AN OPEN HANDSET ALLIANCE
PROJECT.(OHA)
OVERVIEW
1.Open Handset Alliance.(OHA)
2.Introduction To Android
3.Introduction To The Platform
4.Android Architecture
5.Development Tools
6.Conclusion
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Open Handset Alliance
Est. 2007, led by
Google,open source
Main product: Android
Platform
Enthusiastic support from
Industry : both equipment
makers and network operators
INTRODUCTION
TO
ANDROID
WHAT IS ANDROID?
o A complete & modern embedded operating system
o A cutting-edge mobile user experience
o A world-class software stack for building applications
o An open platform for developers, users & industry
Why Android Was Created?
Full phone software stack including applications
Designed as a platform for software development
Android is open.
Android is free..
100% Java Phone
INTRODUCTION
TO
THE PLATFORM : ANDROID
Android Features
Integrated browser based on the open source WebKit engine
SQLite for relational data storage
Media support for common audio, video, and still image formats
(MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, GIF)
Dalvik Virtual Machine optimized for mobile devices
Cellular networking : GSM, EDGE, 3G (hardware dependent)
LAN : Bluetooth, and Wi-Fi (hardware dependent)
Graphics Hardware Acceleration
Camera, GPS and Compass (hardware dependent)
Touch screen and accelerometer for motion sensing
ARCHITECTURE
Libraries
Written in C/C++ - System C Library(libc)
Display/Graphics(SGL)
Media Libraries
SQLite for database management.
LibWebCore- web browser engine-embeddable web
view
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Linux Kernel
Linux Version 2.6
Security, Memory & Process Management
Proven driver model
Efficient computing resource management
Stable and proven OS for mobile platform
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Development Tools
The Android SDK includes a variety of custom tools that help you develop
mobile applications on the Android platform.Three of the most significant
tools are:
1.Android Emulator -A virtual mobile device that runs on our
computer -use to design, debug, and test our applications in an actual
Android run-time environment
2.Android Development Tools Plugin -for the Eclipse IDE - adds
powerful extensions to the Eclipse integrated environment
3.Dalvik Debug Monitor Service (DDMS) -Integrated with Dalvik -this
tool let us manage processes on an emulator and assists in debugging
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Importance Hierarchy(in Order Of Importance)
Foreground Process -required for what the user is currently doing
Service Process -holding a Service - not directly visible to the userrelevant tasks..
Background Process -holding an Activity - not visible to the user - can
kill at any time(stopped)
Empty Process -doesn't hold any active application components(as a
cache to improve start-up time)
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Applications
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CONCLUSION
Android is open to all: industry, developers and users
Participating in many of the successful open
source projects
Aims to be as easy to build for as the web.
Google Android is stepping into the next level of
Mobile Internet
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THANK YOU
?
Android Runtime
Includes a set of core libraries that provides most
of the functionality-JAVA
Every Android application runs in its own process
Dalvik VM executes files in the (.dex) format
Device can run multiple VMs efficiently
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Android Building Blocks
These are the most important parts of the Android APIs:
AndroidManifest.xml
-the control file-tells the system what to do with the top-level components
Activities
-an object that has a life cycle-is a chunk of code that does some work
Views
-an object that knows how to draw itself to the screen
Intents
-a simple message object that represents an "intention" to do something
Notifications
-is a small icon that appears in the status bar(SMS messages)
-for alerting the user
Services
-is a body of code that runs in the background
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Anatomy of an Android Application
There are four building blocks for an Android application:
Activity
-a single screen
Intent Receiver
-to execute in reaction to an external event(Phone Ring)
Service
-code that is long-lived and runs without a UI(Media Player)
Content Provider
-an application's data to be shared with other applications
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Application Framework
Enable applications access data from other applications ,sharing
Providing access to non-code resources
Enables all applications to display alerts in the status bar
Manages the lifecycle of applications
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HISTORY
July 2005
Google acquired Android Inc.
5 Nov 2007
Open HandSet Alliance formedGoogle, HTC, Intel, Motorola, Qualcomm,T-Mobile
Android is the OHA first product
12 Nov 2007
OHA released a preview of the Android OHA
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Life Cycle of an Android Application
An unusual and fundamental feature - process's lifetime is not
directly controlled by the application itself
Deciding factors:
how important
overall memory available
To determine which processes should be killed when low on memory:
"importance hierarchy
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Initial screen
Map
Browser
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