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Android Overview
Dr. Josh Dehlinger
Dr. Siddharth Kaza

Why Mobile App Development?
 The fact that we can! Only a few years ago you had to
be in the Motorola inner circle to do it!
 Mobile platform is the platform of the future
 Double-digit growth in world-wide smartphone ownership3
 Job market is hot
 Market for mobile software surges from $4.1 billion in 2009 to
$17.5 billion by 20121
 2010 Dice.com survey: 72% of recruiters looking for iPhone app
developers, 60% for Android1
 Dice.com: mobile app developers made $85,000 in 2010 and
salaries expected to rise2
 Students (and faculty!) are naturally interested!
1 http://www.businessweek.com/technology/content/oct2010/tc20101020_639668.htm
2 http://it-jobs.fins.com/Articles/SB129606993144879991/Mobile-App-Developers-Wanted-at-Ad-Agencies
3http://www.gartner.com/it/page.jsp?id=1466313

Why Android?
 A lot of students have them
 2010 survey by University of CO1
: 22% of college
students have Android phone (26% Blackberry, 40%
iPhone)
 Gartner survey2
: Android used on 22.7% of
smartphones sold world-wide in 2010 (37.6%
Symbian, 15.7% iOS)
 Students already know Java and Eclipse
 Low learning curve
 CS0 students can use App Inventor for Android
1http://testkitchen.colorado.edu/projects/reports/smartphone/smartphone-appendix1/
2http://www.gartner.com/it/page.jsp?id=1543014

Why Android?
 Transferring app to phone is trivial
 Can distribute by putting it on the web
 Android Market for wider distribution
• It’s not 1984

Various Android Phones
http://cloud.addictivetips.com/wp-content/uploads/2010/09/and

Galaxy Tablet
http://www.samsung.com/global/microsite/galaxytab/10.1/index.html

Android-Powered Microwave
http://www.pocket-lint.com/news/30712/android-powered-microwave-cooking-google
By Touch Revolution – at CES 2010

http://www.google.com/nexus/
Google/Samsung Galaxy Nexus

Brief History
 1996
 The WWW already had websites with color and
images
 But, the best phones displayed a couple of lines
of monochrome text!
 Enter:
 Wireless Application Protocol (WAP) – stripped down
HTTP for bandwidth reduction
 Wireless Markup Language (WML) – stripped down
HTML for content

Brief History
 Many issues (WAP = “Wait And Pay”)
 Few developers to produce content (it wasn’t fun!)
 Really hard to type in URLs using the small
keyboards
 Data fees frightfully expensive
 No billing mechanism – content difficult to
monetize
 Other platforms emerged
 Palm OS, Blackberry OS, J2ME, Symbian
(Nokia), BREW, OS X iPhone, Windows Mobile

Brief History - Android
 2005
 Google acquires startup Android Inc. to start Android platform
 Work on Dalvik VM begins
 2007
 Open Handset Alliance announced
 Early look at SDK
 2008
 Google sponsors 1st
Android Developer Challenge
 T-Mobile G1 announced
 SDK 1.0 released
 Android released open source (Apache License)
 Android Dev Phone 1 released

Brief History cont.
 2009
 SDK 1.5 (Cupcake)
 New soft keyboard with “autocomplete” feature
 SDK 1.6 (Donut)
 Support Wide VGA
 SDK 2.0/2.0.1/2.1 (Eclair)
 Revamped UI, browser
 2010
 Nexus One released to the public
 SDK 2.2 (Froyo)
 Flash support, tethering
 SDK 2.3 (Gingerbread)
 UI update, system-wide copy-paste

Honeycomb
Android3.0-3.
Brief History cont.
 2011
 SDK 3.0/3.1/3.2 (Honeycomb) for tablets only
 New UI for tablets, support multi-core processors
 SDK 4.0/4.0.1/4.0.2/4.0.3 (Ice Cream Sandwich)
 Changes to the UI, Voice input, NFC
Ice cream Sandwic
Android 4.0+

The Android Developer
Website
 http://developer.android.com/index.html
 This should be your homepage for the next
semester!

