android - university of engineering and technology, lahore · icosst 2010 android presentation...

Android

An emerging OS for mobile devices

Presented in Open Source Series Workshop 2010

22-24 December, 2010 © ICOSST 2010

ICOSST 2010 Android Presentation

Agenda

• What is an android? (Part 1)

• Inside Android (Components) (Part 2)

• Writing code for android devices.(Part 3)

• Demonstration (Part 4)




What is an Android? (Part 1)




About Android (Cont…)

• The word “android” literally means a robot. • Android is an OS for the mobile devices. • Android is more than an OS ,it’s complete

software stack. • Mainly developed by Google • Product of Open Handset Alliance • Based on linux kernel • Ranked 1st in sales of smart devices. • 100,000 apps freely available for Android. • Code written in Java language.




About Android

• We can create powerful java applications in android.

• Android phones are called smart mobile devices. • Android has a potential market beyond mobile

devices. • Some of android code being written for non

mobile applications. • Android was made freely available under Apache

open source license in Oct 2008. • Estimated 3 billion users




HTC G1




Features

• Connectivity: WIFI, Bluetooth and GPRS, EDGE, and 3G Hardware: Support for GPS, accelerometers and Cameras.

• Graphics: Built in 2D/3D support including OpenGL.

• Storage: SQLLite • Browser: The web browser is based on Webkit • Supports modern features like multi touch and

multi tasking.




Popular version

Version Name

1.5 Cupcake (Linux 2.6.27)

1.6 Donut (Linux 2.6.29)

2.0/2.1 Éclair (Linux 2.6.29)

2.2 Froyo (Linux 2.6.32)

2.3 Gingerbread (Linux 2.6.35.7)

3.0/2.4 Honeycomb (2011)

3x/2x Ice Cream (2011)




OS trends • Android popularity is growing and will soon

challenge Symbian in 2014 [Gartner.com]




Inside Android Platform (Part 2)




Application Architecture




Inside Android Platform

• Linux Kernel

• Native Libraries

• Android Runtime

• Application Framework




Detailed components




Android Manifest

• Every application must provide a file named “AndroidManifest.xml “

• Contains the configuration information for correctly installing it.

• Contains three things

1. Class names

2. Events

3. Permissions




Developing Applications with Android (Part 3)




Tools Needed

• To develop android applications we need

• IDE: Officially Eclipse is used

• Android SDK

• Android Developer Tools plug-in for Eclipse

• Java Coding in eclipse is very intitutive, provides rich java environment like context sensitive help and code suggestions




Android SDK

• Provides tools and APIs to begin developing applications on the Android using JAVA.

• Used to build, compile, test and debug user applications

• Can be downloaded for Linux, Windows and MAC.

• We can add, delete and update components in android SDK.

• To begin development we need Eclipse IDE with ADT plug-in.




Anatomy of an Android application

Creating and Deploying android application

• Activity

• Service

• Content Provider

• Processes and Tasks.




Bruce Scharlau, University of Aberdeen, 2010

Android applications have common structure

Broadcast receivers can trigger intents that start an application

Data storage provide data for your apps, and can be shared between apps – database, file, and shared preferences (hash map) used by group of applications

Services run in the background and have no UI for the user – they will update data, and trigger events

Intents specify what specific action should be performed

Activity is the presentation layer of your app: there will be one per screen, and the Views provide the UI to the activity





Android applications have common structure

Views such as lists, grids, text boxes, buttons, and even an embeddable web browser

Content Providers that enable applications to access data from other applications (such as Contacts), or to share their own data

A Resource Manager, providing access to non-code resources such as localized strings, graphics, and layout files

A Notification Manager that enables all apps to display custom alerts in the status bar

An Activity Manager that manages the life cycle of applications and provides a common navigation backstack




How it works


Write app in Java

Compiled in Java

Transformed to Dalvik bytecode

Linux OS

Loaded into Dalvik VM




HelloWorld Android

package com.google.android.helloactivity; import android.app.Activity; import android.os.Bundle; public class HelloActivity extends Activity { public HelloActivity() { } @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.hello_activity); } }




Can assume that most have android 2.1 or 2.2

Bruce Scharlau, University of Aberdeen, 2010 http://developer.android.com/resources/dashboard/platform-versions.html



http://developer.android.com/resources/dashboard/platform-versions.html




• Applications can be run on the device or emulator.


Emulator Presented in Open Source Series Workshop 2010




There is a common file structure for applications

code

images

files

UI layouts

constants

Autogenerated resource list





The AndroidManifest lists application details

<?xml version="1.0" encoding="utf-8"?> <manifest

xmlns:android="http://schemas.android.com/apk/res/android" package="com.my_domain.app.helloactivity"> <application android:label="@string/app_name"> <activity android:name=".HelloActivity"> <intent-filter> <action android:name="android.intent.action.MAIN"/> <category

android:name="android.intent.category.LAUNCHER"/> </intent-filter> </activity> </application>




Dalvik Virtual Machine

• Responsible for running android Java programs.

• Optimized for low memory.

• Designed to allow multiple VM instances to run.

• Relies on OS for process isolation, memory management and threading.

• Executes Dalvik(DEX) files

• DEX files are zipped into android package (APK)




Android vs IPhone

• Android is open source but iOS is proprietary. • iOS can only be used on apple machines like

Iphone,Ipad,Ipod • Android has a universe of diverse mobile devices

manufactured by renowned OEMS.For e.g. HTC,Samsung,LG,Sony Ericsson,Dell

• e.g Iphone iOS development is restricted while Android is flexible.

• iOS uses objective C while Android uses wildly adopted Java language.





There are lots of sources of information

• The sdk comes with the API references, sample applications and lots of docs

• Blog http://android-developers.blogspot.com/ which has lots of useful examples, details

• There is http://www.anddev.org



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



http://www.anddev.org


Demonstration




Questions?



android - university of engineering and technology, lahore · icosst 2010 android presentation...

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