Android Overview Shashank Kailash Gajbhiye

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 ownership 3 Job market is hot Market for mobile software surges from $4.1 billion in 2009 to $17.5 billion by Dice.com survey: 72% of recruiters looking for iPhone app developers, 60% for Android 1 Dice.com: mobile app developers made $85,000 in 2010 and salaries expected to rise 2 Students (and faculty!) are naturally interested!

Why Android? A lot of students have them 2010 survey by University of CO 1 : 22% of college students have Android phone (26% Blackberry, 40% iPhone) Gartner survey 2 : 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 AndroidApp Inventor

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

Types of Android Devices

Various Android Phones

Galaxy Tablet

Android-Powered Microwave By Touch Revolution – at CES 2010

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 1 st 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 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 Android Brief History cont 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 Sandwich Android 4.0+

The Android Developer Website This should be your homepage for the next semester!

Distribution of Devices Data collected during a 14-day period ending on January 3, 2012

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:

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

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. 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) 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

Android Architecture

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 Contests (Android Developer Challenge) Selling products from within your app

Android 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 ml ml 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)