Development of a mobile app for Android

Development of a mobile app for Android Alex Reid SuperMondays, February 2010

Alex Reid • Sorry, not the cage ﬁghter • I’m a software developer • Lead development of a projects database here at the University since 2006. • Mobile development • Android mainly but also iPhone and BB

Content • Overview of mobile apps • How you write a mobile app • Differences from web • Mobile device constraints and beneﬁts • Android • Live coding an app from scratch

Mobile Apps • Lots of us carry small computers around with us • Software development kits allow anyone to write apps for these devices • Some great ... some erm. • Easy distribution through AppStores

Ask the Hoff • I did the Android port of this iPhone app by Never Odd or Even LLP • Shake your phone for wisdom from DH • Featured on Radio 1 • Available on AppStore and Market - 59p

Next Metro • We’ve put the Metro timetable inside your Android or iPhone • Tells you how long the next train at your stop will be • Updated from web service when online • With Never Odd. In discussions with Nexus

How to write an app • Decide which device(s) to target • Download, learn and use the SDK • Test your code on an emulator • Publish • Watch the money roll in

What’s in an SDK? • Libraries • IDE integration (Eclipse, XCode) • Frameworks • Simulators / Emulators • Utilities • Documentation

Differences to web • Less of everything - speed, network, storage, memory & screen real estate • Event driven (Flash, Desktop) • Threading • Crash means the process dies • No cross browser differences :) • Cross device differences though :( • APIs can and do change

Be efﬁcient • Think about battery life • Bad code - device turns into a hand warmer • App must be a good multitasking citizen • Ofﬂoad data crunching to a server • Assume networks are slow / transient • Recover gracefully. Don’t hang.

Remember • Emulator can be much faster than device • Phone models vary in speed and spec • Avoid object creation, reuse UI widgets • static, int vs Integer, [ ] vs List<T>, getters... • Load things only when you need them • Careful with compressed media • Watch application size (192MB on Android)

Android • A mobile operating system • Uses a modiﬁed Linux kernel • Not a Linux distro • Apps are written in Java • Apps don’t run as Java - Dalvik VM • Open source: vendors customise it

Android stack

Why Android? • Range of Android devices / vendors • Rich SDK - free to download and use • Available for Mac, Windows and Linux • Low barrier to entry • Java widely used; easy for C# devs • iPhone very Mac centric

SDKs FTW • Fantastic building blocks ... leverage • Rich library of UI controls and widgets • WebKit • SQLite3 relational database engine • Maps • OpenGL • Hardware: Compass, GPS, Accelerometer

Android Tools • Eclipse 3.5 with Android Developer Tools • Well supported and feature rich IDE • UI design • Debugging • Testing • Deploy to emulator and device (via USB) • Publishing and signing wizards

Jargon • Apps consist of at least one screen or Activity • Activities are linked via Intents • Services are faceless and run indeﬁnitely • Content providers make your app’s data available to other apps • content://org.yourapp/people/Alex

Live coding demo • We’re going to construct an app that plays a sound when you press a button • Not a Java tutorial • Just to give you an idea • But by all means ask later or email me

Sad Trombone • Every ofﬁce needs this app! • Add a button • Add code so it responds to clicks • Attach code to play a sound • Fix some bugs • Deploy it to a device

Any questions?

http://www.supermondays.org	620
http://www.androidos.in	35
http://www.slideshare.net	26
http://www.fandroid.org	25
http://translate.googleusercontent.com	4
http://www.supermondays.co.uk	3
http://www.ig.gmodules.com	2
http://10.0.0.227	1
http://www.phiz.net	1
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Development of a mobile app for Android

by AlexJReid on Feb 22, 2010

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