Distribution of Devices
Data collected during a 14-day period ending on January 3, 2012
http://developer.android.com/resources/dashboard/platform-versions.html

What is Google Android?
 A software stack for mobile devices that includes
 An operating system
 Middleware
 Key Applications
 Uses Linux to provide core system services
 Security
 Memory management
 Process management
 Power management
 Hardware drivers

Android Architecture
More details at: http://developer.android.com/guide/basics/what-is-android.html

Mobile Devices: Advantages (as
compared to fixed devices)
 Always with the user
 Typically have Internet access
 Typically GPS enabled
 Typically have accelerometer & compass
 Most have cameras & microphones
 Many apps are free or low-cost

Mobile Devices: Disadvantages
 Limited screen size
 Limited battery life
 Limited processor speed
 Limited and sometimes slow network access
 Limited or awkward input: soft keyboard, phone
keypad, touch screen, or stylus
 Limited web browser functionality
 Range of platforms & configurations across
devices

Mobile Applications
 What are they?
 Any application that runs on a mobile device
 Types
 Web apps: run in a web browser
 HTML, JavaScript, Flash, server-side components,
etc.
 Native: compiled binaries for the device
 Often make use of web services

 Development
process for an
Android app
http://developer.android.com/guide/developing/index.html

Android Apps
 Built using Java and new SDK libraries
 No support for some Java libraries like Swing &
AWT
 Oracle currently suing Google over use
 Java code compiled into Dalvik byte code
(.dex)
 Optimized for mobile devices (better memory
management, battery utilization, etc.)
 Dalvik VM runs .dex files

Building and running
 ADB is a client server program that connects clients on developer
machine to devices/emulators to facilitate development.
 An IDE like Eclipse handles this entire process for you.
http://developer.android.com/guide/developing/building/index.html#detailed-build
Compiled resources
(xml files)
Android Debug Bridge

Building and running (more
details)
 Expand
figure
 Android Interface
Definition
Language (AIDL) –
Definitions to
exchange data
between
applications (think
SOAP)
http://developer.android.com/guide/de
veloping/building/index.html#detailed-
build
Android Asset Packing Tool
Allows processes across
apps to communicate.

Applications Are Boxed
 By default, each app is run in its own Linux
process
 Process started when app’s code needs to be
executed
 Threads can be started to handle time-consuming
operations
 Each process has its own Dalvik VM
 By default, each app is assigned unique Linux ID
 Permissions are set so app’s files are only visible to
that app

Publishing and Monetizing
 Paid apps in Android Market, various other
markets
 Free, ad-supported apps in Android Market
 Ad networks (Google AdMob, Quattro Wireless)
 Sell your own ads
 Services to other developers
 Ex. Skyhook Wireless (
http://www.skyhookwireless.com/)
 Contests (Android Developer Challenge)
 Selling products from within your app

Android Market
 http://www.android.com/market/
Has various categories, allows ratings
Have both free/paid apps
Featured apps on web and on phone
The Android Market (and iTunes/App Store) is
great for developers
 Level playing field, allowing third-party apps
 Revenue sharing

Publishing to Android Market
 Requires Google Developer Account
 $25 fee
 Link to a Merchant Account
 Google Checkout
 Link to your checking account
 Google takes 30% of app purchase price

Android Design Philosophy
 Applications should be:
 Fast
 Resource constraints: <200MB RAM, slow processor
 Responsive
 Apps must respond to user actions within 5 seconds
 Secure
 Apps declare permissions in manifest
 Seamless
 Usability is key, persist data, suspend services
 Android kills processes in background as needed

Leveraging the web
 To keep your apps fast and responsive,
consider how you can leverage the web
 What ____________ can be ________ on a
server or in the cloud?
 Tasks/performed
 Data/persisted
 Data/retrieved
 Beware, data transfer is also expensive and can
be slow

Other design principles
 http://developer.android.com/design/index.html
 Great reference!

Apple vs. Google
 Open Handset Alliance
 30+ technology companies
 Commitment to openness, shared vision, and
concrete plans
 Compare with Mac/PC battles
 Similar (many PC manufacturers, one Apple)
 Different (Microsoft sells Windows, Google gives
away Android)

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Android overview 123

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Editor's Notes