December 15

Android ArchitectureRhama Arya W.

@arya199

www.mreunion-labs.net

Thursday, December 15, 11

Mreunion Labs

March 2010

Bootstrapped startup

Android first

Thursday, December 15, 11

Agenda

• Introduction to Android

• Android Architecture

• Fundamental building blocks

• Ideas, execution, feedback, repeat

• Best practices

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Trends

• Mobile 2.0

• Android, iOS, WP7

• BlackBerry? Symbian?

• One year exp, published a real working Android app on the market, confident interview

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What is Android?

• Not really a Linux

• Based on a linux kernel but it’s not GNU

• No native windowing system

• No (limited?) glibc support

• No GNU/Linux utilities

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What is Android?

• Not just ‘Java on Linux.’

• Not part of the JCP

• Developers write primarily in a customized version of Java

• Similar to Java SE, but not equal

• No AWT, no Swing, no RMI

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What is Android?

• software stack that includes:

• operating system

• middleware

• key applications

• rich set of APIs

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Android Architecture

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Android Architecture• Linux kernel 2.6, providing

• Security

• Memory Management

• Process Management

• Network Stack

• Driver Model

• Abstraction Layer

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Android Architecture

• Dalvik Virtual Machine

• Runs optimized file format (.dex)

• Java .class/.jar files converted into .dex at build time

• Supports multiple virtual machine processes per VM

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Android Architecture

• Dalvik Virtual Machine

• 16bit, register based

• JIT from “Froyo”

• Concurrent GC from “Gingerbeard”

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Android Architecture

• C/C++ Libraries used by various components of the Android system

• Exposed to developers through the Android Application Framework

• SQLite, WebKit, Open GL, libc

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Android Architecture

• Android Application Framework exposing developers to Android’s inner capabilities

• View System, Content Providers, Telephony Manager, Location Manager, Notification Manager, Activity Manager, etc

• Javadoc styled API

• developer.android.com

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Assets

Application Fundamentals

You

XML .apk

Android Manifest

Java classes

multi-user Linux-like systemeach application is a different user

each application has its own processeach process has its own VM runs in

isolation from other applications

possible to have two applications to share the same Linux user ID

request permission to access device dataContentProviders

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Building Blocks

AndroidManifest.xml

Act

iviti

es

Vie

ws

Inte

nts

Serv

ices

Not

ifica

tions

Con

tent

Prov

ider

s

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Building Blocks

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Building Blocks

Activity A

Activity B

• stacked

• only one is visible

• only one is active

• new activities are placed on top

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Building Blocks

ViewGroup

ViewGroup View View

View View View

• Android’s UI

• know how to draw themselves

• respond to events

• described in XML

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Building Blocks

private View view;

public void onCreate(Bundle savedInstanceState) {...setContentView(R.layout.filename);...name = (View) findViewById(R.id.name);...

}

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Building Blocks

Activity A Activity BIntent

SQLite Database

Intents are used to move from Activity to Activity

Describes what the Application wants

Provide late runtime bindings

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Building Blocks

• Services

• Notifications

• ContentProviders

• SQLite Database

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“Idea is worthless. Execution is what matters.”

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Ideas

• Steal, simplify, beautify, improve

• Solve a real problem

• Exercise

• You don’t have to be the first. But be the best

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Execution

Start coding

Use it

Get feedback

One download = one customer = one problem.Prioritize

Learn to say “No”

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Best Practice

• Mobile users are impatient

• Fast, beautiful, intuitive apps

• Minimize actions required per function

• Competitions are fierce

• It’s not easy

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Resources

• http://developer.android.com

• http://stackoverflow.com

• http://android-developers.blogspot.com

• http://helloandroid.com

• http://mreunion.wordpress.com

• id-android-dev@googlegroups.com

Thursday, December 15, 11

Thank Yourhama.arya@gmail.com

@arya199

Thursday, December 15, 11