ANDROID

Agenda

What is android?

Why ?

Application Components

Practical matters

Introduction  Android is an operating system for mobile

devices such as cellular phones, tablet computers and net books.

It was initially developed by Android Inc. which was later purchased by Google.

Google further formed the open handset alliance.

 

Open Handset Alliance The Open Handset Alliance (OHA) is a

business alliance of 78 firms for developing open standards for mobile devices Technically the term “ OPEN STANDARDS “

refers to a specification whose description is freely available .

This means that developers are free to create applications which are valid according to the specification and which will therefore work with software designed for it.

Some major names in OHA   HTC  SAMSUNG ELECTRONICS  MOTOROLA  GOOGLE  NVIDIA ELECTRONICS  INTEL CORP  EBAY  SONY ERRICSON

Android is open source.

The source code of the android operating system isfreely available to anyone.

  Being an open source it has the following

advantages:1. Support2. Cost3. Flexibility

ANDROID ARCHITECTURE

LINUX KERNEL

Android relies on Linux version 2.6 for core system services such as security, memory management, process management, network stack, and driver model.

The kernel also acts as an abstraction layer between the hardware and the rest of the software stack.

Dalvik Virtual Machine The Dalvik VM takes the generated Java class

files and combines them into one or more Dalvik executable (.dex) files.

It reuses duplicate information from multiple class files, effectively reducing the space requirement (uncompressed) by half from a traditional .jar file.

For example, the.dex file of the web browser app in Android is about 200K, whereas the equivalent uncompressed .jar version is about 500K. 

Second, Google has fine-tuned the garbage collection in the Dalvik VM.

Finally, the Dalvik VM uses a different kind of assembly-code generation, in which it uses registers as the primary units of data storage instead of the stack.30 % fewer instructions are accomplished as a result.

We should point out that the final executable code in Android, as a result of the Dalvik VM, is based not on Java byte code but on .dex files instead.

Android 2.2 FROYO

Released may 2010, the Froyo was the most awaited and rumored edition ofthe android till date.

Future Aspects

Google android operating system can be used in net books :

Net books are now the fastest growing segment of the PC market, they are portable, functional and comparatively inexpensive. It would make easier for users of Android powered phones to share information between pc.

Building Blocks

Activities

Layout file

R.Java

Androidmanifest.xml

Important Classes:  Activity Intent Services BroadCastReceivers ContenrProviders

Some Interesting APPS

Lets take a look at some of innovative applications that have been developed for the android.

Virtual qwerty with SWYPE technology

This application produces a virtualqwerty for the user

It has an additional feature that you don’t have to lift your finger from the screen in order to type a word

The word is automatically guessed, based upon the characters travelled across

Conclusion Android is a big revolution in the field of

operating system. Its custom virtual machine optimize memory

and hardware resources in a mobile environment. It can be liberally extended to incorporate new cutting edge technologies as they emerge.

The open source platform will continue to evolve as the developer community works together to build innovative mobile applications.

THANKING YOU