Android is an
operating system based on Linux Kernel. It is designed primarily for
touchscreen mobile devices such as Smart Phones and Tablet Computers. It is
initially developed by Android Inc. Initially,
Andy Rubin founded Android Incorporation
in Palo Alto, California, United States in October, 2003.
in Palo Alto, California, United States in October, 2003.
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| Andy Rubin |
In 17th August 2005, Google
acquired Android Incorporation. The key employees of Android Incorporation
other than Andy Rubin are Rich Miner, Chris White and Nick Sears. Developed
and Managed by the OHA(Open Handset Alliance).
Android Version Images
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| Android Versions |
Features of Android
It is an Open Source. There are lot of applications
that can be chosen by the customer. Application Framework enabling reuse and
replacement of component. Dalvik Virtual Machine optimized for mobile devices. SQLi
for structured data storage. Media support for common audio, video and still
image formats(MPEG4,MP3,AAC,AMR,JPG,PNG,GIF) It
provides support for messaging services (SMS and MMS), web browser etc. Rich
Development Environment including a device emulator, tools for debugging,
memory, performance profiling and an plugin for the Eclipse IDE. Android is a
product of OHA which is lead by Google.
Eclipse IDE
A
multi-language open source software development environment. It has an extensible Plug-in system for
customizing the environment. Mostly
used to write applications in:
•
Java
•
PHP
•
Python
•
Ruby
Open Handset Alliance
It was established on 6th
November 2007. It’s consortium (Association of two or more individuals, organizations) of 84
companies. This group of companies are
allowed to use source code of Android and develop applications. Reason for
Nokia not to develop Android Mobiles is
Nokia is not part of OHA. Quoting from www.OpenHandsetAlliance.com page
Open Handset Alliance a group of 84
technology and mobile companies have come together to accelerate innovation in
mobile and offer consumers a richer, less expensive, and better mobile
experience. Together we have developed Android™, the first complete, open, and free
mobile platform. We are committed to commercially deploy handsets and services
using the Android Platform.
Open Handset Alliance Members
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| Open Handset Alliance Member |
Categories of Android Apps
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| Category of android apps |
Android Architecture
Linux Kernel : Connect the applications to
the hardware
Libraries : why reinvent the wheel every time
Android Runtime : Dalvik VM is optimized to
run Android apps and libraries helps developers to write code
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| Android architecture |
Android Components
The Android Application Development is
dependent on four components. These are
Activity
Service
Broadcast
Receiver
Content
Provider
Activity Lifecycle
Activity
Lifecycle is controlled by 7 methods. An activity is the single screen in
android. It is like window or frame of Java.
onCreate() : - called when activity is first
created.
onStart() :- called when activity is becoming
visible to the user.
onResume() :- called when activity will start
interacting with the user.
onPause() :- called when activity is not
visible to the user.
onStop() :- called when activity is not longer visible
to the user.
onRestart() :- called after your activity is
stopped, prior to start.
onDestroy() :-called before the activity is destroyed.
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| Android Flowchart |
Android Development Environment
1) Eclipse
(IDE)
It is where
you’ll write your code. It is a generic IDE,not specific to Android
development. It’s managed by the Eclipse foundation.
2) Android
Development Tools (ADT)
It is an
Eclipse plugin that adds Android specific functionality to Eclipse.
3) Software Development Kit (SDK)
It contains all
of the lower level tools to build, run and test your Android apps.
4) Android
Packages
You can develop and support multiple
versions of Android from the same development environment.
Installing Software for Android
The simplest
way/technique to install the required software for android application is
by ADT Bundle
It Includes:-
Eclipse IDE
Android SDK
Eclipse Plugin
Download the
ADT bundle form the www.developer.android.com Un jar
it, go to eclipse IDE and start the eclipse by clicking on the eclipse icon.
The another way is by setting up the Eclipse IDE manually. The
software required to setup android for eclipse IDE manually.
Install the JDK
Download and install the Eclipse for
developing android application
Download and Install the android SDK
Install the ADT plugin for eclipse
Configure the ADT plugin
Create the AVD
Create the android application
Limitations
Making source code available to everyone inevitably invites the
attention of hackers. Android
operating system uses more amount of battery as compared to normal mobile
phones. As we call Android is world of applications we continuously need to
connected with the internet which is not possible for all the users.
Future Scope
Android is now stepping up in next
level of mobile internet. There are chances of Android Mobile sales becomes
more then iPhone in next two years. Google may launch another version of
android that starts M because Google is launching all the android versions in
the alphabetical order. There are chances of Android may become the widely used
operating system in world.
