handset Alliance (OHA)?

7.  The first Android mobile handset, the T-Mobile G1, was
released in the United States in October 2008. By the end of
2009 over 20 Android-compatible handsets had been launched
or announced in more than 26 countries on 32 different
carrier networks.
 Rather than being a mobile OS created for a single hardware
implementation, Android is designed to support a large variety
of hardware platforms, from WVGA (Wide Quarter Video
Graphics Array) phones with hard keyboards to QVGA ( Quarter
Video Graphics Array)devices with resistive touchscreens.
 Beyond that, with no licensing fees or proprietary software, the
cost of Android handsets, and is comparatively low.

8. Android SDK
 The Android software development kit (SDK) includes everything you
need to start developing, testing, and debugging Android applications.
 Development Tools
 The Android Emulator
 Full Documentation
 Sample Code
 Online Support

9. Dalvik Virtual Machine – DVM
 One of the key elements of Android is the Dalvik virtual machine. Rather
than use a traditional Java virtual machine (VM) such as Java ME (Java
Mobile Edition)
 Android uses its own custom VM designed to ensure that multiple
instances run efficiently on a single device.
 The Dalvik VM uses the device’s underlying Linux kernel to handle
functionality including security, threading, and process and memory
management.
 All Android hardware and system service access is managed using Dalvik
as a middle tier.

10.  The Dalvik VM executes Dalvik executable files, a format optimized to
ensure minimal memory footprint. You create.dex executables by
transforming Java language compiled classes using the tools supplied
within the SDK.

11. Installing Android
 What You Need to Begin
 Because Android applications run within the Dalvik virtual
machine, you can write them on any platform that supports the
developer tools. This currently includes the following:
 Microsoft Windows (XP or Vista)
 Mac OS X 10.4.8 or later (Intel chips only)
 Linux
 To get started, you’ll need to download and install the following:
 The Android SDK
 Java Development Kit (JDK) 5 or 6

12.  You can download the latest JDK from Sun at
 http://java.sun.com/javase/downloads/index.jsp
 If you already have a JDK installed, make sure that it meets the version requirements listed
above, and note that the Java runtime environment (JRE) is not sufficient.
 Downloading and Installing the SDK
 http://developer.android.com/sdk/index.html
Download android-sdk_r10-windows.zip file
ZIP file containing the API libraries, developer tools, documentation, and several
sample applications and API demos that highlight the use of particular API features.
Install it by unzipping the SDK into a SDK in C drive.

13. Developing with Eclipse
 First Download Eclipse from http://www.eclipse.org/downloads/
 Download and Unzip this file in to your directory (C:).
 Double-click on the file c:eclipseeclipse.exe

14. Creating Hello World
 After you've created an AVD, the next step is to start a new
Android project in Eclipse.
 From Eclipse, select File > New > Project.
 If the ADT Plugin for Eclipse has been successfully installed,
the resulting dialog should have a folder labeled "Android"
which should contain "Android Project". (After you create
one or more Android projects, an entry for "Android XML
File" will also be available.)
 Select "Android Project" and click Next.

16.  Fill in the project details with the following values:
 Project name: HelloAndroid
 Application name: Hello, Android
 Package name: com.example.helloandroid (or your
own private namespace)
 Create Activity: HelloAndroid
 Click Finish.

18.  Here is a description of each field:
 Project Name : This is the Eclipse Project name — the name of the directory
that will contain the project files.
 Application Name : This is the human-readable title for your application — the
name that will appear on the Android device.
 Package Name : This is the package namespace (following the same rules as
for packages in the Java programming language) that you want all your source
code to reside under. This also sets the package name under which the stub
Activity will be generated.
 Your package name must be unique across all packages installed on the
Android system; for this reason, it's important to use a standard domain-style
package for your applications.

19.  Create Activity : This is the name for the class stub that will be
generated by the plug-in. This will be a subclass of Android's Activity
class. An Activity is simply a class that can run and do work. It can create
a UI if it chooses, but it doesn't need to. As the checkbox suggests, this is
optional, but an Activity is almost always used as the basis for an
application.
 Min SDK Version : This value specifies the minimum API Level required
by your application. For more information, see Android API Levels.
 Other fields : The checkbox for "Use default location" allows you to
change the location on disk where the project's files will be generated
and stored. "Build Target" is the platform target that your application will
be compiled against (this should be selected automatically, based on
your Min SDK Version).

20.  You will see the following files created automatically by the SDK.

21.  src : It contains the source packages and java source files. In our src folder
it currently contains the package com.helloAndroid. The package further
contains the java file “helloAndroid.java”.
 gen : It contains the auto generated java files. You do not modify that.
 Android 1.6 : It contains the particular SDK libraries being used for the
current project.
 res : It is one of the other important content folders.
It contains three subfolders for images
drawable –hdpi ,
drawable –ldpi,
drawable –mdpi.
 Layout : The layout contains the main.xml which is called when the application is
started.
 values : Contained in the values folder is used to define strings to be used
within the applications.
AndroidManifest.xml :

22.  Types of Android Applications
 Most of the applications you create in Android will fall into one of the
following categories:
 Foreground An application that’s useful only when it’s in the foreground and is
effectively suspended when it’s not visible.map are common examples.
 Background An application with limited interaction that, apart from when
being configured, spends most of its lifetime hidden. Examples include
call screening applications and SMS auto-responders.
 Widget Some applications are represented only as a home-screen widget.

23.  Android Asset Packaging Tool (AAPT)
Constructs the distributable Android package files (.apk).
The following diagram depicts the components involved in building and
running an application:
Android Debug Bridge (ADB)
The ADB is a client-server application that provides a link to a running
emulator. It lets you copy files, install compiled application packages (.apk),
and run shell commands.

24. Layouts
 LinearLayout Organizes its children either horizontally or vertically.
 TableLayout Organizes its children in tabular form.
 RelativeLayout : Organizes its children relative to one another or to the
parent.
 FrameLayout : Allows you to dynamically change the control(s) in the
layout.

25. The Android Widget Toolbox
 Android supplies a toolbox of standard Views to help you create
simple interfaces. By using these controls, you can simplify your
development and provide consistency between applications.
 The following list highlights some of the more familiar toolbox
controls:
 TextView :
A standard read only text label. It supports multiline display, string
formatting, and automatic word wrapping.
 EditText :
An editable text entry box. It accepts multiline entry and word
wrapping.
 ListView :
A View Group that creates and manages a group of Views used to
display the items in a List. The standard ListView displays the
string value of an array of objects using a Text View for each item.

26.  Button :
Standard push-button
 CheckBox :
Two-state button represented with a checked or unchecked box
 RadioButton :
Two-state grouped buttons. Presents the user with a number of binary
options of which only one can be selected at a time.

27. Thanks
Nirav