Android : a linux-based mobile operating system

Android, a Linux-based Mobile Phone Operating System
Clement Escoffier , akquinet
& Karl Pauls

Karl Pauls
Dipl.-Inform. Freie Universität Berlin
Head of OSGi and Mobile CC - akquinet AG
Member Apache Software Foundation
PMC Apache Felix, Apache Sling, Apache Ace

Clement Escoffier
PHD from Grenoble University, France
Solution Architect in the OSGi and Mobile CC
Member Apache Software Foundation
PMC Apache Felix, Apache Ace
Apache Felix iPOJO project leader

akquinet AG
akquinet AG
€1300k SE
akquinetbusinessconsulting
GmbH €60k SE
Partner Power International GmbH
Partnerbeteiligung

Why Android ?

Open Handset Alliance
Alliance of 47 companies
Technology leaders
Google, Asus, Sprint, LG, Sony Ericson…
Goals
Being better
For consumers
Being open
For developers
Achieving the vision
For mobile operator, handset manufacturers…

So, Android ?
The first open, free and complete stack for mobile phone !
Open
All applications are created equal
Fast & easy application development
Breaking down application boundaries

What’s the result ?
13 news model announced before Christmas !

What’s the result ?

The Marketplace
Stores Android applications
http://www.android.com/market/
From any Android phone
Free publication !
Develop, Sign and Publish your application for free
Growth very quickly

Some application examples

What’s under the cover?

What’s inside ?

The Kernel
Linux 2.6 based
Provides hardware management
File system
Network
3G, Edge, Wifi, Bluetooth…
Camera
Keyboard
Power
That’s critical !
…

Libraries
Graphics
OpenGL, Scalable Image, Animations …
Media
Images (.png, .jpeg, .gif, .bmp)
Video (.mp4, .3gp .wmv)
Audio (.mp3, .mp4, .3gp, .ogg, .wav, .wma … )

Libraries
Database
SQLite
Security
SSL
Webkit
CSS 3
Uses Google Chrome
Animations, Masks …

Runtime
Dalvik
A virtual machine executing applications
Java development language
Java 5 (Generics, Annotations …)
All applications run on the top of their own Dalvik instance
Provides some libraries such as
HTTPClient, XML Parsing, JSON …

Application Framework
Functionalities managed by the system,
But usable by your applications
Examples
Get the current location
Calling, Sending an text message, get contacts
Sending user notifications
…

Applications
All applications
are equals !
are developed in Java
can use any mentioned functionalities
can cooperate together

How to androidize?

Android Applications
AndroidManifest.xml
Activities
Layouts & Views
Services
BroadcastReceiver
ContentProviders
Intents

Manifest
<?xmlversion="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="de.akquinet.jbosscc.kdvmobil.klient"
android:versionCode="1"
android:versionName="1.0.0">
<applicationandroid:icon="@drawable/icon" android:label="@string/app_name">
<activityandroid:name=".Lagerverwaltung"
android:label="@string/app_name">
<intent-filter>
<actionandroid:name="android.intent.action.MAIN" />
<categoryandroid:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-permissionandroid:name="android.permission.INTERNET"></uses-permission>
</manifest>

Activity
Visual user interface for one task. For example,
An activity might present a list of menu items;
Or shows a list of contacts to send messages to
Work together to form a cohesive user interface
Each activity is independent of the others.
Can communicate together
One of the activities is marked as the first one
Moving from one activity to another is accomplished by having the current activity start the next one.
An activity can also make use of additional windows. For example,
A pop-up dialog that calls for a user response in the midst of the activity.
A view hierarchy is placed within an activity's window by the Activity.setContentView() method. The content view is the View object at the root of the hierarchy.

Life cycle

Layout & View
res/layout/main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
</LinearLayout>

Service
Doesn't have a visual user interface
Runs in the background for an indefinite period of time.
For example, a service might play background music
Example: a media player service playing songs from a play list.
Music not handled by an activity
Start a service to run in the background
Keep the music playback service running even after the activity that started it leaves the screen.
Connect to (bind to) an ongoing service
Start the service if it's not already running
Communicate with the service through an interface
Exposed by the service.
E.g., interface allows pause, rewind, stop, and restart the playback.

Life cycle

BroadcastReceiver
Does nothing but receive and react to announcements.
Many broadcasts from the system,
timezone has changed
battery is low,
picture has been taken, or that the user changed a language preference.
Applications can also initiate broadcasts
Data has been downloaded, etc.
An application can have any number of broadcast receivers
Receivers extend the BroadcastReceiver base class.
Broadcast receivers do not display a user interface.
May start an activity in response
May use the NotificationManager to alert the user
Flashing the backlight, vibrating the device, etc.
Place a persistent icon in the status bar

ContentProvider
Make application data available to other applications.
Can be stored in the file system,
In an SQLite database,
Or in any other manner that makes sense.
Implement a standard set of methods
Enables other applications to retrieve and store data
Applications do not call methods directly
ContentResolver object is used
Can talk to any content provider
Cooperates with the provider to manage any interprocess communication that's involved.

Intent
Activities, services, and broadcast receivers — are activated through intents.
Facility for late run-time binding between components
Passive data structure holding an abstract description of an operation to be performed
To launch or get an activity, an Intent object is passed to
Context.startActivity(), Activity.startActivityForResult()
Context.startService() to initiate a service
Context.bindService() to establish a connection
broadcast methods
Context.sendBroadcast(), Context.sendOrderedBroadcast(),
Context.sendStickyBroadcast())
System finds the appropriate activity, service, or set of broadcast receivers
Intent passed to startActivity() is delivered only to an activity, never to a service or broadcast receiver, etc.

Activity, Intent, and Service

RPC

From Source to Deployment

Why choosing Android ?

I’m free

I’m open

I’m a community

Android Perspectives

Android on the phone market
More and more handset manufactures are choosing Android
To compete with the iPHONE
Any chance of success ?
YES
More and more applications are available !

Android on other markets
Android is already used on
Tablet PC
HP Is 'Studying' Android for PC Use
Android Eee PCs are also announced
Q1 2010

OSGi & Android together
OSGi
Comes from the Java wave
Modularity model on the top of Java
Is became very popular in the last 5 years
Why using OSGi on Android ?
Runtime deployment
Dynamism
Plugin architecture
….
Is it possible?
Yes, http://www.ezdroid.com/
Driven by akquinet and luminis

Questions ?
Karl Paulskarl.pauls@akquinet.de
Bülowstraße 66, 10783 Berlin+49 151 226 49 845
Dr. Clement Escoffierclement.escoffier@akquinet.de
Bülowstraße 66, 10783 Berlin+49 175 246 77 17