CS569 Selected Topics in Software Engineering
Spring 2012

Start installation in parallel with this presentation
• Windows + Linux users
– Install Oracle JDK, set PATH and JAVA_HOME
– Install Firefox
– Install Appcelerator’s Titanium Studio
– Install Android SDK
• Mac users
– Install Xcode
– Install Appcelerator’s Titanium Studio
– Optional: Install Android SDK

Differences between one platform and another and another and another and another and another and…
• Physical differences
– Screen size
– Textual input
– Scrolling
• Stylistic differences
– “Back” and “Cancel” buttons
– Placement of navigation bar
– Colors

(2010 Q4 Mobile Developer Report )

• Platforms come and go from fashion
– iOS -> Android right now
– What is next?
• Gotta keep your code from going stale
• Gotta keep your skills from going stale

Option 1: Write platform-independent code, interpose libraries
Your code
Platform-specific binary libraries
Some random platform
This is basically how JavaScript works in web browsers
(each browser implements the ECMA specification for JavaScript and implements specified objects with binary libraries)

Option 2: Write platform-independent code, compile to platform
Your code
Compiler
Platform-specific binary
This is basically how C++ works
(a compiler for each platform compiles the source code into an .exe or whatever binary format is accepted by the target operating system and hardware)
Small runtime library
Some random platform

• Option 1: just libraries, no compiler
– jQTouch – pure
HTML+CSS+JS
– PhoneGap –
HTML+CSS+JS + binary libraries

• Option 2: compiler
– Appcelerator – write JS, compile to binary
– Adobe Air – write ActionScript, compile to Flash
• In practice, both of these require platform-specific runtime libraries, even though they theoretically could compile code to pure binaries that would not require any runtime library.

• (Mostly) platform-specific frameworks
– XCode – compiles Objective C to iOS binaries
– Android SDK – compiles Java to Android binaries

Option Pros Cons
Platform-indep.: libraries -Use existing JS skills
-Very easy to get started
-Nearly 100% portable
Platform-indep.: compiler
-Lowest performance
-Limited API access
-Probably use your JS skills
-Better performance
-Some access to binary API
-Moderately easy to learn
-Nearly 100% portable
Platform dependent code -Best performance
-Access to full binary API
-Maybe new language
-Relatively hard to learn
-Nearly 0% portable

“Hello World” Walkthrough

• http://www.flickr.com/photos/samchurchill/53876132
47/sizes/l/in/photostream/
• http://www.flickr.com/photos/incredibleguy/59801295
38/sizes/s/in/photostream/
• http://www.digitaltonto.com/wpcontent/uploads/2012/01/android-share-ofsmartphone-operating-system-market-nov-14-2011e1328056252645.jpg
• http://www.indeed.com/trendgraph/jobgraph.png?q=i phone%20developer%2C+android%20developer%2C+ mobile%20web%20developer%2C+blackberry%20deve loper
• http://www.flickr.com/photos/eklem/6727262207/size s/z/in/photostream/