introduction to android.rtf

8/18/2019 Introduction to Android.rtf

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Introduction to Android

What is Android?• Linux-based Operating System for mobile devices

• Developed by Android, Inc. (later purcased by !oogle"

• #irst Android pone in October $%%&

• 'ultiple companies producing Android pones Samsung,

)*+,L!,'otorola, ASS, and many oters

i. Google’s mobile platform

• uns on undreds of millions of mobile pones, tablets

• 'ost popular installed mobile OS

• Open Source

ii. Development platform

• 'ultiplatform

• /ased on 0ava

• 1lugins for 2clipse

Android Version


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Code name Version API level

'arsmallo3 4.% A1I level $5

Lollipop 6.7 A1I level $$Lollipop 6.% A1I level $7

8it8at 9.9 - 9.9.9 A1I level 7:

0elly /ean 9.5.x A1I level 7&

0elly /ean 9.$.x A1I level 7;

0elly /ean 9.7.x A1I level 74

Ice +ream Sand3ic 9.%.5 - 9.%.9 A1I level 76,


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"inu# $ernelAt te bottom of te layers is Linux $.4 . *is provides basic

system functionality li=e process management, memory management,

device management li=e camera, =eypad, display etc. Also, te =ernel

andles all te tings tat Linux is really good at suc as net3or=ing and

a vast array of device drivers, 3ic ta=e te pain out of interfacing to

periperal ard3are. *e Android team cose to use tis =ernel because

it provided proven core features on 3ic to develop te Android

operating system. *e features of te Linux $.4 =ernel include

• %ecurit& model' *e Linux =ernel andles security bet3een te

application and te system.

• (emor& management' *e =ernel andles memory

management, leaving you free to develop your app.


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• Process management' *e Linux =ernel manages processes 3ell,

allocating resources to processes as tey need tem.

• )et!or$ stac$' *e Linux =ernel also andles net3or=

communication.• Driver model' *e goal of Linux is to ensure tat te application

3or=s. )ard3are manufacturers can build teir drivers into te

Linux build.

"ibraries

Android>s native libraries.• Libc c standard lib.

• SSL Secure Soc=et Layer

• S!L $D image engine

• Open!L?2S 5D image engine

• 'edia #rame3or= media codecs

• S@Lite Database engine

• eb8it 8ernel of 3eb bro3ser

• #ree*ype /itmap and Bector

• Sufrace'anager +ompose 3indo3 manager 3it off-screen

buffering.

Atop te Linux $.4 =ernel, te Android frame3or= 3as developed

3it various features. *ese features 3ere pulled from numerous open

source proCects. *e output of tese proCects resulted in tese elements

• *he Android runtime' *e Android runtime is composed of 0ava


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core libraries and te Dalvi= virtual macine.

• pen G" +graphics librar&,' *is cross-language, cross-platform

application program interface (A1I" is used to produce $D and 5D

computer grapics.• Web-it' *is open source 3eb bro3ser engine provides te

functionality to display 3eb content and to simplify page loading.

• %"ite' *is open source relational database engine is designed

to be embedded in devices.

• (edia frame!or$s' *ese libraries allo3 you to play and record

audio and video.

• %ecure %oc$ets "a&er +%%",' *ese libraries are responsible for

Internet security.

Android /untime

*is section provides a =ey component called Dalvi= Birtual

'acine 3ic is a =ind of 0ava Birtual 'acine specially designed and

optimied for Android. *e Dalvi= B' ma=es use of Linux corefeatures li=e memory management and multi-treading, 3ic is

intrinsic in te 0ava language. *e Dalvi= B' enables every Android

application to run in its o3n process, 3it its o3n instance of te Dalvi=

virtual macine.

*e Android runtime also provides a set of core libraries 3ic enable

Android application developers to 3rite Android applications using

standard 0ava programming language.

i.Core "ibraries

• 1rovides te functionality of te 0ABA 1rogramming Language

ii.Dalvi$ V(


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• A type of 0ava Birtual 'acine

• egister based (not stac= macine li=e 0B'"

• Optimiation for lo3 memory reEuirements

• 2xecutes .dex (Dalvi=-2xecutable" files instead of .class

• DF tool converts classes to .dex format

Application 0rame!or$

*e Application #rame3or= layer provides many iger-level

services to applications in te form of 0ava classes. Application

developers are allo3ed to ma=e use of tese services in teir applications.

• Activit& (anager' 'anages te activity life cycle of applications

• Content Providers' 'anage te data saring bet3een

applications

• *elephon& (anager' 'anages all voice calls. e use telepony

manager if 3e 3ant to access voice calls in our application.

• Vie! s&stem' )andles te vie3s and layouts tat ma=e up your

user interface (I".

• "ocation (anager' Location management, using !1S or cell

to3er

• /esource (anager' 'anage te various types of resources 3e use

in our Application

Applications

Gou 3ill find all te Android application at te top layer. Gou 3ill


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3rite your application to be installed on tis layer only. 2xamples of

suc applications are +ontacts /oo=s, /ro3ser, !ames etc.

i. *is is 3ere our applications are placed.

ii. Some pre-installed applications

• S'S client app

• Dialer

• eb bro3ser

• +ontact manager

As developers, 3e are able to 3rite an app 3ic replaces any existingsystem app.

1sed "anguages

• App 0ava

• #rame3or= 0ava

•

Libraries +H+

• OS Drivers +

Application Components

i. +ore building bloc=s for Android applications

ii. Apps can publis components for oter applications to use

asyncronous message called Intent

iii. Intents and components defined in a 'anifestfile

iv. 2clipse 3ill generate te manifest for youJ

v. +omponent Description


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1. Activity Single‐screen of an application

2. Service Long‐running bac=ground application

3. +ontent provider 1rovides sared set of application data

4. /roadcast receiver esponds to system broadcast event

Android Development Process

7.Setup te development environment

$.+reate te App

5.*est te App

9.1ublis te App

Installing and Configuring 2our %upport *ools

3.Android supports these platforms'indo3s F1 or later, 'ac OS F

7%.6.& or later (x&4 only"4 buntu.

5.6ava 6D-' Lays te foundation for te Android SD8.

7.Android %D-' 1rovides access to Android libraries and allo3s you to

develop for Android.

8.9clipse ID9 +integrated development environment,' /rings

togeter 0ava, te Android SD8, and te Android Android Development

*ools (AD*" and provides tools for you to 3rite Android programs.

:.Android AD*' Does a lot of te grunt 3or= for you, suc as creatingte files and structure reEuired for an Android app.

introduction to android.rtf

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